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https://science.feedback.org/review/pyramid-shaped-peaks-antarctica-naturally-carved-by-glaciers-not-constructed-by-ancient-civilization/ | Inaccurate | Facebook, YouTube, TikTok, X/Twitter, 2024-03-20 | Ancient civilizations once inhabited Antarctica, as shown by the pyramids there, but the continent’s position and climate rapidly changed due to ‘tectonics and pole shift’. | null | Factually inaccurate: There is no evidence of ancient civilizations or pyramids in Antarctica. The pyramid-shaped landform shown in recent social media videos is called a ‘horn’ or ‘pyramidal peak’ and forms naturally as glaciers carve (i.e., erode) different rock faces. There is also no evidence for a rapid shift in the climate or position of Antarctica on Earth; studies show that Antarctica slowly drifted over millions of years through tectonic plate movements. | The rocky pyramid-shaped feature in Antarctica is a natural landform called a ‘horn’ or ‘pyramidal peak’. These peaks form when three or four intersecting glaciers carve out mountain faces in different directions, thus making a horn or pyramidal shape. They are common in Antarctica and found in many other places on Earth. Scientific evidence shows that Antarctica slowly drifted to its current position over millions of years through tectonic plate movement; not a sudden shift of the poles or crust. | Thawing ice in Antarctica is revealing pyramids and other remnants of an ancient civilization. Antarctica quickly moved across Earth into its current position through plate tectonics and pole shift, causing Antarctica’s surface to flash-freeze. | 1- Hess (2016) McKnight’s Physical Geography: A Landscape Appreciation. 2 – Sugden et al. (2017) The million-year evolution of the glacial trimline in the southernmost Ellsworth Mountains, Antarctica. Earth and Planetary Science Letters. 3 – Palin and Santosh (2021) Plate tectonics: What, where, why, and when?. Gondwana Research. 4 – Zahirovic et al. (2015) Tectonic speed limits from plate kinematic reconstructions. Earth and Planetary Science Letters. 5 – Kulakov et al. (2021) Jurassic fast polar shift rejected by a new high-quality paleomagnetic pole from southwest Greenland. Gondwana Research. 6 – Moulin et al. (2011) An attempt to constrain the age, duration, and eruptive history of the Karoo flood basalt: Naude’s Nek section (South Africa). Journal of Geophysical Research: Solid Earth. 7 – Svensen (2018) Gondwana Large Igneous Provinces: plate reconstructions, volcanic basins and sill volumes. Geological Society, London, Special Publications. | On 20 March 2024, a video on YouTube claimed that ‘Antarctica has pyramids from an ancient civilization’, and that ‘the continent’s surface flash-froze as it rapidly shifted on Earth‘. This video has gathered over 3.4 million views, and in recent months it has been clipped and shared on TikTok, Facebook, and X/Twitter. A quick search on TikTok turns up many of these clips and dozens of similar videos speculating about these alleged ‘pyramids’ and the history of Antarctica. Keys to Antarctica’s geologic past do peek from the ice and lay buried below – but regarding social media claims, what does the scientific evidence show? Pyramid-shaped landform in Antarctica is called a ‘horn’ and is formed through glacial erosion; similar peaks are found around the world A pyramid-shaped mountain (Figure 1) in Antarctica has sparked speculation among social media users who are sharing claims that it is not natural, but rather a pyramid built by an ancient civilization. Although the mountain does have some visual similarities to a pyramid – e.g., having a peak and four sides – there are several clues and lines of evidence indicating that this is a natural mountain peak, as we will detail below. Figure 1 – Unnamed horn located in Antarctica at 79°58’38″S 81°57’44″W (view here). Source: Google Earth screenshot Although this mountain is particularly pyramidal, the shape itself is not rare. Peaks with similar shapes exist around the world and geologists have studied these to understand the natural processes that form them – a field of study called geomorphology. Geologists refer to these types of peaks as ‘horns’ – examples include the famous ‘Matterhorn’ in Switzerland, and the lesser known ‘Alpamayo’ mountain in Peru (Figure 2). Figure 2 – Examples of glacially carved horns: Alpamayo mountain, Peru (left) and the Matterhorn mountain, Switzerland (right). Source: Pexels and Frank R/Wikimedia.org As described in the United States Geological Survey Glossary of Glacier Terminology, horns are “a pointed, mountain peak, typically pyramidal in shape, bounded by the walls of three or more cirques . . . when a peak has four symmetrical faces, it is called a Matterhorn”. Cirques are hollow areas carved into mountains as glaciers move downward and erode (i.e., remove) underlying rock[1]. The intersection of multiple cirques leaves behind a peak (i.e., horn) connected to 3 or 4 ridges – marking the outer boundaries of where the glaciers eroded, as shown in Figure 3 below. Figure 3 – Diagram showing horns, their ridges (i.e., arete), and cirques (i.e., hollowed out areas carved by glaciers). Vertical lines along the faces of the horns represent steep areas resulting from glacial erosion. Source: Illustrated Glossary of Alpine Glacial Landforms: Karen A. Lemke, University of Wisconsin-Stevens Point There is clear evidence of past glacial erosion in this region of Antarctica[2]; however, in some areas, snow and ice cover many of the lower landscape features that make this more apparent. Note that the examples in Figure 2, which are not covered by ice sheets, show less of a pyramidal shape near the base of these mountains. However, the pyramidal peak (Figure 1) shown in social media videos is largely covered in snow and ice, covering many of the landscape features near its base that would likely make it easier to identify as a glacial horn. For this reason, sometimes other observations and information must be gathered from the surroundings to characterize geologic features. This is something that we discussed in a similar past Science Feedback review, linked here. So what do the surroundings tell us? The horn-formation process we described above occurs in cold, glaciated environments, such that of the Ellsworth Mountains of Antarctica where the pyramidal horn is located. Thus, its location matches the environment where this type of peak forms. In fact, this process of glacial erosion is common in Antarctica as evidenced by the number of horns and pyramidal peaks nearby (Figures 4-6). Many pyramidal peaks are documented in a report titled “Geographic Names of the Antarctic” including Abbott Peak, Achilles Mountain, and several others. Figure 4 – A semi-pyramid shaped mountain peak located 9.5 kilometers east-southeast of the mountain shown in Figure 1. Note that with increased snow coverage, this mountain could also appear somewhat pyramid-shaped given the four evenly spaced ridges meeting at a point. Source: Google Earth screenshot Figure 5 – Another pyramidal mountain peak located roughly 230 kilometers north-northwest of the mountain shown in Figure 1. Note that it has a similar pyramid shape, but the snow cover and surrounding ridges in this area makes it clear that this is a mountain that is connected to other peaks and ridges (i.e., not an isolated feature). Source: Google Earth screenshot Figure 6 – Photo of a pyramidal peak near the Princess Elisabeth Station (polar research station). Note the concave eroded faces of the horn, curved ridges, and uniformity of the rock (i.e., no cut blocks, as seen in pyramids), showing evidence of its natural origin and glacial erosion features labeled in Figure 3. Source: International Polar Foundation – René Robert Overall, the peak’s physical characteristics, surrounding glacial environment, and proximity to a number of other pyramidal peaks with similar patterns of glacial erosion, is strong evidence that the pyramidal feature shown in viral social media videos is a natural mountain peak – called a pyramidal peak or horn – formed over time through glacial erosion. Additionally, there is no record of an ancient civilization or any constructed pyramids in Antarctica, which has been surveyed since the early 1900s. Antarctica slowly moved to its current position over millions of years; no evidence of rapid shift A number of viral clips on social media feature Billy Carson speculating about Antarctica’s past. In these videos, Carson claims that ‘Antarctica quickly shifted into its current position on Earth through tectonics and sudden crustal pole shift’. Carson suggests that these two concepts somehow work together; however, they are actually incompatible and only one of them – plate tectonics – is supported by scientific evidence and widely accepted by geology experts[3], as detailed below. As described in Palin and Santosh (2021), “the theory of plate tectonics is widely accepted by scientists and provides a robust framework with which to describe and predict the behavior of Earth’s rigid outer shell – the lithosphere – in space and time”[3]. This well-accepted theory explains that Earth’s outer shell is broken up into different tectonic plates, like a giant jigsaw puzzle (Figure 7), which move around very slowly – i.e., a few centimeters per year[4], or as the USGS explains, roughly at the same rate that your fingernails grow. Figure 7 – Earth’s tectonics plates and continents that overlie them. Source: United States Geological Survey (USGS) Over millions of years, they can carry their overlying continents to different positions on Earth’s surface, and thus sometimes to different climates. Together, these concepts describe the widely accepted theories of plate tectonics and continental drift. In conjunction with past climate variations, these concepts help explain why icy regions (e.g., Antarctica) show geologic evidence of different conditions in their past (e.g., being in warmer climates). Contrary to the universally accepted theories above, some have speculated a ‘cataclysmic pole shift’, caused these climate changes due to rapid shifts in Earth’s crust and poles. However, this does not match the scientific evidence. For example, researchers have studied past shifts in Earth’s poles spanning 160 million years and they explain that the evidence does not support the ‘rapid’ or ‘massive’ polar shift being claimed[5]. Scientific evidence also does not support a rapid shift in Antarctica’s position – a claim suggested in social media videos. Instead, evidence shows that Antarctica began slowly moving to its current position roughly 182 million years ago[6,7]. At that time it was part of a larger supercontinent called Gondwana (Figure 8) – which also included land that we now call South America, Africa, Madagascar, India, Western Australia, and Arabia[7]. To emphasize how slow this transition was, it’s worth noting that East Antarctica and Australia only split from each other around 85 million years ago[7] – 97 million years after Antarctica began separating from Gondwana. Figure 8 – Evolution of Earth’s continents from 250 million years ago to present day. Note that Antarctica was closer to the equator prior to the breakup of Gondwana (or ‘Gondwanaland’) roughly 182 million years ago[6,7], after which it slowly drifted to the south pole over millions of years. Source: USGS Conclusion: There is no evidence of an ancient civilization, nor any pyramids in Antarctica, contrary to claims from viral videos on social media. There are, however, several pyramid or semi-pyramid shaped mountains called ‘horns’ or ‘pyramidal peaks’, which form through glacial erosion. These peaks are well-documented in Antarctica and many other glaciated areas around the world, such as Switzerland and Peru. Contrary to other claims made in these videos, Antarctica did not experience a sudden change in climate due to a sudden shift in the poles or Antarctica’s position on Earth. Scientific evidence shows that Antarctica slowly drifted to its current position over millions of years through tectonic plate movement. |
https://science.feedback.org/review/sea-levels-have-risen-for-over-100-years-despite-misleading-photos-social-media/ | Inaccurate | Facebook, 2024-06-06 | Sea-level rise is not occurring or showing any impacts, based on photographic evidence. | null | Inaccurate: Scientific evidence unambiguously shows rising sea levels based on measurements of global mean sea level and tidal gauge data, even the ones collected near the locations from social media posts claiming that ‘sea level is not rising’. Misleading: It is misleading to show ‘before and after’ photos from select locations without proper context (e.g., tidal conditions) or an appropriate scale (i.e., one in which the sea level rise that has been reported at these locations could be reasonably seen). | Scientists have shown that global mean sea level has risen since the year 1880 by analyzing sea-level data from tidal gauges and satellites. Relative sea level rise – which is measured at a local or regional scale – can vary due to Earth’s shape and ocean dynamics. However, the data collected from the locations shown in ‘before and after’ posts on social media also show evidence of sea level rise. Certain locations around the world are more strongly impacted by the effects of rising sea levels. | There is no evidence of sea-level rise in before and after photos (i.e., from the past and present) from some locations. Therefore, sea-level rise is not occurring or causing negative impacts. | 1 – Church et al. (2011) Sea-level rise from the late 19th to the early 21st Century. Surveys in Geophysics. 2 – Rovere et al. (2016) Eustatic and Relative Sea Level Changes. Current Climate Change Reports. 3 – Slangen et al. (2016) Anthropogenic forcing dominates global mean sea-level rise since 1970. Nature Climate Change. 4 – Horton et al. (2018) Mapping Sea-Level Change in Time, Space, and Probability. Annual Review: of Environment and Resources. 5 – IPCC (2019) Special Report on the Ocean and Cryosphere in a Changing Climate. | Several social media posts have gone viral after sharing ‘before and after’ photos from the past and present to claim that sea-level rise has not occurred. For example, a number of these posts show photos of Sugarloaf Mountain in Brazil, labeled with the years 1880, 1910, and 2020 and captions claiming that sea level is not rising. One such post on Facebook, linked here, has been shared thousands of times. Below we will investigate these claims using scientific evidence, and explore how scientists measure sea-level rise. Scientists determine sea-level rise by collecting and analyzing data, not by comparing a few photos Before investigating the evidence, we will first explain why these viral posts are highly flawed in their ‘method’ of assessing sea-level rise. These posts claim that sea level has not risen based on photos taken at certain locations in different years; examples of which are shown in Figure 1. Figure 1 – Examples of locations shown in social media posts claiming that ‘sea levels have not risen’. The two top left photos are of Fort Denison in Sydney Harbour; the two bottom left photos are of the Statue of Liberty in New York City; and the two photos on the right half of the figure are of Sugarloaf Mountain in Brazil. Source: social media screen captures However, using these photos for comparison is flawed because they are missing critical details and context. There are a number of variables that affect sea level; one of the most important in this case is tidal conditions. Even if two photos are taken at the exact same location on the same day, the sea level at that location will be different at low and high tide (i.e., at different times of the day). As explained by the National Oceanic and Atmospheric Administration (NOAA), tides are changes in sea level that are caused by the gravitational pull on our oceans by the Earth, Moon, and Sun. These forces cause the oceans to bulge outward, roughly in line with the moon, and dip inward at a right angle to this line (Figure 2). Figure 2 – Diagram showing tidal bulge as a result of net gravitational pull on Earth’s oceans. Note that these bulges are exaggerated for visualization purposes, and that as a coastline passes through a bulge, its respective landmass (e.g., continent) has a much higher elevation than the rise in sea-level – and thus does not become fully submerged by the rising oceans. But instead, it experiences a high tide. Adapted from the following source: NASA/Vi Nguyen Because Earth rotates over a 24 hour period, sea-levels change throughout the day as both landmasses and oceans collectively move through these bulge and dip zones. This causes alternating high and low tides every 6 hours. The difference in sea level at low and high tide depends on the position of the Moon. For example, NOAA explains that “the greatest difference in height occurs around new and full moons, 6.27 ft. (1.91 m) and 7.18 ft. (2.19 m) respectively”. An example of sea-level fluctuations over days to weeks with different tides is shown in Figure 3 below. For a more in-depth explanation and visualization of how tides work, see the link here. Figure 3 – Sea-level fluctuations in Santa Barbara, California, over days to weeks. Days are shown on the x-axis and average/mean sea-level height (MSL) in feet is shown on the y-axis. The moon phases are shown above the graph, with the corresponding differences in high and low tide elevations shown directly below them. Note that the largest differences occur during a new moon and a full moon. Source: NOAA Because of the processes described above, it is flawed to compare sea level in two different photos without knowing the date and time, and thus the tidal conditions when they were taken. Hypothetically, an older photo could be taken at a high tide and a newer photo taken at a low tide, disguising the sea-level change occurring between those years. However, even with more context for the photos, there is still another major flaw with this method; they collected no actual measurements, and there is no appropriate scale in the photos. For example, in one of the claim-making posts they show photos of the ocean below a landmark called Sugarloaf Mountain, with a peak of 396 meters (1,299 feet) located in Rio de Janeiro. However, there is no scientific consensus that this landmark, or the others shown in these posts, should show visual changes due to sea level rise that occurred between the photo dates. Over the alleged time period shown in the photos of 1880-2020, global mean sea level (GMSL) has risen roughly 21–24 centimeters (8-9 inches), according to NOAA (Figure 4). However, based on Google Earth measurements, the photo was taken at a distance that shows nearly a 2 kilometer stretch of land – a scale that does not match the magnitude of sea-level rise in this period. Figure 4 – Global average absolute sea-level change (in inches) from 1880-2021, based on tidal gauge measurements (orange line) and recent satellite measurements (blue line). Note that ‘absolute’ sea-level change is used to represent the ocean’s surface, without regard to changes in nearby land elevation. Figure source: United States Environmental Protection Agency (EPA) with data from NOAA and CSIRO (2017)[1] It is also misleading to cherry pick a few locations (e.g., near Sugarloaf Mountain) to show the ‘impacts’ of sea-level rise, because sea-level rise and its effects vary by region. This is part of the reason scientists create flood vulnerability and exposure maps, like the one linked here. One reason for this variability is that steep areas are less susceptible to inundation (i.e., flooding from rising water) than low-lying areas. This occurs because water needs to rise higher to submerge high-elevation areas than does for areas of lower elevation. This is apparent on flatter beaches, for example, because at high tide the ocean moves much further inland than it does on steeper beaches. When scientists study sea-level rise, they do not rely on ‘before and after’ photographs from one location. Instead, they collect data from around the world and use it to observe trends. In doing so, they can measure sea-level rise more accurately, and avoid the uncertainty that comes with comparing photographs without adequate information and scale. So what does the evidence show when scientists properly collect and analyze sea-level data? Data from around the world shows that global mean sea-level has risen over the last century; some areas have risen more than others The social media posts actually make two claims – the explicit claim that sea level is not rising and the implied claim that it is not problematic, otherwise we should see visual evidence of impacts in photos of these locations. The reason these types of posts can convince viewers is that they simplify a complex topic. The underlying assumption in these posts, for example, is that ‘if sea level has risen, these locations – and by extension, all coastal areas – on Earth should show evidence of it in before and after photographs’. However, this disregards an important scientific observation: sea level does not rise at the same rate everywhere on Earth[2] – it is uneven and varies by location, as we will explain below. To evaluate how sea levels change over time, scientists evaluate trends in data from tide gauges and satellites. As shown in Figure 4 from the previous section, these data clearly show that global mean sea level has risen since 1880 – the earliest alleged date of the photos recently shared in these posts. If global mean sea level (i.e., overall sea level) has risen, and sea level does not rise at the same rate everywhere on Earth – what happens at a local or regional level? What changes should we see? That depends on the location. At a local level, some places are more vulnerable to the effects of sea-level rise than others. As we briefly explained earlier, one reason for this is that the terrain (e.g., flatness or steepness) of different areas can affect how ocean water moves inland during tidal changes. For this reason, a photo taken at low tide might show land exposed that would later be submerged in a photo taken at high tide. An example of this is shown in Figure 5 below. Note the difference in land exposure between the photos, which could be misleading without context about the tidal conditions when they were captured. Figure 5 – Photographs taken at high tide (left) and low tide (right) at the Bay of Fundy in Canada. Note that the land exposure changes between high tide and low tide. Source: NOAA SciJinks At a broader/regional scale, there are other physical processes that affect sea-level rise. As we mentioned, sea-level rise is not even – it does not rise in the intuitive way that water does in something like a bathtub. This is because at a planetary scale, there are many other factors at play. As explained by NASA, “The globally averaged trend toward rising sea levels masks deeper complexities. Regional effects cause sea levels to increase on some parts of the planet, decrease on others, and even to remain relatively flat in a few places.” They explain that two of the factors influencing uneven sea-level rise at a regional level are ocean dynamics (i.e., redistribution of water mass by currents, wind, etc.) and varying gravitational strength. They explain that “because the distribution of Earth’s mass is uneven, Earth’s gravity is also uneven. Therefore, the ocean’s surface isn’t actually a perfect sphere or ellipsoid; it is a bumpy surface” (Figure 6). Figure 6 – Visualization of Earth’s gravitational field showing regions with red showing areas where gravity is stronger, blue where gravity is weaker, and a spectrum between. Source: NASA with data from University of Texas Center for Space ResearchDespite local and regional variability, several individual locations – such as those shown in the social media post photos – do in fact show sea-level rise based on tidal gauge data. For example, one of the locations discussed earlier – Sugarloaf Mountain (Figure 1) – that was shared in the posts has nearby sea-level measurements from 1963-2016, which show that sea level rose 12.6 centimeters (4.5 inches) in that period. Another location shown in these posts is Sydney Harbour (Figure 1). Science Feedback has already addressed claims regarding sea-level rise at this location in a previous review, linked here. The results of that review are well-summarized in a quote provided to Science Feedback by Dr. Thomas Frederikse, Postdoctoral researcher at the Jet Propulsion Laboratory/California Institute of Technology: “At Fort Denison, which is the building in the picture [Figure 1], we have two long tide gauge records. One that covered 1886-1993, and one that started in 1915 and is still measuring today. I’ve plotted both individual records and the average of them. Both the records clearly show that sea level is rising in Sydney, and that the rate of the rise is increasing.” A third location from these social media posts is the Statue of Liberty in New York City (Figure 1). As with the other examples, this location also shows a clear rise in sea level; from 1856-2023 the sea level in this area rose by roughly 49.1 centimeters (19.33 inches) (Figure 7). Figure 7 – Relative sea level trend based on data from 1856-2023 at The Battery in New York (close to the Statue of Liberty). Source: NOAA In summary, all three locations above – which are commonly used in social media posts to claim sea levels have not risen – show clear evidence of sea-level rise. In addition, previous Science Feedback reviews have also found evidence that global mean sea level rise is speeding up. As explained in a review from 2021 linked here: while land mass movements and ocean circulation patterns influence sea levels, human-induced climate change is accelerating the rate of sea level rise[3]. This point is also summarized in a 2018 paper by Horton et al.: “a large portion of the twentieth-century rise, including most GMSL rise over the past quarter of the twentieth century, is tied to anthropogenic warming”[4]. The Intergovernmental Panel on Climate Change (IPCC) – the world’s leading authority on climate science – explains that “as a consequence of natural and anthropogenic changes in the climate system, sea level changes are occurring on temporal and spatial scales that threaten coastal communities, cities, and low-lying islands”[5].They also explain that “coastal ecosystems are already impacted by the combination of SLR [sea-level rise], other climate-related ocean changes, and adverse effects from human activities on ocean and land”[5]. Conclusion: Scientists have shown that global mean sea level has risen since the year 1880 by analyzing data from tidal gauges and satellites. Relative sea level rise – that which is measured at a local or regional scale – can vary due to Earth’s shape and ocean dynamics. However, contrary to claims from social media users, even the locations from photos on their posts show rising sea levels based on tidal gauge measurements. Social media posts comparing ‘before and after’ photos of cherry-picked locations to ‘assess’ sea-level rise are flawed because they are missing important details about tidal conditions, scale, and context about how sea levels are measured and vary across Earth. Additionally, implying that there are no impacts is inaccurate because evidence shows that rising sea levels have already caused negative impacts (e.g., to coastal ecosystems). |
https://science.feedback.org/review/colorful-auroras-seen-may-2024-caused-by-mass-ejections-from-sun-not-haarp-experiments/ | Incorrect | Facebook, YouTube, TikTok, X/Twitter, 2024-05-11 | May 2024 auroras were caused by experiments from High-frequency Active Auroral Research Program (HAARP) experiments | null | The origin of auroras in Earth’s atmosphere is well-studied and occur as solar winds and ejections of magnetized plasma from the Sun approach Earth and interact with our planet’s magnetic field. HAARP is incapable of producing the auroras that were observed because their power output is orders of magnitude less than would be necessary to do so. | The High-frequency Active Auroral Research Program (HAARP) is a research facility that uses a high-power, high-frequency transmitter to study the physical properties and behavior of the highest point of the atmosphere, the ionosphere. Radio transmissions from HAARP only cause small effects in the ionosphere that last for a brief span of a few seconds. HAARP is incapable of causing the magnitude of aurora effects witnessed in May 2024; evidence shows these effects were caused by mass ejections of magnetized plasma from the Sun. | The vivid lights seen around the world on May 10 2024 were artificial aurora effects caused by High-frequency Active Auroral Research Program (HAARP) experiments, not by a geomagnetic storm. | 1 – McCoy et al. (2018) Haarp, a Powerful Active Ionospheric Laboratory Open for International Research. 42nd COSPAR Scientific Assembly. 14-22 July 2018, Pasadena, California, USA 2 – Todd Pedersen (2015) HAARP, the most powerful ionosphere heater on Earth. Physics Today. 3– Inan et al. (2004) Multi‐hop whistler‐mode ELF/VLF signals and triggered emissions excited by the HAARP HF heater. Geophysical Research Letters. 4 – Piddyachiy et al. (2011) DEMETER observations of the ionospheric trough over HAARP in relation to HF heating experiments. Journal of Geophysical Research: Space Physics. | On 10 May 2024, solar eruptions caused a several-day geomagnetic storm on Earth, causing a vivid display of colors, called auroras, which were witnessed in skies around the globe. This natural event coincided with experiments by the High-frequency Active Auroral Research Program (HAARP), which triggered dozens of social media users to claim that these experiments were responsible for the widely-seen aurora effects. As of the publication date for this article, one YouTube video gathered over 270K views after discussing some of the claims people are making about HAARP’s connection to the recent auroras. We will investigate the main claims below and explore the scientific evidence for the cause of the recent auroras. Colorful auroras appeared across the globe in May 2024 due to asolar storm that scientists warned about Although the recent auroras were exceptionally wide-spread and a surprise to most who saw them, their presence was not a mystery to scientists. Scientists have long known that certain types of solar activity lead to aurora effects in Earth’s atmosphere. The most well-known example of this phenomenon is the aurora borealis (i.e., the northern lights), which have been documented for centuries – long before the establishment of HAARP in 1990. Auroras are caused by the interactions between solar winds and Earth’s magnetic field (i.e., magnetosphere) which protects our planet, as shown in Figure 1 below. These solar winds contain a plasma of electrically charged particles which interact with Earth’s magnetic field, accelerating electrons along its magnetic field lines (blue lines in Figure 1) which then bombard and energize molecules in Earth’s atmosphere causing them to glow and form auroras. Figure 1 – Simplified illustration (not to scale) showing solar wind (orange arrows) interacting with Earth’s magnetic field (blue) which causes the aurora borealis in a region called the ‘auroral oval (green). Source: Tromsø Geophysical Observatory (TGO) The northern lights are a more regular occurrence in the auroral oval due to the interactions described above and geometry shown in Figure 2 below; however, the Sun occasionally has increased activity (e.g., solar storms) which leads to greater visibility of auroras from other places on Earth, as witnessed on 10-11 May 2024. Figure 2 – Location of the auroral oval (green) where the northern lights are commonly seen. This region can vary with changes in solar winds, which accelerate electrons along the magnetic field lines (thin lines shown above) and down to Earth’s atmosphere where they excite molecules which glow and form auroras. Source: NOAA On 9 May 2024, the National Oceanic And Atmospheric Administration (NOAA) issued a Severe (G4) Geomagnetic Storm Watch due to a series of solar flares and coronal mass ejections (CMEs) that began the day prior. One of the solar flares from sunspot ‘AR3664’ was observed by NOAA’s GOES-16 satellite on 9 May 2024, as shown around the four second mark in the video linked here, and shown in the ‘after’ photo of Figure 3 below as a bright flash of light on the lower right. Figure 3 – Solar flare from sunspot ‘AR3664’ observed by NOAA’s GOES-16 satellite on 9 May 2024. Images screen-captured from NOAA’s GOES-16 video footage, with the before photo (left) captured seconds before the after photo (right). Source: NOAA’s Space Weather Prediction Center (SWPC) NOAA later shared an X/Twitter post explaining that the geomagnetic storms reached level G5 – the highest in the scale from 1-5 – which last occurred in 2003. This solar storm originated from a cluster of sunspots that is roughly 17 times the diameter of Earth, which spewed magnetized plasma that hurtled towards Earth at ~1,800 kilometers/second. Once reaching Earth’s magnetic field, this resulted in an aurora that could be seen from areas on Earth where it is normally not possible. Based on this evidence, we can confidently conclude that a solar storm was responsible for the auroras witnessed around the world on 10-11 May 2024. However, as we noted earlier, dozens of social media posts claimed that HAARP experiments were the cause of these auroras. Examples of these posts can be found in the following links: X/Twitter post, TikTok video 1, TikTok video 2, Facebook post. Below we will explore what HAARP is and the experiments they were conducting. No evidence that the HAARP experiments were related to the auroras observed in May 2024 A press release from HAARP was posted on 13 May 2024, explaining that “the HAARP scientific experiments were in no way linked to the solar storm or high auroral activity seen around the globe”. But what is HAARP and what experiments did they recently conduct? HAARP is a research facility operated by the University of Alaska Fairbanks[1]. It transmits high-frequency radio signals into the highest point of the atmosphere, the ionosphere, using 360 radio transmitters and 180 antennas. The facility covers about 14 hectares (0.14 kilometers squared) near the town of Gakona, Alaska, which is about 250 kilometers northeast of Anchorage, Alaska’s largest city. The radio signals are partially absorbed between 100 kilometers and 350 kilometers in altitude, accelerating electrons in the ionosphere and briefly “heating” it up[2]. By analyzing how radio waves interact with electrons in the ionosphere[3,4], researchers at HAARP are able to study phenomena, such as the effects of the aurora borealis (i.e., northern lights) on radio systems and aircraft communications at high altitudes. The experiments that HAARP conducted between 8-10 May 2024 “supported research proposals from the University of Alaska Fairbanks to study mechanisms for the detection of orbiting space debris”. They explain that these experiments were conducted to help improve collision detection for satellites, and were scheduled roughly a month and a half ahead of the geomagnetic storm. As they HAARP explains in their press release, “the timing was purely coincidental; geomagnetic storms are unpredictable, with lead times before a solar event is detected from Earth measured in minutes, not months”. Beyond the fact that the HAARP experiments were unrelated to the observed auroras in May 2024, the HAARP instruments are also incapable of producing those effects. The maximum radiative power of HAARP’s antennas is 3.6 megawatts[2], whereas a strong geomagnetic storm – such as that observed on 10-11 May 2024 – inputs upwards of 100 gigawatts of power into Earth’s magnetosphere and ionosphere (i.e., the study area of HAARP experiments). This means that the power received from the geomagnetic storm was 10,000 times greater than HAARP’s maximum power output. In a similar explanation from HAARP, they note: “interestingly, coronal mass ejections, like the one associated with the recent geomagnetic storm, typically release more than 10^24 Joules of energy. By comparison, the high- frequency (HF) transmitter at HAARP is only a ~3 megawatt (MW) transmitter; it would take HAARP over 10 billion years to produce enough energy to affect this naturally occurring phenomenon”. Science Feedback has covered the limitations of HAARP’s capabilities in previous claim reviews – an example is linked here. Conclusion: In summary, there is conclusive evidence that the aurora observed around the globe on 10-11 May 2024 was caused by a solar storm that began erupting from the Sun on 8 May 2024. The claims attributing the auroras to HAARP experiments that coincided with this event are simply incorrect. As explained above, not only is HAARP incapable of producing the observed auroras from its limited power output, but the experiments – which were scheduled over a month in advance – were conducted to study space debris, unrelated to auroral effects. |
https://science.feedback.org/review/no-evidence-significant-influence-volcanoes-solar-variability-on-recent-climate-change-contrary-judith-curry-claims-prageru-video/ | Misleading | PragerU, Judith Curry, 2024-04-15 | Climate scientists disagree about how much warming is associated with our emissions and whether this warming is larger than natural climate variability from the sun and volcanic eruptions | null | Misleading: Climate scientists have studied natural climate variability and the contribution of human CO2 emissions to recent climate changes. The resulting evidence unequivocally shows that anthropogenic CO2 emissions are the most significant driver of recent climate change, while natural variability has made a minimal contribution. Unsupported: There is no evidence to support that solar variability or volcanic activity have had a significant impact on recently rising global temperatures at multidecadal to century timescales. In fact, solar intensity is currently declining while global temperatures are rising. | Scientific evidence shows that modern global warming is primarily driven by increasing CO2 emissions from human activities. There is no evidence that solar variations or volcanic activity are substantial drivers of recent climate change. | Climate scientists disagree about how much warming is associated with our emissions and whether this warming is larger than natural climate variability; “Variations in the sun and volcanic eruptions also have a substantial impact [on Earth’s climate], but these are simply unpredictable”. | 1 – IPCC (2021). Sixth Assessment Report. 2 – Zhong and Haigh (2013) The greenhouse effect and carbon dioxide. Royal Meteorological Society Weather. 3 – PAGES 2K Consortium (2019) Consistent multidecadal variability in global temperature reconstructions and simulations over the Common Era. Nature Geoscience. 4 – Le Quéré et al. (2016) Global Carbon Budget 2016. Earth System Science Data. 5 – Knapp et al. (2010) The International Best Track Archive for Climate Stewardship (IBTrACS): Unifying tropical cyclone best track data. Bulletin of the American Meteorological Society. 6 – Lean et al. (2020) Solar irradiance variability: Modeling the measurements. Earth and Space Science. 7 – Gerlach (2011) Volcanic Versus Anthropogenic Carbon Dioxide. American Geophysical Union EOS. 8 – Sully et al. (2019) A global analysis of coral bleaching over the past two decades. Nature. 9 – Vicedo-Cabrera et al. (2021) The burden of heat-related mortality attributable to recent human-induced climate change. Nature. 10 – Lüthi et al. (2023) Rapid increase in the risk of heat-related mortality. Nature. 11 – Ballester et al. (2023) Heat-related mortality in Europe during the summer of 2022. Nature. 12 – Hausfather et al (2019) Evaluating the Performance of Past Climate Model Projections. Geophysical Research Letters. 13 – Robock (2000). Volcanic eruptions and climate. Reviews of Geophysics. Note: Scientists comments were lightly edited for clarity (i.e., information was added in brackets for context and minor punctuation changes were made). | On 15 April 2024, PragerU posted a short video on their website and YouTube titled “The Good News about Climate Change”, which gathered over 500,000 views combined as of the publication date of this review. The video features a former professor, Dr. Judith Curry, who makes claims about the current state of climate change knowledge – the knowns and unknowns, agreements and disagreements. Below we will share our investigation of some of these claims using scientific evidence, followed by evaluations of these claims from scientists with relevant expertise. Recent rises in global temperatures are being driven by CO2 emissions from human activity; evidence shows that natural variability cannot account for these changes In the video, Curry attempts to summarize what climate scientists agree and disagree about on climate change. She claims that they agree on the following: “the average global surface temperature has increased over the last 150 years; humans are adding carbon dioxide to the atmosphere by burning fossil fuels; and, carbon dioxide emissions have a warming effect on the planet.” The claims above do in fact represent some, but not all, of the findings shared by the Intergovernmental Panel on Climate Change (IPCC), the world’s leading authority on climate science. This is an important distinction because it is misleading to imply that these are the only three things that climate scientists agree on – or, more accurately, that the scientific evidence unequivocally shows. For instance the IPCC also reports that “rising greenhouse gas concentrations are driving profound changes to the Earth system, including global warming, sea level rise, increases in climate and weather extremes, ocean acidification, and ecological shifts.”[1] It is well established among scientists that humans are adding carbon dioxide (CO2) to the atmosphere by burning fuels, and that CO2 has a warming effect on the planet through the greenhouse effect. While remaining in the atmosphere, CO2 prevents heat from escaping and consequently warms the surface of Earth – a concept that is popularly known as the greenhouse effect. This is a consequence of the properties of CO2, which allow sunlight to pass through to Earth’s surface, but cause CO2 to absorb and re-emit the energy that returns (i.e., infrared radiation emitted from Earth’s surface after absorbing sunlight)[2] . It is also well established that global mean surface temperature (GMST) has been rising for over 150 years, as shown in Figure 1 below. In the most recent year, 2023, the National Oceanic and Atmospheric Association (NOAA) reported that “The average global land and ocean surface temperature for January–December 2023 was 1.18°C (2.12°F) above the 20th century average of 13.9°C (57.0°F)—the highest global land and ocean temperature for January–December in the 1850–2023 record.” Figure 1 – Observed global mean surface temperatures from 1850 to 2020 using four data sets. The horizontal lines represent different time ranges and are annotated to show the rise in GMST in the respective time periods. Source: IPCC (2021)[1] Although Curry’s claims above about agreement amongst climate scientists are scientifically supported, that ceased to be the case in her following claim that climate scientists disagree about “how much warming is associated with our emissions” and “whether this warming is larger than natural climate variability”. “This is absolutely not true”, explained Dr. Ella Gilbert, Regional Climate Modeller at the British Antarctic Survey, “we know unequivocally that human activity is responsible for the vast majority of observed warming, and that natural factors make up a very small proportion of the changes seen in the last few centuries.” Climate scientists know this because they have investigated the impact of natural inputs (e.g., solar, volcanic, etc.) and human CO2 emissions on global temperatures, and have also compared modern temperature trends to natural variations. This allows scientists to determine the relative contributions of these inputs to global warming and determine how modern global warming compares to natural variability. As shown below in Figure 2, greenhouse gases overall cause the most global warming of all the climate change drivers, and CO2 causes the most global warming of all the greenhouse gases. Figure 2 – The contributions of different drivers to global warming from the present time period (2010-2019) relative to the time period of 1850-1900. The estimates of warming (red) and cooling (blue) from radiative forcing studies (panel (c)) are based on both direct emissions into the atmosphere and their effect, if any, on other climate drivers. Source: IPCC (2021)[1] Scientists have also investigated which physical properties control the climate system and have quantified their influence on global temperatures. By incorporating all these physical properties in global climate models, they have been able to simulate the climate from 1850 to present day. As shown in Figure 3 below, the simulation that only included natural variables (solar and volcanic) was unable to match observed global temperature changes over the period of 1850-2020. However, the addition of human drivers – such as CO2 emissions – lead to a much closer match between simulated and observed temperatures. These simulations also show that human greenhouse gas emissions are the only variable that can reproduce observed temperatures; other natural phenomena (i.e., solar and volcanic influences) fail to explain the recent rise in global temperatures. Figure 3 – Observed and simulated changes in global surface temperature from 1850 to 2020. The black line represents 170 years of observed data and is compared to Coupled Model Intercomparison Project Phase 6 (CMIP6) climate model simulations. The brown area represents the temperature response to both human and natural drivers and the green area to only natural drivers (solar and volcanic activity). Solid colored lines represent the averages, and the shaded areas represent the very likely range for the models. Source: IPCC (2021)[1] The figures above help explain how human inputs, such as greenhouse gas emissions, have driven recent global temperature changes. However, scientists have also compared these changes to natural variations over longer time periods. After analyzing data from the past 2000 years, studies have shown evidence that modern global warming trends are unusual compared to past variations over this period. For example, PAGES 2K Consortium (2019), explains that over the last 2000 years “the largest warming trends at timescales of 20 years and longer occur during the second half of the twentieth century, highlighting the unusual character of the warming in recent decades.”[3]As shown in Figure 4 below, the black line – representing modern instrumental temperature records – shows that recent temperatures have exceeded the upper range of natural (pre-industrial) warming rates of the last 2000 years. Figure 4 – 2000 years of global warming/cooling rates averaged across 51 years and based on paleoclimate records. Modern instrumental temperature records shown in black. Data sourced from Neukom et al. (2019) and PAGES 2k Consortium (2019). Source: University of Bern Note that the warming/cooling rates above are averaged across 51 years; evaluating trends at these timescales (20 years and longer) is important because, as the IPCC explains, “over periods of a couple of decades or less, natural climate variability can dominate the human induced surface warming trend.”[1] That is to say that natural variability has less of an effect at timescales of decades to centuries. So looking at longer time periods allows scientists to better understand how human activities are impacting warming trends, without the ‘noisy’ ups and downs in temperature data observed at shorter timescales. As explained by the IPCC, “over the entire historical period (1850–2019), natural variability is estimated to have caused between -0.23°C and +0.23°C of the observed surface warming of about 1.1°C. This means that either the majority, or all, of the warming has been driven by human activities, particularly emissions of greenhouse gases”[1]. To conclude, Curry’s claim is at odds with the science on this point. Scientific knowledge has demonstrated that the vast majority of the observed warming can only be explained by the forcing created by greenhouse gases added to the atmosphere by human activities. Regarding scientific agreement among climate scientists, Dr. Kerry Emanuel, Professor Emeritus of Atmospheric Science at the Massachusetts Institute of Technology, explained: “There is a widespread scientific consensus that a strong signal of global mean temperature increase has emerged from natural background variability and that it is not caused by other kinds of radiative forcing changes, such as solar output. Of course, as in all scientific endeavors, there is a minority dissent, but in this case that has been reduced to typical background noise levels.” Evidence shows that recent climate change is not being driven by solar variability or volcanoes Over the years, claims continue to pop up regarding the impacts of solar activity and volcanoes on climate change. Science Feedback has addressed many of these in several past reviews, and in each case – now including this film – the claims were inconsistent with available evidence. See examples of these claims in the past reviews linked below: Review: 1: The sun isn’t responsible for current climate change, contrary to claims in Suspicious0bservers YouTube video Review 2: Low solar activity has little effect on Earth’s climate, contrary to claim in The Sun Review 3: Claim that current climate change can be explained satisfactorily by natural cycles and volcanic activity does not have scientific support Review 4: Evidence greenhouse gasses cause global warming denied by Willie Soon in Tucker Carlson interview, resulting in mass social media climate misinformation Curry claims that “Variations in the sun and volcanic eruptions also have a substantial impact [on Earth’s climate], but these are simply unpredictable”. Although this matter has been partially addressed above by comparing natural and human climate drivers, we will further investigate below. To gain expert insight on this matter, we interviewed Dr. Ian Richardson, Principal Research Scientist at the University of Maryland, who studies the interplanetary environment between the Sun and the Earth. After reviewing Curry’s claim, Dr. Richardson commented: “The solar influence on climate appears to be small. Changes in the solar visible and infrared irradiance are only ~0.1%, so the effect is not ‘substantial’ and tracks the 11-year solar cycle, so in this sense the changes are not ‘unpredictable’.” Dr. Richardson’s comment above aligns with evidence found in past Science Feedback reviews on this subject. For example, one of the Science Feedback reviews linked above explains that the rate and magnitude of modern global warming is too high to be caused by solar variability. As shown in Figure 5 below, solar irradiance and global temperatures show opposing trends; solar irradiance has shown no net increase since 1950, but temperatures have continued to rise. If changes in solar activity were a primary driver of recent climate change, we would expect to see global temperatures decrease with total solar irradiance, but the opposite has occurred in recent times. Figure 5 – Comparison of the global surface temperature changes (red) and the Sun’s energy that Earth receives (yellow) in watts per square meter since 1880. One can see that since the 1960s, the global temperature and solar activity have varied in opposite directions. Source: NASA/JPL-Caltech Regarding volcanic influences on Earth’s climate, the IPCC explains that large volcanic eruptions can actually have a cooling effect, as they release small particles into the upper atmosphere which reflect sunlight[1]. However, these effects are short lived; “Volcanic eruptions can cool the climate by a few tenths of a degree for a couple of years, but this is only a short-term effect compared to the long-term warming by human greenhouse gas emissions”, explained Dr. Georg Feulner, Deputy Head of Research Department at Potsdam Institute For Climate Impact Research. He also commented that Curry’s claim “overemphasizes the role of the sun and volcanic eruptions”. Feulner’s comments can be viewed in more detail near the bottom of this review. As shown earlier in Figures 2 and 3, other drivers – such as CO2 emissions from human activities – have had a far greater impact on Earth’s climate in recent times. Volcanic eruptions can also increase atmospheric CO2; however, as explained by Tobias Fischer, Volcanologist and Professor at The University of New Mexico, “during a typical year, volcanic eruptions contribute only about 0.006% of the global anthropogenic CO2 flux. The average CO2 emission of a person living in the USA is about 16 tons of CO2 per year[4] . Therefore, in any given year volcanic eruptions produce only about as much CO2 as 130,000 Americans, or less than the population of Wyoming—the state with the lowest population in the US.” More on this topic can be found in this linked review. Conclusion: and Final Remarks As we have shown above, the claims that Curry makes about climate change drivers are misleading and unsupported. Although Curry accurately listed some (but not all) of the unequivocal climate science findings (e.g., CO2 warms the planet, burning fossil fuels releases CO2, and global temperatures have been rising for 150 years), it was phrased in a misleading way that suggests that those were the only solid findings. This excludes many unequivocal findings that are outlined in the IPCC Sixth Assessment Report, for example. Additionally, her characterization of the uncertainties (i.e., disagreements among climate scientists) does not align with available scientific evidence. The evidence shows that CO2 emissions from human activities are the primary driver of recent rising global temperatures, and there is no evidence that natural variability can account for these changes. On the contrary, natural climate drivers such as solar variability and volcanic activity, have made a minimal impact compared to CO2 emissions from human activities. The information included thus far has addressed the claims that could be investigated using only scientific evidence, without discussion of policy options – which moves into ‘opinion’ territory. For this reason, we have not discussed the underlying message in the video which suggests that “all things considered, planet Earth is doing fine” and that if we focus only on adapting to effects of climate change, there is reason to be optimistic. However, as explained by Richardson, “choosing between either trying to change climate by moving away from fossil fuels or “adapting” to the effects is a red herring. You can do both.” This is why climate scientists discuss climate hazards in terms of both vulnerability (e.g., lack of proper infrastructure) and exposure (e.g., changing climate conditions). The IPCC explains that “continued GHG [greenhouse gas] emissions will further affect all major climate system components, and many changes will be irreversible on centennial to millennial time scales.”[1] They also explain that the available adaptation options will decrease as global warming increases. This provides further reason to focus on both aspects of risk mitigation – reducing known drivers of climate change and improving infrastructure. Scientists’ Feedback: Kerry Emanuel Professor of Atmospheric Science, MIT:There is a widespread scientific consensus that a strong signal of global mean temperature increase has emerged from natural background variability and that it is not caused by other kinds of radiative forcing changes, such as solar output. Of course, as in all scientific endeavors, there is a minority dissent, but in this case that has been reduced to typical background noise levels. On the more consequential question of whether this has caused increases in certain kinds of natural hazards, such as wildfires and hurricanes, there is no general answer that covers them all and we have to look at each hazard in each region. Since the mid 1990s, North Atlantic tropical cyclone activity, including landfalling storms, have been at levels not seen in records going back to 1900, even though there was some elevation of activity in the 1930s as well as the 1950s and 60s. Only about one third of North Atlantic tropical cyclones affect the continental USA, so we have a problem seeing trends with such small numbers, but the decade of the 2000s far surpassed the 1930s in US landfalling hurricane power [based on IBTrACS data][5]. Ian Richardson Research Scientist, NASA/University of Maryland:[In the video, ] there’s a lot of “cherry-picking” of what are generally facts in themselves that are strung together to try to make the point that we shouldn’t move away from fossil fuels. e.g., the Lake Chad example appears to be an inexpert politician not taking account for what appears to be the actual cause of the lake failing and says nothing about the reality of climate change. The 97% “per capita” decrease in the effect of bad weather is a rather meaningless statistic since there has been a huge increase in the population – and hence also in the number of people that are likely to be impacted by such a weather event. Choosing between either trying to change climate by moving away from fossil fuels or “adapting” to the effects is a red herring. You can do both. And it’s only practical to adapt so far. For instance, you can build sea walls, but not everywhere (and how do you choose where? – that’s an economic/political decision that may not be available to poor low-lying countries) and it’s not feasible to keep adding height as sea levels rise. Similarly for controlling water resources which are finite and subject to the effects of climate change. Any models used in science are imperfect but that doesn’t mean that they can’t provide insight and guidance and should be dismissed. Specifically, they may not include solar and volcanic effects because they are assessed to be unimportant. The solar influence on climate appears to be small. Changes in the solar visible and infrared irradiance are only ~0.1%, so the effect is not “substantial” and tracks the 11-year solar cycle, so in this sense the changes are not “unpredictable”. The irradiance has also declined since around 1980 as a result of the ~100 year Gleissberg cycle, whereas global temperature has risen during this time. Solar activity is somewhat “unpredictable” on short timescales[6] (days/weeks) and there is debate about whether for example variations in solar X-rays, ultraviolet radiation and energetic particles can influence the atmosphere and ionosphere on such timescales, but that’s confusing weather with long-term climate variability. Volcanoes are clearly unpredictable. There’s a useful summary at USGS [US Geological Survey]. The main issues with respect to climate change appear to be emissions of sulfur dioxide, which tends to cause atmospheric cooling, and carbon dioxide, which contributes to heating. However, the CO2 contributed by even large volcanoes is small compared to annual (2010) anthropogenic CO2, which is equivalent to 3500 Mount St. Helen’s or 700 Pinatubo eruptions and that volcanos add less than 1 percent of that produced by human activities[7]. Ella Gilbert Research Scientist, British Antarctic Survey:1. Curry’s claim: Climate scientists disagree about the most consequential issues: how much warming is associated with our emissions, and whether this warming is larger than natural climate variability. This is absolutely not true. We know unequivocally that human activity is responsible for the vast majority of observed warming, and that natural factors make up a very small proportion of the changes seen in the last few centuries. For example, the IPCC’s most recent report (AR6) contains the following in its working group 1 report summary for policymakers (section A1.3): “It is likely that well-mixed GHGs contributed a warming of 1.0°C to 2.0°C, other human drivers (principally aerosols) contributed a cooling of 0.0°C to 0.8°C, natural drivers changed global surface temperature by –0.1°C to +0.1°C, and internal variability changed it by –0.2°C to +0.2°C.”[1] i.e. that the contribution of natural factors to warming is *at very least* ten times smaller than that of greenhouse gases, and possibly very much smaller. The impact of natural drivers may not even be causing warming at all[1]. 2.Curry’s claim: “For the past 50 years, the global climate has been fairly benign. In the US, the worst heat waves, droughts, and hurricane landfalls occurred in the 1930s—much worse than anything we’ve experienced so far in the 21st century.” Climate change has been shown to increase the severity and intensity of extreme events such as wildfires, floods and heatwaves (IPCC, 2021). These kinds of events threaten ecosystems (for instance causing mass coral bleaching events, as have been reported recently[8] – see, e.g. Sully et al. 2019) and carry extreme risk to peoples’ lives (Vicedo-Cabrera, 2021; Lüthi et al., 2023)[9,10] – e.g. 70,000 people died in Europe during the heatwave of 2003 and more than 60,000 died in 2022’s European heatwave (Ballester et al., 2023)[11]. Extremes also threaten livelihoods, especially those based on agriculture and natural resource use. That the impacts of individual extreme events are now generally lower than in the 1930s is due to the fact that we are more prepared and have better tools to adapt and plan for extremes. Besides, people are less vulnerable in other ways (thanks to e.g. better health, fewer labour-intensive outdoor jobs and greater economic support), which means the death toll and losses associated with e.g. droughts, wildfires, heatwaves are lower. 3. Far from being “unreliable” and based on incorrect “assumptions”, models are actually very good at making predictions – Hausfather et al. (2019) shows how well even the oldest, simplest models have performed compared to observed climate change[12]. We *can* predict the big picture of climate change (and do so very successfully) – it’s the regional and small-scale changes that are less easy to predict. Georg Feulner Senior Scientist, Potsdam Institute for Climate Impact Research (PIK): Curry’s claim: Climate scientists disagree about the most consequential issues: how much warming is associated with our emissions, and whether this warming is larger than natural climate variability The first part of this statement is misleading, the second part is just wrong. Concerning the first part, the amount of warming associated with emissions is characterized by the climate sensitivity, i.e. the long-term warming after a doubling of the carbon-dioxide levels above pre-industrial concentrations. The latest IPCC assessment puts the climate sensitivity in a likely range of 2.5 to 4 degrees (high confidence)[1], so while we do not know precisely how much Earth will warm under continuing emissions, we are sure that it will warm. Concerning the second part of the statement, the warming already observed in the instrumental record has left the range of natural climate variability. Curry’s claim: “Variations in the sun and volcanic eruptions also have a substantial impact [on Earth’s climate], but these are simply unpredictable” – This statement overemphasizes the role of the sun and volcanic eruptions. Solar variability leads to fluctuations of Earth’s global mean surface temperature of about 0.1 degrees, compared to about 1.3 degrees of warming since the pre-industrial era. Volcanic eruptions can cool the climate by a few tenths of a degree for a couple of years[13], but this is only a short-term effect compared to the long-term warming by human greenhouse gas emissions. And the fact that we cannot predict the future behavior of the sun and volcanoes does not imply that we cannot include their effect in a statistical sense in future projections – in which the temperature change is dominated by human emissions in any case. Comments on other statements in the video: Curry’s claim: “inadequate climate models driven by unrealistic assumptions” Climate models are constantly improved and extensively validated against present-day observations and past climate change. They are based on our best knowledge of the physical, chemical, and biological processes in the Earth system and driven by measured (or reconstructed) input data (e.g. on greenhouse gas concentrations) in the past, and scenarios for future emissions for projections. While the models are not perfect (they would not be models, then), they provide important information about future climate change. Climate scientists typically compare the projections of many models to be able to assess robustness and quantify model uncertainty. On the Lake Chad example – one very specific counterexample of environmental change not caused by climate change does not disprove the multitude of expected negative climate change impacts around the world. |
https://science.feedback.org/review/carbon-isotopes-do-not-show-humans-climate-impacts-too-small-notice-despite-the-daily-sceptic-inaccurate-claim/ | Incorrect | Daily Sceptic, Chris Morrison, 2024-04-08 | Human-caused carbon emissions’ effect on climate is ‘non-discernible’. Measurements of carbon isotope ratios in atmospheric CO2 indicate that it is the recent expansion of a more productive biosphere that has led to increased CO2 concentrations in the atmosphere. | null | Incorrect: Scientific studies demonstrate that fossil fuel emissions are the only cause that can explain both changes in carbon isotope ratios and increased CO2 concentrations in the atmosphere. Cherry-picking: The article supports its claim with only two papers while ignoring the vast body of existing evidence that disproves it. The two papers in question are written by authors with no background in climate science and have been debunked by scientists who showed that they relied on flawed methodologies and made fundamental errors. For example, a more productive biosphere would be a net carbon sink and therefore decrease CO2 concentrations in the atmosphere, rather than increasing them. | Carbon isotope ratios are actually one of the key measurements that show human-caused emissions are responsible for climate change. CO2 emissions from fossil fuels have lower concentrations of both carbon-13 and carbon-14 than CO2 placed in the atmosphere by the natural carbon cycle. Therefore, burning fossil fuels is linked to decreased concentrations of both isotopes in atmospheric CO2. | “Human-caused carbon emissions’ effect on climate is ‘non-discernible’. Measurements of carbon isotope ratios in atmospheric CO2 indicate that it is the recent expansion of a more productive biosphere that has led to increased CO2 concentrations in the atmosphere.” | 1 – Graven et al. (2020) Changes to Carbon Isotopes in Atmospheric CO2 Over the Industrial Era and Into the Future. Global Biogeochemical Cycles. 2 – Hoffman and Rasmussen (2022) Absolute Carbon Stable Isotope Ratio in the Vienna Peedee Belemnite Isotope Reference Determined by 1H NMR Spectroscopy. Analytical Chemistry. 3 – Graven et al. (2017) Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP. Geoscientific Model Development. 4 – Ritchie et al. Key Insights on CO2 and Greenhouse Gas Emissions. Our World in Data. 5 – Clark et al. (2021) SuessR: Regional corrections for the effects of anthropogenic CO2 on δ13C data from marine organisms. Methods in Ecology and Evolution. 6 – Francey et al. (1999) A 1000-year high precision record of δ13C in atmospheric CO2. Tellus B. 7 – Böhm et al. (2002) Evidence for preindustrial variations in the marine surface water carbonate system from coralline sponges. Geochemistry, Geophysics, Geosystems. 8 – Shervette et al. (2021) Radiocarbon in otoliths of tropical marine fishes: Reference Δ14C chronology for north Caribbean waters. PLOS One. 9 – Xiong et al. (2021). Time series of atmospheric Δ14CO2 recorded in tree rings from Northwest China (1957–2015). Chemosphere. 10 – Graven (2015) Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century. Proceedings of the National Academy of Science. 11 – Yu et al. (2022) Estimation of Atmospheric Fossil Fuel CO2 Traced by Δ14C: Current Status and Outlook. Atmosphere. 12 – Watson et al. (1990) Greenhouse Gases and Aerosols. Climate Change: The IPCC Scientific Assessment. 13 – Canadell et al. (2003) Global Carbon Budget 2023. Earth System Science Data. 14 – Suess (1955) Radiocarbon Concentration in Modern Wood. Science. 15 – Keeling (1979) The Suess effect: 13Carbon-14Carbon interrelations. Environment International. 16 – Anderegg et al. (2010) Expert credibility in climate change. Proceedings of the National Academy of Sciences. | Carbon comes in three naturally occurring isotopes on Earth: carbon-12, carbon-13, and carbon-14. Different carbon sources bear different mixtures of the three, and studying these isotopic signatures can help trace how carbon moves across the Earth. For instance, carbon-13 and carbon-14 are less abundant in fossil fuels than in atmospheric CO2, but the concentrations of the two isotopes in atmospheric CO2 have both dropped since the mid-20th century. A large body of scientific evidence has long attributed these declines to extra CO2 pumped into the atmosphere by humans burning fossil fuels[1]. An article authored by Chris Morrison in The Daily Sceptic, an outlet with a track record of scientifically unfounded messages, makes a conflicting claim: that changing isotope signatures in atmospheric CO2 result from the biosphere, rather than human causes like fossil fuel emissions. The article primarily cites “a new paper” published in February 2024 and supports its claim with a second paper published two years earlier. The article then upholds the two papers’ findings as scientific evidence that the human impact on climate change is “non-discernible”. Below, however, we show that the Daily Sceptic builds its claim on a scientifically shaky foundation. The two papers are at odds with decades of scientific results showing that these isotope changes are the direct result of CO2 emissions from human activity. Furthermore, both papers have received heavy criticism from climate scientists for drawing their conclusions from faulty analyses. Additionally, scientists contacted by Science Feedback emphasized that isotope concentrations are far from the only evidence pinning human activity as the primary cause of increased CO2 in the atmosphere. claim 1 (INCORRECT):A lack of carbon-13 is the biosphere’s problem The Daily Sceptic draws the core of its argument from a paper (“the Sci paper”) published in February 2024 in Sci, a journal published by MDPI, which has a reputation as a “predatory” publisher. The Sci paper analyzed historic data showing a decline in the ratio of carbon-13 to carbon-12, the element’s two stable isotopes, and blamed the change not on fossil fuel emissions but on a “more productive and expanded” biosphere. The carbon-13 to carbon-12 ratio is a common measurement in climate science. Carbon-12 accounts for about 99% of Earth’s carbon, and carbon-13 takes up almost all of the remaining 1%. Depending on the origin, the exact concentrations of each vary by a few fractions of a percent (Fig. 1). Climate scientists gauge these variations with δ13C, the deviation of a sample’s ratio of carbon-13 to carbon-12 from a standard benchmark originally derived from a particular type of limestone[2]. In other words, the lower a sample’s δ13C, the higher its carbon-12 content. Figure 1 – The δ13C values of different carbon sources and sinks. Note that fossil fuels have a distinctly lower δ13C than CO2 in the atmosphere and that the modern atmosphere has a lower δ13C than the atmosphere of only several hundred years earlier. Source: Graven et al. 2020[1] δ13C is a telling indicator when used to measure CO2 in the atmosphere (δ13CO2). Plants prefer to photosynthesize carbon-12, making the biosphere’s δ13C lower than δ13CO2. By extension, fossil fuels made from ancient biological matter also hold more carbon-12; when humans burn those fossil fuels, it also releases CO2 with lower δ13C than δ13CO2. The consequences are observed globally: δ13CO2has declined since the beginning of the Industrial Revolution (Fig. 2). Analyses have shown that, after accounting for exchanges between carbon in the atmosphere and carbon in the ocean and terrestrial biosphere, this decline matches the expected change from known fossil fuel emissions[1]. Figure 2 – Several measurements of δ13C from 1850 to 2015. The decline beginning in the late 20th century corresponds to a rise in anthropogenic CO2 emissions. Source: Graven et al. 2017[3] Instead, the Sci paper tried to explain the decline with a scenario that entirely ignored fossil fuel emissions. The paper attempted to calculate the relationship between CO2 and δ13CO2between 1520 and 1997 and noted that both measurements exhibited seasonal cycles as Earth’s biosphere became more active in the Northern Hemisphere spring, then declined in the Northern Hemisphere winter. The Sci paper then used this observation to claim that δ13CO2declined as a consequence of Earth naturally warming since the end of the Little Ice Age in about 1800, which the paper argues boosted the carbon cycle of the planet’s biosphere. The paper claimed the biosphere pumped low-δ13C greenhouse gas into the atmosphere, causing both a δ13CO2 decline and a rise in atmospheric CO2 levels. When Science Feedback asked scientists who studied isotope ratios to comment on the Sci paper, they pinpointed flaws in the paper’s methodology. For instance, although it is true that CO2 activity follows seasonal cycles, the paper’s model neglected to include several key processes impacting δ13CO2. The paper treated the atmosphere as a closed CO2 reservoir, ignoring two-way exchanges with the oceans and terrestrial biosphere that allow isotopic perturbations in the atmosphere to dissipate. More egregiously, the paper explicitly cited the known CO2 emissions from fossil fuels and their isotopic signature[4], then excluded them from its analysis and dismissed them as a driver of CO2 concentration and δ13CO2changes. “What is frustrating and confusing to me is that the author knows that human emissions have increased significantly during the industrial period, enough to explain the rise of CO2,” Sourish Basu, a research scientist at NOAA Global Monitoring Laboratory and an expert in carbon cycle, told Science Feedback in an email. “Early on, the author erroneously concluded that the biosphere must be the main driver behind the atmospheric CO2 budget and fossil fuel emissions must be negligible.” Heather Graven, a climate physicist at Imperial College London, echoed this criticism of the Sci paper. “What he does is he just tries to estimate the isotope composition of the source using a flawed method,” she told Science Feedback via telephone. “He doesn’t really perform a simulation taking into account all the factors.” Basu and Graven also questioned the validity of the Sci paper’s conclusion. “What we see in the atmosphere is because the biosphere and the oceans take up half of our emitted fossil CO2. The biosphere is a net sink, not a net emitter. The author gets this basic fact wrong,” Basu told Science Feedback. Therefore, the scenario that a more productive biosphere could simultaneously push down δ13CO2 and increase the amount of CO2 in the atmosphere makes little sense. “If [the carbon-12] were coming from the biosphere, we would have had to lose carbon,” Graven told Science Feedback. The Daily Sceptic derives the core of its claim from a paper that begins with flawed assumptions and uses a flawed model. Essentially, the paper ignores fossil fuel emissions to argue that they are not the root cause of declining δ13CO2. The paper then uses this flawed model to conclude that the biosphere is responsible for pumping CO2 into the air at unprecedented rates, something that contradicts the majority of available evidence. Meanwhile, numerous studies have explained that measurements of declining δ13CO2 correlate with and are caused by an increase in anthropogenic CO2 from fossil fuel emissions[5-7]. claim 2 (incorrect):Carbon-14 shows that fossil fuels emissions are a drop in the bucket The Daily Sceptic supports its erroneous claim by citing a second paper (“the Health Physics paper”), published in February 2022 in the journal Health Physics, a publication that has no significant relevance to climate science. The Health Physics paper examines carbon-14 data to conclude that fossil fuels are responsible for only a small fraction of atmospheric CO2. Climate scientists do use carbon-14 as an indicator. The isotope is extremely rare: about one in every 1012 carbon atoms is a carbon-14 atom. Carbon-14 is radioactive, with a half-life of about 5,700 years, meaning that fossil fuel carbon, which is hundreds of millions of years old, contains almost no carbon-14 whatsoever (Fig. 3) Therefore, the absence of carbon-14 is a flag for the presence of fossil fuel emissions. Figure 3 – The Δ14C values of different carbon sources and sinks. Note, again, that fossil fuels have a distinctly lower Δ14C than CO2 in the atmosphere. Thanks to nuclear weapons testing, atmospheric Δ14C in the modern day is higher than prior to the 20th century. Graven et al. 2020[1] Specifically, climate scientists use a measure called Δ14C, which is calculated from how much a sample’s carbon-14 concentration varies from that of atmospheric air prior to the invention of nuclear weapons[8]. A lower Δ14C indicates that less carbon-14 is present. In the 1950s and 1960s, carbon-14 released as fallout from nuclear weapons tests caused the Δ14C of atmospheric CO2 (Δ14CO2) to dramatically spike. But after the Partial Nuclear Test Ban Treaty largely ended above-ground tests in 1963, Δ14CO2began to decline just as drastically (Fig. 4). Figure 4 – Measurements of Δ14CO2over time. The decline beginning in the 1960scentury corresponds to the end of nuclear weapons testing and a large increase in human CO2 emissions. Source: Xiong et al. 2021[9] However, Δ14CO2 declined too quickly to be explained by carbon-14 decaying or being exchanged out of the atmosphere, indicating that carbon-14-free CO2 entered the atmosphere from fossil fuel emissions[1]. Multiple studies have clearly demonstrated that anthropogenic fossil fuel emissions are responsible for the ongoing decline in Δ14CO2[10,11]. The Health Physics paper’s three authors, none of whom have an obvious climate science background, created a model to match data on Δ14CO2 dating from between 1750 and 2018. Their model assumed that fossil fuel CO2 contained zero carbon-14 and that any given volume of CO2 cycled out of the atmosphere in about 4 years. The authors’ analysis determined that fossil fuel emissions only accounted for 12% of global CO2 as of 2018. The authors, then, concluded that fossil fuels could not have driven modern-day climate change. Like the Sci paper, the Health Physics paper garnered criticism from scientists for making false assumptions. One published comment in the same journal pointed out a major flaw in the Health Physics paper’s methodology: It conflated atmospheric CO2’s residence time (the amount of time a CO2 molecule actually spends in the atmosphere before being exchanged with the land or the water, which is about 4 years) with its adjustment time (the amount of time an extra volume of CO2 will stay in the atmosphere, which can be millennia). As a result, the Health Physics paper authors drastically underestimated how long fossil fuel CO2 would stay in the atmosphere. This is not a new error; as early as 1990, an IPCC report warned researchers against making it[12]. Furthermore, the comment stated, “Throughout [the Health Physics paper] the authors have failed to cite numerous related and relevant earlier publications in this field and demonstrated a lack of fundamental understanding of biogeochemical carbon cycle processes,” the comment stated. A second comment from a different group, published in the same journal, explained that — in addition to conflating residence time with adjustment time — the Health Physics paper used faulty Δ14CO2data and inadequately addressed the role of carbon-14 from nuclear weapons testing that remained in the atmosphere into the 21st century, both of which led them to further underestimate the fossil fuel contribution to Δ14CO2trends. This comment demanded that Health Science retract the paper, which the journal has not done. Much like the Sci paper, the Health Physics paper derived its conclusions from a flawed methodology. Moreover, the paper ignores that the volume of CO2 from fossil fuel emissions and its impact on the atmosphere at large are both very well-documented from methods such as air sampling[4]. The concentration of CO2 in the atmosphere has risen from about 280 parts per million (ppm) prior to the Industrial Revolution to about 420 ppm today; the Global Carbon Budget attributed about two-thirds of the excess to fossil fuel emissions and the remainder to human-caused land use changes like deforestation[13]. The body of evidence points to fossil fuel emissions as the culprit for atmospheric CO2 rise Despite the two papers’ flaws and their public debunking by scientists, the Daily Sceptic article champions them to assert a lack of a “discernible” human fingerprint on the climate and claims that carbon isotope signatures are an “interesting branch of climate science to investigate”. The reality is that it has been thoroughly investigated for decades. The study of carbon isotope ratios, in fact, predates any scientists reaching consensus about climate change. As early as the 1950s, chemist Hans Suess measured carbon-14 concentrations in wood and connected them to carbon-14-free fossil fuel emissions released starting from the Industrial Revolution[14]. By the late 1970s, climate scientists had measured shifts in δ13CO2and Δ14CO2 matched the predicted changes caused by then-known CO2 emissions[15]. It may be prudent to look at the isotope ratio changes in the bigger picture. We need a culprit that can explain all of the changes we have observed: a culprit that has lower δ13C than atmospheric CO2, a culprit that is sufficiently old for its carbon-14 levels to have decayed to effectively zero, and a culprit that can explain the dramatic increase in atmospheric CO2 concentrations since the industrial revolution. According to Basu, this allows us to rule out alternative carbon sources like volcanic outgassing, for example, which has a high δ13C; instead, the only suitable suspect is the emissions from humans burning fossil fuels. Moreover, the study of isotope ratios is only one branch of many clearly pointing at a human origin for climate change. Supporting this idea, Ralph Keeling, a climate scientist at the Scripps Institute of Oceanography, told Science Feedback in an email: “We don’t need to turn to measurements of isotopes to establish that the CO2 rise is caused by humans. In fact, we know quite well how much CO2 we’ve dumped into the atmosphere over the past 150 years through the burning of fossil fuels, and it’s more than enough to account for the observed rise. The rise started at the time of the dawn of the industrial revolution, and has accelerated since then. Overall, the CO2 rise is a bit similar to the buildup of trash in a landfill. The trash is obviously of human origin, because we know we put it there. There’s not much sense in questioning its human origins.” Indeed, scientists have clearly identified human causes as responsible for all of modern climate change activity[16], as Science Feedback has previously covered. |
https://science.feedback.org/review/data-shows-temperatures-rising-greenland-world-current-global-warming-driven-co2-not-solar-activity/ | Inaccurate | Daily Sceptic, Stephen Andrews, 2024-03-08 | Ice cores from Greenland show no significant warming, casting doubt on the climate change theory | null | Factually inaccurate: The claim that there is no global warming signal from Greenland is in direct contradiction with available observations. Recent studies of ice cores from several locations in Greenland have shown that temperatures are warming faster than the natural variation of the last 1000 years. Rising temperatures in Greenland do not necessarily represent global changes. However, other studies have shown evidence of rising temperatures around the world. Unsupported: There is no evidence to support that solar cycle variation has a greater impact on rising global temperatures than increasing atmospheric CO2. In fact, solar intensity is currently declining while global temperatures are rising. Evidence shows that rising atmospheric CO2 from human activities is the primary driver of modern global warming. Cherry-picking: Ice core data from one location in Greenland is insufficient to represent the entire planet. Numerous recent studies with larger data sets and rigorous statistical analysis show a global warming trend around the world. | The effect of atmospheric CO2 concentrations on global temperatures is well established; as concentrations rise, global warming increases through the greenhouse effect. Scientific studies show that modern global warming is primarily driven by increasing CO2 emissions from human activities. Based on the available scientific evidence, solar variation has had no significant effect on modern global warming compared to rising atmospheric CO2 concentrations. | Ice cores from Greenland show no significant warming, casting doubt on the climate change theory; above a certain concentration of carbon dioxide, it has minimal direct impact on global temperature relative to solar cycles. | 1 – Anderegg et al. (2010) Expert credibility in climate change. Proceedings of the National Academy of Sciences. 2 – Markle and Steig (2022) Improving temperature reconstructions from ice-core water-isotope records. Climate of the Past. 3 – Holme et al. (2019) Varying regional δ18O–temperature relationship in high-resolution stable water isotopes from east Greenland. Climate of the Past. 4 – Hörhold et al. (2023) Modern temperatures in central–north Greenland warmest in past millennium. Nature. 5 – Kaufman et al. (2020) Holocene global mean surface temperature, a multi-method reconstruction approach. Nature. 6 – IPCC (2021). Sixth Assessment Report. 7 – PAGES 2K Consortium (2019) Consistent multidecadal variability in global temperature reconstructions and simulations over the Common Era. Nature Geoscience. 8 – Santer et al. (2013). Human and natural influences on the changing thermal structure of the atmosphere. Proceedings of the National Academy of Sciences. 9 – Pierce and Adams (2009) Can cosmic rays affect cloud condensation nuclei by altering new particle formation rates?. Geophysical Research Letters 10 – Zhong and Haigh (2013) The greenhouse effect and carbon dioxide. Royal Meteorological Society Weather. Note: Scientists comments were lightly edited for clarity (i.e., information was added in brackets for context and minor punctuation changes were made). | The consensus among climate scientists is that modern global warming is primarily driven by increases in atmospheric CO2 from human activities[1]. A major component of studying global warming is comparing present conditions with those of the past. However, taken out of context, these data can be misinterpreted to draw conclusions that are inaccurate and unsupported. A recent example is in an article on The Daily Sceptic, which made several claims about global warming using a small subset of the available climate data, which we will investigate below. Based on ice core data from one part of Greenland, the article claims that “there is no significant global warming signal coming from one of the most sensitive parts of the planet”, and that these data–which show a rising temperature trend in modern times–fall within a normal (natural) variation. However, this claim is in direct contradiction with scientific findings, mischaracterizes the cited data, and excludes sufficient context about how global warming trends are studied. Evidence of Rising Temperatures in Greenland Scientists use climate proxies, such as ice cores, to help them reconstruct past conditions. For example, stable water isotope (δ18O) signals from ice cores can be used to determine past local temperatures[2]. This method was employed in the studies referenced by The Daily Sceptic article. However, the article leaves out critical details about the uncertainties in the data and mischaracterizes the findings. One study the article references has proxy data from 10,000 BCE to 1960 CE; however, this period excludes several recent decades of available climate data. The second paper the article references, Holme et al. (2019), studied proxy data from 1801-2014, which, as the article correctly points out, shows a rising trend in the δ18O signal. However, the article excludes an important conclusion from the study: “the linear δ18O–temperature relationship was unstable with time which implied that the annual-to-decadal variability of δ18O measured in an ice core could not be directly attributed to temperature variability.”[3] Therefore, there is less certainty when using these data to assess Greenland temperature trends over recent decades. There is a study, however, that analyzed recent temperature trends in Greenland compared to natural variation–the main topic of The Daily Sceptic article. Hörhold et al. (2023) analyzed ice core data from central and northern Greenland–a larger study area–to create a high-quality temperature reconstruction for the period of 1000-2011[4]. The study showed that “the warming in the recent reconstructed decade exceeds the range of the pre-industrial temperature variability in the past millennium with virtual certainty (P < 0.001)”[4] (Figure 1). The authors had greater confidence in these temperature trends due to the high correlation between the δ18O data and local temperature data–which was lacking in the Holme et al. (2019) study. Figure 1 – The top graph (solid black line) shows the record of δ18O and the inferred temperature time series from 1000-2011. Existing ice core data was extended to 2011 in this study by re-drilling ice cores–this data is highlighted in red on the top graph. Two trends from these data–1000 to 1800 and 1800 to 2011–are shown as black dashed lines. The number of firn cores used to collect the data are shown as a thin brown line below the top graph. The bottom blue graph represents arctic-wide data (not discussed here). Source: Hörhold et al. (2023)[4] Based on these findings, the claim made in The Daily Sceptic article regarding a lack of global warming signal from Greenland is inaccurate and a mischaracterization of the supporting data. The Hörhold et al. (2023) study–which analyzed more ice core data (with greater spatial coverage) and achieved high data correlation–found clear evidence of warming in Greenland which exceeded the natural variation of the last 1000 years[4]. Evidence of Rising Global Temperatures While proxy data from one location can be used to reconstruct past local temperatures, it is not necessarily sufficient to reconstruct past global temperatures. To explain this, Dr. Joanna Haigh, Emeritus Professor of atmospheric physics at Imperial College London, provided Science Feedback with the following comment about the article: “using one location to represent global warming is invalid. He [the author] refers to Greenland [as] being the most sensitive place without saying how that is defined. There is substantial evidence of larger variations in temperature at different locations [e.g. Dansgaard-Oescher events]. These are not fully understood but are not used to make statements on global parameters.” To better understand global climate change and reduce uncertainty in their studies, scientists use a variety of methods and analyze a greater number of samples. The Daily Sceptic article only cites data from one area in Greenland; however, there are studies which used more proxies and methods to reduce uncertainty. For example, a study by Kaufman et al. (2020) used 679 proxy sites (Figure 2) and five different statistical methods when reconstructing global mean surface temperatures (GMST) for the last 12,000 years[5]. This multi-method approach helped the researchers create an ensemble of global temperature reconstructions that account for the uncertainties of the different methods. By increasing the number of samples and locations they analyze, researchers also have greater confidence that the results better represent global changes, rather than local changes. Figure 2 – Locations of the 679 proxy data sites (green dots) for the 12,000 year temperature reconstruction. Source: Kaufman et al. (2020)[5] The Kaufman et al. (2020) study indicated that there were periods of cooling and fluctuation over the last 12,000 years (Holocene); however, it also showed a modern rise in global warming[5]. As the authors explain, “The distribution of peak global temperatures during the Holocene can also be compared with recent temperatures. The GMST of the past decade (2011–2019) averaged 1°C higher than 1850–1900. For 80% of the ensemble members, no 200-year interval during the past 12,000 years exceeded the warmth of the most recent decade.”[5] The results of this study (Figure 3) show that a rising global warming trend began in the industrial era and has continued to the present day. Figure 3 – Global mean surface temperature over 12,000 years using multiple reconstruction methods. The fine black line shows instrumental data collected from 1900 to 2010. The smaller inset graph shows the most recent 2000 years of data. Source: Kaufman et al. (2020)[5] Kaufman et al. (2020) explain that the comparisons they made between 200-year intervals of the Holocene and modern warming are conservative in the context of IPCC projections, which indicate that temperatures are likely to rise higher than 1°C above pre-industrial temperatures in the next century[5]. They then explain that the IPCC projections give a better comparison between warming in recent decades and the temperatures in the Holocene reconstructions. A number of other studies have also shown evidence that modern global warming trends are unusual compared to past variations. According to The Intergovernmental Panel on Climate Change (IPCC), the world’s leading authority on climate science, the last 1000 years of temperature data and their methods of reconstruction have been well-studied[6]. One of the studies the IPCC refers to, PAGES 2K Consortium (2019), explains that “the largest warming trends at timescales of 20 years and longer occur during the second half of the twentieth century, highlighting the unusual character of the warming in recent decades.”[7] Rising CO2 Has Driven Global Warming, Not Solar Cycle Variability The Daily Sceptic article also claimed that a lack of global warming signal from the data he provided “could be explained by the fact that the relationship of carbon dioxide to global temperature is logarithmic and above a certain concentration there is minimal direct impact relative to solar cycles.” However, this claim is inconsistent with available evidence. In fact, Science Feedback has done several investigations of similar claims about solar influence on climate change, a sample of which are linked below: Review: 1: The sun isn’t responsible for current climate change, contrary to claims in Suspicious0bservers YouTube video Review 2: Low solar activity has little effect on Earth’s climate, contrary to claim in The Sun Review 3: Claim that current climate change can be explained satisfactorily by natural cycles and volcanic activity does not have scientific support These reviews provide several lines of evidence that solar activity is not driving the rise in global temperatures. For example, one review explains that if the Sun were driving global warming, we should see temperatures rising at the surface of the Earth and throughout the Earth’s atmosphere. Instead, the data show Earth’s surface heating up, while the layers of the atmosphere are changing variably–lower altitudes heating, and higher altitudes cooling[8]. Another review found that the rate and magnitude of modern global warming is too high to be caused by solar variations[9]. The physics of both solar cycle variation and atmospheric CO2 are well understood. The IPCC explained that solar activity from the late 19th century to present was not exceptional compared to the last 9,000 years[6]. The IPCC also compared observed temperature changes to models that accounted for both human and natural influences (Figure 4). As shown below, in both the observed data and simulated cases, the addition of human drivers–such as CO2 emissions–lead to a greater rise in global temperatures. Figure 4 – Observed and simulated changes in global surface temperature from 1850 to 2020. The black line represents 170 years of observed and averaged data and is compared to Coupled Model Intercomparison Project Phase 6 (CMIP6) climate model simulations. The brown area represents the temperature response to both human and natural drivers and the green area to only natural drivers (solar and volcanic activity). Solid colored lines represent the averages, and the shaded areas represent the very likely range for the models. Source: IPCC (2021)[6] After reviewing the Daily Sceptic article’s claim about solar variability, Dr. Joanna Haigh provided the following comment: “He [the author] does not define ‘solar cycle’, normally used to refer to [the] 11-year activity cycle; he presumably means longer term solar activity which is currently declining so [it] can’t explain recent global warming.” And in response to the article’s claim of diminishing CO2 impacts, Dr. Haigh commented “Fig.6 in the paper [Zhong and Haigh (2013)] shows logarithmic response in radiative forcing of temperature to CO2 increase – but still rising. In that paper we used 389 ppm [parts per million] as [the] current CO2 concentration. It is now 425 ppm – higher than for millions of years and rising unremittingly.” Dr. Haigh’s explanation highlights that atmospheric CO2 concentration is increasing, and despite the response being logarithmic, global temperatures are, and will continue, rising with increasing CO2 (Figure 5). Figure 5 – Radiative Forcing of CO2 (relative to the atmospheric CO2 concentration of 389 ppm–the concentration at the time of the study). Source: Zhong and Haigh (2013)[10] In other words, the study shows that radiative forcing–the effect of Earth’s atmosphere receiving more energy from solar radiation that it emits back out to space–lessens gradually with increasing CO2 concentrations, but remains positive[10]. The Zhong and Haigh (2013) paper concludes that as CO2 increases in the atmosphere, there is no saturation point at which it will no longer cause radiative forcing–therefore, it will continue to be a factor in global warming. Conclusion: As shown above, the claims that the Daily Sceptic article made about Greenland temperature trends, global warming signals, CO2, and solar cycles are incorrect and unsupported. Scientific evidence on these subjects shows the following: temperatures in Greenland and around the world are rising, the primary driver is increasing atmospheric CO2 from human emissions, and solar variation has had no significant effect on rising modern global temperatures. Although the response is logarithmic, as CO2 concentrations increase, so will global temperatures. This is evident based on climate models and the physics of CO2, which are well understood. After analyzing and modeling the drivers of climate change, the IPCC found no evidence that solar variation can account for the rising trend of global temperatures. Several studies, which reviewed up to 10,000 years of climate proxy data, show that the current rate of global warming is unusual compared to past natural variations. |
https://science.feedback.org/review/arctic-sea-ice-melting-over-past-decades-with-projections-summer-ice-free-conditions-mid-century/ | Incorrect | The Epoch Times, Allan Astrup Jensen, 2024-02-06 | Arctic sea ice is not melting and there is no indication that we should expect the Arctic sea summer ice to disappear completely, as predicted | null | Incorrect: Overall, Arctic sea ice extent and volume have been decreasing since the 1970s, a trend that scientists largely attribute to human-induced global warming. The author of the claim cherry-picks short term fluctuations due to natural variability to suggest otherwise. Scientists forecast the first ice-free summer for the 2050s. | Despite short-term fluctuations due to natural variability, the Arctic sea ice extent and volume has decreased over the past few decades. Scientists have established that this decrease is mostly the result of global warming due to human emissions of greenhouse gasses. | Arctic sea ice is not melting. There is no indication that we should expect the Arctic Sea summer ice to disappear completely, as predicted. CO2 levels don't drive Arctic sea ice decline. | 1 – IPCC (2021) Ocean, Cryosphere and Sea Level Change. In Climate Change 2021: The Physical Science Basis. Contributions of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. 2 – Walsh et al. (2017) A database for depicting Arctic sea ice variations back to 1850. Geographical Review. 3 – Polyak et al. (2010) History of sea ice in the Arctic. Quaternary Science Reviews. 4 – Kinnard et al. (2011) Reconstructed changes in Arctic sea ice over the past 1,450 years. Nature. 5 – Halfar et al. (2013) Arctic sea-ice decline archived by multicentury annual-resolution record from crustose coralline algal proxy. Proceedings of the National Academy of Sciences. 6 – Johannessen et al. (2004) Arctic climate change: observed and modelled temperature and sea-ice variability. Dynamic Meteorology and Oceanography. 7 – Eyring et al. (2021) Human Influence on the Climate System. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. 8 – Perovich et al. (2007) Seasonal evolution and interannual variability of the local solar energy absorbed by the Arctic sea ice–ocean system. Geophysical Research Letters. 9 – Stroeve et al. (2014) Changes in Arctic melt season and implications for sea ice loss. Geophysical Research Letters. | Since the 1970s, satellites have been providing accurate measurements of sea ice extent in the Arctic, revealing a steady reduction in its surface. The yearly extent of Arctic sea ice that survives the entire summer has decreased by approximately 50% from 1979 to 2020 compared to its average extent during the period from 1981 to 2010. Under all Intergovernmental Panel on Climate Change (IPCC) scenarios, even the most optimistic one, the Arctic Sea is expected to reach a mostly ice-free state during some years in the summer as early as the 2040s. An article by The Epoch Times dated 6 February 2024 disseminated claims challenging the scientific observations of declining arctic sea ice and predictions of an ice-free summer in the Arctic, drawing on assertions from a single report and remarks by an independent consulting engineer. Arctic sea ice has been shrinking for decades The title of The Epoch Times article falsely claims that ‘the UN Says Melting Arctic Ice Is Key Indicator of Climate Change—But It’s Not Melting’. This statement is inaccurate, as scientific evidence consistently shows that Arctic sea ice is indeed melting and serves as a critical indicator of climate change. Arctic sea ice grows and shrinks with the seasons, melting from around March to September and reforming in the cold winter months. Scientists study the yearly minimum extent of Arctic sea ice because it provides critical insights into its seasonal cycle and its response to environmental changes. This measurement, taken at the end of the summer melting season, indicates the quantity of sea ice remaining. Satellite records have shown that Arctic sea ice extent has steadily declined over the last four decades. In the 1980s, the September average extent represented close to 50% of the March average; from 2013 to 2022, the ratio was only 35%. Reaching lower minimums indicates a weaker recovery in winter, showing that the Arctic is losing ice and failing to replenish it. In addition, this trend is further reinforced by the fact that sea ice volume is also decreasing. The IPCC notes that: “Current best estimates from reanalyses indicate that September Arctic sea ice volume has reduced by about 72% over the period from 1979 to 2016, […] a conservative estimate.”[1] Regarding the trend from the 2010s onwards, the IPCC explains in its report that there is “low confidence in the amount of decrease over this period […] primarily because of snow-induced uncertainties in the retrieval algorithms, the shortness of the record, and the small identified trend.” Arctic sea ice is forecasted to continue melting The Epoch Times article quotes a report by Allan Astrup Jensen, a chemical risk assessment specialist, claiming that “in the last 17 years, from 2007 to 2023, the [Arctic sea ice extent] downward trend has also been about zero […] Therefore, there is no indication that we should expect the Arctic Sea summer ice to disappear completely, as predicted, in one or two decades.” This assertion contradicts the majority of scientific literature on the subject projecting ice free summers later this century, which represents the best evaluation of human knowledge on the topic. Synthesizing this research, the IPCC reports that the current Arctic sea ice extent, both annually and during the late summer, is at its lowest level since at least 1850, with high confidence. In the same fact-sheet the IPCC states that, under all considered scenarios, the Arctic is expected to reach practically ice-free conditions at its summer minimum at least once before 2050. While Arctic sea ice extent has not declined at a constant rate from 1979 to 2007, the short term fluctuations do not invalidate the overall downward trend (see gray line in Figure 1) and the continued impact of warming expected in the future due to climate change. The last 17 Arctic sea ice yearly minimum extents are the lowest in the satellite record and summer Arctic sea ice loss since 1979 is unprecedented in 150 years, based on historical reconstructions[2] and more than 1000 years of paleoclimate evidence[3,4,5]. Figure 1 – Arctic Sea ice extent as measured by satellites between 1978 and 2022. The long-term trend for 1979 to 2021 is shown by the dashed gray line, while trends over shorter periods are shown in colors: red for 1979 to 1992, blue for 1993 to 2006, and dark green for 2007 to 2021. (source) How increasing CO2 concentrations impact Arctic sea ice? In The Epoch Times’ article, engineer Frank Geisel claims that we do not know whether increased atmospheric CO2 concentrations are driving a decline in sea ice extent and volume. The Epoch Times article’s author picks two CO2 concentration levels and Arctic minimum sea ice extent (in 1979 and 1996) that supposedly supports this claim. However, a physical connection between the two variables cannot be established or dismissed by just cherry-picking two data points, one has to look at all the available evidence and understand the physical mechanism explaining the connection. As explained below, scientists have established that human-induced climate change causes a decline in Arctic sea ice through various scientific observations and analyses. Firstly, observational data have shown a clear trend of shrinking sea ice extent and thickness, especially noticeable each September when the ice reaches its annual minimum. Model simulations show this decline correlates closely with rising global temperatures and increased greenhouse gas emissions, consistent with a direct link between increased greenhouse gases concentrations and diminishing sea ice[6]. The IPCC concluded that “it is very likely that anthropogenic forcing mainly due to greenhouse gas increases was the main driver of Arctic sea ice loss since 1979.”[7] Secondly, studies of the Arctic’s energy balance provide further evidence. Sea ice has a high albedo, meaning it reflects a significant amount of solar energy back into space. As climate change leads to warmer temperatures, sea ice melts, exposing darker ocean water that absorbs more solar energy, leading to further warming and ice loss in a reinforcing feedback loop. This mechanism, well-documented by climate scientists, further demonstrates how increased temperatures from greenhouse gasses directly contribute to the reduction of Arctic sea ice[8]. Lastly, the timing of the melt season has shifted, with ice melting earlier in the spring and freezing later in the fall, further supporting the impact of rising temperatures on sea ice[9]. Records show that increasing global temperatures are happening in tandem with increasing levels of carbon dioxide (see Figure 2, top), while the Arctic has been warming at an even faster rate than the rest of the globe (see Figure 2, bottom), which contributes to Arctic sea ice melting. Figure 2 – Top: yearly temperature anomalies compared to the twentieth-century average (red and blue bars) from 1880 to 2019, based on data from NOAA NCEI, and atmospheric carbon dioxide concentrations (gray line): 1880-1958 from IAC, 1959-2019 from NOAA ESRL (source).Bottom: cumulative/net trend in combined sea and ice surface temperature anomalies for the Arctic Ocean from 1993 to 2022. The cumulative trend is the rate of change (°C/year) scaled by the number of years (30 years). Based on satellite observations from the E.U. Copernicus Marine Service Information (source). Not all the decrease in Arctic sea ice extent is attributed to human induced climate change though. Researchers have found that natural variability accounts for about half of the sea ice decline observed so far; the other half coming from climate change. Therefore, a short period of stable Arctic sea ice extent trend is consistent with the models’ range of predictions. As National Snow and Ice Data Center (NSIDC) scientist Walt Meier pointed out in an article: “Natural variability has bigger effects at shorter timescales. It mainly plays a role over a time span of about 10 to 15 years. As the length of the observation period increases, natural variability has less effect, and the long-term forcing—greenhouse gas emissions—dominates. There is no escaping that we will see an Arctic with no summer sea ice this century if we continue to rapidly increase greenhouse gases in the atmosphere.” |
https://science.feedback.org/review/optimal-atmospheric-co2-dinosaurs-plants-harmful-humans-current-concentration-higher-homo-sapiens-ever-experienced/ | Misleading | Bright Insight, Jimmy Corsetti, 2024-02-04 | High CO2 was fine for the dinosaurs and high CO2 benefits plants today in greenhouses, so more CO2 can’t be bad for humans | null | Flawed reasoning: The fact that elevated atmospheric-CO2 benefited the dinosaurs and benefits plants today does not mean it also benefits humans. In fact, there are potential human health risks from prolonged exposure to the optimal CO2 levels for dinosaurs and plants, in addition to the multiple negative environmental impacts for human society resulting from elevated CO2 and the enhanced greenhouse effect. Missing context: The optimal concentrations of CO2 for dinosaurs and plants would be far beyond the concentrations ever experienced by the human species naturally; they would dramatically change ecosystems. Even just the present level of CO2 in the atmosphere is already higher than it has been for millions of years, and Homo sapiens have only been around for 260-350 thousand years. The magnitude of change and the rate of change presents existential challenges for many species. | Elevated atmospheric-CO2 from human emissions enhances the greenhouse effect, which causes global warming and results in several other significant negative impacts on the ecosystems and natural processes on which humans depend. Plants and animals have different tolerances and responses to elevated CO2, and concentrations which are optimal for some species can be toxic for others. Human emissions have raised CO2 to levels never before experienced by our species, and not seen on Earth for millions of years. | Increasing carbon dioxide (CO2) is not bad for humans because it was much higher during the time of the dinosaurs and they were unaffected. High carbon dioxide also benefits plant growth, which is why CO2 is pumped into greenhouses to boost crop yields. Levels of CO2 are so low right now in comparison to the levels that were good for the dinosaurs and are good for plants, so an increase in CO2 can’t be bad for humans. CO2 is good for life and is not causing a climate crisis. | 1 – Morris et al. (2018) The timescale of early land plant evolution. Proceedings of the National Academy of Sciences. 2 – Foster et al. (2017) Future climate forcing potentially without precedent in the last 420 million years. Nature Communications. 3 – Rae et al. (2021) Atmospheric CO2 over the past 66 million years from marine archives. Annual Review: of Earth and Planetary Sciences. 4 – Jacobson et al. (2019) Direct human health risks of increased atmospheric carbon dioxide. Nature Sustainability. 5 – Azuma et al. (2018) Effects of low-level inhalation exposure to carbon dioxide in indoor environments: A short review on human health and psychomotor performance. Environment International. 6 – Miller et al. (2005) The Phanerozoic record of global sea-level change. Science. 7 – IPCC (2019) Summary: for Policymakers. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate 8 – Tierney et al. (2020) Past climates inform our future. Science. 9 – Zheng et al. (2018) The optimal CO2 concentrations for the growth of three perennial grass species. BMC Plant Biology. 10 – IPCC (2021) Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. 11 – Friedlingstein et al. (2023) Global carbon budget 2023. Earth System Science Data. 12 – Karnauskas et al. (2020) Fossil fuel combustion is driving indoor CO2 toward levels harmful to human cognition. GeoHealth. 13 – Lowe et al. (2018) Possible future impacts of elevated levels of atmospheric CO2 on human cognitive performance and on the design and operation of ventilation systems in buildings. Building Services Engineering Research and Technology. 14 – Diffenbaugh et al. (2013) Changes in ecologically critical terrestrial climate conditions. Science. 15 – IPCC (2023) Summary for Policymakers. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change | During Earth’s 4.5 billion year history, the atmosphere has undergone dramatic changes and only started to appear like it does today around 290 million years ago (mya). Today’s air is composed of several gasses with different concentrations, like nitrogen (78.08%), oxygen (20.95%), argon (0.93%), and carbon dioxide (0.04%). The air 600 mya, for example, had only about one-fifth of today’s oxygen level. Plants first appeared as far back as 500 mya[1]. Reptiles first appeared about 320 mya, and the dinosaurs only existed approximately from 243 mya until 66 mya. Mammals appeared about 225 million years ago, but anatomically modern humans, or homo sapiens, are only 260-350 thousand years old. Humans, dinosaurs, and plants all respire air, although plants do it very differently than mammals and reptiles. Considering these different evolutionary timelines under different atmospheric compositions, can we assume that animals, reptiles, and plants thrive breathing the same air? Is the optimal level of carbon dioxide for dinosaurs and plants also optimal, or at least feasible, for humans? Does all this mean anything for climate change? Youtuber Jimmy Corsetti, who’s channel Bright Insight has 1.61 million subscribers, suggested on X and Instagram that because dinosaurs and plants thrive under very high CO2, increasing in CO2 is good for life on Earth and not bad for humans. This means, according to Corsetti, “CO2 is Not causing a Climate Crisis”. Here we explore the reasons why this claim is misleading because it lacks context and uses flawed reasoning. Optimal carbon dioxide levels for dinosaurs and plants is toxic for humans over the long-term The atmospheric concentration of CO2 during the time of the dinosaurs was much higher than it is today, which currently stands at 422 parts per million (ppm). The article Corsetti screenshotted shows Dr. Paul Olsen’s response to the following question submitted by a reader: “How did plants and animals survive around 200 million years ago when the carbon dioxide concentration went up to 6,000 parts per million?”. Olsen, a geologist and paleontologist at Columbia Climate School’s Lamont-Doherty Earth Observatory, explains that the CO2 concentrations during the time of the dinosaurs (the Mesozoic Era) was in the 2000 to 4000 ppm range and that humans could potentially survive, but only with the help of technological innovations and not because of physiological ability. To be clear, the atmospheric concentration of CO2 during the time of the dinosaurs was never near 6000 ppm as Figure 1 shows[2], and it has never come close to that in the 66 million years since the dinosaurs went extinct[3]. Figure 1 – The rise and fall of atmospheric-CO2 (red trendline) over hundreds of millions of years (top x-axis), based on paleoclimatological reconstructions. Note the short timespan where Homo sapiens have existed, which has only featured low atmospheric-CO2 (right y-axis), especially compared to the Age of the Dinosaurs. Ice ages are indicated by blue shaded areas from the top x-axis. Based on reference [2], modified by Dr. Paul Olsen (source). According to Jacobson et al.’s (2019) recent synthesis of scientific literature from different fields exploring the impacts on CO2 air concentrations on humans, potential health risks can occur with exposure as low as 1000 ppm[4]. While concentrations above 5000 ppm are known to be harmful in both the short and long-term, research indicates that even concentrations below 5000 ppm “poses direct risks to human health”, including inflammation, reduced higher-level cognitive abilities, bone demineralization, kidney calcification, oxidative stress and endothelial dysfunction. Another literature review found physiological changes occur at CO2 exposures levels between 500 and 5000 ppm, effects on cognitive performance begin at 1000 ppm during short-term exposure, and respiratory symptoms are detected in children exposed to indoor CO2 concentrations higher than 1000 ppm[5]. Azuma et al. (2018) concluded that atmospheric CO2 concentration needs to be urgently suppressed to be able to efficiently control indoor concentrations. Most research on this topic is related to indoor environments, with humans under high exposure for limited time-frames corresponding to shift work in potentially hazardous workplace conditions. The Occupational Safety and Health Administration (United States Department of Labor) permissible exposure limit for CO2 is 5000 ppm over 8 hours. Concentrations above 40 000 ppm are considered immediately dangerous to life or health. There has been no research exploring prolonged human environmental exposure (weeks, months, years, lifespan) to elevated CO2 outdoors, especially for vulnerable demographics. Jacobson et al (2019) concluded that removing CO2 from the atmosphere will be necessary if emissions continue at current levels, based on their confirmation that “prolonged exposures as low as 1000 ppm CO2 affect human health and well-being”. In addition, during the Cretaceous period (145-66 mya) which ended when the dinosaurs went extinct, the average temperature was about 5-10°C higher than today and sea levels were 100 meters higher or more[6]. For comparison, the most extreme global warming future scenario (representative concentration pathway (RCP)) under consideration by the IPCC for the year 2100, called RCP8.5 or the “business as usual” scenario, implies a likely temperature increase of 3.2-5.4°C[7]. Figure 2 shows that the fossil-fuel intensive shared socio-economic pathway (SSP), called the SSP5-8.5 scenario, will lead to atmospheric-CO2 concentrations that match or even exceed Eocene or mid-Cretaceous levels[8]. It also illustrates just how unprecedented even a return to even just 1000 ppm CO2 would be, which has not been seen for tens of millions of years. Figure 2 – Comparing paleoclimates (past) with future climate scenarios side-by-side from the year 2020, including both global mean temperature (left y-axis, °C, only for the past) and global atmospheric-CO2 concentration (right y-axis, ppm, logarithmic scale, for the past and the future). Trendlines are smoothed to show long-term trends, and temperature colors are scaled related to pre-industrial levels. The small global maps on the right indicate different shared socio-economic pathway (SSP) scenarios (source). As for plants, Science Feedback has previously addressed flawed claims that because CO2 is used in greenhouses to promote plant growth, high CO2 in the atmosphere is good for the world’s plants and therefore not a concern for humans. Plants need more than just CO2 to photosynthesize and grow; they also need water, sunlight, and other plant nutrients like nitrogen and phosphorus. High CO2 in the atmosphere is directly linked to negative impacts on ecosystems through global warming which will constrain plant growth and limit any benefits from high CO2. For example, the increase in droughts in some regions or flooding in other regions are not beneficial for plants, regardless of high atmospheric CO2 (called the “CO2 fertilization effect”). Karin Kirk puts it simply with the title of her article for Yale Climate Connections: “More CO2 in the atmosphere hurts key plants and crops more than it helps”. But even if we ignore this (and all other climate related concerns of high CO2), and we focus just on maximizing plant growth as we do in greenhouses as referenced by Corsetti, the optimal CO2 levels for plants are still in conflict with human well-being. All plants respond differently to increased CO2, but they all generally follow a downward parabola (upside down “U”), increasing yield with increasing CO2 until reaching an optimal point (vertex) after which yield decreases with increasing CO2 (Figure 3, right). Different plants have different optimums, but many greenhouse recommendations reference ideal concentrations at or surpassing 1000 ppm, assuming no other limiting factors exist. For example, Figure 3 (left) shows how increasing CO2 concentrations helps three species of grasses grow, with their ideal concentrations for biomass yield at 915, 1178, and 1386 ppm[9]. Figure 3 – Left: The impact of elevated CO2 concentrations (x-axis) on above ground biomass (a), below ground biomass (b), and total biomass (c) of three species of perennial grasses as quantified in Zheng et al. (2018). Right: Generalized relationship between CO2 level and plant growth rate. Note that a CO2 concentration of 300 ppm was considered “Normal Air” at the time this illustration was first sketched by Roger H. Thayer (see here for an early version), which has been reproduced over the years despite the global average now being 422 ppm (e.g., like the figure above provided by the Oklahoma State University Extension). As mentioned above, these elevated levels of CO2 concentration in the atmosphere would be potentially harmful for humans when inhaled indefinitely without respite (every hour of every day), especially for vulnerable demographics. So not only does high CO2 raise new challenges for plant growth (such as drought and flooding) and ecosystem stability, the optimum CO2 level for plants is incompatible with human physiology over the long-term. The high CO2 enjoyed by dinosaurs and plants is just not relevant for human well-being, making Corsetti’s suggestions misleading. Because of human activities, carbon dioxide is now higher than our species have ever experienced CO2 is considered the most important greenhouse gas because it has such a long residence time in the atmosphere, it is by far the most abundant, and it contributes the most to global warming and climate change. The direct and indirect environmental impacts of high anthropogenic-CO2 emissions are not just related to temperature increases, but also other changes across different components of the Earth system. Aside from air temperature increase, climate change has been observed with the oceans getting warmer, ice sheets shrinking, glaciers retreating, snow cover decreasing, sea level rising, arctic sea ice decreasing, and extreme weather events increasing in frequency (see here for evidence provided by NASA). Relative to global concentrations in the year 1750, atmospheric CO2 has increased by more than 47% because of human activities[10]. As indicated in Figures 1 and 2, the current level of atmospheric-CO2 (422 ppm) is now higher than the human species has ever experienced. Air trapped in ancient ice cores has demonstrated that CO2 has not been this high for at least the past 800 000 thousand years (ice record limit). NOAA stated in 2022 that CO2 levels are now comparable to the Pliocene Climatic Optimum, between 4.1 and 4.5 million years ago. As a reminder, Homo sapiens have only been around for 260-350 thousand years. Rather than the steep reduction in CO2 emissions needed to meet climate goals and limit global warming, 2023 saw another slight increase compared to year before (+1.1%), increasing 1.5% since before the COVID-19 pandemic, and representing a 10-year plateau of sustained high emissions and no significant reductions[11]. Humans have emitted 40.7 gigatons of CO2 in 2022, with a similar amount estimated for 2023. Increasing anthropogenic CO2 emissions like this raises concerns for human cognition and well-being outside just like it does indoors[12]. Of course, not all regions of Earth have exactly the same CO2 concentration at all times, some can exceed others due to geographical factors. In dense urban areas, especially large cities in low-lying basins, CO2 can build up. And with CO2 concentration increasing by about 2.4 ppm in 2023 worldwide[11], geographically constrained urban areas with high populations like Mexico City and Athens could see local concentrations reaching harmful levels for humans by the end of the century[13]. Finally, claims that elevated CO2 concentrations are not bad for humans as Corsetti suggested in his post generally ignore one more critical aspect: the rate of change. The current rate of increase is estimated to be occurring 10 times faster than any other change of similar magnitude over the past 65 million years[14]. As this is much faster than plants, animals, and humans can evolve and adapt to (other than migration), and faster than ecosystems can sufficiently respond to, the risk of extinction is enormous in the coming decades (up to 29% of land plants and animals at risk of being wiped out with 3°C of warming; we are currently at 1.1°C of warming)[15]. CO2 by itself is not causing a climate crisis; elevated CO2 emissions from human activities are. Conclusion: The claim that because high CO2 was fine for the dinosaurs and high CO2 benefits plants today in greenhouses, high CO2 can’t be bad for humans is misleading. Firstly, the optimal carbon dioxide levels for dinosaurs and plants is, in fact, harmful for humans over the long-term. The age of the dinosaurs (the Mesozoic Era) had atmospheric-CO2 in the 2000 to 4000 ppm range, and plants typically grow best at 1000 ppm of CO2 or greater (like in greenhouses). Humans, on the other hand, can suffer mild health effects from CO2 as low as 1000 ppm even in the short-term, and the effects of permanent exposure to elevated CO2 levels are unknown. This is especially relevant for vulnerable populations, and anyone living in low-lying, densely populated urban areas. Humans as a species have never before experienced the high level of CO2 currently in the atmosphere, which is higher than it has been for as long as ice records can tell us (800 000 years). CO2 by itself is not causing a climate crisis; elevated CO2 emissions from human activities are. |
https://science.feedback.org/review/study-calls-people-grow-their-own-food-years-come-despite-finding-higher-carbon-footprint-compared-conventional-agriculture/ | Misleading | Facebook, The Atlas Society, Social media users, 2024-01-26 | Study and headline saying homegrown food is more carbon intensive than conventional agriculture is meant to discourage and stop people from growing their own food | null | Misrepresents source: New study which quantified a higher carbon footprint of urban agriculture compared to conventional agriculture does not discourage or call for people to stop growing their own food. On the contrary, the study proposed multiple solutions to reduce carbon emissions and calls for maintaining and supporting urban agriculture, including home gardens, as long-term components of sustainable cities. | Although low-tech urban agriculture is expected to be a central component of sustainable cities in the future due to its many social, ecological, and nutritional benefits, new research demonstrates it is not necessarily less carbon intensive than conventional agriculture as commonly assumed. Scientists in general not only argue for long-term maintenance of urban agriculture as a tool for sustainable development, they also find ways to reduce the carbon footprint of home and community gardens, such as reusing the same infrastructure year-over-year. There is no evidence of scientists calling for the restriction of urban agriculture, home gardens, and citizen rights to growing their own food to reduce carbon emissions. | New study and article headline saying homegrown food is worse for the climate than conventional agriculture is ridiculous propaganda meant to discourage and ultimately ban people from growing their own food. Growing your own food in your garden will soon be prohibited in the name of climate change because they say it is more carbon intensive than conventional agriculture. | 1 – Nicholls et al. (2020) The contribution of small-scale food production in urban areas to the sustainable development goals: A review and case study. Sustainability Science. 2 – Lee et al. (2015) Greenhouse gas emission reduction effect in the transportation sector by urban agriculture in Seoul, Korea. Landscape and Urban Planning. 3 – Azunre et al. (2019) A review of the role of urban agriculture in the sustainable city discourse. Cities. 4 – Appolloni et al. (2021) The global rise of urban rooftop agriculture: A review of worldwide cases. Journal of Cleaner Production. 5 – Goldstein et al. (2017) Contributions of local farming to urban sustainability in the Northeast United States. Environmental Science & Technology. 6 – Maureira et al. (2022) Evaluating tomato production in open-field and high-tech greenhouse systems. Journal of Cleaner Production. 7 – Ribeiro et al. (2023) Evidence on how urban gardens help citizens and cities to enhance sustainable development. Review: and bibliometric analysis. Landscape and Urban Planning. 8 – Hacking & Guthrie (2008) A framework for clarifying the meaning of Triple Bottom-Line, Integrated, and Sustainability Assessment. Environmental Impact Assessment Review. 9 – Ikeda et al. (2023) The Role of Urban Gardening in Global Cities: Three Case Studies in Berlin, Rome and Tokyo. In Sustainable Health Through Food, Nutrition, and Lifestyle. Springer Nature. 10 – Orsini & D’Ostuni (2022) The Important Roles of Urban Agriculture. Frontiers for Young Minds. | To meet global food challenges, such as increases in overall food demand alongside decreases in the natural resources needed for food production, urban agriculture is expected to play a critical role in the coming decades[1]. Because of the significant potential for transport carbon emissions reductions when food is grown close to the point of consumption[2], as opposed to in rural areas far away, there is the assumption that urban agriculture can be much less carbon intensive than conventional agriculture. As more scientific studies are performed, we gain more insight into urban agriculture’s full carbon footprint. Hawes et al. (2024) (“the Hawes study”) added more context to this topic by examining life cycle impacts of low-tech approaches in their new study published on 22 Jan. 2024. But what they found was unexpected: individual gardens are about five times more carbon intensive per serving of fruit or vegetables than conventional farming. The study was covered in an article in the Telegraph online, which started a wave of misrepresentation on social media. The Telegraph headline “Carbon footprint of homegrown food five times greater than those grown conventionally” was screenshotted and shared widely in multiple unique posts (such as this and this) alongside the general claim that the study implies urban agriculture is bad for the climate and, therefore, may be banned. One example from a Facebook group with 237 thousand followers has the caption: “Now will they come for your backyard veggie garden? #Reason #GlobalWarming”. Another example from a Facebook group with over one million followers asked: “Which country will be the first to declare home gardens a climate crime? This is absolute lunacy”. Joe Rogan (18.6 million Instagram followers) shared the Telegraph headline with the caption “Anyone that discourages people from growing their own food is not your friend” (over 410 thousand likes). As explained below, the claim that the study’s findings were meant to discourage and stop people from growing their own food misrepresents the original study. The claim is also unsupported within the context of the wider scientific community’s interest in promoting the multiple ecological and social benefits of urban agriculture, regardless of carbon related considerations[3-5]. These benefits were explicitly emphasized in the Hawes study, and again in their explainer article in The Conversation published on the same day, but they were not discussed in the Telegraph’s widely shared article. The Telegraph article also failed to mention that a quarter of home gardens studied outperformed conventional agriculture, which is clearly stated in the study’s publicly visible abstract. No statements against urban agriculture, home gardens, or citizen rights In the Hawes study, there are no statements nor calls against the use of urban agriculture or home gardens. There is also no indication whatsoever that people should not grow their own food. The carbon footprint of food produced using urban agriculture was found to be six times greater than conventional agriculture on average (see below for details). Even with their unexpected findings, the authors highlighted the situations where low-tech urban agriculture outperforms conventional agriculture from a carbon footprint perspective. They suggested best practices to keep low-tech urban farms, individual gardens and collective gardens as long-term fixtures in cities by making them more carbon-competitive. The Hawes study is emphatically not a call to discourage, limit, or criminalize people growing their own food. In an email with Science Feedback, lead and corresponding author Jason Hawes (School for Environment and Sustainability, University of Michigan) reiterated: “We did not call for a ban on urban farming and gardening…our team has more than a century of experience studying the many personal and community benefits that these urban food-growing sites produce…none of our recommendations involved banning the practice – in fact, we suggested that one key [best] practice would be to ensure long-term land tenure for urban agriculture sites.” In the study’s abstract, the authors clearly call for “maintaining [urban agriculture] sites for many years”. In the study’s conclusion, the authors stressed that because of urban agriculture’s many social, nutritional, and environmental benefits (explored below), it is likely to “have a key role to play in future sustainable cities”. There is no evidence that this study has been or will be used in any way, in policies or laws for example, to limit citizen rights to have home gardens as a new strategy to mitigate climate change. The claim that the study’s main finding, as headlined in the Telegraph, is meant as propaganda to discourage urban gardening and stop people from growing their own food is inaccurate. What did the study do, find, and propose? By partnering with individual gardeners, community garden volunteers and urban farm managers at 73 sites across five countries in North America and Europe, Hawes and colleagues tested the assumption that low-tech urban agriculture is less intensive than conventional agriculture. This assumption is mainly based on the fact that transportation emissions, which are very significant for conventional agriculture, are drastically and in some cases entirely reduced in urban agriculture. The study aimed to clarify previous uncertainties from earlier studies, and provide the first large-scale, comprehensive assessment of the full life cycle carbon footprint of different types of low-tech urban agriculture compared to conventional agriculture. Food product emissions were quantified from three types: urban farms (professionally managed, focused on food production), individual gardens (small plots managed by single gardeners) and collective gardens (communal spaces managed by groups of gardeners). For each country, the study included food produced using conventional agriculture both domestically and abroad, considering on-farm impacts, processing and transportation to the city. High-tech urban agriculture was not considered. The carbon footprint of food produced using urban agriculture on average (all three categories) was found to be six times greater than conventional agriculture (420 grams of carbon dioxide emissions equivalent (gCO2e) versus 70 gCO2e per serving), with the individual gardens category being about five times more carbon intensive (340 gCO2e, hence the Telegraph headline highlighting the term “homegrown food”). The main reason why urban agriculture was found to be more carbon intensive than conventional agriculture was the emissions associated with its infrastructure. This includes using raised beds, concrete walkways, small shelters like sheds, and so on, all of which add emissions that are not necessarily comparable to the wide-open fields of conventional farms which can produce food at-scale. In addition, only urban grown tomatoes and asparagus were less carbon intensive than conventionally grown versions among the crops considered. This is likely because conventional tomatoes are already very carbon intensive when grown (i.e., industrial greenhouses) and still need to be transported to the city, meaning urban grown versions are carbon-competitive[6]. Conventionally grown asparagus often requires air-freight importation and when this is factored in “the statistical difference between individual gardens and conventional agriculture vanishes”. Grouping all urban agriculture categories together, 17 of the 73 sites (23%) had less emissions than conventional agriculture, which helped the authors identify best practices to ensure the longevity and sustainability of urban farms, individual gardens and collective gardens in cities, contrary to the claims made on social media. They suggested that practitioners of urban agriculture and policy makers should: maximize the lifespan of farm infrastructure; promote urban waste streams as inputs, and, use farms as sites for education, leisure and community building. Based on the results and expertise of the authors, the Hawes study is in reality a call for people who grow their own food to explore how they can reduce their carbon footprint “by cultivating crops that are typically greenhouse-grown or air-freighted, maintaining [urban agriculture] sites for many years, and leveraging circularity (waste as inputs).” Scientists continue to research and call for more urban agriculture Urban agriculture, farming, and gardening refers to food production in urban areas, including animal husbandry, aquaculture, beekeeping, and horticulture. By enhancing vegetation cover in cities, which increases shade, evapotranspiration, and creates an urban cooling effect, urban agriculture is an internationally recognized option for climate change adaptation (e.g., featured since 2016 in the European Climate Adaptation Platform Climate-ADAPT). Hawes and colleagues are part of the wider scientific community investigating how to minimize the potential costs and maximize the already significant benefits of urban agriculture, especially low-tech approaches and home gardens. Senior researcher Dr. Johannes Langemeyer of the Integrated System Analysis of Urban Vegetation and Agriculture (URBAG) project provided Science Feedback with some insight into the wider context surrounding studies like the one by Hawes and colleagues, in relation to the unique functions of home gardens aside from food production. Based at the Institute of Environmental Science and Technology of Universitat Autònoma de Barcelona (ICTA – UAB), Dr. Langemeyer explained: “Commercial agriculture is primarily optimized for maximizing production yields. In contrast, urban gardening – distinct from urban agriculture – often does not prioritize food production as its primary goal, especially in regions like Europe, the US, and the UK. Urban gardening typically serves multifunctional purposes, such as fostering a connection to nature, providing educational opportunities, and facilitating leisure activities. Therefore, comparing CO2 emissions on the basis of production yield can be misleading, as the objectives of commercial agriculture and urban gardening are fundamentally different. A hypothetical reversal of this comparison might illustrate this point more clearly. For instance, if one were to compare commercial agriculture with urban gardening based on the leisure hours each provides, and possibly the CO2 emissions associated with these leisure hours, the contrast in objectives and outcomes would become more apparent. This perspective highlights the importance of considering the specific goals and functions of different agricultural practices when making such comparisons.” Scientists have been increasingly studying the role of different forms of urban agriculture, like urban community gardens, in driving sustainable development in cities (Fig. 1). There have been at least over 200 independent scientific studies exploring the different sustainable development aspects of urban gardens, with a drastic increase in recent years as scientists have recognized that “promoting urban gardens could be a relevant urban policy directed towards sustainable development”, as concluded by Ribeiro et al. (2023) following a comprehensive bibliometric analysis[7]. Figure 1. Visual overview of the Ribeiro et al. (2023) bibliometric analysis of the scientific literature on urban gardens as tools to promote sustainable development in cities, assessed using the triple-bottom-line framework (see reference [8]).Top: Publications meeting the analysis criteria according to the year of publication (x-axis), demonstrating growth in interest (number of publications indicated in the y-axis). Bottom: The cluster analysis of the publications selected with the most citations, based on the triple-bottom-line sustainable development pyramid. Urban farming can address 13 out of the 17 United Nations Sustainable Development Goals across economic, social and ecological vectors, as demonstrated by some of the outputs of the international GROOF (Greenhouses to reduce CO2 on Roofs) project. Although carbon emissions are a legitimate concern that must be quantified, just as Hawes and colleagues performed for low-tech approaches, urban gardens have been documented across different socio-cultural contexts to do more than just provide food. They also provide public spaces for citizens’ well-being, and serve as meeting places and as places of learning, especially in recent years during the COVID-19 global pandemic[9]. Scientists have even undertaken efforts to encourage the world’s youth to know about and participate in urban agriculture, for example with the article “The Important Roles of Urban Agriculture” published in the journal Frontiers for Young Minds[10]. Opinion articles with titles like “Urban gardening has taken root, and it’s time for cities to encourage new growth” by urban planning experts outside of traditional academia demonstrate the widespread support of urban agriculture as a permanent fixture in urban life, contrary to the claim on social media that studies like Hawes et al. (2024) imply experts want the opposite. The United Nations University even hosts a video series on the role of urban gardens in biodiversity conservation and sustainable development. But just like from the carbon footprint perspective, the social and community aspects of urban agriculture has both benefits and limitations (see here for an overview within the US context, including 40 references of studies by scientists exploring the critical value of urban agriculture). The growth in research interest in urban agriculture and the scientific debate surrounding potential risks and benefits were also outlined in a Global Sustainable Development Report brief in 2015. Overall, as far as we are aware at Science Feedback, there is no evidence of scientists making any efforts related to restricting urban agriculture, home gardens, and citizen rights to growing their own food by citing climate change related concerns. Conclusion: Although low-tech urban agriculture is expected to be a central component of sustainable cities in the future due to its many social, ecological, and nutritional benefits, Hawes and colleagues found it is not necessarily less carbon intensive than conventional agriculture as is commonly assumed. There are multiple ways to reduce the carbon footprint of different kinds of urban agriculture to make them more carbon-competitive with conventional agriculture, such as reusing the same infrastructure year-after-year. The claim that the study and article headline chosen by the Telegraph is meant to discourage and stop people from growing their own food has no support in reality. The study has been misrepresented on social media; there are no statements nor calls against the use of urban agriculture or home gardens within the study or anywhere else among the wider scientific community. On the contrary, Hawes and colleagues clearly call for “maintaining [urban agriculture] sites for many years”, and they concluded that urban agriculture will “have a key role to play in future sustainable cities”. |
https://science.feedback.org/review/us-proposed-bills-hearings-dont-confirm-chemtrails-exist-not-geoengineering-strategy/ | Inaccurate | Facebook, YouTube, Social media users, 2024-01-12 | US state governments are banning chemtrails, confirming secret government programs using chemtrails for various purposes that harm the public and the environment | null | Factually Inaccurate: No US state government has passed laws banning chemtrails, which remain unproven and not supported by any scientific evidence. US congressional documents have been misattributed and misinterpreted as admissions of chemtrail existence. Proposed bills, citizen petitions, and committee geoengineering hearings do not prove the existence or use of chemtrails. | Contrails are trails of condensing water vapor left in the wake of airplanes. They do not contain harmful chemicals as proposed by "chemtrail" conspiracy theories, which are not supported by any evidence. Although some politicians have proposed bills to ban chemtrails or related conspiratorial concepts, they are not evidence of their existence and no such bills have been passed. Chemtrails are increasingly conflated with solar geoengineering strategies, like stratospheric aerosol injection, but these strategies are real proposals currently being explored by scientists to limit anthropogenic global warming and have not been implemented at scale. | There are secret government programs using chemtrails for various purposes that harm the public and the environment. This is confirmed by New Hampshire and Texas state governments referencing and forbidding chemtrails, and a Tennessee government hearing on the development of geoengineering projects like stratospheric aerosol injection. These sources prove chemtrails are real, harmful, and distinct from contrails. Climate change mitigation is not the real reason behind geoengineering. | 1 – Shearer et al. (2016) Quantifying expert consensus against the existence of a secret, large-scale atmospheric spraying program. Environmental Research Letters. 2 – Burns et al. (2016) What do people think when they think about solar geoengineering? A review of empirical social science literature, and prospects for future research. Earth’s Future. 3 – Tingley and Wagner (2017) Solar geoengineering and the chemtrails conspiracy on social media. Palgrave Communications. | There is no credible, scientific evidence that chemtrails exist and are distinct from contrails. Claims that chemtrails exist have been addressed multiple times previously on Science Feedback (e.g., here). Yet, on 12 Jan. 2024, social media user “OFF GRID with DOUG and STACY” (701 thousand Facebook followers, 1.19 million YouTube subscribers) posted a video to their accounts claiming multiple US state governments have confirmed the existence of chemtrails in the text of bills and committee hearings designed to protect citizens from their negative effects, asking the question: “So, if they don’t exist, if there’s no such thing, why are they trying to ban them?” This post, which specifically references the US state governments of New Hampshire, Texas, and Tennessee, has been viewed over 200 thousand times between YouTube and Facebook, receiving tens of thousands of likes and shares. Several other similar claims are also being widely shared on different online platforms by other accounts currently. This review explains why this claim is based on inappropriate sources and is factually inaccurate, broken down by state. Misrepresented, misattributed, and exaggerated sources New Hampshire claim On 19 Dec. 2023, a New Hampshire House Bill was introduced by Rep. Jason Gerhard [R] (main sponsor) and Rep. Kelley Potenza [R] (co-sponsor). The bill (HB1700) was to be known as ‘The Clean Atmosphere Preservation Act’ but was voted “Inexpedient to Legislate” as of 31 Jan. 2024. This means that the bill is considered killed. The post author inaccurately claims “New Hampshire is now actively trying to ban chemtrails over their state.” The bill text does not refer to the term “chemtrails”. Instead, the bill is a proposal for “AN ACT prohibiting the intentional release of polluting emissions, including cloud seeding, weather modification, excessive electromagnetic radio frequency, and microwave radiation and making penalties for violation of such prohibition.” Terms like cloud seeding and other strategies of geoengineering have been publicly and openly debated for decades and are still under debate by scientists, who are uncertain whether the risks are comparable to unmitigated global warming. Chemtrails, on the other hand, have never been scientifically verified and therefore do not have a universally accepted definition that can be used to objectively verify if proposed bills like HB1700 are intended to ban them. The Merriam-Webster dictionary defines chemtrails as “a long-lasting airplane contrail believed to be composed of harmful chemical or biological agents that are dispersed as part of a conspiracy (as to manipulate the environment or the population)”. Contrails are streaks of condensed water vapor created in the air by an airplane or rocket at high altitudes (the factors of their formation are described further in a previous Science Feedback claim review). Chemtrails are not chemtrails, despite photos and videos of contrails continuously used as evidence for chemtrails. Most importantly, HB1700 was simply a proposal for a new law. Legislators in the US, like Rep. Jason Gerhard [R], are generally free to propose bills on a wide range of topics, regardless of their scientific foundation. Citizens, interest groups, and others can suggest a bill idea directly to legislators, but formal bill proposals must be sponsored by a legislator and go through many steps (outlined here), including potentially undergoing major changes and amendments. It can take months to years before a bill is either accepted or rejected. A bill proposal text is not to be taken literally because it must first be debated and approved by the New Hampshire General Court. But in the video post, HB1700 is taken for fact, for example with the post author repeating the specific text “The general court finds…” without providing viewers crucial context that this language is only true if the bill becomes a law. The post author inaccurately claims that New Hampshire is trying to ban chemtrails despite the fact that HB1700 does not refer to chemtrails and is simply a proposal that was sponsored by 2 of the 424 New Hampshire legislators. The progress of the bill can be reviewed here. Texas claim While appearing to read from an internet article from The People’s Voice (formerly known as Your News Wire, one of the most prolific sources of fake news on Facebook), the post author states that: “Texas made history last year when state representatives looked into changing a law to ban dangerous atmospheric aerosol spraying without prior approval and testing of the chemicals being sprayed.” This is inaccurate. In reality, The People’s Voice article refers to an online petition to “…prohibit the continuation of aerosolized spraying” of substances and particulates which “…is extremely harmful to our health and our environment”. Chemtrails are not referenced anywhere in the petition text, but it further states that there is a covert military program to control weather whereby “weather modification is frequently used to justify the spraying” of things like “aluminum oxide and other toxic metal compounds”. A previous Science Feedback claim review explained that allegations of secret large-scale atmospheric programs using chemtrails lack any supporting evidence (i.e., proof) and foundation (i.e., hypothetical basis)[1]. There are no scientific studies nor any existing data confirming elevated global atmospheric, soil, sediment, or water concentrations of the various chemicals that chemtrails are claimed to spread. With thousands of signatures and comments and featuring a photo of contrails, the petition webpage states that it is an initiative from “concerned Texas citizens who demand our State Legislators pass legislation to protect our families, pets, crops, water and environment from any and all negative side effects of…spraying of our sky”. Regardless of the lack of any legitimate and scientifically verifiable supporting evidence, the post author exaggerates the following: “They’re literally admitting they’re allowing people, willy-nilly, to spray in the skies chemicals that have not even been tested for human consumption, or what they could do to the environment, or anything else.” After claiming chemtrails are real and anyone stating otherwise is “gaslighting” later in the video, the post author introduces another bill proposal, saying “Now here’s Texas HR 2977”. However, HR 2977 was a Congressional Bill from the 107th Congress of the US Government (not Texas), proposed in 2001 by Ohio Rep. Dennis Kucinich [D] as the “Space Preservation Act of 2001”. It was intended to “preserve the cooperative, peaceful uses of space for the benefit of all humankind by permanently prohibiting the basing of weapons in space.” Bill HR2977 never passed, but it did explicitly refer to “chemtrails” among various so-called exotic weapons such as extraterrestrial weapons. The post author goes on to claim “I like how Texas actually concluded that little video segment there with the radio waves, mood altering stuff, chemtrails, the aluminum, all these kinds of things going on, all the things the conspiracy people have been talking about for quite a while are right in your face.” Once again, legislators can propose bills on a wide range of topics, regardless of their scientific basis. Bill proposals do not, in and of themselves, prove the existence of all terms included in the text. Tennessee claim The post author also claims that the Tennessee government held a major hearing about geoengineering, alluding to chemtrails being a form of geoengineering (discussed further below). In reality, the document that is quoted comes from an official hearing (see here for full hearing text, see here for hearing video footage) on the subject of geoengineering in 2009/2010 during the 111th Congress of the US Government (not Tennessee), specifically for the Committee on Science and Technology of the House of Representatives. Geoengineering to mitigate negative impacts from climate change and slow global warming are typically grouped into two categories: actively removing carbon dioxide from the atmosphere with different strategies to reduce the greenhouse effect; and reflecting sunlight from the planet to reduce heat inputs. Chemtrails, as generally defined, are not related to the topics that were discussed in the hearing. Chemtrails were mentioned in passing as a joke by subcommittee chairman Hon. Brian Bard, with reference to the need to be transparent with the public on geoengineering strategies if they are ever used in the future. In 2009, the potential risks, challenges and opportunities of geoengineering strategies had become more mainstream, which is why it was presented to the Committee on Science and Technology on the national stage at this hearing. It received wide dissemination in the public at the time, and is still openly explored in the public sphere. Additional context on chemtrails misinformation and their conflation with solar geoengineering The People’s Voice was one of the main sources of the misinformation on social media related to the inaccurate claims posted by OFF GRID with DOUG and STACY in January 2024. Its 19 Jan. 2023 story on the Texas citizen petition was misleadingly titled “Texas Becomes First State To Potentially Outlaw Chemtrails”. Nearly one year later, 3 Jan. 2024, The People’s Voice published another article inaccurately titled “New Hampshire Becomes Second U.S. State To Ban Chemtrails”, misinforming its readers on the New Hampshire proposed bill HB1700. Both articles were written by Your News Wire co-founder Sean Adl-Tabatabai who has a record of influential climate misinformation articles and who also founded The People’s Voice. These articles preceded multiple social media accounts repeating similar inaccurate claims in addition to the ones addressed above. For example, in the days since the most recent article from The People’s Voice, an Instagram account released three video posts on chemtrails as toxic climate/geoengineering, with the third on 19 Jan. 2024 claiming there are now two US states that have outlawed “climate engineering” while filming contrails. A post from another Instagram account repeated inaccurate claims from The People’s Voice article on the New Hampshire proposed bill HB1700, and repeated the inaccuracy that the bill had been passed and chemtrails have been banned. This is certainly not the first time government documents, whether hearings, bill proposals, policy agendas, or scientific reports, have been misrepresented as proof of the chemtrail conspiracy. Social media posts in recent years inaccurately claimed the UN is creating climate change using geoengineering and chemtrails, and the chemtrails are a key tool used to control the weather, with climate change being only a cover-up. Last year, the Mexican government announced a ban on solar geoengineering after an American start-up tested atmospheric sulfur injections from balloons over Mexico without any notice or approval. However, this ban was misrepresented on social media as a ban on chemtrails, despite chemtrails being unrelated to the new Mexican law and unsupported by any scientific evidence. Inaccurate claims that a 2022 CNBC story was actually as an admission of a secret chemtrail program went viral on social media. The story was about a new five-year plan assessing the use of solar and other interventions to mitigate climate change coordinated by the White House Office of Science and Technology Policy and US federal agencies, as directed by Congress. One intervention to be researched is stratospheric aerosol injection. Professor David Keith, a solar geoengineering expert leading a research group dedicated to this topic, told the Associated Press by email that aerosol injection would not leave contrails like those left by planes. Chemtrails remain unproven, unverified, and undiscovered by science. A 2016 study which surveyed of some of the world’s top atmosphere experts, consisting of atmospheric chemists with expertise in condensation trails and geochemists working on atmospheric deposition of dust and pollution, virtually every single respondent did not believe there is any scientific evidence for a secret large-scale atmospheric program using chemtrails[1]. Even when assessing data that conspiracy theorists claim is proof of chemtrails, such as elevated concentrations of specific elements in soils, sediments, and water bodies in remote locations, the overwhelming majority of the respondents stated that there are simpler and better supported explanations. As widely covered in the media, scientists are exploring the risks, rewards, and potential impacts of geoengineering technologies to mitigate climate change, including cloud seeding, solar geoengineering and carbon capture, none of which involve chemtrails. Solar geoengineering covers various hypothetical technologies and strategies that are meant to reflect sunlight out of Earth’s atmosphere to limit ongoing anthropogenic global warming. Ideas proposed for high altitudes, some of which being actively researched but not implemented, include placing a large mirror in orbit, thinning cirrus clouds, or spraying aerosols in the stratosphere (i.e., stratospheric aerosol injection) (Fig. 1). Figure 1 – Six of the most commonly proposed solar geoengineering options. They have different approaches, shortcomings, costs, and feasibility, but they are all designed to reduce the amount of solar radiation in Earth’s atmosphere and therefore limit ongoing anthropogenic global warming (source). There is a general unfamiliarity among the public with solar geoengineering[2]. Adding to the confusion and misinformation online, inaccurate conflations between chemtrails and solar geoengineering are increasing on social media. Science Feedback has addressed this issue in a previous claim review, pointing to the lack of any evidence for chemtrails and lack of evidence that solar geoengineering is happening and having a catastrophic effect on the ecosystems and human health. Tingley & Wagner (2017) found that between 30-40% of the general US public and as much as 60% of social media discourse believes in chemtrail conspiracy theories which “renders rational conversations around solar geoengineering and its potential role in climate policy even more difficult”[3]. Nevertheless, solar geoengineering proposals have been and continue to be publicly evaluated by scientists and government organizations (see here for scientists’ comments on some of the most popular strategies), weighing the pros and cons of each before recommendations are presented to elected officials, just like when they were discussed in front of the US Congress in 2009. Conclusion: Various accounts on social media inaccurately claim that US state and federal proposed bills and congressional hearings confirm the existence or use of chemtrails, with some states even banning chemtrails. However, no state governments have passed laws banning chemtrails, and bill proposals and the texts from congressional hearings are not evidence for the existence of chemtrails. Chemtrails as entities distinct from contrails remain unproven, unverified, and undiscovered by science. Chemtrails are increasingly conflated with solar geoengineering strategies, like stratospheric aerosol injection, which are real proposals currently being explored by scientists to mitigate climate change and limit anthropogenic global warming, but which have not been implemented. UPDATE (1 February 2024): We updated this review to indicate the new status of New Hampshire bill HB1700, which has been updated to “Inexpedient to Legislate” as of 31 Jan. 2024. This means that the bill is considered killed. |
https://science.feedback.org/review/evidence-greenhouse-gasses-cause-global-warming-denied-willie-soon-tucker-carlson-interview-mass-social-media-climate-misinformation/ | Incorrect | Tucker Carlson Network, Willie Soon, 2024-01-09 | Carbon dioxide does not cause global warming, scientists are 90% sure it’s the Sun; The climate problems blamed on carbon dioxide (such as ocean acidification and negative impacts on polar bears) are not real | null | Incorrect: The hypothesis that the Sun is responsible for climate change is inconsistent with real-world observations. Scientific consensus based on overwhelming evidence shows that greenhouse gasses like carbon dioxide are the main cause of current global warming, beyond reasonable doubt. Inaccurate: Elevated atmospheric carbon dioxide causes the enhanced greenhouse effect which has multiple direct and indirect impacts on the hydrosphere and biosphere, including ocean acidification and the reduction of arctic sea ice, which affects polar bear populations. Flawed reasoning: The fact that Saturn’s moon Titan is much colder than Earth despite having more methane does not mean that methane does not cause global warming on Earth as a greenhouse gas. In fact, methane causes the greenhouse effect on Titan just as it does on Earth. | The causes of climate change and global warming are well-known among the international scientific community. Scientific consensus based on overwhelming evidence, beyond reasonable doubt, shows that anthropogenic greenhouse gas emissions are the main driver of current global warming, not the Sun. Elevated atmospheric carbon dioxide has multiple direct and indirect impacts on the hydrosphere and biosphere, including ocean acidification and arctic sea ice loss due to global warming which affects polar bears. | We don’t know what is causing climate change, but we are around 90% sure it’s the Sun. Methane is on Saturn’s moon Titan and it has no global warming; it is cold because it is far from the Sun. There’s also no consensus on the role of CO2. The climate problems of CO2 are artificial and made-up; it does not cause issues like ocean acidification or make any difference to polar bear populations. | 1 – Lockwood (2008) Recent changes in solar outputs and the global mean surface temperature. III. Analysis of contributions to global mean air surface temperature rise. In Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences. 2 – Santer et al. (2023) Exceptional stratospheric contribution to human fingerprints on atmospheric temperature. Proceedings of the National Academy of Sciences. 3 – Sloan et al. (2016) Cosmic rays, solar activity and the climate. Environmental Research Letters. 4 – IPCC (2021) Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. 5 – Friedlingstein et al. (2022) Global carbon budget 2022. Earth System Science Data Discussions. 6 – Gazeau et al. (2007) Impact of elevated CO2 on shellfish calcification. Geophysical Research Letters. 7 – Molnár et al. (2020) Fasting season length sets temporal limits for global polar bear persistence. Nature Climate Change. 8 – Stern et al. (2016) Sea-ice indicators of polar bear habitat. The Cryosphere. 9 – Bromaghin et al. (2015) Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline. Ecological Applications. 10 – Lunn et al. (2016) Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay. Ecological Applications. 11 – Hörst (2017). Titan’s atmosphere and climate. Journal of Geophysical Research: Planets. 12 – MacKenzie et al. (2021). Titan: Earth-like on the outside, ocean world on the inside. The Planetary Science Journal. 13 – Myers et al. (2021) Consensus revisited: quantifying scientific agreement on climate change and climate expertise among Earth scientists 10 years later. Environmental Research Letters 14 – Lynas et al. (2021) Greater than 99% consensus on human caused climate change in the peer-reviewed scientific literature. Environmental Research Letters 15 – IPCC (2023) Summary for Policymakers. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change | Review: Dr. Willie Soon, an astrophysicist and aerospace engineer who has received “much” of his research funding from the oil and gas industry, made multiple claims during an interview with Tucker Carlson denying the role of greenhouse gasses like carbon dioxide (CO2) and methane in driving global warming. The original video on the Tucker Carlson Youtube page from 9 Jan. 2024 has since been split into numerous snippets, shared, liked, and viewed millions of times across multiple social media platforms. The core of Soon’s claims are inconsistent with science, as we will demonstrate below for three main claims Soon makes within the first third of the interview. Greenhouse gasses drive recent global warming, not the Sun Soon: “We may not know exactly what is causing climate change, we suspect it’s the Sun. We have a lot of evidence to show that it’s probably the Sun. Very high percentage, you know like I would say 90% we are sure” (minute 12:47) The drivers of climate change and global warming are well-known among the international scientific community. There is a straightforward history spanning back to the mid-19th century of how scientists have reached the consensus on anthropogenic climate change, which is that CO2 and other greenhouse gasses like methane emitted by human activities are causing current global warming. Scientists have known for over a century that CO2, in particular, is a key greenhouse gas that is strengthening the greenhouse effect in the atmosphere. Like the other known infrared-absorbing greenhouse gasses, CO2 absorbs and re-emits heat and therefore maintains a higher temperature in the atmosphere than non-greenhouse gasses. Since the first experiments, like those of Eunice Newton Foote in 1856, countless more studies have tested and validated the warming effect of increased atmospheric-CO2. Solar irradiance (the amount of power per unit area of solar energy reaching the Earth in the form of electromagnetic radiation, measured in watts per meter squared, W m–2) and its influence on the climate are well-understood by scientists and the evidence shows clearly that solar variability cannot account for the recent warming[1]. The effect of rising rates of atmospheric greenhouse gasses, on the other hand, has been well established by decades of scientific research. The Sun’s activity has been monitored since the beginning of the 20th century, and although solar irradiance can have yearly fluctuations, there has not been a statistically significant increase in recent decades, as opposed to global temperatures (Fig. 1). Solar irradiance has decreased since the 1960’s while global temperatures have increased. The warming influence of CO2 has been much greater than that of the Sun over the past century. Figure 1 – Comparison of the global surface temperature changes (red) and the Sun’s energy that Earth receives (yellow) in watts per square meter since 1880. One can see that since the 1960s, the global temperature and solar activity have varied in opposite directions, which wouldn’t be the case if the Sun was responsible for global warming (source). Soon claims the Sun is causing global warming, which means it is causing the recent warming observed at the surface of the Earth (i.e., the troposphere). If this was true, we should be able to observe warming at every layer of the atmosphere, especially at the top which receives the most radiation. Solar radiation reaching the surface on a clear day is around 1000 W m–2, while at the top of the atmosphere it is 1361 W m–2. However, the upper layers of the atmosphere (i.e., the stratosphere) have not increased in temperature in tandem with the surface layer. The temperature in the lower stratosphere (high altitude) has actually fallen while the temperature of the lower troposphere (low altitude) has risen, one of the main “human fingerprints on atmospheric temperature”[2]. This observation is consistent with the enhanced greenhouse effect, where heat-trapping gasses like CO2 in the troposphere cause temperature to increase. This observation is inconsistent with Soon’s claim. Estimates of the potential contribution of solar radiation to recent global warming further contradict Soon’s claim. At the high end, a 2016 study concluded that “the contribution of changing solar activity either through cosmic rays or otherwise cannot have contributed more than 10% of the global warming seen in the twentieth century”[3]. The IPCC has compiled robust estimates of all of the contributors to observed global warming, concluding that solar activity was a virtually non-existent factor in comparison to anthropogenic greenhouse gasses (Fig. 2). When comparing the effective radiative forcing (ERF, aslo measured in units of watts per meter squared (W m–2)) of global warming contributors since 1750, CO2 has an ERF of 2.16 W m–2, and methane is at 0.54 W m–2. Because these values are positive, they represent energy added to the Earth system, unlike the insignificant ERF for solar (indistinguishable from zero). Figure 2 – Top: The contributions of different drivers to global warming from the present time period (2010-2019) relative to the time period of 1850-1900 (source). The estimates of warming (red) and cooling (blue) from radiative forcing studies (panel (c)) are based on both direct emissions into the atmosphere and their effect, if any, on other climate drivers. Bottom: Change in effective radiative forcing from 1750 to 2019 by greenhouse gasses, ozone, stratospheric water vapor, surface albedo, contrails and aviation-induced cirrus, aerosols, and solar. The anthropogenic total category represents the combined positive and negative effects of human activities (everything except solar). The solid bars represent best estimates with very likely (5–95%) ranges represented by the error bars (source). Multiple direct and indirect environmental impacts of elevated CO2 in the atmosphere Soon: “What we know now is CO2 ain’t gonna cause nothing. It’s not gonna change much of the climatic system…it won’t make any difference with the polar bear population…it won’t even cause what they call ocean acidification” (minute 8:39) CO2 is considered the most important greenhouse gas because it has such a long residence time in the atmosphere, it is by far the most abundant, and it contributes the most to global warming and climate change (Fig. 2). Relative to global concentrations in 1750, atmospheric CO2 has increased by 47%[4]. Methane, which breaks down into CO2 after around a decade in the atmosphere, has increased by 156%. Through the enhanced greenhouse effect, human emissions of these gasses have resulted in an increase in average global temperature of more than 1°C since record keeping began in the second half of the 19th century. As temperature is pivotal to Earth’s climate system, Soon’s general claim that CO2 “ain’t gonna cause nothing. It’s not gonna change much of the climatic system” is at odds with reality. The direct and indirect environmental impacts of high anthropogenic-CO2 emissions are not just related to temperature increases, but also other changes across different components of the Earth system. Aside from air temperature warming, climate change has been observed with the oceans getting warmer, ice sheets shrinking, glaciers retreating, snow cover decreasing, sea level rising, arctic sea ice decreasing, and extreme weather events increasing in frequency (see here for evidence provided by NASA). Soon’s specific claims that CO2 does not make any difference with the polar bear populations nor cause ocean acidification are inaccurate and explored in detail in Box 1. Box 1. The impacts of CO2on polar bears and ocean acidification. Contrary to what Soon claims, CO2is directly linked toocean acidification. Theocean has absorbed between 20-30%of total anthropogenic CO2emissions in recent decades[5]. The excess carbon that is absorbed makes the oceans more acidic because when CO2dissolves in seawater, it forms carbonic acid, which lowers the pH of the ocean. Global surface ocean waters have increased in acidity by about 30% (because of a pH drop of 0.1) since the beginning of the Industrial Revolution, matching increases in atmospheric-CO2from human emissions (Fig. 3). Ocean acidification also causes a decline in carbonate ion concentrations and the calcium carbonate saturation state. When this lowers, carbonate minerals will dissolve, which can have implications for organisms with exposed calcium carbonate shells and skeletons, from corals to oysters, clams, and mussels. It has already been shown from experiments that the structure and function of marine species, particularly organisms with calcium carbonate shells or skeletons, are affected by ocean acidification[6]. Figure 3 –Recent trends in surface (< 50 m) ocean carbonate chemistry over the period 1988–2015 at the Hawaii Ocean Time-series (HOT) Program in the North Pacific. The upper panel shows the similar increase in CO2(CO2, as concentration in air (ppm)) in the atmosphere (red points) and surface ocean (blue points). The bottom panel shows a decline in seawater pH (light blue points, primary y-axis) and carbonate ion (CO32−) concentration (green points, secondary y-axis) (source). By driving global warming and reducing arctic sea ice extent, it is also well established that global warming has and will continue to negatively impact polar bear populations. A 2020 study estimated that, “with high greenhouse gas emissions, steeply declining reproduction and survival will jeopardize the persistence of all but a few high-Arctic subpopulations [of polar bears] by 2100”[7]. Because polar bears depend on sea ice for hunting, and because their main prey seals also depend on sea ice for breeding and making dens, arctic sea ice loss is making it more difficult for polar bears to hunt[8]. Studies correlating local losses in sea ice habitat with polar bear populations found that some subpopulations have already been negatively affected[9-10]. Loss of sea ice is occurring in almost all polar bear subpopulations, with arctic sea ice extent trending downwards since reliable satellite record keeping began in 1979 (Fig. 4). The downward linear trend in Arctic sea ice extent for December over the over four decades of satellite records is 43 400 square kilometers per year, or 3.4 percent per decade relative to the 1981 to 2010 average. Based on the linear trend, December has lost 1.97 million square kilometers of ice since 1979, equivalent to three times the size of Texas. Leading polar bear population experts Dr. Andrew Derocher and Dr. Ian Stirling told Science Feedback in a previous claim review that “Current [polar bear] declines are due to climate change associated loss of sea ice”, and “Several [polar bear] populations…declined significantly as a direct result of climate warming causing steady loss of sea ice”, respectively. Figure 4 –Monthly December ice extent shows a decline of 3.4 percent per decade over the period from 1979 to present day (source). Titan is climatically distinct from Earth and yet methane still causes the greenhouse effect on both Soon: “Titan…it’s very cold by the way, so it’s minus 290 degrees Fahrenheit. Hint, hint, hint, where is the global warming there, right, if it’s full of methane?…because it’s far away from the Sun that’s what it is.” (minute 2:33) Titan is much colder than Earth because it is far from the Sun, but Soon uses flawed reasoning to claim this means methane does not cause global warming (on Titan or on Earth). Dr. Sarah Hörst, Associate Professor at John Hopkins University and one of the world’s leading experts on Titan’s atmosphere and climate[11], explained to Science Feedback that “Titan receives substantially less Sunlight than the Earth so it should be about 82 Kelvin (-191.15 °C) but the greenhouse effect provided by methane results in a surface temperature that is about 12 K warmer”. Titan orbits Saturn, which is 1.4 billion kilometers away from the Sun on average, compared to Earth’s average distance of 150 million kilometers. Titan’s average temperature is around -179 °C (-290 °F), compared to Earth’s at around +15°C. So, even though Titan is still very cold (-179°C) because it is so far from the Sun, it would be even colder (-191 °C) without methane causing the greenhouse effect like it does on Earth. Titan receives approximately 1% of the solar radiation that Earth receives. Furthermore, of the solar radiation reaching the top of Titan’s atmosphere, only 10% reaches the surface (compared to 57% for Earth). Titan’s distinct atmosphere to Earth actually features both a greenhouse effect (provided by methane and collision-induced absorption) and an anti-greenhouse effect (from the stratospheric haze layer). For comparison, an Earth without methane and all the other greenhouse gasses causing the greenhouse effect, would be around -33°C colder. There are other reasons why Soon’s comparison of Earth and Titan to deny methane’s role in the greenhouse effect is flawed. At Earth’s current temperature, the atmosphere is able to hold on average 0.4% water vapor ranging from 4% in the humid tropics to nearly 0% in the polar regions. Water vapor, a known greenhouse gas explored in a previous Science Feedback claim review, is responsible for about half of the natural greenhouse gas effect keeping Earth warm. Titan, on the other hand, has virtually no water vapor anywhere because it is so cold and it has no liquid water. Overall, Titan has a completely different atmospheric composition, pressure, and gravity than Earth. Both Titan and Earth have a stratified atmosphere with a troposphere, stratosphere, mesosphere, and thermosphere, but Titan’s is much more extended because of its lower surface gravity (reaching heights of 15–50 km compared to Earth’s 5–8 km)[12]. Although Earth and Saturn’s moon Titan are the only two astronomical bodies with significant atmospheres and surface seas with stable liquids in the solar system, Titan’s climate cannot be directly compared to Earth’s. Titan’s atmosphere is mostly molecular nitrogen (about 95%) and methane (about 5%), compared to Earth’s 78% and 0.00018%, respectively. There is no widely accepted answer for how so much methane appeared on Titan, but there is no mystery that hydrocarbons can exist without originating from organic lifeforms like fossil fuels from plants and animals. Methane exists off Earth as a gas, liquid, or as ice. It is found on Neptune, Uranus, and there’s so much on Titan that it rains methane and there are lakes and rivers of liquid methane (and ethane). It is one of the most abundant types of ice detected outside of our solar system too, and scientists have even managed to create methane in a laboratory under space-like conditions. Additional context As we have shown above, Soon made multiple incorrect claims about the science of how greenhouse gasses like CO2 and methane are driving global warming. In the video, Soon also claimed the scientific evidence for global warming driven by CO2 is “all artificial” and dreamed up by the “tyranny of the few”. First, as we have shown, the science of climate change is actually built on real evidence that has been studied and compiled by tens of thousands of scientists over decades. Second, climate contrarians like Soon are, in fact, the extreme minority who have a disproportionately large influence over public opinion. Nearly all scientists agree greenhouse gas emissions are the cause of global warming. Among scientists with the most climate-related expertise, the consensus reaches 100%[13]. A recent peer-reviewed scientific study analyzing thousands of other peer-reviewed scientific studies found that 99% of the scientific literature confirms human greenhouse gas emissions cause global warming[14]. In the most recent IPCC report (AR6), the very first text line (line A.1.) of the “Summary: for Policymakers” directly contradicts Soon by stating “Human activities, principally through emissions of greenhouse gasses, have unequivocally caused global warming”[15]. The report confirms there has been 1.1°C of global warming since the period 1850-1900 and it explicitly identifies CO2 from human emissions as the leading cause (Fig. 2). As an indication of the scientific robustness of AR6, just the contribution from Working Group 1 alone was written by 234 of the world’s leading climate scientists coming from 66 countries. It included nearly 4 000 pages of research based on more than 14 000 scientific papers as supporting references and was critiqued and revised by over 1 500 expert reviewers. Incorrect and inaccurate claims like those made by Dr. Willie Soon in his interview with Tucker Carlson reach millions of people, amplified across social media platforms; they become super-spreaders of climate misinformation. |
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Dataset Card for Science Feedback
Dataset Description
A dataset consisting of Science Feedback's climate change claim/article reviews web-scraped with Python. Science Feedback's climate change reviews are one of, if not, the only existing gold-standard dataset that was written by nonpartisan climate change experts. Read more about Science Feedback here: https://science.feedback.org/about/.
Dataset Sources
The reviews were extracted from https://science.feedback.org/reviews/?_topic=climate.
- Repository:
- Paper [optional]: [More Information Needed]
- Demo [optional]: [More Information Needed]
Curation Rationale
This dataset was created to test and fine-tune The Endowment for Climate Intelligence (ECI)’s climategpt model’s performance on non-binary climate change claims. This will help determine its usefulness in real world applications where claims do not always fall under the binary categories “correct” and “incorrect.” For testing and fine-tuning, the verdicts were consolidated into 5 categories to increase the number of samples per class and to avoid confusing the model with too many categories without enough samples (see merge_science_feedback_labels.ipynb in github repository).
Data Fields
- url: The URL of the claim/article review.
- verdict: A keyword or float assigned by the reviewer to label the claim (social media, podcast, etc.)/article on a scale of scientific credibility. Check https://science.feedback.org/process/ for more information on Science Feedback’s methodology. The latest reviews use keyword verdicts but Science Feedback used to use a numerical credibility scale (-2.0 to 2.0).
- source: The source of the claim/article being reviewed.
- claim: The main claim of the source made concise (social media, podcast, etc.). This is unique to sources that have a keyword verdict.
- headline: Headline of the article being reviewed. This is unique to sources that have a float verdict.
- verdict_detail: Explanation for why the verdict was given.
- key_takeaway: A summary, or key takeaway, of the review.
- full_claim: The full claim of the source. The full claim section is always present when the claim is present.
- references: The references listed at the bottom of the claim review (if it exists)
- review: The text that reviews the claim/article in question and supports the verdict.
Source Data
According to Science Feedback, "Science Feedback editors select claims or articles for review that are the most viral on social media and/or are published by sources with large readership. Either must contain potentially verifiable claims in the scientific realm." (https://science.feedback.org/process/)
Data Collection and Processing
Used Python's requests and BeautifulSoup libraries to loop through each claim/article review page and extract the html file as a string. Also used pandas library to save extracted data fields as a csv file. Extracted reviews were minorly processed for consistency in format:
- Text not part of the review was omitted (e.x.: “SEE OUR METHOD OF EVALUATION →”) (lines 52, 75-76 of main code)
- The “VERDICT DETAIL” heading was omitted (line 52 of main code)
- New line and tab characters (“\n” and “\t”) were replaced by a space and empty string respectively (line 52 of main code)
- A “: ” was added after each scientist and heading’s title (lines 80-86, 93-105 of main code)
- e.g.:
- “Amber Kerr Researcher, Agricultural Sustainability Institute, University of California, Davis” → “Amber Kerr Researcher, Agricultural Sustainability Institute, University of California, Davis: ”
- "Scientists' Feedback..." → "Scientists' Feedback: ..."
- e.g.:
- References were split from the main review (lines 108-117 of main code)
- Removed “+” from verdicts of type float
Who are the source data producers?
"The Science Feedback association is a not-for-profit organisation registered in France whose mission is defined in its status as to improve the credibility of science-related information online, in the media and on social media." (https://science.feedback.org/about/)
Dataset Card Authors
Joongeun Choi
Dataset Card Contact
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