Arguments
Explaining climate change science & rebutting global warming misinformation
Global warming is real and human-caused. It is leading to large-scale climate change. Under the guise of climate "skepticism", the public is bombarded with misinformation that casts doubt on the reality of human-caused global warming. This website gets skeptical about global warming "skepticism".
Our mission is simple: debunk climate misinformation by presenting peer-reviewed science and explaining the techniques of science denial, discourses of climate delay, and climate solutions denial.
The undeniable science of extreme weather
Posted on 1 October 2025 by Guest Author
This is a re-post from The Climate Brink by Kevin Trenberth
A new analysis issued by the National Academies of Science, Engineering, and Medicine (NASEM) found that the evidence linking rising greenhouse gas emissions to negative human health outcomes is “beyond scientific dispute.” Climate change is real and it has already resulted in major damage.
The main cause is increasing atmospheric greenhouse gases of carbon dioxide, methane and nitrous oxide, all from human activities. Because carbon dioxide has a very long lifetime (hundreds to thousands of years), it is cumulative emissions that matter and the U.S. is the biggest contributor (although China, with a population 4x bigger than the U.S., has been a bigger annual contributor for the last two decades).
Carbon dioxide concentrations (of 425 ppm annualized in 2025) measured at Mauna Loa (Hawaii) have increased by over 50% relative to pre-industrial values (of 280 ppm).
These aspects have been well documented and understood for many years, and, with some hiccups, led to the Paris Agreement in 2015, a legally binding international treaty on climate change, adopted by 195 parties to limit global warming to well below 2°C, preferably to 1.5°C, compared to pre-industrial levels.
Not only have temperatures already risen by 1.5°C, mainly since the 1970s, increases in heat waves have also occurred and caused substantial damages. Many other extremes have also increased and are related to global warming, but in much less obvious ways. As temperatures rise, it seems fairly reasonable that there will be more high temperatures. But it is more than the overall rise in temperatures that is in play. Changes also relate to location, especially land versus ocean, and weather and weather patterns.
As temperatures rise, the water holding of the atmosphere increases by about 7% per °C (a physical law called the Clausius-Clapeyron equation), and this is observed to be happening over the oceans (where the supply of water is unlimited). The relative humidity tends to remain about the same on average. The reason is that rain events occur when the relative humidity exceeds about 85%. So if there is too much moisture, it rains out the excess. If it is too dry, then it doesn’t rain and evaporation occurring at the surface increases relative humidity.
Moreover, because the amount of moisture depends on temperatures, the values differ enormously with latitude and height. In mid-latitudes, typical column amounts are about 2.5 cm (an inch), but values can easily be double that in the tropics and subtropics, or less than half at high latitudes. The near-global average atmospheric water vapor has increased by 7% since the 1990s (Figure below) but these numbers are dominated by the tropics and vary with phenomena like El Niño.
Fact brief - Are humans responsible for climate change?
Posted on 30 September 2025 by Sue Bin Park
Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.
Are humans responsible for climate change?
Our rapid burning of fossil fuels has caused a buildup of heat-trapping carbon dioxide gas in our atmosphere.
Until we started burning fossil fuels, the CO2 moving between the Earth’s atmosphere, oceans and land remained relatively steady for thousands of years. Fossil fuel burning took trapped carbon from the solid Earth, where it had been safely stored for millions of years, and injected it — as CO2 — into our atmosphere.
Humans have emitted more than one trillion metric tons of carbon dioxide since the Industrial Revolution — about one-third of atmospheric CO2 today.
The carbon dioxide released by human activity is unique. Certain forms of carbon that are rare in natural CO2 are found in larger amounts in fossil fuels. Because of that, human-generated CO2 has a ‘fingerprint’ that can be detected in air samples.
This CO2 has raised temperatures at a rate not seen in millions of years.
Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact
This fact brief is responsive to quotes such as this one.
Sources
American Geophysical Union Changes to Carbon Isotopes in Atmospheric CO2 Over the Industrial Era and Into the Future
Frontiers in Earth Science Carbon Isotope Chemostratigraphy Across the Permian-Triassic Boundary at Chaotian, China: Implications for the Global Methane Cycle in the Aftermath of the Extinction
Environmental Defense Fund 9 ways we know humans caused climate change
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Revisiting the Geoengineering Question
Posted on 29 September 2025 by Zeke Hausfather
This is a re-post from The Climate Brink
I have a new guest essay in the New York Times with David Keith that builds off my earlier Climate Brink post The Geoengineering Question. Below I’ve included some more detailed thoughts that couldn’t make it into the published piece given the word limit constraints.
We are already geoengineering the planet today, but badly. Humans are cooling the climate today by emitting 75 million metric tons of sulfur dioxide into the lower atmosphere, almost entirely as a byproduct of burning fossil fuels. This cooling offsets about 0.5C of warming that would have otherwise occurred from CO2 and other greenhouse gases, but it comes at the cost of millions of premature deaths per year caused by the sulfate aerosols.
Sulfur emissions are declining sharply as countries started cleaning up air pollution. Global SO2 emissions today are 48% lower than they were in 1979 and 40% lower than in 2006 (China saw a massive 70% decline since 2008!). This is the primary contributor to the acceleration in global warming in recent years. Cutting air pollution saves lives and is unequivocally worth doing, but it is also driving about a quarter (~0.14C) of the approximately 0.5C warming the world has experienced between 2007 and 2024.
This raises a question worth debating: would it be worth considering putting a tiny portion of the sulfur we currently emit into the upper atmosphere to compensate for additional warming we will experience as we cut air pollution?
2025 SkS Weekly Climate Change & Global Warming News Roundup #39
Posted on 28 September 2025 by BaerbelW, John Hartz, Doug Bostrom
Stories we promoted this week, by category:
Climate Change Impacts (7 articles)
- Tens of thousands more people will die from wildfires in US over next 25 years, researchers say "Western states will be most impacted overall, with the largest number of projected deaths in California" Cilmate, The independent, Julia Musto, Sep 19, 2025.
- Hurricane Gabrielle makes a run for the Azores "A hurricane watch is up, while two other Atlantic systems percolate, and far south China braces for Typhoon Ragasa." Eye on the Storm, Yale Climate Connections, Bob Henson, Sep 23, 2025.
- Super Typhoon Ragasa: 17 killed in Taiwan and Hong Kong battered as storm hits China "Chinese businesses and schools shut and residents in high-rises ordered to evacuate as storm makes landfall on Guangdong coast" World, The Guardian, Amy Hawkins & Agencies, Sep 24, 2025.
- Nearly 2 million evacuated as Ragasa slams into southern China, after killing at least 14 in Taiwan CNN World, Jessie Yeung, Wayne Chang & Laura Sharman, Sep 25, 2025.
- Tropical Storm Humberto could tangle with another developing storm, with high stakes for the US East Coast CNN, Briana Waxman, Sep 25, 2025.
- Hurricane Humberto strengthened into a rare Cat 5, but there’s another storm the US needs to watch CNN Weather, Briana Waxman & Andrew Freedman, Sep 27, 2025.
- State of climate change: How healthy is our planet? "Scientists say we've already exceeded seven of nine planetary boundaries contributing to Earth's stability, life support and resilience. This poses a risk, but it's not all bad news." Deutsche Welle, Jeannette Cwienk, Sep 24, 20224.
Climate Policy and Politics (7 articles)
- Australia has an Everest to climb if it wants to protect itself from climate catastrophe. But do we have the political resolve? "The National Adaptation Plan is only a small step towards a comprehensive strategy to build resilience into Australia’s economy" Opinion is Free, The Guardian, Opinion by Erwin Jackson, Sep16, 2025.
- The Cartoon Villain's Guide to Killing Climate Action Why the DOE Climate Working Group report process is so opaque The Climate Brink, Andrew Dessler, Sep 18, 2025.
- Despite congressional threat, National Academies releases new climate report Things have changed since 2009: We're more certain about the problems. Science - Ars Technica, John Timmer, Sep 19, 2025.
- Judge deals Trump’s war on wind its first major setback "The order comes amid a broader assault on renewable energy by the administration that threatens to leave the U.S. short of the power it needs." Climate, The Washington Post, Jack Spring & Evan Halper, Sep 22, 2025.
- ‘I worry about the future of my daughter’: the ‘silent majority’ who care about the climate crisis "Readers who are part of the 80-89% of the population who want to see climate action tell us their ideas on how to make their voices heard" Environment, The Guardian , Danielle Renwick, Sep 24, 2025.
- US is violating human rights laws by backing fossil fuels, say young activists in new petition "Petition says that US government’s protection of fossil fuel interests has put people in harm’s way" US News, The Guardian, Dharna Noor, Sep 24, 2025.
- National Weather Service at ‘breaking point’ as storm approaches "Staffing cuts under the Trump administration mean forecasters are struggling to maintain normal operations." Politics, The Washington Post, Hannah Natanson & Brady Dennis, Sep 27, 2025.
Skeptical Science New Research for Week #39 2025
Posted on 25 September 2025 by Doug Bostrom, Marc Kodack
Open access notables
Changes Observed in Cloud-Top Heights by MISR From 2002 to 2021, Davies & Moroney, Journal of Geophysical Research: Atmospheres
We analyzed cloud heights measured by the Multiangle Imaging SpectroRadiometer on the Terra satellite from 1 April 2002–31 March 2021. Throughout these 19 years, the equatorial crossing time of Terra's orbit varied by less than 1 min from its mean value. This variation created a homogeneous time series of deseasonalized and deregionalized height anomalies unaffected by sun-glint position changes. We analyzed the changes in effective cloud height (i.e., the integral of cloud occurrence weighted by cloud-top height) and the influence of all altitudes, from the surface to 20 km, on the effective height. We show that cloud fractions tended to decrease at low altitudes, especially in the tropics, and to increase at high altitudes for most latitudes. The globally effective height has very likely risen, at an average rate of about 1 m/yr. The rise was most significant at high latitudes, reaching 5 ± 1 m/yr between 45°N and 65°N. Tropical high clouds have risen, but this was offset by a reduction in tropical low clouds, resulting in an insignificant change in tropical effective height. The increase in effective height typically reduces the outgoing longwave radiation, thereby augmenting the cloud greenhouse effect. The observed height increase may be an adjustment to the radiative forcing of the stratosphere over 19 years that presumably causes changes in upper tropospheric stability, the tropopause, the Brewer-Dobson circulation, etc. If so, the observed height increase should be included in modeling the effective radiative forcing.
A Storyline Climate-Change Attribution Study of a High-Impact Hailstorm in Switzerland, Trapp et al., Geophysical Research Letters
We employed a “storyline” approach to explore possible anthropogenic climate change influences on the extreme hail event in Switzerland on 28 June 2021. An ensemble of factual WRF simulations with randomly perturbed initial and boundary conditions was compared to an ensemble of counter-factual simulations in which a mean climate change signal was removed from the model conditions. Using data from six GCMs, this signal was computed using differences between data averaged over current-day and pre-industrial time intervals. Relative to counter-factual simulations, factual simulations exhibited overall more hail, particularly for diameters ≥3 cm. This is consistent with increased CAPE but minimal changes in melting depth over this region in the current day. We quantified the fraction of attributable risk and concluded that the geographical areas covered by hail of diameters ≥3 and 5 cm appear to have been increased by the meteorological changes attributable to climate change.
Wildfire smoke exposure and mortality burden in the US under climate change, Qiu et al., Nature
Wildfire activity has increased in the US and is projected to accelerate under future climate change 1–3. However, our understanding of the impacts of climate change on wildfire activity, smoke, and health outcomes remains highly uncertain, due to the difficulty of modeling the causal chain from climate to wildfire to air pollution and health. Here we quantify the mortality burden in the US due to wildfire smoke fine particulate matter (PM2.5) under climate change. We construct an ensemble of statistical and machine learning models that link climate to wildfire smoke PM2.5, and empirically estimate smoke PM2.5-mortality relationships using data on all recorded deaths in the US. We project that smoke PM2.5 could result in 71,420 excess deaths (95% CI: 34,930 - 98,430) per year by 2050 under a high warming scenario (SSP3-7.0) – a 73% increase relative to estimated 2011-2020 average annual excess deaths from smoke. Cumulative excess deaths from smoke PM2.5 could reach 1.9 million between 2026-2055. We find evidence for mortality impacts of smoke PM2.5 that last up to three years after exposure. When monetized, climate-driven smoke deaths result in economic damages that exceed existing estimates of climate-driven damages from all other causes combined in the US 4,5. Our research suggests that the health impacts of climate-driven wildfire smoke could be among the most important and costly consequences of a warming climate in the US.
Do Climate Models Support Claims of Volcanic Global Catastrophes?, McGraw & Polvani Polvani, Geophysical Research Letter
Climate models have been claimed to support the popular belief that large volcanic eruptions greatly imperil human populations worldwide. These models provide estimates of historical post-eruption climates where observations and paleorecords are lacking. However, as we show, simulations of the last millennium's largest eruptions broadly disagree on resulting climates and typically produce more extreme outcomes than the moderate cooling and ordinary precipitation conditions recorded in tree rings. We demonstrate that strong cooling greatly strengthens the post-eruption precipitation anomalies in simulations. Conversely, simulations with paleoproxy-consistent volcanic surface cooling show post-eruption precipitation to be unexceptional at most locations. Climate models hence do not substantiate the claims that intense eruption-induced wet and dry anomalies have caused widespread historical catastrophes. We suggest that future assessments of global volcanic risk focus on impacts of moderate cooling and on equatorial Africa and South America, which evidence the only regional precipitation responses that are robust across simulations.
From this week's government/NGO section:
The Implications of Oil and Gas Field Decline Rates, McGlade et al., The International Energy Agency
Much attention today focuses on uncertainties affecting the future evolution of oil and natural gas demand, with less consideration given to how the supply picture could develop. However, understanding decline rates – the annual rate at which production declines from existing oil and gas fields – is crucial for assessing the outlook for oil and gas supply and, by extension, for market balances. The authors – using their analysis of the production records of around 15,000 oil and gas fields around the world – explore the implications of accelerating decline rates, growing reliance on unconventional resources, and evolving project development patterns for the global oil and gas supply landscape, for energy security and for investment. They also provide regional insights.
Paying for Climate Chaos: U.S. Federal Subsidies for Fossil Fuel Production, Rees et al., Oil Change International
The authors reveals the scope of federal government subsidies for fossil fuel production. The federal government currently hands the fossil fuel industry an estimated $34.8 billion annually, further enriching Big Oil and Gas CEOs, shareholders, and investors.
Effects of Human-Caused Greenhouse Gas Emissions on U.S. Climate, Health, and Welfare, Committee on Anthropogenic Greenhouse Gases and U.S. Climate: Evidence and Impacts, National Academies of Sciences, Engineering, and Medicine
The report’s authoring committee found that EPA’s 2009 finding that human-caused emissions of greenhouse gases adversely affect human health and welfare was accurate, has stood the test of time, and is now reinforced by even stronger evidence. Today, many of EPA’s conclusions are further supported by longer observational records and multiple new lines of evidence. Moreover, research has uncovered additional risks that were not apparent in 2009.
119 articles in 48 journals by 744 contributing authors
Physical science of climate change, effects
Changes Observed in Cloud-Top Heights by MISR From 2002 to 2021, Davies & Moroney, Journal of Geophysical Research: Atmospheres Open Access 10.1029/2025jd044629
Intensifying Climatic Effects of the Indian Ocean Dipole Exaggerates Australia Bushfires Risk, Wang et al., Journal of Geophysical Research: Atmospheres 10.1029/2025jd043936
The Cartoon Villain's Guide to Killing Climate Action
Posted on 24 September 2025 by Guest Author
This is a re-post from The Climate Brink by Andrew Dessler
Let’s run a thought experiment. Imagine that you’re the Secretary of Energy. But you’re not just any public servant. You're a former fossil fuel executive, and you’re cartoonishly, mustache-twirlingly evil.
Your singular goal is to keep America hooked on fossil fuels — a dirty, expensive product that enriches you personally — by slowing as much as possible the deployment of clean, cheap renewable energy that benefits everyone else.
One of the main obstacles to your plan is the EPA’s “endangerment finding,” the EPA’s judgment that greenhouse gases threaten public health and welfare. To push your agenda, you need to overturn it. And, to do that, you need to attack the very foundations of climate science itself.
How would you do it?
Fortunately for you, the tobacco playbook is sitting right there on your illegally-logged mahogany desk, open to page one. It is the time-tested manual for manufacturing doubt. As you read it, your plan comes into focus:
step 1: commission the lie
First, you need a report that claims climate science is weak, even if the claim is nonsense. Climate science is arguably the most scrutinized and replicated field in history. Over 200 years, the scientific community has built an incredibly robust understanding of our climate system.
So you go out and find five writers — the usual suspects1 — willing to produce the report you need. They write it, and it’s as good as promised: a document designed to create the illusion of deep, foundational uncertainty.
Fact brief - Has the IPCC overestimated climate change impacts?
Posted on 23 September 2025 by Sue Bin Park
Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.
Has the IPCC overestimated climate change impacts?
The Intergovernmental Panel on Climate Change compiles the consensus of thousands of models, and many independent lines of research suggest its estimates were more conservative than what was subsequently observed.
For example, sea-level rise predictions in earlier IPCC reports were later found to be too low compared to recently observed melting of ice sheets and thermal expansion. Studies show IPCC’s mid-range forecasts have been highly accurate, but reports often understate high-end risks.
IPCC reports must be approved by nearly 200 governments and only include findings supported by multiple lines of evidence. That tends to filter out less certain, but still possible, worst-case scenarios.
However, IPCC’s latest 2021 report now states it is virtually certain that human CO2 emissions have been the main driver of warming since the mid-20th century. Given their historically cautious approach, its recent warnings carry even more weight.
Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact
This fact brief is responsive to quotes such as this one.
Sources
American Geophysical Union Evaluating IPCC Projections of Global Sea-Level Change From the Pre-Satellite Era
IPCC AR6 Summary for Policymakers.
IPCC AR6 Longer Report
Climate Central Report: IPCC Underesimates Climate Risks
Live Science 4 Things to Know About the IPCC's Climate Change Report
Please use this form to provide feedback about this fact brief. This will help us to better gauge its impact and usability. Thank you!
Koonin providing clarity on climate?
Posted on 22 September 2025 by Ken Rice
This is a re-post from And Then There's Physics
It seems that the US Department of Energy has now disbanded the Climate Working Group that drafted the report that I discussed in this post. However, about a week ago, Steven Koonin – one of the authors of the report – had an article in the Wall Street Journal titled At Long Last, Clarity on Climate. Clarity is a bit of a stretch. Personally, I think it more muddied the waters, than brought clarity.
A general point that I didn’t really make in my previous post (and that has just been highlighted in a comment) is that it is explicitly focussed on the US. The richest country in the world probably is more resilient than most others and could well decide that it’s better to deal with the impacts of climate change than committing too much now to avoiding them. I happen to disagree with this as I think it ignores how the US has benefitted from something that will negatively impact others, ignores that countries can’t really exist in isolation, and ignores that there are potentially outcomes that even wealthy a country will struggle to deal with. However, I can see how some might conclude this, although it might be good if they were much more explicit.
What I thought I would do is try to address some of the claims and conclusions made in Steven Koonin’s article. There’s an element of truthiness to the article; some claims may be true, but they don’t really support the argument being made.
For example, he says:
While global sea levels have risen about 8 inches since 1900, aggregate U.S. tide-gauge data don’t show the long-term acceleration expected from a warming globe.
U.S. tide-gauges may indeed not show the expected long-term acceleration, but the rate of global sea level rise is indeed accelerating.
Similarly, he says that:
2025 SkS Weekly Climate Change & Global Warming News Roundup #38
Posted on 21 September 2025 by BaerbelW, John Hartz, Doug Bostrom
Stories we promoted this week, by category:
Climate Policy and Politics (5 articles)
- Ani Dasgupta talked to 100 climate experts. He came away optimistic. In his new book, ‘The New Global Possible,’ Dasgupta shares what he learned from talking with dozens of climate luminaries and how that can reshape how we think about climate action. Interview, Yale Climate Connections, Michael Svoboda, Sep 9, 2025.
- Climate impacts are real — denying this is self-defeating The US administration is attempting to undermine efforts to curb greenhouse-gas emissions. It will ultimately leave that country, and the world, worse off. Naturee, Editorial, Sept 10, 2025.
- Trump's Energy Department disbands group that sowed doubt about climate change NPR Topics: Climate, Jeff Brady, Sep 13, 2025.
- National Academies Publish New Report Reviewing Evidence for Greenhouse Gas Emissions and U.S. Climate, Health, and Welfare NAS, News Release, Sep 17, 2025.
- Q&A: Will China and the BRICS fill the ‘leadership gap’ on climate change? "Amid a rapidly fracturing geopolitical order, there have been growing calls for China to “step into [the] leadership gap” left by the US on climate change." Policy, Carbon Brief, Anika Patel, Sep 18, 2025.
Climate Change Impacts (4 articles)
- Sea Surface Temperatures Hit 97.7 F: ‘One of the Highest’ Ever Recorded Newsweek, Jess Thomson, Aug 27, 2025.
- Millions of Australians at risk from rising sea levels and heat deaths to soar, national climate risk assessment report warns National climate risk assessment report finds heat-related deaths would surge 450% in Sydney if global heating surpasses 3C The Guardian, Dan Jervis-Bardy, Sep 15, 2025.
- Cascading, compounding’: five key takeaways from Australia’s national climate risk assessment "From rising heat-related deaths to the environmental and economic cost of climate change, here’s what the landmark report warns" Environment, The Guardian, Graham Readfearn, Sep 15, 2025.
- The Atlantic’s remarkable 20-day quiet period finally ends "Tropical Storm Gabrielle in the central Atlantic is the basin’s first tropical cyclone since Tropical Storm Fernand dissipated on August 28." Eye on the Storm, Yale Climate Connections, Jeff Masters & Bob Henson, Sep 17, 2025.
Getting involved with Climate Science via crowdfunding and crowdsourcing
Posted on 19 September 2025 by BaerbelW
This article was originally published in December 2016 and was updated on September 13 2025 to add the long-term Climate.us project as well as "Dr Gilbz" on Patreon. We also cleaned-up the overall list as some previously listed projects are no longer active. The prior version from April 2022 is available here.
At a guess, many of you reading this post are already making good personal choices to help mitigate climate change. Some of you would perhaps like to do more. So, here are some suggestions where you can get actively involved either via crowdfunding, where you make a monetary contribution or via crowdsourcing, where you contribute your or your computer's time to sift through different sets of data.
This post is divided into four sections:
Ongoing crowdfunding - sites and groups listed here are continously looking for contributions
Shortterm crowdfunding - these are projects with a target amount and a set deadline
Crowdsourcing - projects looking for your (or your computer's) time
Projects supported by Skeptical Science Inc. - our own projects you can contribute to
Ongoing crowdfunding
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In June 2025, under pressure from the Trump administration, NOAA shut down daily operations of its award-winning Climate.gov website. They hid Climate.gov’s home page and froze its social media channels. Just like that, one of the most popular, most trustworthy sources of climate science information on the internet went silent. The team that built Climate.gov is fighting back with an effort to build a nonprofit successor: Climate.us. Donate to join the fight. |
Climate Science Legal Defense Fund (CSLDF)
| The Climate Science Legal Defense Fund was established to make sure that legal actions are not viewed as an attack against one scientist or institution, but as attacks against the scientific endeavor as a whole. As well. the CSLDF protects individual scientists facing unfair legal attacks by organized groups. Given the current climate - pun most definitely intended - in the U.S. the CSLDF's work is unfortunately becoming ever more important. Link to donation page |  |
The Australian Climate Council
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After thousands of Australians chipped in to Australia's biggest crowd-funding campaign, the abolished Climate Commission has relaunched as the new, independent Climate Council. We exist to provide independent, authoritative climate change information to the Australian public. Why? Because our response to climate change should be based on the best science available. Link to donation page |
Citizens’ Climate Education (CCE)
| Your donation to Citizens’ Climate Education will train ordinary citizens to promote fair, effective, and non-partisan climate change solutions. Citizens’ Climate Education’s volunteers understand that we owe it to tomorrow’s generations to face our climate challenges today. These informed, respectful citizens work to build a clean and prosperous future, leading elected officials towards solutions that reduce carbon pollution, create jobs, and strengthen the American economy. Link to donation page |  |
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Adam Levy is a doctor in atmospheric physics from the University of Oxford. During his research he saw the huge gap between what we know about climate change and how we talk about it. So he created the ClimateAdam channel dedicated to explaining climate change in playful and engaging ways: everything from the crucial science to the actions we can all take. In order to grow his channel, he set up a Patreon project. |
| InsideClimate News is an essential, global voice that exposes the truth about the climate crisis. We connect the dots to those responsible, so that you can hold them accountable. As we enter our 10th year, we’re launching The InsideClimate Circle to ensure that our award-winning nonprofit news organization remains fiercely independent and courageously persistent. Link to membership page |  |
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Ella Gilbert is a climate scientist with a penchant for cold places and a serious passion for clouds. She makes irreverent videos about climate science, Antarctica, weather and anything climate related which she publishes on her "Dr Gilbz" Youtube channel. Climate change affects us all, and so everyone should be able to understand how, why and what the solutions are. But, there just ain't enough people making climate change and climate science digestible - especially women - and Ella thinks that it's time we put a stop to that. You can support her work on Patreon. |
| Dave Borlace has been conscious of environmental issues since studying for a BSc in Technology with the Open University back in the late 1990s. In early 2017 Dave set off on a quest to create climate communication videos that aim to decode the sometimes overwhelmingly complicated and confusing scientific information around climate change and explain the concepts in the sort of plain English that he, and hopefully you, can understand. As well as looking at the causes and consequences of climate change, Dave also presents news of the technological breakthroughs that may help us avoid, or at least mitigate, the worst of those consequences. To support this work Dave has now set up a Patreon page. |  |
Skeptical Science New Research for Week #38 2025
Posted on 18 September 2025 by Doug Bostrom, Marc Kodack
Open access notables
The weak land carbon sink hypothesis, Randerson et al., Science Advances
Over the past three decades, assessments of the contemporary global carbon budget consistently report a strong net land carbon sink. Here, we review evidence supporting this paradigm and quantify the differences in global and Northern Hemisphere estimates of the net land sink derived from atmospheric inversion and satellite-derived vegetation biomass time series. Our analysis, combined with additional synthesis, supports a hypothesis that the net land sink is substantially weaker than commonly reported. At a global scale, our estimate of the net land carbon sink is 0.8 ± 0.7 petagrams of carbon per year from 2000 through 2019, nearly a factor of two lower than the Global Carbon Project estimate. With concurrent adjustments to ocean (+8%) and fossil fuel (−6%) fluxes, we develop a budget that partially reconciles key constraints provided by vegetation carbon, the north-south CO2 gradient, and O2 trends. We further outline potential modifications to models to improve agreement with a weaker land sink and describe several approaches for testing the hypothesis.
The spatial extent of heat waves has changed over the past four decades, Skinner et al., Communications Earth & Environment
The spatial extent of an extreme heat event influences the total exposure of people and natural systems to heat-related stresses, straining water, energy, and emergency management resources. Here, we quantify how the contiguous area of individual heat wave events varies across heat wave types, time of year, and in response to observed climate change within the Berkeley Earth Surface Temperature Dataset. Across the mid-high latitudes, cold season heat waves cover areas that are 1.25 to 3 times larger than warm season events, and daytime heat waves impact 1.25 to 2 times the area of nighttime heat waves. The reverse relationship is found throughout tropical regions. Average heat wave size, regardless of type or season, has increased across most land in recent years, often by 1.5 to 2 times in the mid-latitudes. The contiguous spatial extent of dry soil anomalies and lower tropospheric subsidence events have also increased in some locations, potentially contributing to the increases in heat wave size.
Systematic attribution of heatwaves to the emissions of carbon majors, Quilcaille et al., Nature
Extreme event attribution assesses how climate change affected climate extremes, but typically focuses on single events. Furthermore, these attributions rarely quantify the extent to which anthropogenic actors have contributed to these events. Here we show that climate change made 213 historical heatwaves reported over 2000–2023 more likely and more intense, to which each of the 180 carbon majors (fossil fuel and cement producers) substantially contributed. This work relies on the expansion of a well-established event-based framework1. Owing to global warming since 1850–1900, the median of the heatwaves during 2000–2009 became about 20 times more likely, and about 200 times more likely during 2010–2019. Overall, one-quarter of these events were virtually impossible without climate change. The emissions of the carbon majors contribute to half the increase in heatwave intensity since 1850–1900. Depending on the carbon major, their individual contribution is high enough to enable the occurrence of 16–53 heatwaves that would have been virtually impossible in a preindustrial climate. We, therefore, establish that the influence of climate change on heatwaves has increased, and that all carbon majors, even the smaller ones, contributed substantially to the occurrence of heatwaves. Our results contribute to filling the evidentiary gap to establish accountability of historical climate extremes.
Health losses attributed to anthropogenic climate change, Carlson et al., Nature Climate Change
Over the last decade, attribution science has shown that climate change is responsible for substantial death, disability and illness. However, health impact attribution studies have focused disproportionately on populations in high-income countries, and have mostly quantified the health outcomes of heat and extreme weather. A clearer picture of the global burden of climate change could encourage policymakers to treat the climate crisis like a public health emergency.
From this week's government/NGO section:
China’s Green Leap Outward: The rapid scaleup of overseas Chinese clean-tech manufacturing investments, Xiaokang Xue and Mathias Larsen, Net Zero Policy Industrial Lab, Johns Hopkins University
A rapid acceleration in overseas investment by Chinese green technology manufacturers is reshaping the global clean-tech landscape. Since 2022 alone, investments have surged past USD 220 billion, spanning sectors such as batteries, solar, wind, new energy vehicles (NEVs), and green hydrogen. These investments now reach 54 countries across every major region. The authors offer the first comprehensive overview of China’s expanding global green manufacturing footprint, drawing upon our database. For example, Chinese firms have pledged at least USD 227 billion across green manufacturing projects. A high-end estimate approaches USD 250 billion. This surge of overseas green manufacturing investment is unprecedented; it now surpasses the USD 200 billion (in current 2024 dollars) invested by the US over four years of the Marshall Plan, at a time of similar American dominance of manufacturing in key industries.
Taking Stock 2025, King et al., Rhodium Group
The first seven months of the second Trump administration and 119th Congress have seen the most abrupt shift in energy and climate policy in recent memory. After the Biden administration adopted meaningful policies to drive decarbonization, Congress and the White House are now enacting a policy regime that is openly hostile to wind, solar, and electric vehicles and seeks to promote increased fossil fuel production and use. In this year’s Taking Stock report—Rhodium Group’s annual independent outlook of the evolution of the US energy system and greenhouse gas (GHG) emissions under current policy—we find the US is on track to reduce GHG emissions by 26-41% in 2040 relative to 2005 levels. On the way to 2040, we estimate GHG emissions levels will decline 26-35% in 2035, a meaningful shift from our 2024 report, which showed a steeper decline of 38-56% by that point. Emissions outcomes vary due to a range of expectations for economic growth, future fossil fuel prices, and clean energy cost and performance trends, which we combine to create low, mid, and high emissions scenarios. In the high emissions scenario, the most pessimistic outlook on decarbonization, the pace of decarbonization more than halves through 2040, with annual average GHG reductions of 0.4% from 2025 through 2040 compared to 1.1% from 2005 through 2024. In the mid and low emissions scenarios, the pace of decarbonization accelerates instead, with annual average reductions of 1.4% and 1.9% through 2040, respectively, representing a 22% and 70% acceleration, compared with the pace of the last two decades.
126 articles in 54 journals by 750 contributing authors
Physical science of climate change, effects
Global Water Cycle Pattern Amplification: Contributing Factors and Mechanisms, Lyu et al., Open Access 10.1029/2024jc022278
Neglecting land–atmosphere feedbacks overestimates climate-driven increases in evapotranspiration, Zhou & Yu, Nature Climate Change 10.1038/s41558-025-02428-5
Observations of Clouds and Radiation Over King George Island and Implications for the Southern Ocean and Antarctica, Rowe et al., Journal of Geophysical Research: Atmospheres Open Access 10.1029/2024jd042787
Climate change is accelerating, scientists find in ‘grim’ report
Posted on 17 September 2025 by dana1981
This is a re-post from Yale Climate Connections
he amount of heat trapped by climate-warming pollution in our atmosphere is continuing to increase, the planet’s sea levels are rising at an accelerating rate, and the Paris agreement’s ambitious 1.5°C target is on the verge of being breached, according to a recent report by the world’s top climate scientists.
“The news is grim,” said study co-author Zeke Hausfather, a former Yale Climate Connections contributor, on Bluesky.
A team of over 60 international scientists published the latest edition of an annual report updating key metrics that are used in reports of the Intergovernmental Panel on Climate Change, the leading international scientific authority on climate change.
Earth out of balance
Climate change is caused by variations in Earth’s energy balance – the difference between the planet’s incoming and outgoing energy. Nearly all incoming energy originates from the sun. The Earth absorbs that sunlight and sends it back out toward space in the form of infrared light, or heat. Greenhouse gases such as carbon dioxide absorb infrared light, and so increased levels in those gases trap more heat in the atmosphere, warming the planet’s surface and oceans.
The new report finds that as a result of this increasing greenhouse effect, Earth’s energy imbalance has been consistently rising every decade. In fact, the global imbalance has more than doubled just since the 1980s. And from 2020 to 2024, humans exacerbated the problem by adding about 200 billion more tons of carbon dioxide-equivalent greenhouse gases to the atmosphere.
This increase in trapped energy has continued to warm Earth’s surface temperatures. The new study estimated that at current rates, humans will burn enough fossil fuels and release enough climate pollution to commit the planet to over 1.5°C of global warming above preindustrial temperatures within about three more years, in 2028.
The most recent report from the Intergovernmental Panel on Climate Change, published in 2021, concluded that average temperatures had increased 1.09°C since the late 1800s. The new study updates this number to 1.24°C, driven largely by the record-shattering hot years of 2023 and 2024.
The paper also finds that global surface temperatures are warming at a rate of about 0.27°C per decade. That’s nearly 50% faster than the close to 0.2°C-per-decade warming rate of the 1990s and 2000s, indicating an acceleration of global warming.
Human-caused and total observed average global surface temperature increase since the Industrial Revolution. Created by Dana Nuccitelli with data by https://climatechangetracker.org/igcc from June 17, 2025.
Fact brief - Has the greenhouse effect been falsified?
Posted on 16 September 2025 by Sue Bin Park
Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.
Has the greenhouse effect been falsified?
The greenhouse effect is basic physics that has been known for nearly 200 years. Without it, the Earth would not be warm enough for life.
Greenhouse gases like carbon dioxide act like an insulating blanket. By preventing some outgoing heat from escaping the atmosphere by absorbing and re-emitting it, they keep Earth around 33°C (59°F) warmer than it would be otherwise.
In comparison, the Moon, lacking an atmosphere, swings from 120°C (248°F) in daytime to -130°C (-202°F) at night. Venus’s thick CO2-rich atmosphere always keeps surface temperatures above 450°C (842°F).
Laboratory tests show these gases trap heat at specific wavelengths, and satellites have directly measured those same wavelengths being trapped and reradiated.
It is no coincidence that as human-caused CO2 continues to increase in the atmosphere, more energy is being absorbed from the Sun than is being lost back into space, all while surface and air temperatures continue to rise.
Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact
This fact brief is responsive to quotes such as this one.
Sources
NASA What is the greenhouse effect?
NASA Weather on the Moon.
NASA Venus facts.
NASA Climate Forcings and Global Warming.
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What you need to know about AI and climate change
Posted on 15 September 2025 by Guest Author
This is a re-post from Yale Climate Connections by Daisy Simmons
Is AI saving the world or breaking it? As the era-defining technology leapfrogs from what-if to what-next, it can be hard for us humans to know what to make of it all. You might be hopeful and excited, or existentially concerned, or both.
AI can track Antarctic icebergs 10,000 times faster than humans and optimize renewable energy grids in real time – capabilities that could help us fight climate change. But it also consumes incredible amounts of energy, and ever more of it, creating a whole new level of climate pollution that threatens to undermine those benefits.
All that dizzying transformation isn’t just the stuff of news headlines. It’s playing out in daily conversations for many of us.
“Have I told you what Chatty and I came up with yesterday?” My dad and I talk every Sunday. “It’s an environmental detective show – you’ll star in it, of course.”
He’s mostly retired and spends a lot of time at home while my stepmom is at work, so he’s happy to have found an exciting new hobby: storytelling sessions with his AI pals (the above-referenced ChatGPT, as well as Claude and “Gemmy,” aka Gemini). This is a good thing, I think. He should be having some fun in his sunset years.
But then the conversation turned to a much less fun AI story: I told my dad my sixth grader said he’d felt pressured to dumb down an essay at school because a classmate got heat for using AI. What made the teacher suspect the kid? She flagged it for college-level vocabulary. “Well, that just ain’t right,” said my dad. Agreed.
Grim laughter was my brother-in-law’s reaction to the subject of my son’s essay. Once a rock star graphic designer (literally for rock bands), he said AI has killed creative career prospects for all our kids. But who knows, he said, maybe it will solve climate change – or maybe it will only make it worse.
That tension is what brought me here. The more I read and heard, the more I saw that he and I are not alone in struggling with this topic. To help make sense of the complexity, I asked Ann Bostrom, the chair of the National Academies of Science’s Roundtable on Artificial Intelligence and Climate Change, what she thought of my brother-in-law’s comment. In a nutshell: Is AI good or bad for the climate? The answer is decidedly not straightforward.
“Right now, there is serious uncertainty about what can or might happen with AI,” she said. “But that’s partially because it’s a new tool we’re developing – AI is a tool. So what it does, or what it can do, is a function of what we do with it.”
2025 SkS Weekly Climate Change & Global Warming News Roundup #37
Posted on 14 September 2025 by BaerbelW, John Hartz, Doug Bostrom
Stories we promoted this week, by category:
Climate Policy and Politics (9 articles)
- Chevron’s Boss Says the World Will Need Oil for a ‘Long, Long Time’ "Mike Wirth, who has seen many booms and busts over the more than 40 years he has been with the energy giant, said that 'when the world stops using oil and gas, we’ll stop looking for it'." US Economy, The New York Times, Q&A by Jordyn Holman, Aug 31, 2025.
- Politicians now talk of climate 'pragmatism' to delay action-new study The Conversation, Steve Westlake, Sep 04, 2025.
- Former staffers of Climate.gov are attempting to launch a new site: Climate.us Climate.gov went dark after cuts from the Trump administration. Now, a group of former employees are trying to revive it under a new domain. NPR Topics: Climate, Mary Louise Kelly, Sep 04, 2025.
- The Energy Sector Has Spent Hundreds of Millions of Dollars on Lobbying This Year. Watchdogs Say That’s Only Half The Story "Fossil-fuel firms receive US subsidies worth $31bn each year, study finds" Fossil Fuels, Inside Climate News, Aidan Hughes, Sep 8, 2025.
- Top US Energy Official Lobbies for Fossil Fuels in Europe "European climate experts say the pro-fossil fuel arguments are based on climate disinformation." Fossil Fuels, Inside Climate News, Bob Berwyn, Sep 9, 2025.
- Fossil-fuel firms receive US subsidies worth $31bn each year, study finds "Figure calculated by Oil Change International has more than doubled since 2017 but is likely a vast understatement" Fossil Fuels, The Guardian, Dharna Noor, Sep 9, 2025.
- Feds try to dodge lawsuit against their bogus climate report Meanwhile, Congress is trying to keep serious scientists from weighing in. Ars Technica, John Timmer, Sep 12, 2025.
- EPA will halt greenhouse gas reporting for big polluters Critics say the move would erase data that’s needed for future climate rules. E & E News, Jean Chemnick, Sep 12, 2025.
- Orsted Sues Trump Administration in Fight to Restart Its Blocked Wind Farm "The Danish company behind Revolution Wind, a $6 billion project off Rhode Island, said the federal government had unlawfully halted work on the wind farm." The New York Times, Brad Plumer & Karen Zraick, Dec 4, 2025.
Climate Science and Research (5 articles)
- When is a climate model 'good enough?' Models will always have bugs. How do scientists decide which ones are most important and how many is too many? EOS, Saima May Sidik, Sep 10, 2025.
- Geoengineering Won’t Save Us From Global Warming, New Study Says "The research by a team of top ice and climate scientists debunks some speculative technological climate fixes for preserving the polar ice caps." Science, Inside Climate News, Bob Berwyn, Sep 10, 2025.
- World’s Largest Fossil Fuel and Cement Producers Are Responsible for About Half the Intensity of Recent Heat Waves, New Study Shows "Scientists say such source attribution could help power litigation aimed at holding the fossil fuel industry accountable for damages from heat waves and other extreme weather linked to climate change." Fossil Fuels, Inside Climate News, Dana Drugmand, Sep 10, 2025.
- Skeptical Science New Research for Week #37 2025 In this week's edition highlights we see the long arm of the laws of physics, as rivers in Alaska are polluted by sulfides liberated as permafrost degrades. Skeptical Science, Doug Bostrom & Marc Kodack, Sep 11, 2025.
- Utility-Scale Solar Can Withstand Severe Hailstorms. Here’s How stow' mode, panels can tolerate run-ins with even large balls of ice." Inside, Clean Energy, inside Climate News, Dan Gearino, Sep 12, 2025.
Skeptical Science New Research for Week #37 2025
Posted on 11 September 2025 by Doug Bostrom, Marc Kodack
Open access notables
Wild, scenic, and toxic: Recent degradation of an iconic Arctic watershed with permafrost thaw, Sullivan et al., Proceedings of the National Academy of Science
The streams of Alaska’s Brooks Range lie within a vast (~14M ha) tract of protected wilderness and have long supported both resident and anadromous fish. However, dozens of historically clear streams have recently turned orange and turbid. Thawing permafrost is thought to have exposed sulfide minerals to weathering, delivering iron and other potentially toxic metals to aquatic ecosystems. Here, we report stream water metal concentrations throughout the federally designated Wild and Scenic Salmon River watershed and compare them with United States Environmental Protection Agency (EPA) chronic (4-d) exposure thresholds for toxicity to aquatic life. The main stem of the Salmon had elevated SO42− concentrations and elevated SO42−: Ca relative to a predisturbance baseline for most of its length, consistent with increased sulfide mineral weathering. Most of the tributaries also had elevated SO42− concentrations and elevated SO42−: Ca, especially those in the upper watershed. The Salmon River mainstem consistently exceeded EPA chronic exposure thresholds for total recoverable iron, total recoverable aluminum, and dissolved cadmium from its first major tributary to its mouth. Nine of ten major tributaries that we sampled exceeded EPA thresholds for at least one metal on at least one of three sampling dates. Our findings indicate that habitat quality for resident and anadromous fish has been severely degraded in the Salmon River watershed. Loss of important spawning habitat in the Salmon and many other streams in the region might help explain a recent crash in chum salmon returns, which local communities depend upon for commercial and subsistence harvest.
Speleothem evidence for Late Miocene extreme Arctic amplification – an analogue for near-future anthropogenic climate change?, Umbo et al., Climate of the Past
Our estimate of > 18 °C of Arctic warming supports the wider consensus of a warmer-than-present Miocene and provides a rare palaeo-analogue for future Arctic amplification under high-emissions scenarios. The reconstructed increase in mean surface temperature far exceeds temperatures projected in fully coupled global climate models, even under extreme-emissions scenarios. Given that climate models have consistently underestimated the extent of recent Arctic amplification, our proxy data suggest Arctic warming may exceed current projections.
Long-term decline in montane insects under warming summers, Sockman, Ecology
Widespread declines in the abundance of insects portend ill-fated futures for their host ecosystems, all of which require their services to function. For many such reports, human activities have directly altered the land or water of these ecosystems, raising questions about how insects in less impacted environments are faring. I quantified the abundance of flying insects during 15 seasons spanning 2004–2024 on a relatively unscathed, subalpine meadow in Colorado, where weather data have been recorded for 38 years. I discovered that insect abundance declined an average of 6.6% annually, yielding a 72.4% decline over this 20-year period. According to model selection following information theoretic analysis of 59 combinations of weather-related factors, a seasonal increase in insect abundance changed to a seasonal decline as the previous summer's temperatures increased. This resulted in a long-term decline associated with increasing summer temperatures, particularly daily lows, which have increased 0.8°C per decade. However, other factors, such as ecological succession and atmospheric elevation in nitrogen and carbon, are also plausible drivers. In a relatively pristine ecosystem, insects are declining precipitously, auguring poorly for this and other such ecosystems that depend on insects in food webs and for pollination, pest control, and nutrient cycling.
Addressing methane emission feedbacks from global wetlands, Ury et al., Nature Sustainability
Earth-system feedback loops that exacerbate climate warming cause concern for both climate accounting and progress towards meeting international climate agreements. Methane emissions from wetlands are on the rise owing to climate change—a large and difficult-to-abate source of greenhouse gas that may be considered indirectly anthropogenic. Here we illustrate the power of emissions reduction from any sector for slowing the progress of earth-system feedbacks.
From this week's government/NGO section:
About half of Americans understand that global warming is increasing homeowners insurance costs, Ettinger et al., Yale University and George Mason University
A large majority of Americans (82%) say the cost of homeowners insurance is increasing, including about two-thirds (66%) who say it is increasing “a lot.” A majority of Americans (69%) think disasters such as hurricanes, floods, and wildfires contribute to increasing homeowners insurance costs, including nearly half (47%) who say such disasters contribute “a lot.” About half of Americans (48%) think global warming contributes to increasing homeowners insurance costs. More Democrats than Republicans say that global warming contributes to the increasing cost of homeowners insurance. Although many Americans understand that global warming contributes to rising homeowners insurance costs, more attribute the cost increases to corporate profits, disasters (such as hurricanes, floods, and wildfires), inflation, and rising property values. Democrats and Republicans hold similar views about these other factors’ roles in increasing insurance costs.
Reporting extreme weather and climate change. A Guide for Journalists, Ben Clarke and Friederike Otto, World Weather Attribution
Extreme weather events, such as heatwaves, heavy rainfall, storms and droughts, are becoming more frequent and stronger in many parts of the world as a result of human-caused climate change. However, not all events are becoming more likely, and changes are uneven across the world. These events often have widespread effects on society, including the loss of crops and farmland, destruction of property, severe economic disruption and loss of life. Following an extreme event with severe impacts, a great deal of public interest is generated in its causes. Increasingly, the dominant question is: “Was this event caused by climate change?” This guide is intended to help journalists navigate this question.
74 articles in 46 journals by 443 contributing authors
Physical science of climate change, effects
Changes in atmospheric circulation amplify extreme snowfall fueled by Arctic sea ice loss over high-latitude land, Liu et al., Weather and Climate Extremes Open Access 10.1016/j.wace.2025.100802
Climate-sensitive chemical weathering feedbacks in a Glacial River Basin, Northeast Qinghai-Tibet Plateau, Li et al., Global and Planetary Change 10.1016/j.gloplacha.2025.105053
Enhanced West Antarctic ice loss triggered by polynya response to meridional winds, O'Connor et al., 10.5194/egusphere-egu25-13728
The Fix is In
Posted on 10 September 2025 by Guest Author
This is a re-post from The Climate Brink by Andrew Dessler
My last post described our 450-page response to the DOE Climate Working Group report. This DOE report seems designed to muddy the waters about climate science — it’s a new iteration of the Merchants of Doubt. We found the report used selective misquoting of the scientific literature (cherry picking), omission of contrary results from the scientific literature, and simple errors due to a lack of understanding of the science to reach its conclusions. Further commentary of the process is in this post.
A reporter asked me for a comment on a post on Dr. Judy Curry’s blog about our review of the DOE Climate Working Group report. In her post, she said:
Let me first say, wow, this is generous and far better than I expected. Only referring to me as “unhinged” once is a W and I’ll take it. Near the end of her post, she wrote:
When I read the underlined portion (added by me), I said to myself, “so that’s how they’re going to do it.” Yes, the fix is in — everyone should understand that this is a show trial for climate science and the inevitable outcome of this “debate” will be that climate science is found to be too uncertain to justify climate policy. And now I think I know how they’ll do it.
Let me walk you through it, starting with an explanation of how peer review works.
Fact brief - Has Arctic sea ice recovered?
Posted on 9 September 2025 by Sue Bin Park
Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. You can submit claims you think need checking via the tipline.
Has Arctic sea ice recovered?
Arctic sea ice, in both extent and volume, continues to decline.
The only fair comparison for Arctic sea ice is to a full 12 months prior, as ice accumulates each winter and melts each summer.
By that metric, Arctic sea ice extent set a record low maximum in March 2025, the month when ice is at its highest. Arctic sea ice volume for July 2025 was the 5th lowest on record.
There are two types of sea ice: thin “first-year” ice and thick “multi-year” ice. First-year ice grows and shrinks with the seasons and fluctuations in ocean currents and wind patterns.
These short-term ups and downs do not change the decline of multi-year ice. Satellite records since 1979 show continued loss in both extent and volume of multi-year ice.
Since that year, June ice extent loss has totaled more than 3 million square kilometers, nearly twice the size of Alaska.
Go to full rebuttal on Skeptical Science or to the fact brief on Gigafact
This fact brief is responsive to quotes such as this one.
Sources
NSIDC Sea Ice Today
NSIDC Sea Ice - Science
Polar Science Center PIOMAS Arctic Sea Ice Volume Reanalysis
NSIDC The peak of summer, the depths of winter
Please use this form to provide feedback about this fact brief. This will help us to better gauge its impact and usability. Thank you!
The merchants of doubt are back
Posted on 8 September 2025 by Guest Author
This is a re-post from The Climate Brink by Andrew Dessler
If you don’t follow climate policy closely, you may not know that the Trump administration is launching an effort to overturn one of the most fundamental pillars of American climate policy: the scientific finding that carbon dioxide endangers human health and welfare (the so-called “Endangerment Finding”). If successful, this move could unravel virtually every U.S. climate regulation on the books, from car emissions standards to power plant rules.
To support this effort, the Department of Energy hand-selected five climate contrarians who dispute mainstream science to write a report, which ended up saying exactly what you would expect it to say: climate science is too uncertain to justify policies to limit warming.
I’m guessing that the goal here is very much like what the tobacco companies did in the 1960s, 1970s, and 1980s. Their goal was not to win the debate that cigarettes were safe — they clearly understood they could not — but to muddy the waters enough to head off regulations on their business.
Thus, the DOE report is designed to do exactly the same thing: muddy the waters enough that the government can claim there’s too much uncertainty to regulate carbon dioxide.
I am part of a group of 85+ scientists who have submitted a 400+ page comment to the DOE critiquing their report. You can find a link to the comment and our press release here. If you are a reporter, science communicator, podcaster, etc., who wants an interview, please email us.
You can find bios for the author team here. It is a humbling group to be a part of, full of brilliant and high-achieving individuals, many of whom I have admired for years. The team’s ranks include six members of the National Academy of Sciences, two Fellows of the Royal Society, at least two MacArthur “Genius” Fellowship recipients, and numerous Fellows of the American Geophysical Union, American Meteorological Society, and the American Association for the Advancement of Science. Reinforcing their prominence in the field, many of these authors also wrote papers that were (mis)cited by the DOE report.
2025 SkS Weekly Climate Change & Global Warming News Roundup #36
Posted on 7 September 2025 by BaerbelW, John Hartz, Doug Bostrom
Stories we promoted this week, by category:
Climate Policy and Politics (8 articles)
- How to organize a peaceful and effective climate protest "Are you ready to organize your first event on behalf of the planet? Here are some ideas and tips on how to make it successful." Yale Climate Connections, Colleen M. Crary, Aug 28, 2025.
- Historians See Autocratic Playbook in Trump’s Attacks on Science "Authoritarians have long feared and suppressed science as a rival for social influence. Experts see President Trump as borrowing some of their tactics. The New York Times, William J. Broad, Aug 31, 2025.
- Trump cuts to climate satellites will make weather prediction harder, scientists say The Trump administration is scrapping satellite observations of Earth that officials say go beyond the essential task of predicting the weather. Washingto Post, Scott Dance, Sep 1, 2025.
- Dozens of scientists find errors in a new Energy Department climate report NPR News, Julia Somon, Sep 2, 2025.
- The merchants of doubt are back But this time, it's the U.S. government pushing doubt The Climate Brink, Andrew Dessler, Sep 02, 2025.
- Meet the UN-backed `green` investors` group that invested in fossil fuels Despite having pledged to reach net-zero emissions, major members of Net Zero Asset Managers hold billions of dollars’ worth of fossil-fuel stocks, including those in “carbon bomb” projects, while marketing their funds as green and sustainable. DeSmog, Giorgio Michalopoulos and Stefano Valentino, Sep 03, 2025.
- The fix is in Judy Curry unwittingly spills the beans The Climate Brink, Andrew Dessler, Sep 04, 2025.
- The Trump Administration Wants to Switch Off Climate Satellites The Trump administration wants to switch off and possibly destroy the climate-monitoring technology. New York Times, Sachi Kitajima Mulkey, Sep 05, 2025.
Climate Change Impacts (6 articles)
- Summer 2025 ranks among Spain's hottest ever after historic August heatwave "Extended periods of high temperatures this summer have significantly increased wildfire risks and put vulnerable communities on alert across Spain.? Green, EuraNews, Aug , Jesús Maturana, Aug 26, 2025.
- Deadly Floods in Punjab Devastate Pakistan’s Breadbasket Housing communities and businesses that rely on agriculture have been destroyed in the country’s largest province." Asia Pacific, by Elian Peltier & Zia ur-Rehman, Photographs by Asim Hafeez, by Asim Hafeez, Aug 31, 2025.
- ‘It happened so fast’: the shocking reality of indoor heat deaths in Arizona " ‘It happened so fast’: the shocking reality of indoor heat deaths in Arizona Heat deaths could surge in the state as energy poverty linked to Trump’s energy and trade policies burns" US News, The Guardian, Nina Lakhani, Aug 31, 2025.
- Climate change is making rollercoaster harvests the new normal Phys.org, University of British Columbia, Sep 03, 2025.
- Japan and South Korea record hottest summers in history "Record temperatures come amid scientists’ warnings that climate change is causing more frequent extreme weather events." Aljelzeera, Staff, Sep 3, 2025.
- Humans Are Altering the Seas. Here’s What the Future Ocean Might Look Like. "Some marine ecosystems could soon be unrecognizable, according to new research." Interactives, The New York Times, by Delger Erdenesanaa Graphics by Mira Rojanasakul; Photographs and Video by Madeline Gray, Dec 24, 2025.
