A new assessment from America’s most influential scientific advisory panel says climate attribution science has moved beyond asking whether human-induced global warming is causing deadly heat waves, floods and wildfires. As more and more abnormal situations occur, the focus is on how serious the future impacts will be.
“As the frequency of multiple types of extreme weather increases, the likelihood that they occur simultaneously or in succession across the same location or region increases,” the 14 authors wrote in the extreme weather attribution report prepared by the National Academies of Sciences, Engineering, and Medicine, an independent organization chartered by Congress to advise the U.S. government on science and technology.
The trend toward “further compounding, cascading, and record-breaking phenomena” challenges existing attribution research methods that aim to find the climatic signature of acute events in limited geographic areas, the scientists wrote. They also argued that more attribution research could help communities adapt to increasingly extreme conditions.
Attribution science measures how much human-induced global warming loads the dice on extreme weather events, making them more likely or more severe. Recent research shows that extreme weather events like the deadly heat dome that occurred in the Pacific Northwest in 2021 and the heat wave earlier this summer that killed more than 5,000 people in Europe would not have been possible without human-induced warming.
To determine how global warming will affect extreme events, researchers compare their intensity and likelihood of occurrence in our current climate to the same events modeled in a world without anthropogenic emissions. Combining observational data, weather/climate models, and statistical models can help quantify the impact of anthropogenic warming on extreme events.
The authors write in their report that attribution scientists should develop common standards for studying extreme phenomena so that different research groups can more easily compare and verify each other’s results. It also recommended that rapid attribution studies, currently published within days of a major disaster, be periodically reviewed to ensure that the methods keep pace with advances in climate science.
The report says the next big advances will come from stronger climate models that can better simulate localized extreme events such as severe thunderstorms and hail, and improved weather and impact data, especially in parts of the world where observations are still limited. It also calls on scientists to work more closely with local authorities and communities to ensure that attribution research provides useful information for disaster planning, recovery, and estimating climate-related losses.
In a webinar Thursday, atmospheric scientist James Harrell, chairman of the reporting committee, said the field of attribution of extreme events has proliferated since 2016, when the NAS released its last report on the subject. Harrell, a professor and Scott Chancellor Chair in Environmental Science and Engineering at Colorado State University, said improved climate models and a more complete record of climate measurements from Earth and satellites will help place extreme events in historical context.
“Human influence was clearly detected in several important categories of extreme events, including extreme heat, heavy rainfall, and combinations of high temperature and dryness,” he said.
He said the committee is careful to distinguish between areas where there is high confidence in the attribution of extreme events – heat waves, extreme precipitation, tropical storm strength, and dangerous wildfire weather – and smaller-scale events such as severe thunderstorms and hailstorms that are difficult to model and have limited observational records.
“Recognizing these limitations is one of the strengths, not weaknesses, of attribution science,” he said, adding that the attribution research community is “increasingly transparent” about where it is reliable and where further progress is needed.
Attribution science “helps connect global climate change and local experiences to improve public understanding,” he said. It also helps governments and businesses better understand emerging risks. He said attribution research is also increasingly fitting into policy, regulatory and legal contexts.
The 2026 report shows that scientists are much more confident than a decade ago in pinpointing how anthropogenic warming will affect hurricanes and other tropical weather systems.
A 10-year-old report described wildfires as one of the most difficult hazards to attribute to fires because they depend on a complex combination of weather, vegetation and other factors. But now, the committee has concluded that scientists are confident that more frequent hot, dry fire weather is the cause of large wildfires.
The report acknowledges that the behavior of individual fires remains complex and it is difficult to pinpoint their causes, but it cites wildfires as a feature of compound disasters that are increasing in a warming climate, with heat and drought fueling fires and causing cascading effects such as smoke, flooding and landslides.
“A clear statement”
Michael Mann, a climatologist at the University of Pennsylvania, said the new report is a “clear and positive statement that anthropogenic climate change is indeed influencing the occurrence and intensity of extreme weather events.” He acknowledged that scientific advances had increased confidence in the results of attribution studies, and said he was refuting “negative claims from fossil fuel groups and right-wing think tanks.”
Mann noted a passage in the report that acknowledged the “structural and observational” limitations of attribution modeling, and said those weaknesses “almost certainly lead to models underestimating the impact of climate change on persistent summer extremes.”
This story is funded by readers like you.
Our nonprofit newsroom provides free advertising for our award-winning climate coverage. We rely on donations from readers like you to continue our work. Donate now to support our work.
donate now
He said the scrutiny can be attributed, at least in part, to NAS’s “overly conservative approach in addressing these controversial topics, especially given the toxic political atmosphere that exists in the United States, where climate science is being aggressively attacked by a climate change-denying president and cabinet, and a fossil fuel-fueled Republican Congress.”
The field is expanding to investigate the human and economic impacts of extreme weather events, including deaths and economic losses, the report said.
The region has received significant scientific and social attention in recent years, as events such as Hurricane Helen in 2024, the Pakistan floods in 2022, and the East African drought in 2020-2023 have had significant societal impacts. By attributing extreme events and their impacts to climate change, scientists can provide additional information that can help inform decision makers and communities to better manage and respond to climate change risks,” the authors write.
Davide Faranda, research director for climate physics at France’s National Center for Scientific Research, said the new report highlights how much attribution science has matured over the past decade, studying the attribution of extreme weather events, including clear-air turbulence, which is dangerous for air traffic. He recently co-authored a study on the link between global warming and extreme hailstorms.
Attribution research no longer relies solely on modeling, he said. Researchers are now combining their models with long-term observations and other evidence, allowing them to test the same events using independent methods. If those approaches yield similar results, confidence in the results increases.
Aerial view of a flooded residential area in Jaffarabad district, Balochistan province, Pakistan, August 30, 2022. Credit: Fida Hussain/AFP via Getty Images
Platforms such as World Weather Attribution, Climate Central, and ClimaMeter use these tools to “provide scientifically robust information within days of an event, and we are beginning to extend this capability with predictive-based attribution even before an event has fully developed,” he added.
The next frontier in this field will come from highly localized hazards such as severe thunderstorms, he said. Recent experimental work combining atmospheric circulation models with detailed measurements from weather instruments and “physically informed AI” suggests this is becoming a reality, and “could ultimately help support adaptation, preparedness and climate risk management at regional scales,” he added.
He said evolving attribution science from a retrospective scientific practice to a practical capability will ultimately “support early warning systems, adaptation planning, and climate risk management.”
About this story
As you may have noticed, this article, like all news we publish, is free to read. That’s because Inside Climate News is a 501c3 nonprofit organization. We don’t charge subscription fees, keep our news behind paywalls, or fill our website with ads. We provide climate and environmental news free to you and anyone who wants it.
That’s not all. We also share our news for free with dozens of other news organizations across the country. Many of them cannot afford to do their own environmental journalism. We’ve established bureaus across the country to report on local news, partner with local newsrooms and co-publish stories to ensure this important work is shared as widely as possible.
The two of us started ICN in 2007. Six years later, we won the Pulitzer Prize for national reporting and now run the nation’s oldest and largest dedicated climate newsroom. We tell the story in its entirety. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We explore solutions and inspire action.
Donations from readers like you fund all aspects of our work. If you haven’t already, will you support our ongoing work, our coverage of the biggest crises facing our planet, and help us reach more readers in more places?
Please make a tax-deductible donation. Each one makes a difference.
thank you,
bob berwin
reporter, austria
Bob Barwin is an Austria-based reporter who has covered climate science and international climate policy for more than a decade. Previously, he reported on the environment, endangered species, and public lands for several Colorado newspapers, and also worked as editor and associate editor for a community newspaper in the Colorado Rockies.
