Extreme Event Attribution

Extreme event attribution (EEA) is a scientific field that analyzes whether and to what extent human-caused climate change influenced an individual extreme weather event, such as a specific heat wave or hurricane.

A new report from the National Academies of Sciences, Engineering, and Medicine,

Attribution of Extreme Weather and Climate Events and Their Impacts 2026 states that "decades of data and research indicate that human-caused climate change is altering the frequency, intensity, and other characteristics of classes of extreme weather and climate events, such as hurricanes, record-breaking heat waves, and extreme rainfall events."

"Confidence in EEA varies considerably by event type, with the highest confidence in relation to temperature extremes and lowest confidence for severe convective

storms. The position of each type of event on the graph above reflects the assessment by the report’s authoring committee of the current level of understanding of the effect of

climate change on the event type (x-axis) and the current scientific confidence in capabilities for the attribution of specific events within the event type (y-axis). This figure is updated from the NASEM 2016 report. The bubble size for each event type is proportional to the number of EEA studies conducted."

The New York Times notes that "the report doesn’t make recommendations on how attribution science should be used in policy and the law, though it notes that attribution findings could be relevant in several types of legal cases.

A June 26, 2026, NYT article Oil Industry Lawyers Fight a $50 Billion Climate Case in Oregon reported on a $50 billion lawsuit seeking to hold fossil fuel companies responsible for a heat wave in Portland, Oregon, five years ago. Multnomah County cited an attribution study that concluded that a record-shattering 2021 summer heat wave in the Pacific Northwest would have been “virtually impossible” without human-caused climate change.

The Times states that "the case is one of nearly 40 lawsuits that have been filed by state and local governments across the country arguing that the fossil fuel industry should be held accountable for its role in accelerating climate change."

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The National Academies of Sciences, Engineering, and Medicine is a private, non-profit institution that operates under a 1863 congressional charter. They provide "independent, trustworthy advice and facilitate solutions to complex challenges by mobilizing expertise, practice, and knowledge in science, engineering, and medicine." They envision a nation and world that rely on scientific evidence to make decisions that benefit humanity." At the core of their work is an "unwavering commitment to objectivity, scientific rigor, and truth."