Washington DC - The US' leading scientific body is set Thursday to launch a major report on the link between climate change and extreme weather, a growing research field now underpinning lawsuits seeking billions in damages from the fossil fuel industry.

Top US science body readies climate report as The National Academies of Sciences, Engineering, and Medicine, an independent body chartered in 1863 under President Abraham Lincoln, will publish Attribution of Extreme Weather and Climate Events and Their Impacts, its first update on the topic since 2016.

Ahead of its publication, Republican lawmakers have sought to cast doubt on the authors' work – sending, for example, a letter in April to the president of NASEM alleging bias and demanding details on the authors' professional ties.

Separately, Senator Ted Cruz and others have introduced the "Stop Climate Shakedowns Act," a bill that would block climate damage lawsuits from proceeding in court, in a move critics call a de facto immunity shield for fossil fuel companies.

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Dozens of such lawsuits are working their way through courts across the country. In one example, Multnomah County in Oregon is suing fossil fuel giants including BP, Chevron, and ExxonMobil for more than $51 billion for pollution that fueled a deadly 2021 heat dome in the Pacific Northwest during which hundreds died.

Attribution science seeks to untangle how much human-caused climate change shaped a specific heat wave, storm, or flood, and its findings now shape litigation and policy.

The field first emerged in the 1990s and gained credibility as the UN's climate panel incorporated the work into its assessments. It is now more visible than ever thanks to the rise of rapid analysis studies that can detect the signature of global warming on disasters within days, rather than years.

The nonprofit Union of Concerned Scientists says it expects a coordinated campaign to target both the report and its individual authors.

"The Academies have released reports on all types of different scientific developments and advances. I'm not aware of any that have been subject to this level of scrutiny," Carly Phillips, a senior scientist who works on climate litigation issues for UCS, told AFP.

She added that it comes "on the heels of this growing number of attacks on attribution science specifically by the fossil fuel industry and its allies."

While Republicans in Congress have introduced an immunity bill, President Donald Trump's administration has sued states pursuing such actions, and sought to kill "Climate Superfund bills" that require polluters to pay into a fund used for climate damages.

Meanwhile, Trump's Environmental Protection Agency has rescinded the 2009 Endangerment Finding, a scientific determination that global warming emissions endanger public health and must be regulated.