Climate scientists have been attributing storms, droughts and heatwaves to global warming for two decades. Now, they are tracing the chain of responsibility all the way back to the producers of fossil fuels. A study published in Nature in September 2025 shows that around one-quarter of the heatwaves recorded over 2000–23 can be directly linked to greenhouse-gas emissions from individual energy giants…some of whom include (the former Soviet Union, China (coal), Gazprom, Exxon Mobile, Chevron, National Iranian Oil Company, Saudi Aramco, BP, Shell, India (Coal)) The findings could provide fresh evidence to support lawsuits seeking to hold companies accountable for their impacts on the climate.

More than one-quarter of the 213 events recorded would have been “virtually impossible” without human-induced global warming, the study found. The emissions linked to energy companies and other major carbon emitters increased the likelihood of some 53 heatwaves by a factor of more than 10,000.

This is not the first time that climate impacts have been attributed to fossil-fuel producers, but this study go one step further than its predecessors and link individual companies directly to specific heatwaves. Legal experts say it’s a line of evidence that could feed into climate litigation that focuses on specific events, such as the 2021 heatwave that hammered the US Pacific Northwest in 2021. Already, a county government in Oregon has filed a US$52-billion civil lawsuit against fossil-fuel companies for contributing to that event.

Excerpts from Jeff Tollefson, Heatwaves linked to carbon emissions from specific companies, Nature, Sept. 10, 2025