Big Oil’s Emissions Caused about 25 Percent of Heat Waves since 2000

> 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 today in **Nature** shows that around one-quarter of the heatwaves recorded over 2000–23 can be **directly linked** to greenhouse-gas emissions from individual energy giants.

> The findings could provide fresh evidence **to support lawsuits** seeking to hold companies accountable for their impacts on the climate. “I cannot as a scientist assign legal responsibilities for these events,” says lead author Yann Quilcaille, a climate researcher at the Federal Institute of Technology in Zurich, Switzerland. “What I can say is that **each one of these carbon majors** is contributing to heatwaves, making them more intense and also making them more likely.”

> 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 Quilcaille and his team go one step further than their 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.