A new study directly links hundreds of major heatwaves since 2000 to the emissions from fossil fuel and cement producers. Among its fundings, the researchers conclude that as many as a quarter of all heatwaves since the start of this century would have been “virtually impossible” without emissions from any of the world’s 14 largest fossil fuel and cement producers.
The study, published Wednesday in the journal Nature, shows that greenhouse gas emissions from 180 of the world’s biggest cement, oil, and gas producers have significantly contributed to climate change over the last two decades.
They linked the emissions to 213 heatwaves, finding the pollution made the extreme heat more likely and intense. Of those 213 events, 53 were made 10,000 times more likely as a result of the emissions, according to the researchers.
The fight for climate accountability
The findings could bolster legal efforts to hold the world’s biggest polluters responsible for the consequences of their emissions, experts said. In July, the International Court of Justice ruled that states that fail to prevent climate harm may have to pay compensation, and in May, a German high court ruled that major emitters can be held liable for climate impacts. And some U.S. states have passed similar laws.
Still, despite dozens of lawsuits filed since 2004, no court has penalized emitters for causing climate change, researchers wrote in an accompanying viewpoint.
“I cannot as a scientist assign legal responsibilities for these events,” lead author Yann Quilcaille, a climate researcher at the Federal Institute of Technology in Switzerland, told Nature. “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.”
Trying to attribute human-caused climate change
This study is an example of attribution science, which specifically aims to quantify how human-caused global warming shapes specific extreme weather events, including heatwaves. Evidence suggests that climate change will increase both the frequency and intensity of future heatwaves, but attribution science aims to tell scientists whether climate change worsened a particular heatwave that has already occurred.
Backed by decades of research and endorsed by the UN’s Intergovernmental Panel on Climate Change (IPCC), attribution science a powerful methodology, but it comes with clear limitations. Attribution science can’t tell us whether climate change “caused” an extreme weather event, but it can indicate how much more likely or severe it was in a world with climate change compared to a world without.
180 ‘carbon majors’ produce half of all global emissions
Quilcaille and his colleagues assessed the historical greenhouse gas emissions from 180 “carbon majors,” a group that includes fossil fuel companies, state-owned entities, and fossil fuel and cement emissions produced by nation states.
In all, these sources were responsible for nearly 57% of historical global emissions between 1850 and 2023, the analysis revealed.
The researchers then used climate models to compare global temperature trends in a world with greenhouse gas emissions to temperatures in a world without those emissions. Then, they estimated the impact of human-driven global warming on 213 heatwaves recorded between 2000 and 2023, finding direct links to top emitters and these extreme weather events.
“For a while, it was argued that any individual contributor to climate change was making too small or too diffuse a contribution to ever be linked to any particular impact. And this emerging science, both this paper and others, is showing that that’s not true,” Chris Callahan, a climate scientist at Indiana University who was not involved in the study, told The Associated Press.
