Overview

• The peer-reviewed paper, led by ETH Zurich researchers and published Wednesday in Nature, analyzes 213 heatwaves recorded between 2000 and 2023.
• Human-driven warming made heatwaves about 20 times more likely in 2000–2009 and 200 times more likely in 2010–2019 versus 1850–1900, with 55 events effectively impossible without warming.
• Emissions traced to the 180 firms account for roughly 60% of cumulative CO2 since 1850 and explain about half of the global surface temperature change in 2023.
• Major contributors include entities from the former Soviet Union, China’s coal sector, and oil majors such as Saudi Aramco, Gazprom, and ExxonMobil, with the 14 largest coal companies driving the biggest share.
• The analysis considers full value chains yet relies on reported events that undercount Africa and South America, and the authors say the results could bolster polluter-pays cases and will be extended to other extremes.