Summary/Abstract
In this report, the authors assess the influence that anthropogenic climate change has had on heat waves from May 1, 2024 to May 1, 2025. The report concludes that human-driven climate change is making dangerous heat events longer and more likely.
The report’s key findings include:
- “Over the 12-month period, 4 billion people — about 49% of the global population — experienced at least 30 days of extreme heat (hotter than 90% of temperatures observed in their local area over the 1991-2020 period).”
- “In 195 countries/territories, climate change at least doubled the number of extreme heat days, as compared to a world without climate change.”
- “All 67 extreme heat events — identified as significant based on record-setting temperatures or major impacts to people or property — were found to be influenced by climate change.”