1267. Heat Action Day

Due to climate change, extreme heat continues to occur around the world. Researchers from World Weather Attribution, an international group of scientists investigating how climate change affects the intensity and probability of occurrence of extreme weather events; Climate Central, a group of scientists that investigates and reports the facts about climate change and its impacts; and the Red Cross Red Crescent Climate Centre assessed the impact of human-induced climate change on dangerous heat waves over the past 12 months (from May 1, 2024 to May 1, 2025).

The study, released ahead of Heat Action Day on June 2, found that human-induced climate change is exacerbating dangerous extreme heat for billions of people and increasing the duration and frequency of heatwaves. Key findings from the report include:

• In the past 12 months, 4 billion people, roughly half the world's population, experienced 30 or more days with temperatures exceeding 90% of those observed in their region between 1991 and 2020.
• In 195 countries and territories, the number of extreme heat days increased at least twice as much as they would have without climate change.
• All 67 heat events identified as significant based on record temperatures or significant impacts on people and property were found to be influenced by climate change.

The report also demonstrates the importance of tracking and reporting the impacts of extreme heat and offers practical solutions to reduce heatstroke risks.

(Reference)
Giguere, Otto, Tannenbaum, Vahlberg, et al. (2025). Climate Change and the Escalation of Global Extreme Heat: Assessing and Addressing the Risks. Climate Central, Red Cross Red Crescent Climate Centre, World Weather Attribution. https://www.climatecentral.org/report/climate-change-and-the-escalation…

Contributor: IIYAMA Miyuki, Information Program