Nearly half of the world's population suffered an extra month of extreme heat last year. This is indicated in a new report prepared by scientists from World Weather Attribution, Climate Central, and the Red Cross Red Crescent Climate Centre on the occasion of the Heat Action Day, which will be celebrated on June 2, highlighting climate change as responsible for this situation.
"There is no place on Earth that has not been affected by climate change, and heat is its deadliest consequence," says Kristina Dahl, Chief Scientist at Climate Central.
Specifically, during the 12-month period between May 2024 and May 2025, 4 billion people experienced at least 30 additional days of extreme heat, defined as temperatures exceeding 90% of historical observations in the region.
"Climate change is here, and it kills. With every barrel of oil burned, every ton of carbon dioxide released, and every fraction of a degree of warming, heatwaves will affect more people," says Friederike Otto, Professor of Climate Science at Imperial College London and co-director of World Weather Attribution.
The report includes a comprehensive analysis of the effect of climate change on extreme heat worldwide. In the case of Spain, our country experienced 48 days of extreme temperatures. But without human-induced climate change, it would have been only 18 days, according to this report. This means that climate change has added a month of extreme temperatures in Spain. The study also concludes that last summer's heatwave, between July 18 and 23, was ten times more likely due to climate change.
In 195 countries, climate change at least doubled the number of days of extreme heat and increased the likelihood of the 67 most severe heat episodes that occurred last year. The study illustrates not only the magnitude of the problem but also the urgent need for adaptation and heat mitigation measures in the face of rising global temperatures.
"These frequent and intense episodes of high temperatures are associated with a wide range of effects, such as heat-related illnesses, deaths, pressure on healthcare systems, crop losses, decreased productivity, and transportation disruptions," says Mariam Zachariah, a researcher on global weather event attribution at the Centre for Environmental Policy at Imperial College London.
Last Wednesday, the World Meteorological Organization (WMO), a UN agency, projected that the planet will likely exceed the 1.5°C threshold compared to pre-industrial levels with a 70% probability between 2025 and 2029. The planet is set to continue at an unprecedented level of global warming, after 2023 and 2024 were the warmest years on record, as stated by the UK Met Office based on forecasts from ten international centers.
Roop Singh, Head of Urban Planning and Attribution at the Red Cross Red Crescent Climate Centre, stated: "The evidence of the link between climate change and heatwaves is undeniable. Through our interactions, we know that people are feeling the increasing heat, but they do not always understand that it is due to climate change and that it will significantly worsen."