Heat Action Day Report: Climate Change and the Escalation of Global Extreme Heat

London Experiences Heatwave Captured by Christian Julliard

A team of researchers from World Weather Attribution, in partnership with Climate Central and the Red Cross Red Crescent Climate Centre, conducted a study to analyze the impact of human-induced climate change on severe heat waves in the last 12 months. Released in anticipation of Heat Action Day on June 2, the research revealed that approximately 4 billion individuals, which accounts for roughly 49% of the global population, encountered a minimum of 30 additional days of extreme heat. This extreme heat was defined as temperatures surpassing 90% of the recorded temperatures in their local regions during the 1991-2020 timeframe and was found to be at least twice as likely due to human-caused climate change.