A new report from scientists at World Weather Attribution, the Red Cross Red Crescent Climate Centre and Climate Central assesses the influence of human-caused climate change on extreme heat waves over the past 12 months, from May 15, 2023, to May 15 2024.
It found that human-caused climate change is increasing dangerous extreme heat for billions and making heat events longer and more likely.
The study used World Weather Attribution criteria and identified 76 extreme heat waves across 90 different countries.
Out of the 76 events, the study assessed seven in-depth. This included:
● The extreme humid heat in South and Southeast Asia in May 2023,
● The extreme heat in Southern Europe, North America and China in July 2023,
● The early and prolonged heat that affected millions of people across Argentina, Brazil, Paraguay, and Bolivia in September 2023,
● The hottest-ever October (2023) in Madagascar,
● Dangerous humid heat in the coastal regions of West Africa in February 2024,
● The deadly heat in the Sahel region during Ramadan 2024,
● The most recent extreme heat that affected all of Asia, from Israel, Palestine, Lebanon and Syria in the west, to Myanmar, Thailand, Vietnam and the Philippines in the east during April 2024.
It was found that in all of these studies, human-induced climate change was a key driver.
In many cases, including in Southern Europe, the southern United States and Mexico, the Sahel region, West Africa, Thailand, Lao PDR, and the Philippines, the report notes that the high temperatures observed would never have occurred without human-induced climate change.
Further, over the 12-month period, 6.3 billion people (78 per cent) experienced at least 31 days of extreme heat (hotter than 90 per cent of temperatures observed in their local area over the 1991-2020 period) that was made at least two times more likely due to human-caused climate change.
Across this period, human-caused climate change added an average of 26 days of extreme heat across all places in the world, than there would have been without a warmed planet.
The report outlines that these extreme heat events put billions of people at risk, including in densely populated areas of South and East Asia, the Sahel, and South America.
Read the full report here.