Heat at Climate Shift Index level 3 or higher persisted for June-August period in 79 countries
Countries with the lowest historical emissions experienced three to four times higher than seasonal temperatures this June-August days than G20 countries - the world's largest economies - according to an analysis by Climate Central published today.
Almost half of the world's population of 3.8 billion people or 48 per cent experienced at least 30 days of significantly warmer temperatures in June-August due to human-caused climate change.
Heat at Climate Shift Index (CSI) level 3 or higher persisted for at least half the June-August period in 79 countries throughout Central America, the Caribbean, the Arabian Peninsula, and parts of Africa.
CSI level 3 indicates that climate change made the conditions at least three times more likely. Using the CSI, Climate Central's peer-reviewed attribution system, the analysis quantified the influence of climate change on daily temperatures across the world.
The change in likelihood is scored on a five-point scale, with 1 (at least 1.5 times more likely) through 5 (at least 5 times more likely), representing temperatures made more common by climate change.
Countries with the lowest emissions experienced approximately three to four times more June-August days with very strong climate fingerprints than the G20 countries (the world's largest economies).
In India, one state and two Union Territories experienced more than 60 days at CSI level 3 or higher - Kerala, Puducherry, and Andaman and Nicobar Islands.
Eleven states experienced average temperatures of 1 degree Celsius or more above the long-term (1991-2020) average. Three states and two Union Territories had a summer average CSI above 3 - Kerala, Andaman and Nicobar, Puducherry, Meghalaya, and Goa.
The analysis shows that countries that felt the strongest effects of climate change have contributed the least to carbon pollution. At least 1.5 billion people felt a strong influence of climate change every day from June 1 to August 31 this year.
According to the analysis, the Earth just had its hottest Northern Hemisphere summer on record, and many parts of the globe experienced record-shattering and dangerous heat from June through August.
The influence of climate change was inequitably distributed throughout the world, with residents of G20 nations exposed, on average during the period, to 17 days of temperatures made at least three times more likely.
Residents of the United Nations' Least Developed countries (47 days) and Small Island Developing States (65) were exposed to far more days of three or above on the CSI.
"Virtually no one on Earth escaped the influence of global warming during the past three months," Andrew Pershing, Climate Central's vice president for science, said.
The influence of climate change was inequitably distributed throughout the world
"In every country we could analyse, including the Southern Hemisphere where this is the coolest time of the year, we saw temperatures that would be difficult - and in some cases nearly impossible - without human-caused climate change. Carbon pollution is clearly responsible for this season's record-setting heat," Mr Pershing said.
Record-breaking heat also occurred in the ocean, elevating the risk of rapidly-intensifying tropical cyclones like Hurricane Idalia and coral bleaching events like those impacting Florida and the Caribbean.
Heat waves are the deadliest weather-related hazards, and their rising global frequency and intensity is consistent with well-established scientific understanding of the consequences of carbon pollution - mainly from burning coal, oil, and natural gas.