New Delhi: From June to August this year, many parts of the globe experienced unusual heat, made at least three times more likely by climate change as per a report released on September 18 by Climate Central, an independent group that analyses data on climate change and its impact on people.
The report found that human-caused climate change increased heat-related health risks for billions, and made extreme heat events longer and more likely around the globe. India was the South Asian country that was most affected: for at least 60 days between June and August, more than 20.5 million people experienced unusually warm temperatures caused by climate change. The cities of Thiruvananthapuram, Vasai-Virar, Kavaratti, Thane, Mumbai, and Port Blair witnessed 70 days or more of unusual heat caused by climate change.
Constant heat for three continuous months, worldwide
The team analysed how climate change caused higher temperatures across the world from June to August 2024, using their Climate Shift Index. Climate Central’s global Climate Shift Index (CSI) launched in 2022 maps the influence of climate change on daily temperatures across the world. The CSI levels range from -5 to +5, with positive levels indicating temperatures that are becoming more likely due to climate change, and negative scores that indicate conditions that are becoming less likely.
For example, a CSI level of three means that a temperature occurs three times more frequently at a location when compared to a world without human-caused climate change.
The current study by Climate Central looked at CSI levels across 22 major regions across the world, spanning 218 countries, territories, or dependencies; 254 states, territories, or provinces of the largest countries; and 940 cities around the world.
The data revealed that one in four people in the world constantly experienced climate change-caused heat throughout this time: on every single day in June, July, and August, the unusually higher temperatures they experienced was made at least three times more likely by climate change.
Global exposure to this climate change-induced heat peaked on August 13, 2024. On this day, 4.1 billion people – which is half of all people worldwide – experienced heat, also made at least three times more likely by climate change.
Due to climate change, the average person experienced 17 extra days of “risky heat” – days with temperatures hotter than 90% of the temperatures recorded in a local area from 1991-2020, when heat-related health risks increase – between June and August this year.
Around 25% of the world’s population – that’s more than 2 billion people – experienced a staggering 30 or more days of risky heat, which climate change again made at least three times more likely. This included nearly the entire population of the Caribbean and at least three in every four people in Western Asia, Micronesia, Northern Africa and Southern Europe. As many as 72 countries experienced their hottest June-August period since at least 1970 this year. The report also found that 180 cities in the Northern Hemisphere (which experiences summer from June to August) had at least one dangerous extreme heat wave (at least five consecutive days with temperatures hotter than 99% of temperatures recorded in that city from 1991-2020). In these 180 cities, “extreme heat waves of this intensity and duration are, on average, 21 times more likely today because of human-caused climate change”, the report found.
In Asia alone, 333 million people were exposed to at least 60 days of unusual heat, which climate change made at least five times more likely.
Indians at risk
According to the report, June-August this year was India’s second-hottest season since at least 1970 (last year was the first).
During 29 days in these three months, temperatures were at least three times more likely because of climate change. For at least 60 days, more than 20.5 million people experienced these unusually warm temperatures caused by climate change. This made India the Southern Asian country with the most people exposed to temperatures driven by climate change.
More than 426 million people – out of the total 1.38 billion people in India – experienced at least seven days of “risky heat” days. A smaller proportion – 112 million people – experienced at least 30 days of these health-threatening temperatures.
Among the Indian cities that witnessed a significant number of days of warmer temperatures than normal that were caused by climate change were Thiruvananthapuram, Vasai-Virar, Kavaratti, Thane, Mumbai, and Port Blair. All these cities experienced 70 days or more with temperatures made at least three times more likely because of climate change.
Mumbai witnessed 54 days of such temperatures, and Kanpur and Delhi “experienced long streaks of temperatures considered dangerous to human health, with mean temperatures above 39°C”, per the report’s India analysis, which were made four times more likely because of climate change.
The results, both globally and for India, are not surprising: a similar report by Climate Central that analysed CSI levels during just nine days in June this year found that extreme temperatures made at least three times more likely by human-induced climate change may have affected 619 million Indians. A prolonged heat wave affected various regions of India in June, resulting in over 40 cases of heatstroke and more than 100 fatalities by the time it subsided in mid-June.
As per the report published on June 27 this year, more than 60% of the world’s population – 4.97 billion people – faced extreme heat that was made at least three times more likely by climate change between June 16 and 24.
