Asia’s Killer April Heat Wave Was Made Much Worse by Climate Change

(Bloomberg) — The April heat wave that swept through Asia, bringing temperatures as high as 46C (115F) in some places, was much more severe and likely to occur than it would have been in a world without climate change, scientists have concluded.

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Extreme heat affected hundreds of millions across the region last month, adding to the plight of 1.7 million people displaced by the war in Gaza as well as those without access to cooling. Hundreds of people died from heat-related causes, although more fatalities were likely to have gone unreported, according to the researchers.

The World Weather Attribution (WWA) group used computer models and ground observations to trace the footprint of heat-trapping gases in the affected area.

“What we wanted to know is whether such temperatures were possible in the past, and whether they will be like this going into the future.” said Mariam Zachariah, a climate change researcher at the Grantham Institute of Imperial College London and lead author of the study.

The scientists found that in areas such as Palestine and Israel, climate change made the heat wave five times more likely than it would have been in pre-industrial times, and 1.7C hotter.

In the Philippines, where temperatures were 1.2C higher, the researchers estimated that this year’s heat wave would have been impossible without decades of burning fossil fuels.

In South Asia, which was the focus of two such studies in 2022 and 2023, abnormal heat was found to be 45 times more likely to occur, and to be 0.85C higher due to climate change.

The WWA researchers also looked at whether El Niño, the naturally occurring warm current in the Pacific Ocean, may have played a part in the event. They concluded that while it raised temperatures in the Philippines by about 0.2C, it did not influence the West Asian heatwave.

The study drives home the prospect of “wide-ranging systemic impacts on the economy,” said Ashish Fernandes, chief executive officer of the consultancy Climate Risk Horizons. “If you look at the major economic indicators that are problematic right now in India, you see food inflation, low level productivity, unemployment,” all of which will worsen with each new heat wave.

A separate study in 2022 found that heat may contribute to 650 billion hours a year of lost labor globally, having cost an estimated $2.1 trillion equivalent in 2017 alone.

“I would describe this is as a chronic inflammation of the body,” Fernandes said. “You are not collapsing and dying, but it makes your life harder in every way.”

Heat action plans are in place in countries like India, the WWA scientists note, albeit not at a sufficient scale to protect the most vulnerable from temperature stress.

“The scale of the problem and people impacted in a country like India is enormous,” said Jaya Dhindaw, a sustainability expert at the World Resources Institute, citing the many people who lack resources to protect themselves from extreme heat. “It is a matter of survival.”

The reality on the ground is also complex, said Aditya Valiathan Pillai, a fellow with the think tank Sustainable Futures Collective who in 2023 carried out an extensive analysis of India’s heat action plans at a state level.

“Putting preparedness front and center as a major strategy across the many thousands of local governments in this country is a very big challenge,” he said. Funding is often scarce, but public awareness about heat exposure risks is what’s still lacking in India, as people are only now starting to understand that high temperatures can kill as well as decrease productivity.

None of this is easy, he said, but getting myriad local administrations to work together “may well result in a resiliency framework for the country which would be an example for other heat-prone nations in the developing world.”

–With assistance from Coco Liu.

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