The South Asia heat wave is the “emergency” phase of climate change

A weeks-long “infinite” heat wave is “near uninhabitable levels” in India and Pakistan — and it’s still getting worse

One of the most intense early-season temperature surges in recorded history is smoldering across South Asia. 

Translated into heat stress on human bodies, this heatwave has approached “uninhabitable” levels — and is a preview of truly dangerous climate change in one of the most heat-vulnerable places on Earth. Experts are already calling it one of the worst heatwaves in modern historyan “infinite” heat wave that has unleashed widespread suffering.

In India, both March and April broke records for the hottest months ever in the northern and central parts of the country. Temperatures in the capital New Delhi soared to 117 degrees F (47.1 degrees C) on Saturday, one of the hottest places anywhere on the planet. It is so hot there that landfills keep spontaneously bursting into fire — sending local air quality to 10 times safe levels

First-hand accounts of the heat were simply miserable as millions made due without air conditioning after national electricity demand soared to the highest level ever, forcing widespread blackouts. It was so hot in eastern India, on woman was able to make bread on a car’s hood:

In Pakistan, temperatures on Sunday rose to 121 degrees F (49.5 degrees C) at Nawabshah, the hottest temperature recorded in the Northern Hemisphere so far in 2022. Throughout the heat wave so far, urban areas have been subjected to emergency power cuts of up to eight hours per day. Extreme heat illness is made more difficult as much of the heatwave coincided with the holy month of Ramadan, where many Muslim people fast during daylight hours. 

The extreme duration has made this not really a heat wave, but more of a heat season.

After a series of unusual duststorms and lingering drought during January and February, more than a billion people — around 1-in-5 people on the planet — have already experienced high temperatures in excess of 100 degrees F (38 degrees C) during March and April from Burma and Bangladesh to Pakistan, Iran, and into the Middle East and North Africa. These regions are no strangers to hot days, but a heat wave of this magnitude and duration — up to 14 degrees F (8 degrees C) hotter than normal for weeks on end — is likely unprecedented in at least 122 years of local record-keeping.

This heat wave is directly linked to climate change. A study earlier this year found that “heat wave frequency and intensity drastically increased in India during the twentieth century due to “anthropogenic forcings”, with “significant risk and detrimental effects on human health” driven by fossil fuel burning. “Model simulations indicate occurrence of unprecedented heat waves in the future never observed in the observational period,” the study’s authors wrote.

The extreme duration has made this not really a heat wave, but more of a heat season. April’s record temperatures piled on top of a record hot month of March in India and Pakistan, and are expected to continue for four to six more weeks until the annual monsoon rains arrive in early June. This year there have been heat adaptation efforts to shift work schedules across India to cooler morning hours and increase ventilation in school buildings, but the needs are still enormous.

The long-lasting nature of this heat wave is a telltale sign of the broadening of the summer warm season in the tropics around the world due to climate change, adding stress to natural systems that have been in balance for thousands of years. Essential crops have withered in the fields, adding to concerns of food scarcity at a moment of global economic turmoil. 

In Nepal, record temperatures in March and April are threatening a surge in floodwaters from melting glaciers. Kathmandu recorded its hottest spring temperatures on record, and the Pakistan Meteorological Department warned of the possibility of damaging floods flowing downstream.

As bad as this heat wave has been, it will get worse in the coming weeks. As the winds across South Asia gradually shift from northwest to southwest with the onset of the annual monsoon, humidity will increase — greatly increasing the danger of the heat on human bodies. As the absolute moisture content of the air increases, the ability of the human body to cool itself down by sweating decreases — there’s simply nowhere for your sweat to evaporate to. Since hotter air can hold more moisture than cooler air, there’s a point where simply being outdoors will be deadly. In some parts of India, that point could be quickly approaching.

According to a 2020 report, “India could become one of the first places in the world to experience heat waves that cross the survivability limit for a healthy human being resting in the shade, and this could occur as early as next decade.” Even if global warming is limited to 2 degrees C, India’s heat waves will be five times longer in the 2040s than they are now.

That makes heat wave prevention across South Asia one of the most urgent climate priorities across the entire world. The easiest way to do that, according to the UN, is to implement heatwave early warning systems that prioritize care for those most vulnerable, and to greatly limit greenhouse gas emissions everywhere on Earth.