Fossil fuel, cement companies make heatwaves 50 pc more intense: Study

Emissions from the world’s largest fossil fuel and cement producers could be directly responsible for making an average heatwave 50 per cent more intense since the pre-industrial era, a new study in Nature has suggested.

The research, conducted by European scientists including experts at ETH Zurich, examined 213 major heatwaves between 2000 and 2023, drawing on data from the international Emergency Events Database. These included the catastrophic 2022 heatwave in India, when temperatures in parts of north India touched 49°C, crippling power supply and damaging crops.

The study found that emissions from just one “carbon major” could be linked to as many as 16 to 53 extreme heatwaves — events that, the researchers stressed, would have been “virtually impossible” in a world without human-driven global warming.

“The emissions of the carbon majors contribute to half the increase in heatwave intensity since 1850-1900,” the authors wrote, noting that all 180 companies and states studied — from Saudi Aramco and Gazprom to China, India and Chevron — played a role in amplifying the severity of heat extremes.

India appears twice in the story of global warming: as a victim of increasingly deadly heat and as a major emitter through its dependence on coal. Extreme heat is already among the deadliest climate risks for the country, which faces rising mortality, productivity losses, and economic shocks. The 2022 heatwave, for instance, cut India’s wheat harvest and forced a sudden ban on exports, sending global food prices soaring.

Yet, India remains the world’s third-largest emitter of carbon dioxide, behind China and the United States. With coal powering over 70 per cent of its electricity, India’s emissions are set to keep rising in the short term even as it ramps up solar and wind capacity.

Analysts say this dual reality complicates India’s stance in climate negotiations: it is simultaneously a frontline sufferer of extreme heat and a contributor to the emissions that make such events more likely.

The Nature study is part of a growing field of “attribution science” — research that links climate change to specific weather disasters. Such evidence, experts argue, could eventually strengthen legal and financial claims against polluters, a development that may have implications for India. Vulnerable states like Bihar, Uttar Pradesh, and Rajasthan — which routinely endure life-threatening temperatures — could find leverage to demand climate finance and compensation at international forums.

But domestically, the findings also highlight India’s urgent need to adapt its cities, agriculture and energy systems. Heatwaves are now starting earlier in the year, lasting longer and affecting wider areas. Studies have shown that by 2050, without adaptation, India could lose the equivalent of 34 million full-time jobs due to productivity declines from heat stress.

The authors underline that human-caused climate change made a typical heatwave 20 times more likely in the 2000s, and nearly 200 times more likely in the 2010s. A quarter of the heatwaves analysed were deemed “virtually impossible” without climate change.

“Depending on the carbon major, their individual contribution is high enough to enable the occurrence of 16-53 heatwaves that would have been virtually impossible in a pre-industrial climate,” the researchers said.

For India, the warning is stark: even as the country pushes for green energy leadership, its heavy reliance on coal — coupled with rapid urbanisation and inadequate heat preparedness — leaves millions exposed to the kind of punishing extremes that scientists now link directly to the world’s biggest emitters.

With PTI inputs