Explained: What the Lancet Countdown 2026 report says about heat and health in India

What is the report? The Lancet Countdown on Health and Climate Change released its 2026 report on Wednesday (28 October). Led by University College London (UCL) and developed in collaboration with the World Health Organization (WHO), it tracks 54 indicators linking climate change and health. It draws on the work of 146 researchers from more than 100 institutions in over 30 countries.

How much of India’s heat is down to climate change? People in India experienced an average of 10.6 heatwave days a year during 2016–2025, The Indian Express reported from the report. Of these, 5.3 days, or half, were directly attributable to climate change.

How does heat affect daily life? People in India were exposed to more than 2,600 hours a year when heat posed a moderate or higher risk of heat stress during moderate outdoor activity, such as brisk walking. That is over 200 hours more than the annual average in the 1990s. Hot nights also cost sleep: an estimated 64 hours a year were lost during 2021–2025, about three hours more a year than during 1986–2005.

What about work and money? Heat exposure caused an average loss of 193 billion potential labour hours a year in India during 2016–2025, 75% higher than the 1990s average. The report does not give a standalone estimate of heat-related deaths in India. But it puts the monetised value of heat-related deaths among people over 65 at an average of US$33.8 billion a year during 2021–2025, up 205% from 2000–2004.

Who is most exposed? India ranked among the top countries for heatwave exposure for both infants and older adults, along with China, the US and Russia, The Hindu reported, citing PTI.

And the rest of the world? Annual average heat-related deaths rose by nearly 36% in the years after the Paris Agreement compared with the decade before, according to WHO. In 2023 alone, heat was linked to a record 710,000 deaths globally, more than 70% of them attributable to human-caused climate change.

What do the authors want? “A decade after the Paris Agreement, our findings are unambiguous: the health harms of climate change are growing faster than the world’s response to them, and in many cases even accelerating,” said Marina Romanello, executive director of the Lancet Countdown at UCL. Progress, she said, “has been too slow, too small, and isn’t reaching those who need it most. That is why we are calling for climate change to be formally recognised as a global health emergency, with health placed at the centre of every climate decision.”