Current El Nino could cause 451,000 heat-related deaths, study finds

This year's El Nino could cause an estimated 451,000 additional deaths from extreme heat worldwide in the first half of the climate pattern, according to a University of Chicago report released Wednesday.

The mortality projections cover the period from June 2026, when the current El Nino began, through February 2027.

The Climate Impact Lab estimates the number of extremely hot days could rise by 44% compared with normal years, with the heaviest toll expected in countries with fewer resources to adapt.

The Sahel region is projected to record 66,800 additional heat deaths from September through February. Southeast Asia could see nearly 39,000 additional deaths, while India and Brazil are projected to record 15,800 and 13,300, respectively.

“This is such a large number that it can be numbing, but it is made up of parents and children, grandparents and neighbors, people going to work, caring for families, and living their lives,” says Michael Greenstone, a co-founder of the Climate Impact Lab

Researchers said tens of thousands of deaths could be prevented through targeted emergency response and resilience measures, including early-warning systems, cooling centers and protections for outdoor workers.

They said reducing deaths from extreme temperatures should be central to preparations for El Nino, alongside efforts to address food security risks.

The report described the current El Nino as a “postcard from our future,” saying it is bringing temperatures similar to what could become normal in about 20 years without greater adaptation.

“Increasing emergency response and better targeting our efforts can save many lives this year. But 20 years from now, once today's extreme temperatures become the new normal, we don't want to be in a constant state of emergency,” said Tamma Carleton, the Climate Impact Lab's faculty head of research, urging preparation and resources to prepare for the future.

Researchers said they will update the death projections as El Nino develops.

The World Meteorological Organization has also warned that the current El Nino could become the strongest on record.​​​​​​​