El Niño Could Cause Up to 451,000 Additional Heat-Related Deaths, Researchers Say

The current El Niño could contribute to as many as 451,000 additional heat-related deaths worldwide between June 2026 and February 2027, according to a report released by researchers at the University of Chicago’s Climate Impact Lab, Sibi Arasu reported for The Associated Press (AP).

Researchers estimate that the current El Niño could substantially increase extreme-heat exposure and heat-related mortality worldwide through February 2027.

The estimate represents deaths above the number expected during a typical year and is a model projection, not a count of confirmed deaths.

The Climate Impact Lab said the number of extremely hot days could increase by 44% compared with normal years.

The researchers compared temperature and mortality relationships across more than 24,000 regions worldwide and used seasonal temperature forecasts to estimate the potential mortality impact.

The report has not yet undergone peer review, although its methodology draws on previously peer-reviewed research.

The greatest projected impacts are expected in poorer and hotter regions, where populations generally have fewer resources to adapt to extreme temperatures. The Climate Impact Lab projected particularly large impacts in parts of Africa and Asia.

Michael Greenstone, a co-founder of the Climate Impact Lab and a co-author of the report, said the danger from extreme heat could continue beyond February as the effects of the El Niño event persist.

The researchers emphasized that the projections are intended to help governments target measures such as early heat warnings, cooling centers, access to water and expanded health-system capacity.

The estimated death toll could change as weather conditions develop and the researchers update their forecasts.