El Niño could cause 451,000 more heat deaths compared to normal year, group says

An estimated 451,000 more people could die as a result of excessive heat in the first nine months of the current El Niño compared with a typical year, according to a report from the University of Chicago's Climate Impact Lab.

"That's on top of the impacts from droughts, wildfires and flooding expected from hotter temperatures and shifting rainfall patterns as this El Niño could become the strongest on record," the research hub said in a news release Wednesday.

Map shows which regions face highest risks

Countries across the Global South are forecast to see the greatest impacts, with Nigeria, Sudan, Niger and Chad expected to record more than 65,000 heat-related deaths combined. The Philippines, Vietnam, Thailand, Cambodia and Indonesia are expected to record close to 40,000 deaths collectively, while Brazil and India could also see high death tolls, according to researchers. 

The projected global toll "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," Michael Greenstone, a cofounder of the Climate Impact Lab, said in a statement.

El Niño is a climate pattern characterized, in part, by above-average ocean temperatures in a portion of the Pacific Ocean near the equator. It influences extreme weather events across the globe, in different ways and to varying degrees depending on the region. In some places, the onset of El Niño correlates with intense heat, drought and flooding, which can be even harsher when El Niño is particularly powerful, like it is this year.

Meteorologists have warned of the current El Niño's potentially historic consequences since it developed at the start of the summer. The World Meteorological Organization forecast earlier this month that this El Niño could become the strongest on record, with its most severe impacts still ahead. 

The U.N. agency predicted the "supersized" phenomenon won't reach its peak intensity until closer to the end of 2026. The U.S.-based Climate Prediction Center expects El Niño will likely remain in place through the Northern Hemisphere's winter season, and possibly last into spring.

Greenstone said the Climate Impact Lab's report "allows decisionmakers to see exactly where emergency actions can be taken to save tens of thousands of lives in the coming months." It can also help humanitarian organizations decide how to allocate emergency funds and other resources. It emphasized that "heat warnings, health outreach to vulnerable populations, cooling centers and hydration stations, worker protections, and expanded health system capacity can all help people cope with extreme heat."