Researchers Project 451,000 Heat Deaths From El Niño by February; UNICEF Says 347 Million Children at Risk

Since NOAA and the WMO detailed a strengthening El Niño earlier this month, the focus has shifted from temperature charts to body counts, hunger and coastlines. The projections are estimates, not tallies. They are large.

The projected death toll

More than 450,000 additional people are projected to die from heat linked to the El Niño by February, according to a report from the Climate Impact Lab. The estimate covers June 2026 through February 2027. Elevated heat deaths are expected to continue until June or July 2027.

The projections use peer-reviewed methods that track the month-by-month relationship between temperature and extra deaths across 24,378 regions worldwide. The hardest-hit countries over the next six months are projected to be Nigeria, Indonesia, Sudan, India and Brazil. The United States ranks in the top 20, with 3,500 projected additional heat deaths.

The figure excludes deaths from droughts, wildfires and flooding, which the report's authors say El Niños also bring.

"The estimate of 451,000 people is such a large number that it can be numbing," said Prof. Michael Greenstone of the University of Chicago, a co-founder of the Climate Impact Lab and a co-author. Co-author Tamma Carleton of the University of California, Berkeley said better targeting and emergency response "can save many lives this year." The authors point to practical steps: better heat forecasts, cooling centres, extra medical staffing at peak heat and protections for outdoor workers.

Children, drought and flood

UNICEF says more than 347 million children in nearly 100 countries and territories are expected to see unusually wet or dry conditions between October and December. "For children, El Niño is far more than a weather pattern," UNICEF Executive Director Catherine Russell said. She cited displacement, malnutrition, water shortages, disease outbreaks and school closures.

UNICEF adds that 1.1 billion children, nearly half the world's total, already face at least three overlapping climate hazards such as drought, extreme heat or floods.

Papua New Guinea shows what that looks like on the ground. Its government declared the event in June, set up a task force and approved a $112 million supplementary budget. About 1.2 million people are estimated to need direct food relief. Water shortages, crop losses, dwindling food reserves and higher prices are already reported.

In the Greater Horn of Africa, wetter-than-normal conditions could raise the risk of river and flash flooding and waterborne disease. UNICEF warns children in conflict zones such as Yemen, Sudan and Afghanistan face acute risks because El Niño can magnify existing hunger.

How strong is it

The Niño 3.4 index, a measure of tropical Pacific sea surface temperatures, surpassed every previous El Niño in September, including 1997 and 2015, according to UNICEF's account. Wired reports NOAA's forecast calls for a three-month average anomaly of 2.7°C above normal for October to December. The previous record for that measure is 2.4°C, set in 1982-83. The same report says daily readings have already hit 3.4°C.

Harvard's Peter Huybers describes it as "an anomalous El Niño riding on top of a high temperature trend." Forecasters expect global temperatures and weather extremes to hit new highs, especially in 2027.

Does climate change make El Niño stronger?

The scientists do not agree on how much. Francisco Estrada of the National Autonomous University of Mexico says the magnitude and frequency of El Niño have increased over the past 60 years. "You can't separate El Niño from global warming. They're inextricably linked," he said.

Christopher Callahan of Indiana University is more cautious. "I have more questions than I have reactions," he said. He notes that many models struggle to represent long-term temperature trends accurately, and the relationship remains an active research area. Harvard's Daniel Schrag, for his part, calls El Niño "an internal mode of variability shaped by the geometry of the Pacific Ocean." He says he has found signs of the cycle in fossil corals going back at least 120,000 years.

The Climate Impact Lab authors call this El Niño a "postcard from our future," pushing temperatures to levels the climate crisis is projected to deliver in about 20 years.

Higher seas on the West Coast

The effects are also reaching American shorelines. Sea levels along the West Coast are set to rise by 6 inches to a foot this month as Kelvin waves, pulses of warm water, move north from California toward Oregon and Washington at about 150 miles a day. The waves are expected to keep passing through from October to February.

NOAA Fisheries oceanographer Michael Jacox said the wave will not flood anything by itself. It raises the baseline. A high tide or storm surge arrives on top of water that is already 6 inches higher, so "the effects can be amplified."

The waves also warm the ocean and push cold, nutrient-rich water deeper, which affects marine life.

In Papua New Guinea, the largest agricultural and food security impacts are expected to begin in November, within the forecast October to December peak. That is the first real test of whether the response funding matches the need.