A group of scientists, economists and data engineers based at the University of Chicago, known as the Climate Impact Lab, has released a new study finding that roughly half a million lives could be lost due to excessive heat tied to El Niño by February 2027. ABC13 Houston’s report brings together peer-reviewed approaches measuring how temperature affects death rates across thousands of locations with seasonal weather predictions.
The El Niño Context
A natural climate pattern known as El Niño raises global temperatures. This year’s instance has entered “super-sized” territory and is on track to set a record for strength. When paired with the continued warming caused by human activity, the heat effects could prove significant.
Though heat is the deadliest form of extreme weather, tracking of heat deaths remains poor even in wealthy nations. The report puts the estimated count of lives lost from El Niño heat at 451,000, running from June 2026, when it arrived, through February 2027. That figure rests above the ordinary toll of heat-related deaths.
Why the Number Could Rise
Scientists project the tally to rise. The weather pattern known as El Niño is expected to persist through the spring season in the Northern Hemisphere, which means its warm effects will carry over into the summer months ahead. Heat-related fatalities would join the deaths anticipated from other El Niño-linked disasters, such as fires, floods and droughts.
Though the report has yet to pass outside review, its conclusions were reached through peer-reviewed methods.
The Scale of the Projection
Experts estimate that El Niño will push up global land temperatures by 1.2 degrees Celsius (2.1 Fahrenheit) over the next few months. This extra warmth matches what climate models show for 20 years down the road. The study finds it will also bring about 44% more days of extreme heat than a typical year would deliver.
Before the world has adjusted, the authors say the present El Niño is a “postcard from our future” that has already arrived.
Where the Deaths Are Expected
The nations hardest hit lie largely within the developing world. Nigeria sits atop the projection, expected to lose 31,400 lives. Indonesia, Sudan, India and Brazil all rank among those at high risk. The United States shows up among the top 20 affected countries, with a projected 3,500 deaths.
The study drew on peer-reviewed methods examining how temperature affects mortality across over 24,000 regions around the world, matching death counts against the same months from an ordinary year spanning 1996 through 2025.
What Experts Say
Raquel Nunes, associate professor in health and environment at the University of Warwick in England, who was not involved in the report, said the estimate “is plausible as a modeling exercise, but it should not be viewed as a definitive prediction.”
“Its value lies in highlighting the potentially severe consequences of El Niño-driven extreme heat and the urgent need for preparedness.”
Why the Report Was Published Early
The study is still awaiting peer-review, but the scientists released the shorter report first because of El Niño’s rapid strengthening. “Given that there is still time now for policymakers and others to take action to prevent these deaths, we felt our findings couldn’t wait for the peer review process to play out,” said a Climate Impact Lab spokesperson.
What Countries Can Do
The report lists several steps governments can take:
- Early heat warnings
- Health action plans
- Ensuring cooling and hydration centers are available
- Expanding healthcare coverage
Tamma Carleton, who serves as the faculty head of research for the Climate Impact Lab and an assistant professor at the University of California, Berkeley, was the report’s co-author. She said that “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.”
The Bottom Line
The Climate Impact Lab has published a peer-reviewed forecast with regional data and a defined timeline. The researchers decided to release their work before it had completed its full review process in order to encourage urgent action.
The figure is so large it can numb a person. Yet it is composed of parents and children, grandparents and neighbors, individuals going to work, caring for families, and simply living their lives.
Source material: “Super-sized El Niño could cause more than 450,000 heat deaths by February, study suggests,” ABC13 Houston.
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