A University of Chicago-based research team warns that a record-breaking super El Niño could trigger nearly half a million excess heat deaths globally by February 2027. Developing nations, particularly in Africa and Asia, face the highest risks from temperatures that mirror conditions projected for decades into the future.
The powerful El Niño event driving global temperatures to unprecedented highs could result in up to 451,000 additional heat-related fatalities between its arrival in June and the end of February 2027, according to a report published by the Climate Impact Lab. Researchers combined seasonal temperature forecasts with localised mortality data across more than 24,000 regions worldwide to project the death toll, comparing expected outcomes against a 1996 to 2025 baseline.
By analyzing the link between excess mortality and temperature across 24,378 regions while considering local vulnerability and climate, the study’s authors reached their projections. To estimate the excess deaths potentially caused by El Nino heat relative to the 1996-2025 average, they integrated these results with temperature forecasts. Their methodology will be published in a peer-reviewed journal.
The study’s authors describe the current weather pattern as a postcard from the future, bringing global land temperatures that could run about 1.2 degrees Celsius higher than normal. That spike is expected to generate 44 percent more extremely hot days than a typical year, pushing planetary warmth toward levels climate change would otherwise take another twenty years to reach.
Professor James Renwick, a climate scientist at Victoria University who was involved with the Intergovernmental Panel on Climate Change for two decades, informed Morning Report that a tenth of a degree is significant when discussing global temperatures.
The estimates for next year are for a global average about 1.7C above pre-industrial, which is about 0.2C warmer than present. So… it's like average temperatures will be in about 20 years' time, given the rates of warming we've got at the moment, Professor James Renwick said
Global Hotspots and the Heavy Toll on the Global South
Developing nations with fewer resources to manage extreme weather will bear the brunt of the crisis. Michael Greenstone, a co-founder of the group and the study’s co-author, noted that heat is most dangerous in places that are already hot and relatively poor, where populations lack widespread air conditioning and reliable water infrastructure.
Michael Greenstone stated, adding that the highest number of casualties is anticipated in impoverished nations already grappling with high energy costs and food insecurity, caused in part by the effects of the war in Iran and climate change.
The report found that the Sahel region of Africa—consisting of semi-arid countries on the southern edge of the Sahara Desert—is likely to be the hardest hit, with approximately 66,800 extra deaths attributed to the heat.
Renwick informed New Zealand media that, as is common with climate change, the nations suffering the most severe consequences are often those with the fewest resources and those that likely contributed the least to the issue.
Mitigation Strategies and Anticipatory Financing
While the projections paint a stark picture, the report emphasizes that heat warnings and cooling centres could prevent thousands of deaths if governments act before temperatures peak. Recommended interventions include expanding hospital capacity, setting up hydration stations, protecting outdoor workers, and conducting targeted outreach to vulnerable elderly populations.
Lingering Risks and Regional Weather Disruption
Although this El Niño is expected to end by then, Michael Greenstone said the heat danger will likely persist beyond February. The fallout of the weather phenomenon could be felt well into next summer, he added.
According to a research report released Wednesday, the record global heat driven by this year’s potent El Niño, combined with shrinking water supplies, wildfires and severe droughts, could result in nearly 500,000 additional deaths worldwide by the close of February.
Meanwhile, scientific teams emphasize that the projections serve as an urgent warning of the conditions communities worldwide will face routinely within decades if greenhouse gas emissions continue unabated.