A new analysis from the Climate Impact Lab warns that the current, record-breaking El Niño weather pattern could lead to 451,000 additional deaths globally between June 2026 and February 2027. The report, released Wednesday by the University of Chicago-based team of scientists and economists, suggests that the combination of natural climate variability and human-induced global warming is creating a lethal environment. These projected fatalities are in addition to typical annual heat-related mortality rates and do not account for deaths caused by other El Niño-driven disasters such as floods, fires, or droughts.
Researchers estimate that El Niño will drive global land temperatures 1.2 degrees Celsius above average, resulting in a 44% increase in extreme heat days compared to a standard year. The study, which utilizes peer-reviewed methodologies, warns that these conditions serve as a preview of the climate expected in two decades. While the report has not yet undergone formal peer review, authors stated they released the findings early to allow policymakers time to implement life-saving interventions.
Michael Greenstone, a co-founder of the Climate Impact Lab and professor at the University of Chicago, emphasized the human cost behind the data. "We have long been able to predict the impacts of temperatures on crops, and now we can predict their impact on the worst outcome — death," Greenstone said. "This 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."
The Global South is expected to bear the brunt of the crisis, with Nigeria projected to face the highest toll at 31,400 deaths. Other nations at significant risk include India, Indonesia, Sudan, and Brazil. The United States is also included in the top 20, with an estimated 3,500 deaths. Raquel Nunes, an associate professor at the University of Warwick who was not involved in the study, noted that while the figure is a plausible modeling exercise, it should be viewed as a call for urgent preparedness rather than a definitive prediction.
To mitigate the impact, the report recommends that governments implement early heat warning systems, establish cooling and hydration centers, and bolster healthcare capacity. Tamma Carleton, a co-author and assistant professor at the University of California, Berkeley, stressed the importance of immediate action. "Increasing emergency response and better targeting our efforts can save many lives this year," Carleton said. "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."
