More than 451,000 additional deaths are projected globally over the next six months due to the intensified heat brought on by the current super El Niño event, according to climate scientists. This forecast accounts only for excess fatalities linked directly to elevated temperatures and does not include further deaths expected from El Niño-induced droughts, wildfires, and flooding.
The forecast covers the period from September through February, coinciding with the end of current temperature projections, though elevated heat-related mortality is anticipated to continue until mid-2024. The countries expected to be most affected include Nigeria, Indonesia, Sudan, India, and Brazil. The United States also ranks among the top 20 nations, with an estimated 3,500 additional heat-related deaths during this timeframe. Other regions vulnerable to severe impacts include Africa’s Sahel belt and Southeast Asia.
El Niño is a naturally occurring climate phenomenon characterized by periodic warming of surface waters in the central and eastern tropical Pacific Ocean. However, researchers emphasize that the intensity of the present event, which recently surpassed the highest temperature ever recorded for El Niño, is amplified by the ongoing human-driven climate crisis. Scientists have described the heat escalation as unprecedented, with some labeling it "mind-blowing" and "Godzilla-level."
The projections were generated by combining peer-reviewed statistical methods that analyze historical relationships between monthly temperature variations and heat-related mortality across more than 24,000 global regions with updated El Niño temperature forecasts. The baseline comparison period spans from 1996 through 2025. This method allows identification of regions most at risk and provides guidance on where preventive measures could save lives.
Potential interventions discussed by researchers include improved heat forecasting systems, the establishment of cooling centers, increased staffing for healthcare facilities during heatwaves, and protections for outdoor workers. Experts stress that timely action can substantially reduce heat-related fatalities in the current crisis.
“This estimate of 451,000 deaths represents a sobering figure made up of individual lives—parents, children, grandparents, neighbors—simply living their daily lives,” said Professor Michael Greenstone, co-founder of the Climate Impact Lab at the University of Chicago and co-author of the report. He noted the urgency of disseminating these findings ahead of formal peer review due to the pressing nature of the situation.
Dr. Tamma Carleton of the University of California, Berkeley, described the event as a "postcard from our future," reflecting temperature extremes expected globally two decades from now if greenhouse gas emissions continue unchecked. She emphasized the importance of mobilizing resources to develop and implement tools that can mitigate heat-related harms as these conditions become more common.
In addition to health impacts, the current El Niño is anticipated to disrupt global food supplies, with the United Nations’ World Food Programme warning that the event may push approximately 50 million people into acute hunger and trigger widespread increases in food prices. Historical precedence underscores the severity of such events: the major El Niño of 1877-1878 led to tens of millions of deaths globally, largely due to drought and famine.
Experts caution that while El Niño cycles naturally, climate change is intensifying their effects by raising baseline temperatures. Friederike Otto at Imperial College London noted that this “redistribution of energy” on top of a warmed planet will produce unprecedented heat extremes with significant consequences for health, food security, and water availability worldwide.
The findings highlight the growing challenges posed by a warming climate and underscore the need for proactive adaptation and mitigation strategies to protect vulnerable populations as extreme heat events become more frequent and severe.