Super El Niño Could Cause Over 450,000 Heat-Related Deaths, Scientists Warn

The current Super El Niño event could result in an estimated 451,000 excess heat-related deaths by February 2027, according to a new forecast by the Climate Impact Lab. The study, compiled by scientists from the University of Chicago, projects that this El Niño will cause 44% more extremely hot days than a typical year.

Sea surface temperatures have already reached 3.07°C (5.5°F) above average, matching the record set by the 2015-2016 El Niño, with projections suggesting it could become the hottest event in 1,000 years. Of the more than 400,000 projected excess deaths from June through February, researchers anticipate 239,000 will occur in the next six months.

The study's authors noted that if El Niño persists until spring, residual impacts like prolonged high temperatures could extend heat-related deaths into the following summer. The majority of the predicted casualties are expected in the "Global South." Nigeria is projected to have the highest death toll, with 31,000 additional heat-related deaths between September and February compared to a normal year. Indonesia and Sudan are expected to see 19,300 and 17,600 excess deaths, respectively. The Sahel region in Africa, which includes Niger, Chad, Nigeria, and Sudan, could experience 66,800 heat-induced deaths in the next six months.

Southeast Asian nations, including the Philippines, Vietnam, Thailand, and Cambodia, are projected to collectively suffer an additional 19,400 deaths. To estimate the potential death toll, the research team analyzed temperature forecasts and historical data correlating heat with mortality across more than 24,000 global regions. The "mortality forecasts" were calculated relative to average years between 1996 and 2025.

Scientists warn that these anomalous temperatures could become the new normal within decades if adaptation measures are not implemented. While many regions have existing preventative measures such as early warning systems and access to cooling technologies, the researchers emphasize the need for greater investment in preparedness and a more granular understanding of effective life-saving strategies across diverse climates and health systems.

The El Niño phenomenon is already being linked to various global events, including wildfires in Indonesia, delayed monsoon rains in India, and severe droughts in Central America. These droughts have led to crop and livestock losses and reduced water flow in the Panama Canal, impacting trade.