Study projects El Niño may drive 450,000 excess deaths by February
A new analysis estimates that the ongoing El Niño could cause around 450,000 additional deaths worldwide by February due to higher temperatures. The projection, based on historical temperature-mortality relationships and seasonal forecasts, highlights that most deaths will occur in the southern hemisphere, with further impacts expected later in the north. Researchers urge proactive measures like checking on vulnerable people and providing cooling resources.
The projection stems from a 2022 study that mapped temperature-mortality curves across 24,000 global regions, using decades of historical data or extrapolations from similar areas. This U-shaped relationship—where deaths rise in both extreme cold and heat—varies locally based on infrastructure and adaptation, such as air conditioning access. Combining these curves with seasonal forecasts from the European Centre for Medium-Range Weather Forecasts yielded the estimate.
The forecast covers September to February, projecting 240,000 additional deaths, on top of roughly 210,000 already estimated since June. Geographically, the southern hemisphere bears the initial brunt—Nigeria could see over 30,000, Indonesia 19,000, Brazil 13,000—while a later northern wave may hit India and Pakistan. Demographically, the elderly are most sensitive, followed by infants under four.
This projection could place significant strain on public health systems, particularly in lower-income regions of Africa and South Asia where heat adaptation is limited. The concentration of deaths among the elderly and infants may overwhelm local healthcare capacity during peak seasons. Proactive measures, such as targeted outreach and cooling resources, could mitigate some impact, but the scale suggests substantial societal disruption and potential widening of health inequalities across affected populations.