The greatest threat in tropical countries
According to the forecast of scientists from the Climate Impact Lab and the University of Chicago, from September 2026 to February 2027, additional heat related to the El Nino phenomenon may lead to approximately 451,000 deaths. premature deaths worldwide.
Scientists combined data showing how high temperatures have affected deaths in the past with temperature forecasts for the coming months. The analysis covered 24,378 regions around the world. The average number of heat-related deaths in the years 1996–2025 was used as the reference point.
The effects of El Nino will not be the same in all parts of the world. The most vulnerable countries are Africa and Southeast Asia.
The countries with the highest projected excess heat-related deaths include Nigeria, Indonesia, Sudan, India and Brazil. In Nigeria, the number may reach approximately 31,400. such deaths, in Indonesia - about 19.3 thousand, and in Brazil - about 13.3 thousand.
The United States is also among the 20 countries most exposed to the effects of heat. Scientists estimate that in this country there may be approximately 3.5 thousand. additional heat-related deaths.
A major threat also concerns the African Sahel and parts of Southeast Asia. The analysis shows that in the Sahel itself, including, among others, Nigeria, Sudan, Niger and Chad, the number of additional deaths will reach approximately 66.8 thousand.
El Nino is not only about heat
El Nino affects more than just temperature. The phenomenon may also change the distribution of rainfall, leading to droughts, floods and fires in various parts of the world. It may also cause losses in agriculture and problems with access to water.
This means that the real effects of El Nino may be more serious than the sheer number of deaths associated with the additional heat. However, the authors of the analysis do not provide a single number covering all possible consequences of the phenomenon.
El Nino can also affect food availability and prices. The World Food Program warned that the effects of this phenomenon could lead to acute hunger for approximately 50 million people and contribute to an increase in food prices.
El Nino is breaking records
The current El Nino already stands out from previous cases of this phenomenon. On Monday, the temperature difference in the tropical Pacific reached a record 3.05 degrees Celsius. This is more than during the previous record El Nino in 2015. According to forecasts, the phenomenon may further intensify before the expected peak at the end of 2026.
El Nino is a natural climatic phenomenon that occurs every few years. This time, however, its effects overlap with global warming. This means that the phenomenon occurs in a world that is already much warmer than several decades ago.
El Nino causes huge changes in the distribution of energy in the atmosphere and oceans. It is particularly dangerous because it occurs today in a much warmer climate that has been changed by human activity, Prof. told the Guardian. Friederike Otto from Imperial College London. As she emphasized, in many places it may mean unprecedented extreme temperatures and related health problems, water shortages and a threat to food security.
"Postcard from the Future"
The report's authors describe the current El Nino as a "postcard from the future." The idea is that the temperatures experienced during this exceptionally strong event may resemble conditions that the world is expected to experience more often in about 20 years as the climate continues to warm.
If we prepare better for heat waves and react faster, we can save many lives this year, argues Dr. Tamma Carleton from the University of California at Berkeley, co-author of the analysis.
Scientists also indicate what can be done to reduce the number of deaths during heatwaves. They mention, among others: earlier warning of high temperatures, opening places where you can cool down, increasing the number of medical staff during the greatest heatwaves and better protection of people working outdoors.
Michael Greenstone, co-founder of the Climate Impact Lab and professor at the University of Chicago, emphasizes that behind the number 451,000 specific people are hiding.
451 thousand people is a number so large that it is difficult to imagine. However, behind each of these people there is someone's family, loved ones and neighbors. These are people who go to work, take care of their families and just live their lives, Greenstone said.
Scientists emphasize that forecasting which regions may suffer the most from heatwaves allows us to better prepare for the threat. Thanks to this, the authorities can strengthen emergency services, medical facilities and places where residents can take shelter from high temperatures in advance.
The forecast covers the period until February 2027, because that is the date of temperature forecasts used by scientists. According to the authors of the analysis, the increased number of heat-related deaths may persist even until June or July next year.
