New Delhi: More than 450,000 people are projected to die from the additional heat brought by the super El Niño over the next six months, according to estimates by climate scientists.
The projected toll comes on top of early deaths linked to temperatures already driven higher by the climate crisis. The impact is expected across the world, from Indonesia and India to Nigeria and the US. Further deaths are also expected from the droughts, wildfires and flooding associated with El Niños.
The heat deaths have been estimated at regional level, with researchers saying the projections could help identify where measures to protect people can be put in place and save lives. These measures could include better heat forecasts, cooling centres where people can shelter, increased staffing for medical facilities during the hottest periods and protections for outdoor workers.
The El Niño currently heating up the planet burst through the highest temperature ever recorded for the phenomenon on Monday, several months before its expected peak. The heat is so much greater than previous events that scientists have called it “mind-blowing” and “Godzilla-level”. El Niños are natural climate events but may be made worse by global heating.
“The estimate of 451,000 people is such a large number that it can be numbing, but it is made up of parents and children, grandparents and neighbours, people going to work, caring for families, and living their lives,” said Prof Michael Greenstone, co-founder of the Climate Impact Lab and at the University of Chicago, who co-authored the report.
The estimate covers the period from September to February 2027, when current temperature forecasts end. However, elevated levels of heat deaths are expected to continue until June or July 2027.
The most affected countries over the next six months are expected to be the tropical nations of Nigeria, Indonesia, Sudan, India and Brazil. The US is among the 20 most affected nations, with 3,500 projected additional heat deaths. More broadly, the Sahel region in Africa and south-east Asia are expected to be heavily affected.
Researchers described the El Niño as a “postcard from our future”, as it pushes temperatures to levels the climate crisis is projected to deliver in 20 years’ time.
“Increasing emergency response and better targeting our efforts can save many lives this year,” said report co-author Dr Tamma Carleton at the University of California, Berkeley. “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.. We need to mobilise now to design, deploy and evaluate the tools that will save lives in the years ahead.”
The projections were made using peer-reviewed methods that track the month-by-month relationship between temperature and additional heat deaths across 24,378 regions worldwide. Researchers combined this data with forecasts for higher temperatures caused by El Niño in the coming months. The baseline used was the number of heat deaths recorded in the average month from 1996 to 2025.
“People have been able to forecast when there’s going to be shocks to crops, and give advance warning of that,” said Greenstone. “This new report is opening the door to being able to do it for an even more important outcome – I would say the most important outcome – which is death.”
The report will be submitted to a peer-reviewed journal, but Greenstone said that, given the urgency of the situation, “it would have been irresponsible to sit on it”.
Food supplies are also expected to be affected by El Niño, with the World Food Programme warning in August that its impacts were likely to push about 50 million people into acute hunger and drive prices up.
A major El Niño in 1877-1878 led to more than 50m deaths due to drought and famine, with India, Brazil and China severely affected.
Prof Friederike Otto, at Imperial College London, told the Guardian on Monday: “The [current El Niño] event is a huge redistribution of energy in the climate system and is dangerous, because it is unfolding on top of a much warmer, human-influenced climate system.
“So, in many places around the world we will see never-before-experienced heat extremes, with all their consequences on health, food security and water stress. El Niño comes and goes, but as long as we continue to burn fossil fuels, it occurs on an increasingly hotter baseline, making it much more difficult for communities to deal with the consequences.”
