New tracker maps the human cost of El Niño’s extreme heat

Pakistan and other developing countries need better heat warnings and emergency plans as a new tracker projects 857,000 deaths worldwide from extreme heat linked to El Niño through March.

A new online tool developed by the Climate Impact Lab at the University of Chicago shows where extreme heat linked to El Niño could cause the most deaths. The El Niño Heat Mortality Tracker provides monthly estimates of heat-related deaths and forecasts up to six months ahead. It also tracks estimated deaths since the weather pattern began in June.

The tool can help governments, health officials and aid organisations identify areas at greatest risk and direct resources where they are needed most. For Pakistan, where extreme summer temperatures can put lives at risk, such information highlights the need for better heat warnings, public awareness and emergency health services.

The tracker builds on a report released by the Climate Impact Lab last month. The earlier report examined where extreme heat linked to El Niño could cause the greatest loss of life through February. The updated tracker extends the forecast through March and estimates that the total death toll could reach about 857,000 worldwide. Of these, around 373,000 deaths are projected over the six-month period from October to March.

Michael Greenstone, a co-founder of the Climate Impact Lab and a professor of economics at the University of Chicago, said the research helps identify where extreme heat is most likely to cause deaths.

He said forecasting the effects of extreme heat gives decision-makers an opportunity to identify the most vulnerable communities and take action before lives are lost.

The tracker shows that the greatest burden of heat-related deaths is expected to fall on countries in the Global South, including many developing nations.

Nigeria is projected to record the highest number of deaths over the next six months, with about 56,000 deaths expected. India follows closely, with around 55,000 projected deaths, most of them in March. Indonesia could see about 29,000 deaths, while Brazil is expected to record around 19,000 deaths during the same period.

These figures are forecasts, not confirmed deaths, and actual outcomes may differ.

The findings also highlight the need for countries such as Pakistan to prepare for extreme heat. High temperatures can place additional pressure on hospitals, threaten the health of outdoor workers and increase risks for people who have limited access to cooling facilities.

Early warnings, better access to healthcare, cooling centres and measures to protect people working outdoors can help reduce heat-related deaths. Governments can also use forecasts to prepare hospitals and emergency services before temperatures rise.

The Climate Impact Lab’s Adaptation Inventory collects research on measures that have been shown to reduce the harm caused by extreme heat. These include early warning systems, improved healthcare access, cooling centres and protections for outdoor workers.

Tamma Carleton, the Lab’s faculty head of research and an assistant professor at the University of California, Berkeley, said the new data showed where action was most urgently needed as communities faced the effects of El Niño.

She added that preparing for extreme heat was important alongside efforts to address other risks associated with the weather pattern, including threats to food supplies.

For Pakistan, the findings underline the importance of treating extreme heat as a public health concern. Better forecasting, timely public warnings and practical protection for vulnerable people can help authorities prepare for dangerous temperatures and reduce preventable deaths.

Source: Climate Impact Lab, University of Chicago.