Heat Deaths Hit a Record: Why Experts Want a Global Health Emergency

Heat deaths linked to climate change have reached a record high, and health harms are growing faster than the world's response, according to The Lancet's 2026 Countdown on Health and Climate Change. ScienceAlert reported that the report's authors are calling for climate change to be formally recognized as a global health emergency.

What did the Lancet Countdown find?

The report says risks tied to extreme heat and drought continue to rise faster than climate action, even as investment in moving away from fossil fuels has grown over the past decade. Marina Romanello, executive director of The Lancet Countdown, said the pace of many climate-related health threats is accelerating while the economic toll hits vulnerable sectors and communities hardest.

This is the 10th year of the Countdown, which brings together experts in public health, climate, energy, data and economics to track climate change's impact through 54 health indicators.

How many people are dying from heat?

In 2023, 71.5 percent of heat-related deaths worldwide could be attributed to climate change, according to the estimates. The total was 710,000 deaths; without climate change, the figure would be around 200,000.

Over the longer run, an estimated 540,800 deaths each year from 2016 to 2023 were linked to heat. Climate change was responsible for 68 percent of them, or 369,900 deaths a year. That is up from 55 percent a year in the previous decade, 2006-2015.

What does heat cost the economy?

In 2025, heat cost the global economy around $1.07 trillion in lost productivity just by interrupting people's ability to work, ScienceAlert reported. The biggest losses to gross domestic product were in Southeast Asia and Africa. Agriculture and construction were hit especially hard because they rely on people doing physically demanding work outdoors.

What about drought and floods?

The report also points to drought spreading while other areas flood. Drought can quickly lead to food shortages, malnutrition, poorer water and air quality and mental health problems, the authors say. Floods raise the risk of infectious, respiratory and digestive diseases. Both extremes strain health systems that are already stretched, according to the report.

The authors also noted that by 2040 the world's 100 largest oil and gas companies plan to produce 150 percent more fossil fuel than would be consistent with keeping global warming below 1.5°C.

What do the experts want to happen?

The researchers say the World Health Organization and the United Nations should declare climate change a global health emergency. They also call for governments to be coordinated so that human health sits at the center of climate decisions, and for more grant-based funding for climate and health programs. They urge governments to treat fast, fair reductions in greenhouse gas emissions as a global health priority.

Romanello said the numbers “point to a clear emergency.” She added that real progress has been made in clean energy, health system readiness and health-protective regulation, and that these are already benefiting local communities, but that progress has been too slow and too small and is not reaching the people who need it most.

What does this mean for ordinary people?

The report ties climate change to deaths during hot weather, lost working days and pressure on hospitals. According to the authors, the effects fall hardest on vulnerable communities and on workers in jobs done outdoors. They also say that health-centered climate action is already working: Anthony Costello, a Countdown co-chair and global health expert, said cleaner air, more resilient health care and warning systems are protecting health and saving lives around the world.

Costello added that the pace and scale of emissions cuts remain far out of step with the pace and scale of the harm. The call for an emergency declaration is a recommendation from the report's authors; it is not a decision by the WHO or the UN.

Around Prague, based on reporting by ScienceAlert