As record heat interrupts work, overloads hospitals, and claims thousands of lives, international experts are calling for climate change to be officially recognized as a global health emergency. The call comes in The Lancet’s 2026 Countdown on Health and Climate Change, which shows risks and harms from extreme heat and droughts continue to rise faster than climate action, despite growing investment in the transition away from fossil fuels.
“The rate of increase in many climate-related health threats is accelerating, while heat deaths linked to climate change have reached a record-high, and the economic toll is battering vulnerable sectors and communities the hardest,” says climate health researcher Marina Romanello, executive director of The Lancet Countdown.
It has been 10 years since the first Countdown report was published, bringing together experts in public health, climate, energy, data, and economics to track impacts on 54 different health indicators.
Health Harms Are Growing Faster Than the Response
The authors of the latest report are seriously concerned about how slow the international community has been to protect human health.
“A decade after the Paris Agreement, our findings are unambiguous: the health harms of climate change are growing faster than the world’s response to them, and in many cases even accelerating,” Romanello says.
“Real progress has been made in clean energy, health system readiness, and health-protective regulation, all of which are already delivering health benefits to local communities. However, progress has been too slow, too small, and isn’t reaching those who need it most. That is why we are calling for climate change to be formally recognized as a global health emergency, with health placed at the center of every climate decision.”
Heat Deaths Reach Record High
In 2023, 71.5 percent of heat-related deaths worldwide can be attributed to climate change. The total was 710,000 deaths. If it were not for climate change, that number would be around 200,000, according to estimates.
Between 2016 and 2023, an estimated 540,800 deaths each year were linked to heat. Climate change was responsible for 68 percent of them (369,900), a big jump from 55 percent of heat-linked deaths per year in the previous decade, 2006-2015. In 2025, heat cost global economic productivity around US$1.07 trillion just by interrupting people’s ability to work, with the greatest losses seen in GDP of countries in Southeast Asia and Africa.
Globally, agriculture and construction were hit hardest, because they depend on people doing physically demanding work outdoors. The human body has its limits, and increasingly, outdoor conditions are becoming unbearable, if not lethal.
“These numbers point to a clear emergency,” says Romanello.
Drought, Floods, and Compounding Risks
“The risks become even more profound when you consider how different hazards interact and compound. At the same time, drought is spreading, and the world is swinging to water extremes, some drying out, while others are flooding,” Romanello adds. Drought can quickly lead to food shortages, malnutrition, poor water and air quality, and mental health issues. Floods increase risk of infectious, respiratory, and digestive diseases. Both extremes put already-stretched health systems under strain. Meanwhile, by 2040 the world’s 100 largest oil and gas companies are planning to exceed fossil fuel production by 150 percent of what would be needed to keep global warming below 1.5°C.
A Plan to Address the Crisis
The researchers lay out a clear plan. They say the World Health Organization (WHO) and United Nations must declare climate change a global health emergency, coordinate governments to put human health at the center of climate decisions, and increase grant-based funding for climate and health initiatives. They also call on global governments to “prioritize and promote the urgent, just, and equitable reduction of greenhouse gas emissions as a global health imperative.”
“Ten years ago, we proposed that responding to climate change could offer the greatest health opportunity of the 21st century through adaptation efforts and rapid progress in phasing down fossil fuels. A decade on, we have proof that health-centered climate action works: cleaner air, more resilient healthcare and warning systems are protecting health and saving lives globally. But the pace and scale of emissions reduction remains entirely out of step with the pace and scale of the harm,” says global health expert and Lancet Countdown co-chair Anthony Costello.
Q&A
Q: Why is Lancet calling climate change a health emergency?
A: Because heat deaths, work loss, and drought and flood-related diseases are accelerating faster than climate action. In 2023, climate change was linked to 710,000 heat deaths, with economic losses of $1.07 trillion in 2025.
Q: How many heat deaths are linked to climate change?
A: In 2023, 71.5% of all heat deaths (510,000 of 710,000) were attributable to climate change. From 2016-2023, climate change caused 68% of heat-linked deaths annually, up from 55% in 2006-2015.
Q: Who is most affected?
A: Workers in agriculture and construction doing physical labor outdoors, and communities in Southeast Asia and Africa with the greatest GDP losses, plus vulnerable groups facing food, water, and health system strain.
Q: What does the report want WHO and governments to do?
A: Formally declare climate change a global health emergency, put health at the center of every climate decision, increase grant-based funding, and urgently and equitably cut greenhouse gas emissions.
FAQ
1. What is the Lancet Countdown?
A 10-year initiative tracking 54 health indicators related to climate change, involving experts in public health, climate, energy, data, and economics.
2. What were the key numbers in the 2026 report?
710,000 heat deaths in 2023 (71.5% due to climate change), 540,800 heat-linked deaths per year from 2016-2023, and $1.07 trillion in work productivity lost to heat in 2025.
3. Why is economic productivity affected?
Extreme heat prevents people from working safely outdoors, especially in agriculture and construction, reducing hours and output.
4. What about fossil fuel plans?
The report notes that by 2040, the 100 largest oil and gas companies plan to produce 150% more than the level compatible with keeping warming below 1.5°C.
5. Where can I read the report?
The Lancet Countdown on Health and Climate Change 2026, led by executive director Marina Romanello and co-chair Anthony Costello.
Disclaimer: This article is for informational purposes only and summarizes The Lancet Countdown 2026 report. It does not constitute medical or policy advice. Heat-related health risks vary by location and individual health. Follow local health guidance during extreme heat and consult healthcare professionals for heat-related illness.
