The lack of action on climate change claims millions of lives every year and puts health care systems under strain. “The climate crisis has become a health crisis,” states the latest Lancet Countdown report, published today in collaboration with the World Health Organization (WHO).
The Lancet researchers have found that 12 of 20 key indicators tracking health threats have reached record levels, showing how climate inaction is costing lives, straining health systems, and undermining economies. WHO and other partners are urgently calling for public health to be recognized as a driver for action on climate change.
‘Unprecedented impact’
According to the report, some governments still spend more on subsidizing fossil fuel companies than on their health care systems. The report highlights 2.5 million deaths caused by factors including air pollution, heat, drought, and wildfires. Droughts and heatwaves also led to food insecurity for 124 million people in 2023. Climate change is currently having an ‘unprecedented impact’ on public health, according to a press release.
“Cleaner air, healthier food, and resilient health care systems can save millions of lives and protect current and future generations,” concludes the report. “Measures such as phasing out fossil fuels, using renewable and green energy, making agriculture more sustainable, and combating deforestation could save tens of millions of lives every year.”
Regional differences
There are, however, significant regional differences. In wealthy countries like the Netherlands, the number of deaths attributable to factors such as traffic, cooking with gas, and agricultural activities has been declining for years.
But in emerging countries like India, that number is actually rising because much of our production has moved there. “We’ve essentially exported our pollution problems,” says Professor of Air Quality Maarten Krol (Wageningen University) in the Dutch Volkskrant.
Tropical diseases
The heat and other weather extremes have economic consequences, and the report also warns of an increase in tropical diseases. Shorter, milder winters and longer summers are giving mosquitoes that transmit diseases such as dengue fever an increasing foothold in Europe.
As the world prepares for COP30 in Belém, Brazil, the findings of the 2025 Global Report of the Lancet Countdown provide a key evidence base for accelerating health-centered climate action.
WHO will build on this momentum through the forthcoming COP30 Special Report on Climate Change and Health, a collaborative effort highlighting the policies and investments needed to protect health and equity, and to deliver the Belém Action Plan, the expected landmark outcome of COP30.
