The Lancet Countdown published a new report on health and climate change

The World Health Organization (WHO) and global partners are urging the world to see protecting people’s health as the strongest reason to take climate action. A new global report released today warns that heavy dependence on fossil fuels and poor adaptation to a warming planet are already causing serious harm to human health. 

The Lancet Countdown on Health and Climate Change, established in partnership with Wellcome, which continues to provide core funding, is led by University College London in collaboration with the World Health Organization (WHO) and 71 academic institutions and UN agencies around the world. Now in its ninth year, the report offers the most comprehensive assessment to date of the health impacts of climate change and the shared benefits of urgent climate action, released in the lead-up to COP30 in Brazil.

The 2025 Lancet Countdown Report on Health and Climate Change, prepared with the WHO, shows that 12 out of 20 key indicators of health and climate risks have reached record levels. The report finds that not taking action on climate change is already costing lives, putting pressure on health systems, and damaging economies.

Some of the key findings from the report are: 

• Rising heat-related deaths - Heat-related deaths have increased by 23% since the 1990s, reaching an average of 546,000 deaths per year. In 2024, the average person experienced 16 days of dangerous heat that would not have happened without climate change. Infants and older adults were especially vulnerable, experiencing more than 20 heatwave days each —a fourfold increase over the last two decades.
• Wildfire and drought impacts -  Droughts and heatwaves left around 124 million more people struggling with moderate or severe food insecurity in 2023.
• Economic strain - Heat exposure caused the loss of 640 billion potential labour hours in 2024, equal to US$1.09 trillion in lost productivity..
• Fossil fuel subsidies vs. climate finance - Governments spent US$956 billion on fossil fuel subsidies in 2023 — over three times the amount promised to help climate-vulnerable countries. 
• Benefits of climate action -  Between 2010 and 2022, cleaner air from reduced coal use prevented about 160,000 premature deaths every year. Renewable energy reached a record 12% of global electricity, supporting 16 million jobs worldwide. In 2024, two-thirds of medical students received training on climate and health.  

As the world prepares for COP30 in Belém, Brazil, the 2025 Lancet Countdown Report offers crucial evidence to accelerate health-centred climate action. Building on this momentum, the WHO will release a COP30 Special Report on Climate Change and Health, outlining the policies and investments needed to protect health, promote equity, and advance the Belém Action Plan.