The 2025 report of the Lancet Countdown on health and climate change

This annual scientific assessment examines the relationship between climate change and human health, drawing on 57 indicators developed by 128 experts from 71 institutions worldwide. It evaluates climate-related health hazards, adaptation and resilience, emissions reduction, economic and financial systems, and public engagement.

The report identifies worsening health impacts associated with rising temperatures, extreme weather, air pollution and infectious diseases. It estimates that heat-related mortality has increased by 23% since the 1990s, reaching approximately 546,000 deaths annually. It also examines the continuing health consequences of fossil fuel dependence and insufficient investment in climate adaptation.

Alongside these risks, the assessment highlights the health benefits of climate action, including cleaner air, healthier diets and more resilient communities. It emphasises the importance of coordinated policies, investment and healthcare professional education in protecting population health and accelerating progress towards a low-carbon future.

Access requirements: Free access. Registration may be required to view the report's findings and supporting resources on the Lancet Countdown website.

Citation: Romanello M, Walawender M, Hsu SC, Moskeland A, Palmeiro-Silva Y, Scamman D, et al. The 2025 report of the Lancet Countdown on health and climate change: climate change action offers a lifeline. The Lancet. 2025;406(10521):2804–2857. https://doi.org/10.1016/S0140-6736(25)01919-1