The 2025 report of the Lancet Countdown on health and climate change
The Lancet
The 2025 Lancet Countdown on Health and Climate Change
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The Problem
Mean annual temperatures exceeded 1.5°C above pre-industrial levels for the first time in 2024, the same year greenhouse gas emissions hit record levels. Climate change is destabilizing the planetary systems human life depends on, and its health consequences keep breaking new records.
The Approach
This ninth, most comprehensive Lancet Countdown report, authored by 128 multidisciplinary experts, tracks 20 indicators across five domains: climate impacts, adaptation, mitigation, economics and finance, and public/political engagement, revealing where progress is reversing and where opportunity remains.
What We Found
546K Estimated yearly heat-related deaths
639B Potential work hours lost to heat in 2024
12 Indicators set new records
Heat-related deaths rose 63% since the 1990s. Infants were exposed to 389% more heatwave days in 2024 vs. 1986–2005, and adults over 65 to 304% more. A record 61% of global land experienced extreme drought in 2024. Wildfire smoke caused a record 154,000 deaths. Economic losses from extreme weather reached $304 billion, yet insurance coverage fell from 67% to 54%.
Clean energy transition: solar panels on Lake Titicaca, the human dimension of climate adaptation.
My Contribution
I contributed to Section 5: Public and Political Engagement, which tracks whether society is responding to the crisis across five actors: media (health-climate coverage fell 15% in 2024), individuals (climate-health search interest rose from 49.4 to 59.9), scientists (publications near record highs), governments (UN General Debate mentions dropped from 62% to 30%), and corporations. The paradox: public and scientific engagement is growing while political commitment retreats, exactly when action matters most.
Why It Matters
12 of 20 health indicators set alarming new records as some leaders disregard the evidence. The world is heading toward 2.7°C of heating by century’s end. Adaptation funding remains grossly insufficient, and fossil fuel production plans exceed 1.5°C-consistent limits by 189%. Climate action is no longer optional: it is a lifeline.
Citation
Romanello, M., Walawender, M., Hsu, S.-C., … Roa, J., … Costello, A. (2025). The 2025 report of the Lancet Countdown on health and climate change: climate change action offers a lifeline. The Lancet, 406, 2804–2857. DOI: 10.1016/S0140-6736(25)01919-1
Citation
@article{romanello2025,
author = {Romanello, M. and Walawender, M. and Hsu, S.-C. and Roa, J.
and Costello, A.},
title = {The 2025 Report of the {Lancet} {Countdown} on Health and
Climate Change},
journal = {The Lancet},
date = {2025-12-13},
url = {https://jorgeroac.com/publications/papers/peer-reviewed/lancet-countdown-2025/},
doi = {10.1016/S0140-6736(25)01919-1},
langid = {en}
}