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. Despite ever more urgent calls to act, greenhouse gas emissions rose to record levels that same year. Climate change is increasingly destabilizing the planetary systems on which human life depends – and its health consequences are breaking concerning new records.
The Approach
Authored by 128 multidisciplinary experts worldwide, this ninth – and most comprehensive – Lancet Countdown report tracks 20 indicators across five domains: climate change impacts and exposures, adaptation and resilience, mitigation and co-benefits, economics and finance, and public and political engagement. It reveals where progress is being reversed and where opportunities remain.
What We Found
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%. The health threats of climate change have reached unprecedented levels across every dimension monitored.
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 with Health and Climate Change – the domain that tracks whether society is responding to the crisis. This section monitors engagement across five key actors: the media (newspaper coverage of health and climate fell 15% in 2024), individuals (Google search interest in “climate change health” rose from 49.4 to 59.9), scientists (peer-reviewed articles on health and climate remained near record highs), governments (mentions of health and climate in UN General Debate statements dropped from 62% in 2021 to 30% in 2024), and corporations. My work helped quantify a troubling paradox: while public and scientific engagement is growing, political commitment is retreating – precisely when decisive action is most needed.
Why It Matters
As some world leaders disregard scientific evidence in favor of short-sighted interests, 12 of 20 health indicators have set alarming new records. The world is heading toward a potentially catastrophic 2.7°C of heating by the end of the century. Adaptation funding remains grossly insufficient, and fossil fuel production strategies exceed 1.5°C-consistent limits by 189%. Climate change 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{m.2025,
author = {M. , Romanello and M. , Walawender and S.-C. , Hsu and , ...
and J. , Roa and A. , Costello},
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}
}