The 2025 Report of the Lancet Countdown on Health and Climate Change: Climate Change Action Offers a Lifeline.

Driven by human-caused greenhouse gas emissions, climate change is increasingly claiming lives and harming people's health worldwide. Mean annual temperatures exceeded 1.5 degrees C above those of pre-industrial times for the first time in 2024. Despite ever more urgent calls to tackle climate change, greenhouse gas emissions rose to record levels that same year. Climate change is increasingly destabilising the planetary systems and environmental conditions on which human life depends. Authored by 128 multidisciplinary experts worldwide, the 2025 report of the Lancet Countdown on health and climate change is the ninth-and most comprehensive-assessment of the links between climate change and health. The data in this report reveal that, as the health risks and impacts of climate change break concerning new records, progress is being reversed across key areas, further threatening health and survival. However, the evidence in this report also exposes important opportunities to accelerate action and prevent the most catastrophic impacts of climate change.