The latest Lancet Countdown 2025 report has delivered one of its starkest assessments to date, concluding that 12 of the 20 key indicators tracking how climate change affects human health have reached record levels. The findings underline a rapidly accelerating global health crisis in which climate impacts are no longer future risks but present realities.
One of the most alarming trends is the rise in heat-related mortality. According to the report, deaths linked to extreme heat have surged by 63% since the 1990s, with an average of 546,000 fatalities each year. Researchers warn that this trajectory reflects both growing exposure to extreme temperatures and insufficient adaptation measures.
The analysis also points to intensifying drought conditions, a heightened risk of mosquito- and tick-borne diseases, and a growing number of extreme precipitation events—all of which increasingly strain public health systems worldwide.
The economic toll is mounting as well. Heat-related labor productivity losses have reached their highest level on record, resulting in annual global damages approaching $1 billion.
Taken together, the indicators portray a world where climate change is eroding health and well-being faster than governments and health systems can respond. The report urges policymakers to accelerate mitigation and adaptation efforts, arguing that the window for preventing further irreversible harms is rapidly narrowing.