The 2025 China report of the Lancet Countdown on health and climate change: empowering cities for synergistic action

According to the World Meteorological Organization (WMO), 2024 was the hottest year on record. China had unprecedented heat and heavy precipitation, with a national average temperature of 10·9°C, 1·01°C higher than the historical average (1991–2020), and annual precipitation of 697·7 mm, which is 9·0% higher than the average. As 2025 marks the 10th anniversary of the Paris Agreement and a key juncture for submitting new contributions, accelerating global climate action is imperative, especially in cities, which account for 58% of the world's population and 70% of total carbon emissions.
The sixth annual Lancet Countdown China report on health and climate change, led by the Lancet Countdown Asia Centre at Tsinghua University and coauthored by 80 experts from 27 institutions, tracks 33 indicators across five domains. This year's report features several key updates. Methodologically, the Countdown used the China Meteorological Administration's Chinese global land-surface reanalysis product (CRA40) reanalysis dataset to replace European reanalysis product (ERA5, the fifth generation European Centre for Medium-Range Weather Forecasts reanalysis dataset) data for improved accuracy. The report expanded 17 indicators from the provincial to city level to support targeted local policy making. Furthermore, the report introduced three new indicators—sleep loss (indicator 1.1.4), compound heatwaves (indicator 1.1.5), and the Greenspace Exposure Inequality Index (indicator 2.2.3), along with two new panels on city-level research. As with previous years, where possible, all indicators have been updated with the latest data and methodological refinements.