The 2026 Report of the Lancet Countdown on Health and Climate Change finds that many of the health risks and harms of climate change grew faster in the decade since the Paris Agreement was introduced (2016–2025) than in the decade before it (2006–2015). Clean energy investment, health system leadership, more health-protecting legislation, and growing scientific evidence helped deliver real health gains, but not enough to offset the rapidly growing harm from fossil-fuel-driven climate change. The report's authors call for climate change to be formally recognized and addressed as a global health emergency, and for health to shape both climate policies and funding priorities to prevent climate change.

The 10th Lancet Countdown annual report, led by University College London (UCL), and produced in collaboration with the World Health Organization (WHO), represents the work of 146 multidisciplinary researchers from more than 100 institutions across more than 30 countries. Published ahead of the 31st UN Conference of the Parties (COP31), it tracks 54 indicators of the health impacts of climate change and the health effects of climate action, including four new indicators introduced this year covering the availability of water in land (indicator 1.2.2), healthcare sector greenhouse gas footprint assessments (indicator 3.5.2), climate-related health research funding (indicator 4.3.4), and legislative engagement with health and climate change (indicator 5.5). New this year, the report includes an updated media engagement indicator (indicator 5.1), and now also attributes estimated heat-related deaths to human-caused climate change (indicator 1.1.5).