Average annual heat-related deaths rose nearly 36%

WHO’s summary of the 2026 Lancet Countdown on Health and Climate Change says average annual heat-related deaths in the years after the Paris Agreement rose nearly 36% versus the previous decade. Heat was linked to roughly 710,000 deaths worldwide in 2023, with more than 70% of the burden attributed to human-caused climate change. The report also records worsening drought, greater exposure to hydrological extremes and economic losses from heat exposure. At the same time, global clean-energy investment reached a record $2.1 trillion in 2025, and countries reducing fossil-fuel air pollution are estimated to be preventing thousands of premature deaths. The report brings together 146 researchers from more than 100 institutions in over 30 countries and follows 54 indicators. It calls for mitigation, adaptation, early warning and resilient health systems. Attribution and avoided-death figures come from models and comparative risk assessment, not case-by-case diagnoses, and regional data quality and adaptive capacity vary.