Lancet Countdown: 710,000 heat-related deaths in 2023, climate change to be seen as a health emergency

Heat was associated with a record 710,000 estimated deaths worldwide in 2023, and 71.5% of them can be attributed to climate change, according to the 2026 report of the Lancet Countdown on Health and Climate Change, published on 27 October 2026.

The authors identify fossil fuels as the central obstacle: they still supply 80.7% of global energy, energy-related CO2 emissions hit a record 37.8 Gt in 2024, and fossil fuel-derived air pollution caused 2.78 million deaths in 2023, unchanged since 2016. The 100 largest oil and gas companies are on track to exceed their share of 1.5°C-compatible production by 150.2% by 2040, up from 137.9% a year earlier. The report estimates that a health-protective phase-out could prevent up to 3.85 million deaths a year from outdoor air pollution caused by…