Lancet Countdown 2026: Heat Linked to a Record 710,000 Deaths in 2023, More Than 70% Attributed to Climate Change
The 2026 Lancet Countdown on Health and Climate Change, released on October 28, found that heat was linked to an estimated record 710,000 deaths in 2023 alone, with 71.5 per cent of them attributable to human-caused climate change — more than were caused by malaria or HIV. The report's authors call for climate change to be formally recognised as a global health emergency, with health placed at the centre of every climate decision.
The tenth annual report, led by University College London and produced in strategic collaboration with the World Health Organization, draws on 146 researchers from more than 100 institutions across more than 30 countries and tracks 54 indicators. Heat was linked to an average of 540,800 estimated deaths a year between 2016 and 2023, of which 68 per cent (369,900) were caused by climate change, up from 55 per cent (219,100) a year in 2006–2015. In total, climate change is estimated to have caused almost three million heat deaths between 2016 and 2023.
Heat also cut people's capacity to work: heat exposure cost the global economy an estimated US$1.07 trillion in potential income in 2025 — 0.91 per cent of global economic output and the third consecutive year above US$1 trillion — with agriculture and construction absorbing the biggest shares, 38 and 29 per cent respectively. In 2025, 51.8 per cent of the world's land experienced extreme drought for at least one month, the second-worst level on record.
"A decade after the Paris Agreement, our findings are unambiguous: the health harms of climate change are growing faster than the world's response to them, and in many cases even accelerating," said Professor Marina Romanello, the Lancet Countdown's Executive Director. WHO Director-General Tedros Adhanom Ghebreyesus said climate change is one of the greatest threats to health facing humanity, while stressing that solutions are within reach. The report, published ahead of the COP31 climate conference in Türkiye in November, also noted a positive trend: global clean-energy investment reached a record US$2.1 trillion in 2025.
Source: GSM · USA (original Chinese edition)
Photo: 图：长期干旱后龟裂的土地（资料图）。照片：CC BY-SA 4.0，经 Wikimedia Commons。 / Photo: Cracked earth after prolonged drought (file photo). CC BY-SA 4.0, via Wikimedia Commons.
