The latest Lancet Countdown report on health and climate change, published Wednesday, calls for the World Health Organization to formally declare climate change a global health emergency, according to ABC News. The report finds that heat-related deaths and other climate-driven health harms are accelerating faster than the global response.
Led by University College London in collaboration with the WHO, the assessment draws on 146 experts from over 100 institutions in more than 30 countries. It tracks 54 indicators and concludes that many health risks expanded more rapidly in the ten years since the Paris Agreement took effect in 2016 than in the preceding decade, Phys.org reported.
On average, heat was associated with roughly 541,000 estimated deaths annually from 2016 through 2023, with 68 percent attributable to human-caused climate change, up from 55 percent in the previous decade, according to the findings. In 2023, the hottest year on record, heat-related deaths reached 710,000, with 71.5 percent driven by climate change, exceeding annual deaths from malaria or HIV. Nearly 3 million heat deaths are estimated to have been caused by climate change over the eight-year period.
"A decade after the Paris Agreement, our findings are unambiguous," said Marina Romanello, executive director of the Lancet Countdown at UCL. She added that climate-related health harms are outpacing the world's response, and in many cases the rate of increase is accelerating.
Extreme drought covered 51.8 percent of global land for a month or more in 2025, marking the second-worst year on record, The Independent noted. The area hit by drought has expanded more than 700 percent faster since 2016 compared with 2006 to 2015. Satellite observations show that since 2003, 43 percent of land has been drying out while 37 percent has been getting wetter. Together they push more than 80 percent of land into hydrological extremes that threaten crops, water supplies and sanitation, DW reported.
Heat also cost the global economy an estimated $1.07 trillion in lost potential income in 2025, the third consecutive year losses topped $1 trillion. Southeast Asia and Africa bore the brunt, with losses equivalent to 3.9 percent and 3.2 percent of GDP respectively. Agriculture and construction, both outdoor and physically demanding, absorbed 38 percent and 29 percent of those losses.
The report notes progress: clean energy investment reached a record $2.1 trillion in 2025, 82 percent more than fossil fuel investment, and renewables grew from 5.5 percent to 13.5 percent of global electricity between 2016 and 2023. Cleaner air prevented an estimated 323,000 deaths annually in 77 countries. Yet fossil fuels still supply over 80 percent of global energy, emissions hit a record high in 2024, and fossil fuel air pollution kills an estimated 2.73 million people each year.
Fifty-six WHO member states now have national health adaptation plans, up from 14 in 2015. The authors recommend a new WHO instrument, broader than the existing Public Health Emergency of International Concern mechanism, to coordinate sustained global action across sectors. The report is published ahead of the UN COP31 climate conference next month.