The 2026 Lancet Countdown on health and climate change, led by University College London with the World Health Organization, was published October 28 with a stark framing: climate change has become a global health emergency.

The 10th annual report draws on 146 researchers at more than 100 institutions in over 30 countries and tracks 54 indicators covering heat, air pollution, drought, disease and economics.

Its executive director, Marina Romanello, said the findings are unambiguous — the health harms of climate change are growing faster than the world's response, and in many cases accelerating.

The authors are calling on the WHO and the United Nations to formally declare climate change a health emergency, arguing the designation would shift climate action from voluntary commitments to coordinated emergency management.

The headline number is heat. The report links heat to an estimated 710,000 deaths in 2023 — the latest year with available data — with more than 71% of those fatalities attributable to human-caused climate change, a toll researchers say exceeded deaths from malaria or HIV that year.

Across 2016 to 2023, nearly 3 million deaths were connected to climate change, and average annual heat-related deaths rose almost 36% after the Paris Agreement took effect. The past 11 years were the hottest on record.

ABC Australia reports that developing countries had the highest proportion of heat-related deaths, which the authors say reflects the disproportionate impact on those least responsible for warming.

Severe heat killed more than 50,000 people across Europe this past summer, per recently released peer-reviewed studies.

The report documents a world swinging between water extremes.

In 2025, more than half of the world's land — about 52% — experienced extreme drought for at least a month, and ABC News reports the pace of land hit by extreme drought accelerated roughly 700% between 2016 and 2025 versus the decade before Paris.

Very extreme rainfall also increased, with the affected land share rising from 14.8% in 2006-2015 to 17.2% in 2016-2025, lifting flood and landslide risk. Exposure to high wildfire risk grew as well, ABC Australia reports.

Heat is also an economic drag: heat exposure cost 573 billion potential work hours and $1.07 trillion in income in 2025, according to ABC Australia's reading of the report, with low- and middle-income countries hit hardest — the third straight year losses topped a trillion dollars.

The report is not all dire. Global clean energy investment grew more than 7% in 2025 to a record $2.1 trillion — 82% more than fossil fuel investment, per ABC News — and renewables grew from 5.5% of global electricity generation in 2016 to 13.5% in 2023.

Cleaner air paid a human dividend: ABC News reports an estimated 323,000 deaths a year prevented in dozens of countries, while ABC Australia puts the figure at 400,000 deaths prevented in 2023 compared to 2016 from improved air quality, plus 85,000 avoided across 75 countries from cleaner transport and air pollution controls.

Yet fossil fuels still supplied over 80% of global energy, and the resulting air pollution causes about 2.7 million deaths a year. The authors also cite fossil fuel lobbying and disinformation as an obstruction to progress.

The authors lay out six priorities for a health-centered response.

Per Euronews, they want the WHO and UN to use existing resources for a formal recognition that would strengthen health surveillance and early warning systems, rapidly mobilize resources, establish legally binding accountability, and introduce preventive public health measures — moving climate action from voluntary pledges to mandatory emergency management.

Their recommendations also include an immediate global ban on new fossil fuel exploration, a complete phase-out of coal-fired power by 2035, a shift toward predominantly plant-based diets, a shared pool of climate and health data, and more grants and low-interest loans from wealthier countries.

Gulf News notes the recommendation is a call for recognition by the report's authors, not a WHO emergency declaration.

The report lands just weeks before the COP31 climate conference in Türkiye, and the authors want health and well-being made core objectives and measures of success in all climate action.

The report also flags that a severe El Niño threatens to compound climate impacts and trigger unprecedented humanitarian crises.

ABC Australia reports the study found real progress since Paris — with projected warming by 2100 cut from up to 3.5°C toward 2.6°C — but calls global action grossly insufficient, and singles out the United States for promoting fossil fuel expansion and withdrawing from the Paris Agreement.

The key question for climate watchers is whether the emergency appeal produces stronger health protection, financing and emissions commitments at COP31, or symbolic recognition without enforcement.