Scientists Urge UN to Declare Climate Change a Global Health Emergency as Heat Deaths Hit Record Highs

LONDON, 28 October 2026 — Scientists behind one of the world's most closely watched annual health-and-climate trackers have urged the United Nations to formally declare climate change a global health emergency, warning that the health damage caused by a warming planet is now growing faster than the world's response to it. The call comes in the tenth annual report of the Lancet Countdown on Health and Climate Change, published in The Lancet on 28 October 2026, just weeks before governments gather in Antalya, Türkiye, for the COP31 climate summit in November.

Illustration: A city enduring an extreme heatwave, with residents seeking shade beneath trees under a hazy sky.

What Happened

The 2026 Lancet Countdown report, led by University College London and produced in collaboration with the World Health Organization (WHO), draws on the work of 146 researchers from more than 100 institutions in more than 30 countries. It tracks 54 indicators of how climate change affects health, and of how climate action affects health, and its central conclusion is blunt: many health harms grew faster in the decade after the Paris Agreement entered into force, from 2016 to 2025, than in the previous decade, from 2006 to 2015.

The report's authors are calling for climate change to be formally recognised and addressed as a global health emergency, for a new WHO instrument to enable a coordinated global response, and for governments to put health at the centre of every climate decision, from emissions targets to climate funding priorities. Their priorities include urgent and fair cuts in greenhouse gas emissions, sustained investment in science, and climate finance for health delivered as grants rather than loans, so that countries can adapt without taking on more debt.

Professor Marina Romanello, executive director of the Lancet Countdown at University College London, said the findings were unambiguous: the health harms of climate change are growing faster than the world's response to them, and in many cases are accelerating, while real progress in clean energy, health system readiness and health-protective regulation is too slow, too small and is not reaching those who need it most. Helen Clark, former prime minister of New Zealand and chair of the board of the Lancet Countdown, described the report as a stark warning that climate change is a health emergency, and said what is missing is not evidence but the political will to act on it.

The most striking finding concerns heat. According to the report, heat was linked to an average of 540,800 estimated deaths per year between 2016 and 2023, of which 68 percent, or 369,900 deaths, were attributed to human-caused climate change. That compares with 55 percent, or 219,100 deaths per year, in 2006 to 2015. In 2023 alone, the hottest year in that period, heat was linked to a record 710,000 estimated deaths, exceeding deaths from malaria or HIV, with 71.5 percent of them driven by climate change. Altogether, the report estimates that climate change caused almost 3 million heat deaths between 2016 and 2023.

The economic toll of heat is also mounting. The report estimates that heat reduced people's capacity to work productively in 2025, costing the global economy an estimated US$1.07 trillion in potential income, equivalent to 0.91 percent of global economic output. That marks the third consecutive year in which losses have topped US$1 trillion. South-East Asia and Africa were hit hardest, with losses equivalent to 3.9 percent and 3.2 percent of gross domestic product respectively, compared with 0.2 percent in Europe and 1.5 percent in the Americas. Agriculture and construction, both dominated by outdoor and physically demanding jobs, absorbed the biggest share of the losses, at 38 percent and 29 percent respectively, because heat directly impairs labour productivity and puts workers' health at risk. In Africa, where agriculture accounts for 71 percent of heat-related potential income losses, the impact is particularly pronounced.

Background

The Lancet Countdown was set up to track, year by year, whether the world is protecting health as the climate changes. Its tenth report arrives a decade after the Paris Agreement, adopted in December 2015, which set out to limit global warming to 1.5 degrees Celsius above pre-industrial levels. The report finds that while progress has been made in some areas, many detrimental health indicators linked to climate change are moving in the wrong direction, and in several cases the deterioration has accelerated since the agreement took effect.

Water extremes are worsening alongside the heat. More than half the world's land, 51.8 percent, was hit by extreme drought for at least a month in 2025, the second-worst year on record after 2023, and since 2016 the area affected by drought has grown more than 700 percent faster than it did in 2006 to 2015. A new satellite-based analysis identifies growing extremes in water storage: since 2003, 43 percent of the world's land has seen a long-term drop in water storage, becoming drier, while a separate 37 percent has seen a long-term rise, becoming wetter. Together these hydrological extremes affect more than 80 percent of the world's land and threaten crops, food supplies and sanitation. Very extreme rainfall is also becoming more common, reaching almost 17.2 percent of global land each year in 2016 to 2025, up from 14.8 percent the previous decade, increasing the risk of floods, landslides and waterborne disease.

Illustration: Cracked earth and a shrinking reservoir during a prolonged drought.

Yet the report is not a catalogue of unrelieved bad news. Since the Paris Agreement, cleaner energy, more resilient health systems, more health-protecting legislation and growing scientific evidence have delivered real health benefits to local communities. Global investment in clean energy grew 7.2 percent in 2025 to a record US$2.1 trillion, 82 percent more than the US$1.16 trillion invested in fossil fuels, and such investment has helped renewable electricity grow from 5.5 percent of total generation in 2016 to 13.5 percent in 2023. Cleaner air has prevented an estimated 323,000 deaths a year in at least 77 countries where air pollution from fossil fuels has fallen since 2016.

Health systems are also taking early action. A quarter of WHO member states, 56 of 194, now have a national plan for adapting health services to climate change, up from just 14 in 2015, and 47 have separately completed a vulnerability assessment to underpin such plans. Almost half of WHO member states reported having a health surveillance system that incorporates climate information, and more than half of respondents, 75 of 145, reported having at least one climate-informed health early warning system. Importantly, the report finds that health early warning systems are slowing down the increase in deaths from extreme weather events in the places that have them. Legal momentum is building as well: national laws referencing both climate change and health have risen roughly 50-fold since 2000, most of that growth since 2016. Funding for climate-related health research has also increased, up 655 percent between 2016 and 2024, from US$42 million to US$316 million, though almost all of it, 84 percent, still goes to researchers in the world's wealthiest countries, leaving evidence gaps where the risks are often greatest.

Progress on the transition away from fossil fuels continues to fall short, the report documents. The world's 100 largest oil and gas companies are now planning to produce 150 percent more fossil fuels by 2040 than is compatible with keeping warming to 1.5 degrees Celsius, up from 138 percent in the previous year's assessment. Fossil fuels still supply more than 80 percent of the world's energy, and climate-heating emissions reached a record high in 2024. Despite gains in some countries, fossil-fuel air pollution still kills an estimated 2.73 million people a year worldwide. Production plans persist despite rising fossil fuel costs straining public finances: global net fossil fuel subsidies reached record levels in 2022 to 2024, net subsidies have doubled since 2016, with a cumulative US$6.20 trillion allocated since the Paris Agreement, and ten countries spent more on fossil fuel subsidies in 2024 than on their health systems.

Why It Matters

The emergency-declaration call matters because it would change how climate change is treated inside the world's health machinery. A formal recognition as a public health emergency of international concern, the mechanism the researchers point to, could in principle unlock a more coordinated international response, pooled data and faster finance. Even short of that formal step, putting health at the centre of climate negotiations reframes emissions cuts not as an abstract environmental goal but as a direct measure of lives saved, working days preserved and hospitals kept standing during heatwaves, floods and droughts.

The figures give that argument unusual force. Heat deaths are not a distant projection: the report's estimates cover deaths that have already occurred, with attribution methods that compare recorded heat deaths with those estimated to have occurred in a scenario without climate change. The economic numbers tell a parallel story. When heat cuts the ability to work outdoors, the losses fall hardest on farm workers and builders in the poorest regions, and they compound year after year. That is why the authors pair their emissions demand with a finance demand: grants, not loans, for health adaptation in vulnerable countries, so that coping with a crisis those countries did little to cause does not deepen their debt.

The report also matters as a reality check ahead of COP31. The summit in Antalya arrives a week after the UN Environment Programme warned that holding warming to 1.5 degrees Celsius is no longer possible and that the focus must now be on making the overshoot as short-lived as possible. Against that backdrop, the Lancet Countdown authors argue that health-centred climate action is one of the few strategies with proven, near-term payoffs: cleaner air, more resilient healthcare and warning systems are already, in the words of co-chair Professor Anthony Costello, protecting health and saving lives globally. The problem, Costello said, is that the pace and scale of emissions reduction remains entirely out of step with the pace and scale of the harm.

What Happens Next

All eyes now turn to COP31 in Antalya, where negotiators will test whether health moves from the margins of climate talks to their centre. The report's authors want governments to use the summit to agree on coordinated health action, grant-based finance for health adaptation, and emissions cuts deep enough to slow the heat, drought and rainfall extremes documented in the report. Whether the emergency declaration itself gains traction will depend on WHO member states and the UN system, and the authors acknowledge that such a step would require political agreement that has so far proved elusive.

Illustration: Delegates gathered at an international climate summit hall ahead of COP31.

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Frequently Asked Questions

What is the Lancet Countdown?

The Lancet Countdown on Health and Climate Change is an annual tracker, led by University College London in collaboration with the World Health Organization, that monitors how climate change affects health and how climate action affects health, using 54 indicators compiled by researchers from more than 100 institutions.

What does the 2026 report actually call for?

Its authors call for climate change to be formally recognised as a global health emergency, for a new WHO instrument to coordinate the response, for health to be placed at the centre of every climate decision, and for grant-based, rather than loan-based, climate finance for health adaptation.

How many heat deaths does the report link to climate change?

The report estimates heat was linked to an average of 540,800 deaths per year between 2016 and 2023, with 68 percent attributed to human-caused climate change, and to a record 710,000 deaths in 2023 alone, with 71.5 percent driven by climate change.

Is there any good news in the report?

Yes. Clean energy investment hit a record US$2.1 trillion in 2025, renewable electricity grew from 5.5 percent of generation in 2016 to 13.5 percent in 2023, cleaner air prevented an estimated 323,000 deaths a year in at least 77 countries, and health early warning systems are slowing the rise in extreme-weather deaths where they exist.

What happens at COP31?

COP31, the 31st UN climate conference, takes place in Antalya, Türkiye, in November 2026, where governments negotiate climate action. The Lancet Countdown authors hope health will be central to its outcomes, including on emissions, adaptation finance and health system resilience.

Sources

• The Lancet / EurekAlert, "Experts call for climate change to be declared a global health emergency, as many health impacts outpace climate action," 28 October 2026.
• Le Monde, "Climate change: Scientists call for declaration of 'global health emergency' after new report," 28 October 2026.
• ScienceAlert, "'Record High': 146 Experts Call to Declare Climate Change a Global Health Emergency," updated 29 October 2026.
• Amnesty International, "COP31 must amplify people power, not oil lobby voices," 29 October 2026 (context on COP31).