- The 10th indicator report of the Lancet Countdown on Health and Climate Change suggests that some of the health harms of climate change grew faster in the decade since the Paris Agreement entered into force (2016–2025) than in the previous decade (2006–2015) as climate action fails to keep pace.
- Annual average heat-related deaths rose by nearly 36% globally after the Paris Agreement was introduced. In 2023 alone, heat was linked to a record 710,000 deaths with more than 70% of that toll attributable to human-caused climate change.
- Extreme drought affected nearly 52% of the world’s land for at least a month in 2025 (the second-highest level on record), while a new satellite-based analysis suggests that since 2003, 80% of the world’s land has faced significant shifting patterns of increasing dry and wet groundwater storage conditions, with implications for food security and sanitation.
- Globally, clean energy investment reached a record US$2.1 trillion in 2025, almost double what was invested in fossil fuels, and 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. Yet fossil fuels still supply more than 80% of the world’s energy, and the 100 largest oil and gas companies are on track to exceed 1.5°C-compatible production levels by 150% by 2040 – up from 138% from last year.
- The report’s authors are calling for climate change to be formally recognised and addressed as a global health emergency, and for health to be placed at the centre of every climate decision, from emissions reductions to funding priorities.
**Country Data Sheets and Infographics available – see Notes to Editors**
The 2026 Report of the Lancet Countdown on Health and Climate Change finds that many of the health risks and harms of climate change grew faster in the decade since the Paris Agreement was introduced (2016–2025) than in the decade before it (2006–2015). Clean energy investment, health system leadership, more health-protecting legislation, and growing scientific evidence helped deliver real health gains, but not enough to offset the rapidly growing harm from fossil-fuel-driven climate change. The report’s authors call for climate change to be formally recognised and addressed as a global health emergency, and for health to shape both climate policies and funding priorities to prevent climate change.
The 10th Lancet Countdown annual report, led by University College London (UCL), and produced in collaboration with the World Health Organization (WHO), represents the work of 146 multidisciplinary researchers from more than 100 institutions across more than 30 countries. Published ahead of the 31st UN Conference of the Parties (COP31), it tracks 54 indicators of the health impacts of climate change and the health effects of climate action, including four new indicators introduced this year covering the availability of water in land (indicator 1.2.2), healthcare sector greenhouse gas footprint assessments (indicator 3.5.2), climate-related health research funding (indicator 4.3.4), and legislative engagement with health and climate change (indicator 5.5). New this year, the report includes an updated media engagement indicator (indicator 5.1), and now also attributes estimated heat-related deaths to human-caused climate change (indicator 1.1.5).
“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,” says Professor Marina Romanello, Executive Director of the Lancet Countdown, based at University College London. “Real progress has been made in clean energy, health system readiness, and health-protective regulation, all of which are already delivering health benefits to local communities. However, progress has been too slow, too small, and isn't reaching those who need it most. That is why we are calling for climate change to be formally recognised as a global health emergency, with health placed at the centre of every climate decision.”
Many health harms accelerating faster than a decade ago
Heat was linked to an average of 540,800 estimated deaths per year between 2016 and 2023, 68% of them (369,900) caused by climate change, up from 55% (219,100) per year in 2006–2015. In 2023 alone, the hottest year in that period, heat was linked to a record 710,000 estimated deaths, exceeding those from malaria or HIV, with 71.5% of them driven by climate change. Altogether, climate change is estimated to have caused almost 3 million heat deaths between 2016 and 2023.
Heat also reduced people’s capacity to work productively in 2025, costing the global economy an estimated US$1.07 trillion in potential income (0.91% of global economic output), the third consecutive year that losses topped US$1 trillion. South-East Asia and Africa were hit hardest, with losses equivalent to 3.9% and 3.2% of GDP, respectively, compared to 0.2% in Europe and 1.5% in the Americas. The agriculture and construction sectors, both largely outdoor and physically demanding jobs, absorbed the biggest share of the losses (38% and 29% respectively), because heat directly impacts people’s labour productivity, and puts workers’ health at risk. The impact is particularly pronounced in Africa, where agriculture accounts for 71% of heat-related potential income losses.
More than half the world's land (51.8%) was hit by extreme drought for at least a month in 2025, the second-worst year on record after 2023. Since 2016, the area affected by drought has grown more than 700% faster than it did in 2006–2015. In addition, a new satellite analysis identifies growing extremes in water storage. Since 2003, 43% of the world's land has seen a long-term drop in water storage (getting drier) while a separate 37% has seen a long-term rise (getting wetter), together creating hydrological extremes affecting more than 80% of the world's land and threatening crops, food supplies, and sanitation. Very extreme rainfall is also becoming more common, reaching almost 17.2% of global land each year in 2016–2025, up from 14.8% the previous decade, and increasing the risk of floods, landslides and waterborne disease.
“These numbers point to a clear emergency,” says Professor Romanello. “The rate of increase in many climate-related health threats is accelerating, while heat deaths linked to climate change have reached a record-high, and the economic toll is battering vulnerable sectors and communities the hardest. The risks become even more profound when you consider how different hazards interact and compound. At the same time, drought is spreading, and the world is swinging to water extremes, some drying out, while others are flooding. This isn't a gradual worsening; it's a step change that must be recognised as the global health emergency it is”
Despite gains, progress is falling short
Cleaner energy, more resilient health systems, along with more health-protecting legislation and growing scientific evidence have brought real health benefits to local communities since the 2016 Paris Agreement, but these gains are still too slow, too insufficient, and too inconsistent to offset the growing risks.
Global investment in clean energy grew 7.2% in 2025, to a record US$2.1 trillion, 82% more than the US$1.16 trillion invested in fossil fuels. Such investment has helped renewable electricity grow from 5.5% of the total generation in 2016 to 13.5% in 2023. Health gains are already evident, with cleaner air preventing an estimated 323,000 deaths a year in at least 77 countries where air pollution from fossil fuels has fallen since 2016. However, rising overall energy demand and slow system change means fossil fuels still supply over 80% 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.
Health systems are taking important early action: a quarter (56 of 194) of WHO member states 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 plans. Beyond planning, almost half of WHO member states declared already having a health surveillance system that incorporates climate information, and more than half (75 of 145 respondents) declared 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 those places which 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 since 2016. Funding for climate-related health research has also increased, up 655% between 2016 and 2024 from US$42 million to US$316 million, though almost all of it (84%) still goes to researchers in the world's wealthiest countries, leaving evidence gaps where the risks are often greatest.
“Ten years ago, we proposed that responding to climate change could offer the greatest health opportunity of the 21st century through adaptation efforts and rapid progress in phasing down fossil fuels and other emission sources”, says Prof Anthony Costello, Co-Chair of the Lancet Countdown. “A decade on, we have proof that health-centred climate action works: cleaner air, more resilient healthcare and warning systems are protecting health and saving lives globally. But the pace and scale of emissions reduction remains entirely out of step with the pace and scale of the harm.”
Fossil fuel expansion and funding gaps raise the risk
The report finds that progress on the transition away from fossil fuels is continuing to fall short. Fossil fuel production plans are increasingly misaligned with the Paris Agreement’s 1.5°C goal, with the world's 100 largest oil and gas companies now planning to produce 150% more fossil fuels by 2040 than is compatible with keeping warming to 1.5°C, up from 138% in 2025 [see page 261 in the appendix].
Production plans persist despite rising fossil fuel costs, which are straining public finances. In response to energy price spikes, global net fossil fuel subsidies reached record levels in 2022–2024, and ten countries spent more on them in 2024 than on their health systems. Net subsidies have doubled since 2016, with countries allocating a cumulative US$6.20 trillion to them since the Paris Agreement was introduced.
Despite the critical need to move away from fossil fuels to protect health and lives, vested interests continue to obstruct progress. The report details how lobbying and disinformation by fossil fuel interests and their political allies continue to weaken support for climate action, despite growing scientific evidence linking climate change and health. The report also finds that national governments, international organisations, and the private sector are now less engaged with health and climate change, reversing previous progress.
Adaptation funding is falling far short of what's needed: the health adaptation needs quantified so far by developing countries (as classified by UNFCCC) put the minimum cost at US$3.3 billion a year, based on data from only 48 of the 79 countries that have completed these estimates. Yet only around a third of this declared need, US$1.1 billion, was committed in 2024. This substantial financing gap is reflected in countries’ ability to translate adaptation priorities into action, with finance and human resourcing identified as the top barriers to implementation of Health National Adaptation Plans. Shrinking foreign aid budgets, including cuts to Overseas Development Assistance, risk widening this gap and placing the heaviest burden on the most vulnerable countries.
A call to declare a global health emergency
A decade after the Paris Agreement, the report's authors are calling for climate change to be formally declared 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 include urgent, fair cuts to 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 [see detail on the six priority recommendations in Panel 1].
“This report is a stark warning that climate change is a health emergency. What's missing is not evidence, but the political will to act on it,” said Helen Clark, former Prime Minister of New Zealand and Chair of the Board of the Lancet Countdown. “Governments must double down on their climate action commitments and rebuild momentum for international co-operation. This must go hand in hand with rapid emissions reductions and significantly greater support for adaptation, particularly for the communities least responsible for climate change and most vulnerable to its impacts.”
NOTES TO EDITORS
The Lancet Countdown was established in partnership with Wellcome, which continues to provide core financial support.
It is led by University College London (UCL) and works with more than 300 researchers from more than 100 institutions worldwide to track the evolving links between climate change and health, in strategic collaboration with the World Health Organization.
A full list of the report’s authors, their institutions, and declarations of interest is provided in the paper.
The labels have been added to this press release as part of a project run by the Academy of Medical Sciences seeking to improve the communication of evidence. For more information, please see: http://www.sciencemediacentre.org/wp-content/uploads/2018/01/AMS-press-release-labelling-system-GUIDANCE.pdf. If you have any questions or feedback, please contact The Lancet press office: pressoffice@lancet.com
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Journal
The Lancet
Method of Research
Computational simulation/modeling
Subject of Research
People
Article Title
The 2026 Report of the Lancet Countdown on Health and Climate Change
Article Publication Date
27-Oct-2026
COI Statement
SA is affiliated with the international finance organisation, Asian Development Bank (ADB), Manila, Philippines. The views expressed are those of the author and do not necessarily reflect the views and policies of ADB, its Board of Governors, or the Governments they represent. PJB, EC, GG-S, IH, MMH, JJH, JI, YP-S, MRo, MSa, MW, HW, and LW were compensated for their time while drafting and developing The Lancet Countdown’s report via The Lancet Countdown: Tracking Progress on Health and Climate Change Wellcome Trust grant (grant number 304972/Z/23/Z). PJB received support for travel from the Wellcome Trust via The Lancet Countdown: Tracking Progress on Health and Climate Change grant (grant number 304972/Z/23/Z) and for the Intergovernmental Panel on Climate Change (IPCC)–Wellcome Trust co-sponsored Expert Meeting on Climate Change and Health. PCo was compensated for their time by the University of Sydney. CD acknowledges funding from the European Commission via the European Research Council (ERC) Starting Grant FLORA (grant number 101212897), from the Agence Nationale de la Recherche via the Pref-Alim project, and by the European Commission Horizon Europe programme via the GREENGROCER project (grant number 101182025); and has received support from the American Geophysical Union editors fund to attend the European Geosciences Union conference in 2025 and 2026. ND, RH, and MRo were supported by the European Commission’s Horizon Europe Programme via the CATALYSE project (grant number 101057131, with UK Research and Innovation (UKRI) reference number 10041512). ME acknowledges funding from the Commonwealth Fund; and acknowledges fees received from the National Health Service in England for personal consulting. GG-S acknowledges funding from the National Institute for Health and Care Research (NIHR) UK for the Global Health Research Group on Diet and Activity (NIHR133205 with sub-award contract number G109900-SJ1/171 with University of Cambridge). JG and AJP were supported by the Bezos Earth Fund via grant funding for attribution science. RH was supported by the European Commission’s Horizon 2020 programme via the FirEUrisk project (grant number 101003890). JJH acknowledges a grant from National Institutes of Health; a grant from the National Institute of Standards and Technologies; a grant from the Wellcome Trust; a grant from the Global Fund for HIV/AIDS, TB and Malaria; a grant from Gates Ventures; and a grant from the National Oceanic and Atmospheric Administration. JJH also acknowledges a license to his institution (no payments to him) from the Community Heat and Resilience Tool; acknowledges fees received from McNaul, Ebel, Nawrot & Helgren, PLLC, for a legal consultation; acknowledges honoraria from Columbia University, Harvard University, and the University of Arizona for lectures; has received support from Academy Health; and is a Board member of the Seattle Parks Foundation. OJ acknowledges funding from the National Health and Medical Research Council Ideas via an investigator grant; and holds a patent for Environmental Measurement Unit. WM was provided access to data for free by Dimensions.ai (Digital Science) as part of their scientometric researcher programme. KMi acknowledges funding from the American Academy of Sleep Medicine. JCM was supported by the Wellcome Trust via the DESTINY project (grant number 313586/Z/24/Z) and the PATHFINDER2 project (project number 227165/Z/23/Z); and acknowledges funding from the Quadrature Climate Foundation via the “State of Carbon Dioxide Removal” project, from the European Research Council/Horizon Europe programme via the GENIE project (grant number 951542), from the Wellcome Trust via the “What Works Climate Solutions” project (grant number 334512/Z/25/Z) and the DEST project, from the German Ministry for Research and Education via the ARIADNE project (grant number 03SFK5J0), and from the European Commission’s Horizon Europe programme via the CAPABLE project (grant number 101056891). MM-L was sponsored by the University of São Paulo and the Universal Scientific Education and Research Network (USERN) to present a summary of the 2025 Lancet Countdown Report in Brazil. CR acknowledges funding from Karl Storz Endoscopy (UK); has received royalties from Up to Date; and has received fees from the UK Health Alliance on Climate Change and Surgical Innovations. MRo acknowledges investments in the fossil fuel industry through her employer’s (University College London) pension scheme, Universities Superannuation Scheme. MRo, JCS, and MW were supported by the European Commission’s Horizon Europe programme via the IDAlert project (grant number 101057554, with UKRI reference number 10056533). RNS acknowledges funding from the Massachusetts General Hospital Fund; acknowledges honoraria from the Wellcome Trust, the University of Michigan, the Mayo Clinic, the Academy of Behavioral Medicine Research, the University of Oregon, Cambridge College, the Cleveland Clinic Foundation, and Agency for Healthcare Research and Quality (AHRQ); received support for travel from the Wellcome Trust, the National Academy of Science, Engineering, and Medicine, the International Society of Behavioral Medicine, the University of Oregon, and the Cleveland Clinic Foundation; and acknowledges participation and involvement in The National Academies Climate Crossroads Advisory Committee, The National Academy of Medicine Grand Challenge Steering Committee, and the AHRQ Study Section. CSc acknowledges support from the World Health Organization. JCS was supported by the European Commission’s Horizon Europe programme via the BEPREP project (grant number 101060568). JDSh acknowledges funding from the Commonwealth Fund and the ECRI; has received royalties from Up to Date; has received fees from the Institute for Healthcare Improvement; has received honoraria for lectures delivered at the University of Southern Carolina, the University of British Columbia, and the George Washington University, as well as for the Healthcare Information and Management Systems Society and Project Echo and the Endocrine Society; has received support for travel and accommodations from the American Society of Anaesthesiologists, the International Society for Quality Improvement and the National University of Singapore; and is the Chair of the Committee on Environmental Health for the American Society of Anesthesiologists and the Chair of the Sustainability Committee for the World Federation of Societies of Anaesthesiologists (all unpaid). MSo was supported by the European Commission via Horizon Europe funded project healthRiskAdapt (grant number 101157458) and by the Research Council of Finland VFSP-WASE (grant number 359421). MSp acknowledges funding from the Wellcome Trust (Career Development Award number 225318/Z/22/Z) and the European Commission’s Horizon Europe Programme via the CATALYSE project (grant number 101057131), the BrightSpace project (grant number 101060075), and the ACT4CAP project (grant number 101134874). GS acknowledges funding from the MacArthur Foundation, the HT Foundation, the KR Foundation, and Climate Social Science Network; acknowledges fees received from a law firm, with an non-disclosure agreement in place precluding them from identifying the firm’s name; has received honoraria for lectures from the Oxford Climate Journalism Network; has received support for travel from the UC Davis Storer Lectureship in the Life Sciences award; and acknowledges unpaid academic advisory board memberships in the Cambridge 1·5˚C-Aligned Corporate Bond Index working group, Finance for Environmental and Social Systemic Change, the University of Cambridge, and Campus Climate Network. FT was compensated for their time by the University of Sydney; and acknowledges funding from the University of Sydney (USYD) via a USYD Horizon Fellowship. JT was supported by the European Commission via the ATMOPOLIS project (grant number 101238690). AU was supported by the Research Council of Finland via the Atmosphere and Climate Competence Center (ACCC) project (grant number 359342), the Finnish Foreign Ministry via the IBA-ILMA Project (grant number 13798–23), and the European Commission’s Horizon Europe programme via the CAMEO project (grant number 101082125). JTWW received funding from the University of Sydney via a Faculty of Medicine and Health Completion Scholarship and from the Deeble Institute via a Deeble Institute Research Scholarship; and has received travel grants from Wiser Healthcare to attend the Preventing Overdiagnosis Conference in Oxford, UK (2025), and from Healthy Environments and Lives to attend the Health Services Research Conference in Wellington, NZ (2026). All other authors declare no competing interests.