Climate Inaction Killing Millions Annually, Warns 2025 Lancet Countdown Report: WHO Urges Health-Centered Climate Action Ahead of COP30.
Geneva:
A stark new report from the Lancet Countdown on Health and Climate Change, released today in collaboration with the World Health Organization (WHO), has warned that climate inaction is now claiming millions of lives each year. The 2025 report reveals that 12 of 20 key indicators tracking the health impacts of climate change have reached record levels, underscoring how dependence on fossil fuels and slow adaptation efforts are already devastating public health, straining economies, and eroding global wellbeing.
“The climate crisis is a health crisis. Every fraction of a degree of warming costs lives and livelihoods,” said Dr Jeremy Farrar, WHO’s Assistant Director-General for Health Promotion, Disease Prevention, and Care. “Climate inaction is killing people now in all countries. However, climate action is also the greatest health opportunity of our time. Cleaner air, healthier diets, and resilient health systems can save millions of lives now and protect future generations.”
Rising Heat-Related Deaths and Food Insecurity
According to the Lancet Countdown 2025 report, the rate of heat-related mortality has surged 23% since the 1990s, with an estimated 546,000 people dying annually due to extreme heat. In 2024, the average person experienced 16 days of dangerous heat that would not have occurred without human-driven climate change. Infants and older adults faced even greater exposure, enduring more than 20 heatwave days each, marking a fourfold increase in just two decades.
Extreme weather events also contributed to worsening hunger. In 2023, 124 million people faced moderate to severe food insecurity as droughts and heatwaves devastated crops and disrupted food supplies.
Economic Toll of Heat and Fossil Fuel Dependence
The economic impact of rising temperatures continues to mount. In 2024 alone, 640 billion potential labour hours were lost to heat exposure, equivalent to a US$1.09 trillion productivity loss. Meanwhile, the costs of heat-related deaths among older adults were estimated at US$261 billion.
Despite the urgent need for a transition to clean energy, governments worldwide spent US$956 billion on net fossil fuel subsidies in 2023 — more than triple the funds pledged annually to support climate-vulnerable nations. Alarmingly, 15 countries allocated more money to fossil fuel subsidies than to their entire national health budgets.
Health Benefits of Climate Action
The report emphasizes that decisive climate action is already delivering measurable health gains. Between 2010 and 2022, efforts to reduce coal-derived air pollution prevented an estimated 160,000 premature deaths each year. Renewable energy generation also reached a record 12% of global electricity in 2024, creating 16 million jobs worldwide.
Progress in medical education is encouraging, with two-thirds of medical students globally now receiving formal instruction in climate and health.
“We already have the solutions to avoid a climate catastrophe,” said Dr Marina Romanello, Executive Director of the Lancet Countdown at University College London. “Rapidly phasing out fossil fuels, shifting to healthier diets, and adopting sustainable agriculture could save over ten million lives annually while cutting pollution and greenhouse gases.”
Health Sector Leading by Example
The health sector itself has emerged as a model for sustainable transformation. Between 2021 and 2022, global health-related greenhouse gas emissions fell 16%, even as care quality improved.
Data from WHO show that 58% of Member States have now completed a Health Vulnerability and Adaptation Assessment, and 60% have developed a Health National Adaptation Plan, signaling growing preparedness for climate-related threats.
Cities and local governments are also taking the lead: of 858 cities reporting to the Lancet Countdown, 834 have completed or plan to complete climate risk assessments. Clean energy transitions at the municipal level are already yielding cleaner air, healthier jobs, and economic growth.
Looking Ahead to COP30: Health at the Heart of Climate Action
As the world gears up for COP30 in Belém, Brazil, the 2025 Lancet Countdown report serves as critical evidence for placing health at the center of climate negotiations. WHO plans to release a COP30 Special Report on Climate Change and Health, aimed at guiding policies and investments that protect health and equity, while advancing the Belém Action Plan—expected to be a landmark outcome of the conference.
About the Lancet Countdown
Established in partnership with the Wellcome Trust and led by University College London, the Lancet Countdown works with WHO and over 70 academic and UN institutions worldwide. Now in its ninth year, it provides the most comprehensive assessment of the health impacts of climate change, highlighting both the dangers of inaction and the immense co-benefits of urgent climate action.
The 2025 Lancet Countdown report paints a clear picture — climate change is not a distant threat but a present-day public health emergency. Yet, it also affirms that meaningful climate action offers one of the greatest health opportunities of the century, capable of saving millions of lives while building a more equitable and sustainable future.
