The 2025 Lancet Countdown on Health and Climate Change has revealed that global failure to act on climate change is costing millions of lives every year through heat, air pollution, food insecurity, and disease spread.
The report, led by University College London in collaboration with the World Health Organization, the London School of Hygiene & Tropical Medicine, and 70 partner institutions, highlights how continued dependence on fossil fuels and slow climate action are driving escalating health and economic crises worldwide.
Read Also: Kano Police join Climate Advocate to tackle environmental challenges
Read Also: Climate Change: A global crisis in the making demanding urgent attention
According to the findings, 12 of 20 key health indicators have reached record highs as extreme weather events intensify.
Heat-related deaths have risen by 23% since the 1990s, with an average of 546,000 deaths annually between 2012 and 2021.
The year 2024 was the hottest on record, exposing vulnerable populations to over 300% more heatwave days compared to previous decades.
Wildfire smoke pollution alone caused about 154,000 deaths in 2024, while droughts and floods affected over 60% of global land surfaces, worsening food insecurity and disrupting livelihoods.
The report also warns that infectious diseases like dengue are spreading faster, with transmission potential rising by nearly 50% since the 1950s.
Air pollution from fossil fuel burning caused millions of premature deaths, including 28,000 in the UK in 2022.
Unsustainable diets and food systems contributed to 11.8 million global deaths that could have been avoided through healthier, climate-friendly choices.
Economically, heat exposure led to 639 billion hours of lost productivity in 2024, costing the world $1.09 trillion, nearly 1% of global GDP.
Meanwhile, governments spent $956 billion in fossil fuel subsidies in 2023—three times the support pledged to vulnerable nations at COP29.
Despite these alarming trends, researchers noted some progress, including a 16% drop in health sector emissions and record renewable energy growth.
Experts urge urgent investment in clean energy, sustainable food systems, and resilient health infrastructure to save lives and secure long-term prosperity.
Dr. James Milner of LSHTM emphasized that while the world remains off-track, the opportunity to protect health while tackling climate change has never been greater.
