By Abdullahi Lukman
A new Lancet Countdown on Health and Climate Change report warns that global inaction on climate change and continued reliance on fossil fuels are causing millions of preventable deaths each year from heat, air pollution, disease, and food insecurity.
The 2025 report, titled Running on Empty, was led by University College London (UCL) in collaboration with the World Health Organization (WHO), the London School of Hygiene & Tropical Medicine (LSHTM), and over 70 global partners.
It found that 12 of 20 key health indicators have reached record highs, underscoring how delayed climate action is driving a worsening global health crisis.
Between 2012 and 2021, heat-related deaths rose by 23% compared to the 1990s, averaging 546,000 annually. In 2024—the hottest year on record—infants and older adults faced over 300% more heatwave days than the late 20th-century average.
Wildfire smoke caused 154,000 deaths last year, while extreme rainfall, droughts, and floods affected over 60% of global land area, disrupting food systems and livelihoods.
Climate change is also fueling disease spread, with dengue transmission potential rising nearly 50% since the 1950s.
Meanwhile, air pollution linked to fossil fuel combustion caused millions of deaths globally, including 28,000 in the UK in 2022.
High-carbon diets contributed to 11.8 million diet-related deaths worldwide the same year.
Economically, the report estimated that heat exposure in 2024 led to 639 billion lost labour hours — an income loss of $1.09 trillion, nearly 1% of global GDP.
Governments spent $956 billion on fossil fuel subsidies in 2023, more than triple the support pledged to vulnerable nations at COP29.
Despite grim findings, the report highlights progress in clean energy and health-sector emissions.
Global health-related emissions fell 16% between 2021 and 2022, and renewable energy reached record levels, preventing an estimated 160,000 premature deaths annually.
Researchers say solutions are within reach. Cleaner energy, resilient health systems, and sustainable food policies could deliver immediate and long-term health gains.
“The world remains far off-track, but climate action offers an unprecedented opportunity to protect lives and drive sustainable development,” said Dr. James Milner of LSHTM.
Professor Tafadzwa Mahbhaudi, Director of Lancet Countdown Africa, added that climate action is “one of the greatest health opportunities of the 21st century,” capable of creating jobs, reducing poverty, and building resilience against future climate shocks.
