Climate Crisis Devastating Human Health: Lancet Countdown Warns of Rising Heat-Related Deaths and Economic Strains

Strategic Insights -

The World Health Organization and global partners are sounding the alarm on the devastating impact of climate inaction, as a new report warns that continued reliance on fossil fuels and failure to adapt to a heating world are costing lives, straining health systems, and undermining economies. The 2025 report of the Lancet Countdown on Health and Climate Change, produced in collaboration with WHO, finds that 12 of 20 key indicators tracking health threats have reached record levels.

Key Takeaways:

  • The rate of heat-related mortality has increased 23% since the 1990s, resulting in an average 546,000 deaths per year.
  • The average person was exposed to 16 days of dangerous heat in 2024 that would not have been expected without climate change.
  • Droughts and heatwaves were associated with an additional 124 million people facing moderate or severe food insecurity in 2023.
  • Heat exposure caused 640 billion potential labour hours to be lost in 2024, with productivity losses equivalent to $1.09 trillion.
  • Governments spent $956 billion on net fossil fuel subsidies in 2023, more than triple the annual amount pledged to support climate-vulnerable countries.
  • An estimated 160,000 premature deaths were avoided every year between 2010 and 2022, from reduced coal-derived outdoor air pollution alone.
  • Renewable energy generation reached a record 12% of global electricity, creating 16 million jobs worldwide.
  • Two-thirds of medical students received education in climate and health in 2024.
  • Cities, communities, and the health sector are leading the way in climate action, with nearly all reporting cities (834 of 858) having completed or planning to complete climate risk assessments.
  • Health-related greenhouse gases (GHG) emissions fell 16% globally between 2021 and 2022, while improving care quality.

Statistics:

  • 546,000 average heat-related deaths per year
  • 16 days of dangerous heat in 2024 that would not have been expected without climate change
  • 124 million additional people facing moderate or severe food insecurity in 2023
  • 640 billion potential labour hours lost in 2024 due to heat exposure
  • $1.09 trillion in productivity losses equivalent to heat exposure in 2024
  • $261 billion in costs of heat-related deaths among older adults
  • $956 billion in net fossil fuel subsidies in 2023
  • 160,000 premature deaths avoided every year between 2010 and 2022, from reduced coal-derived outdoor air pollution
  • 16 million jobs created by renewable energy generation
  • 60% of Member States having completed a Health National Adaptation Plan
  • 58% of Member States having completed a health Vulnerability and Adaptation assessment

Sources:

  • World Health Organization
  • Lancet Countdown on Health and Climate Change
  • University College London
  • Wellcome
  • Lancet Countdown was established in partnership with Wellcome, which continues to provide core financial support.