The latest report from the Lancet Countdown on Health and Climate Change highlights global heatwave exposure for infants and older adults, mentioning countries like China, the U. S., and Russia. These nations face significant challenges as climate change continues to impact vulnerable populations.
Globally, the total number of heatwave days decreased from the historical high in 2024, which saw 15.3 billion person-days for older adults and 2.3 billion person-days for infants. However, 2025 still recorded the second-highest exposure levels, with older adults experiencing 10.8 billion person-days and infants 1.1 billion person-days of heatwaves. On average, older adults faced 12.8 heatwave days per individual, while infants encountered 8.7 days.
The report, led by researchers at the U. K.'s University College London, highlights the growing health impacts of climate change, which have accelerated since the 2016 Paris Agreement. Despite some progress in clean energy and health system readiness, the response to climate change is not keeping pace with its health consequences.
Marina Romanello, executive director of the Lancet Countdown and a professor at University College London, emphasized the urgency of the situation. She stated that the health harms of climate change are increasing faster than the global response, calling for climate change to be formally recognized as a global health emergency. Romanello advocates for placing health at the center of climate decisions, including emissions targets and climate funding.
The report calls for urgent and equitable reductions in greenhouse gas emissions, sustained investment in scientific research, and climate finance for health initiatives to be provided as grants rather than loans. This approach aims to help countries adapt without incurring additional debt.
In 2023, the hottest year between 2016 and 2025, heat was linked to an estimated 710,000 deaths, surpassing fatalities from malaria or HIV. Of these deaths, 71.5% were attributed to climate change, contributing to an estimated total of nearly 3 million heat-related deaths from 2016 to 2023.
Despite some advancements in clean energy and health-protective regulations, Romanello noted that progress has been insufficient and has not reached those most in need. The report underscores the need for a coordinated global response, potentially through a new World Health Organization instrument, to address the health impacts of climate change effectively.
