Ahead of COP31, the 2026 Lancet Countdown on Health and Climate Change finds that climate-related health harms are accelerating faster than the global response, even as clean energy investments and climate action begin to deliver measurable health benefits, according to a press release by the World Health Organization (WHO). Released on 28 October 2026, the report tracks global trends across 54 indicators linking climate change and health. It calls for climate change to be formally recognized and addressed as a global health emergency.
The report is produced by an international collaboration of researchers and institutions led by University College London and developed in strategic collaboration with WHO. It arrives a decade after the Paris Agreement entered into force. The 2026 edition brings together the work of 146 researchers from more than 100 institutions across over 30 countries. WHO serves as a strategic collaborator of the Lancet Countdown, providing technical leadership on climate change and health.
Annual average heat-related deaths increased by nearly 36% in the years following the Paris Agreement compared with the previous decade. In 2023 alone, heat was linked to a record 710,000 deaths globally, with more than 70% of that burden attributable to human-caused climate change. The report highlights worsening drought conditions, increasing exposure to hydrological extremes, and substantial economic losses linked to heat exposure. It also notes advances in climate-resilient health systems, including wider adoption of national health adaptation plans and climate-informed early warning systems. Global investment in clean energy reached a record US$ 2.1 trillion in 2025.
“Climate change is already harming health in every region of the world, and the evidence shows that many of these impacts are accelerating,” said Dr Diarmid Campbell-Lendrum, Head, Climate change, Air Quality and Energy and Health Unit.
He added that the report demonstrates climate action is a health intervention. Cleaner energy, stronger health systems and early warning systems are saving lives today. As countries prepare for COP31, placing health at the center of climate policies can help protect communities and strengthen resilience. The authors urge integrating health considerations across climate mitigation, adaptation and financing decisions.
WHO is responding to climate-related health risks through surveillance, early warning systems, health adaptation planning, technical guidance and emergency response operations. It also acts as Secretariat for the Alliance for Transformative Action on Climate and Health (ATACH). Since September, WHO has been responding to the expected health impacts of the ongoing El Niño event through a graded emergency response and a Global Incident Management Team. Under the International Health Regulations (2005), public health events that meet the criteria of a public health emergency of international concern may include those driven by climate change. The findings set the stage for health-focused discussions at COP31.