The Lancet: climate change's health impacts rose over the past decade

A 2026 Lancet Countdown report on health and climate change, published in the medical journal The Lancet, found that the health impacts of climate change have accelerated globally over the past 10 years. Despite progress made since the 2015 Paris Agreement, the report said climate-related health risks are speeding up, and it called for a declaration of a global health emergency.

Prepared under the leadership of University College London with the World Health Organization (WHO) and involving 146 researchers from more than 100 institutions, the report estimated that extreme heat caused an average of more than 540,000 deaths a year worldwide in 2016-2023. It said 68% of these deaths were directly attributable to climate change. In 2023 alone, heat-related deaths reached about 710,000, with more than 71% linked to climate change.

The report estimated that extreme heat caused work and productivity losses equal to over $1 trillion in potential income worldwide in 2025. Global clean energy investment reached $2.1 trillion in 2025, but fossil fuels continued to meet more than 80% of global energy supply. Lancet Countdown Executive Director Marina Romanello said the findings were clear.