Planetary and human health are inseparably connected; yet, health-care systems produce considerable amounts of greenhouse gas emissions, waste and pollution. A growing movement to measure and mitigate the health sector’s own climate damage is underway, supported by national policies and clinical innovation.

The health of our planet is inextricably linked to human health and well-being, as Earth provides for our most basic needs: fertile land for food production, safe water to drink and clean air to breathe. Human activity has been degrading our planet’s life-support system through pollution of land, water and air, and threatens our ability to thrive and survive equitably. Human influence on the climate system is undisputed1 and affects human health through three main pathways. First, extreme weather, such as heatwaves, flooding, wildfires, storms and droughts, affects physical and mental health, for example through injuries, trauma and heat-related illness. Second, alterations in the global carbon cycle, water cycle and biosphere integrity lead to new patterns of zoonotic and vector-borne diseases, such as malaria and dengue fever, reduced pollination, crop failure, food and water shortages and rising sea levels. Third, resulting effects on social systems precipitate loss of livelihood, rising prices of food and fuel, disruption of supply chains, pressure on health and care services, armed conflict and forced migration. Importantly, the heating of the climate disproportionately harms marginalized groups, including those living in poverty and in the global south2.