Human health and well-being depend on the natural environment, which is the source of clean air, water, healthy soils and food. The natural environment comprises ecosystems, which when healthy and thriving, also confer protection against climate change and disaster risk. Ecosystems include for example forests, marine and freshwater ecosystems, grasslands and mountains and comprise a range of different species that interact with each other and the surrounding environment. The stability and health of ecosystems, however, depend on biodiversity.

Biodiversity has many more strong links to health; examples include the prevention of infectious disease outbreaks and pandemics, nutritional diversity and food security, and the provision of medicines. Ecosystems and biodiversity are directly threatened by human activities such as land use change, overexploitation of resources, climate change, pollution and invasive alien species. Reducing pressure on the natural environment, from deforestation to intensive and polluting agricultural practices, to unsafe management and consumption of wildlife, will protect the environment that humans rely on, for their health and ultimately their economy.