What Earth’s Sixth Mass Extinction Event Means for Humans and Their Future

Nature’s work supports people

Biodiversity includes all life, from microbes in the human gut to whales in the ocean. Species work together to regulate weather, maintain healthy soil, filter water and support food production—benefits known as ecosystem services.

Rebecca Shaw, chief scientist at WWF, said people experience these benefits every day, often without noticing them. She described biodiversity loss as an early warning that the natural systems people depend on for food, freshwater and clean air are coming apart.

Intensive farming, fossil fuel use and pollution, including plastics and chemicals, are putting ecosystems under pressure. WWF’s Living Planet report says monitored vertebrate populations have declined by an average of 73% over the past 52 years, with freshwater ecosystems down 85%.

Water and food depend on nature

Wetlands illustrate the consequences of biodiversity loss: about 85% disappeared between 1700 and 2000. A University of Waterloo study found that marshes and swamps in Southern Ontario provide C$4.2 billion (€2.63 billion) in water filtration services annually, removing nutrients such as phosphorus.

Biodiversity can support medicine

Natural compounds provide the basis for many modern medicines, with about 50% of medicines coming from them. Penicillin, produced by a mold, is estimated to have saved more than 500 million lives.

Louise McRae, a research fellow at the Zoological Society of London and contributor to WWF’s Living Planet report, said the UK and other countries depend on food imports and ecosystems abroad. She said this makes global biodiversity important to protect.

Some species have no substitute

Species can sometimes take over another’s ecological role, but this is not always possible. Keystone species have an unusually large influence on their environments, so their loss can cause wider effects.

Oysters are one example. Wild populations are declining, and 85% of oyster reefs have been lost worldwide; an adult oyster can filter up to 50 gallons of water a day. Shaw said oysters may seem unimportant, but their disappearance matters because of the work they do in ecosystems.