What Earth's sixth mass extinction event means for humans

From the tiniest microbes in the human gut to giant whales in the ocean, biodiversity is the sum of all life on the planet. It's another word for nature. And because nature is like a team, every player has a job. When various species from trees to animals work together, they regulate weather, maintain soil health, purify water and support food production. These benefits are known as ecosystem services and they underpin human wellbeing. "It is really an abstract concept, but we experience it absolutely every day," said Rebecca Shaw, chief scientist at conservation group WWF "And we almost never think about it when nature is functioning." But as it declines, she and other scientists are calling on the world to really think about it.