But could nature be "antifragile"? The latest entry in the Planet Earth series reminds us of the beauty and vulnerability of the world. But some think there is room for optimism.
Eye-popping Planet Earth bears sombre message
Whale done: Right whales almost went extinct, but today there are 12,000 around the world. Glossary
Great Barrier Reef - The world's largest coral reef system found off the coast of Australia.
Charles Darwin - His book, On the Origin of Species by Means of Natural Selection, is the founding work of evolutionary biology.
Perish - Die.
Nassim Nicholas Taleb - Taleb is a Lebanese-American essayist and statistician.
Ecosystems - Complex networks of living things that rely on each other to survive.