David Attenborough warned it is difficult to overstate the environmental crisis facing the planet as he was interviewed live on stage by Britain's Prince William.
The veteran broadcaster urged leaders to care for the natural world as he spoke with the prince at the World Economic Forum in Davos, Switzerland.
The Blue Planet and Dynas- ties narrator stressed the "frightening" mechanisms humans have for destruction, and warned how a healthy natural world was "absolutely essential" to human life.
"The future of the natural world is in our hands. We have never been more powerful," Attenborough said.
"We can wreck it with ease. We can wreck it without even knowing we are doing it, and if we wreck the natural world, in the end we wreck ourselves.
"It is difficult to overstate it. We are now so numerous, so powerful, so all-pervasive, the mechanisms that we have for destruction are so wholesale and so frightening that we can actually exterminate whole ecosystems without even noticing it."
Attenborough also discussed his new nature documentary, Our Planet, saying streaming it on Netflix would allow it to be seen by millions around the world.
Describing the modern technology used in his documentary-making, he said: "The facilities we have are un- believable. We can go everywhere. The natural world has never been exposed to this degree before."
Prince William described it as a "personal treat" to be interviewing Attenborough.
He has spoken of his fondness for watching Attenborough's programmes as a child and previously described him as having "the single most important impact in my conservation thinking".