Broadcaster and naturalist Sir David Attenborough has played an extraordinary role in connecting people to the wonders of the natural world over the course of his 60-year career.
This week, he has been in Davos to receive a Crystal Award for his leadership in the fight against climate change and to take part in a number of panel discussions on the future of our planet, including a one-on-one interview with HRH the Duke of Cambridge.
Prince William asked Sir David about his life's work, the perilous state of the natural world, and to share his advice for young people and world leaders on how to better care for our planet.
Here are some key quotes from the discussion:
On the way the natural world has changed since he started broadcasting in the 1950s
"The natural world then seemed like an unexplored world... I went to West Africa for the first time and it was a wonderland. You'd just step off from the beaten track... and it seemed to me as a newcomer, unexplored and exciting and everywhere you turned you saw something new.
"The human population was only a third of the size of what it is today... you really did get the feeling of what it might have been like to be in the Garden of Eden."
On not being surprised at the popularity of television programmes on the natural world
"I don't believe that the child has yet been born who didn't look at the world around it with those fresh eyes and wonder.
"If you lose that first wonder, you've lost one of the most greatest sources of delight and pleasure and beauty in the whole of the universe. Caring for that brings a joy and enlightenment which is irreplaceable. That is one of the great pleasures of life."
On the impact of technology on filmmaking
"Fifty or 60 years ago... very few people in Britain or indeed Europe had actually seen a pangolin or an armadillo, so it didn't matter how badly or amateurishly you were, if you showed a shot of an armadillo... people weren't looking at it critically, they just saw an armadillo... so making natural history films in those days was comparatively easy. Just show the animals and people were astounded.
"The facilities we now have are unbelievable. We can now go everywhere. We can go to the bottom of the sea, we can go into space, we can use drones, we can use helicopters... we can speed things up, we can slow things down, we can film in darkness, so the natural world has never been exposed to this degree before."
On speaking out about climate change
"I don't think there was anybody in the 1950s who thought that there was a danger that we might annihilate part of the natural world... the notion that human beings might exterminate a whole species was not something people thought about, and if it did occur... it seemed the exception.
"Now of course we are only too aware that the whole of the natural world is at our disposal, that we can do things accidentally that exterminate a whole area of the natural world, and all the species that live within it.
"Now, there are more people living in towns than in the wild, so it means that the majority of the human race are out of touch to some degree with the richness of the natural world."
On the level of urgency around climate change
"It's 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.
"We have now to be really aware of the dangers of what we are doing. And we already know the plastic problems in the seas is wreaking appalling damage upon marine life. The extent of which we don't yet fully know."
On why world leaders have taken to long to react
"Because the connection between the natural world and the urban world, the human society, since the Industrial Revolution, has been remote and widening.
"We didn't realise the effects of what we were doing 'out there'. But now we are seeing that almost everything we do has it's echoes, its duplications and implications across the natural world.
"The natural world, of which we are a part, is incredibly complex and it has connections all over the place. If you damage one, you can never tell where the damage is going to end up, because of all the broken connections. And if you break all of them, then suddenly the whole fabric collapses and you get eco-disaster."
On what young people can do to help avoid climate catastrophe
"We have to recognise that every breath of air we take, every mouthful of food we take, comes from the natural world. And if we damage the natural world, we damage ourselves. We are one coherent ecosystem. It's not just a question of beauty, or interest, or wonder - the essential ingredient of human life is a healthy planet. We are in danger of wrecking that.
"We are destroying the natural world, and with it ourselves."
On his message to Davos participants
"Care for the natural world. Not only care for the natural world, but treat it with a degree of respect and reverence.
"The future of the natural world is in our hands. In our daily lives, the thing I really care for... is not to waste the riches of the natural world on which we depend. it's not just energy, but it's also dealing with the natural world with a degree of respect. Don't throw away food, or throw away power, just care for the natural world, of which we are a part."