Sir David Attenborough is preparing to publish his "vision for the future" of Earth.
The 94-year-old natural historian plans to detail the "dreadful damage" caused by humanity in his new book, but he also intends to outline ways "we can begin to turn things round".
David, who will publish ‘A Life on Our Planet’ in October, explained: "This book records some of the dreadful damage mankind has already wrought upon the natural world, and the real and imminent danger that things could get much, much worse if we do not act now.
"But it is also a hopeful book: it offers a different future. It describes some of the ways in which we can begin to turn things around, if only we all have the will to do so.
"Surely together we must now find that determination, and begin to make that change, for the sake of all the inhabitants of our planet."
David has "been a witness" to the destruction caused by humanity.
But the award-winning documentary-maker remains hopeful that some of the damage can be reversed "if we act now".
He said: "As a young man, I felt I was out there in the wild, experiencing the untouched natural world – but it was an illusion.
"The tragedy of our time has been happening all around us, barely noticeable from day to day: the loss of our planet’s wild places, its biodiversity.
"I have been a witness to this decline, and this book contains my witness statement, and my vision for the future – the story of how we came to make this, our greatest mistake. And how, if we act now, we can yet put it right."
The release of ‘A Life on Our Planet’ will coincide with a Netflix documentary film of the same name, commissioned by the World Wildlife Fund.