“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.”
Ebury, the publisher, said the book would be “intimate, urgent and impassioned”.
It will “present his view on the future that lies ahead if we continue as we are, and a plan for how to avoid that future”.
“The earth’s life-support machine, the thing we humans rely upon for everything we need, runs on its biodiversity,” Attenborough said.
“Yet the way we live on earth now is sending it into a decline. I have been a witness to this decline.
“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 book will reflect on Attenborough’s career, exploring and documenting the natural world, and the decline of the planet’s environment and biodiversity he has observed firsthand.
It will be released in October to coincide with the release of a Netflix documentary film of the same title, commissioned by the World Wide Fund for Nature.