Hot on the heels of his brother's unexpected book announcement, Prince William is to release a guide to saving the planet through his Earthshot Prize scheme,
William, 39, launched the Earthshot Prize in 2020 to award and scale up projects around the world which are working on solutions to saving the planet.
On Wednesday, the prize announced its own book, Earthshot: How To Save Our Planet written by Colin Butfield and Johnnie Hughes, with an exclusive introduction from the Duke of Cambridge.
It comes soon after Prince Harry, William's younger brother, said he would be writing his memoirs, due out in late 2022.
Alongside the royal brothers, their wives Meghan and Kate have also released books this year. Meghan produced The Bench, a children's book based on a poem she wrote for Harry for Father's Day, and Kate wrote the foreword for Hold Still, a collection of photographs taken during the COVID-19 pandemic.
Announcing the book, Earthshot said it "will be the authoritative book of The Earthshot Prize, highlighting the urgency of the environmental challenges facing our world while also providing readers with inspirational case studies of the incredible solutions happening globally to repair our planet".
As well as an introduction from William, the book features contributions from naturalist and broadcaster Sir David Attenborough, environmental activist Hindou Oumarou Ibrahim, singer Shakira and former astronaut Naoko Yamazaki.
Watch: Prince William reveals details of the first Earthshot Prize awards ceremony
The book will be released at the same time as a five-part BBC series in the autumn, which was also created by its authors, Butfield and Hughes.
Butfield is the former executive director at the international conservation charity WWF, and Hughes is a producer and director who was behind David Attenborough: A Life On Our Planet.
They said in a joint statement: "The Earthshot concept is simple: we have 10 years to turn the tide, 50 ingenious ideas, and one goal – to save our planet.
"What we need is action and optimism.
"Our book reaches from the coral reefs of Mexico, via palm oil plantations in Borneo and sheep farms in Australia, to the forests of Kenya.
"It’s an explanation of how we’ve got to this point, and how – by acting collectively – we can fix it."
No preview of William's introduction has been shared in the announcement.
Earthshot is the Duke of Cambridge's biggest royal project and has been touted as being to him as the Prince's Trust or Duke of Edinburgh scheme were to Prince Charles and Prince Philip.
The prize will give away £50m over the course of 10 years, giving five winners £1m each every year, to develop their solutions to problems the world faces, like climate change, restoring nature, and cleaning the air.
The first awards night is to be held at Alexandra Palace in north London on 17 October.
Earthshot: How To Save Our Planet will be published by John Murray in the UK, Europe and across the Commonwealth on 30 September, and in North America on 5 October.