The Duke of Cambridge warned that the world's future is at a "tipping point" as he launched his ambitious £50 million Earthshot Prize.
In a series of interviews, William set out his ambition to use his global environmental competition to encourage the public, scientists, businesses and even cities to come up with ideas, solutions and technologies to "repair our planet" within 10 years.
With younger generations led by teenage activist Greta Thunberg calling for action, the duke said they would not stand for a "lack of hope".
William also admitted that his children have been badgering him to adopt a greener lifestyle to help the planet, and that the threat to the natural world has at times left his eldest son, Prince George, feeling despondent.
Interviewed in the grounds of Kensington Palace a few weeks ago, William told BBC Radio 4's Today programme: "These are grave times for the environment, but I do believe with human ingenuity, and I do believe with younger generations speaking up like they are now, that they will not stand for this lack of hope, with this lack of idea that we can't fix some of these big solutions."
He said he feels the world is at a "tipping point" and that he wants to "hand the planet in a better state then we found it" to his children and grandchildren.
The future king spoke about taking on a global leadership role to safeguard the environment when he spoke to Sky News.
"This is me putting my stamp on what I can do in my position to really galvanise and increase the interest and tackle some of these issues and drive a decade of change to help repair the planet," he said.
And he is prepared to go to places that feel "uncomfortable", or make others feel the same, to "make a difference".
William said the fight against coronavirus has been allocated huge resources and the same commitment should be shown to saving the natural world.
We have just 10 years to repair the planet. By 2030, let's choose to:
🐢 Protect and restore nature💨 Clean our air🌊 Revive our oceans♻️ Build a waste-free world🌍 Fix our climate
— The Duke and Duchess of Cambridge (@KensingtonRoyal) October 8, 2020
He told Sky News: "We found over £190 billion ... to fix and help the recovery through Covid. We can do the same for the environment."
The Earthshot Prize takes its inspiration from the Apollo Moon landings, nicknamed Moonshot, which helped advance mankind's technological achievements, and features five categories or Earthshots, which organisers say, if achieved by 2030, would improve life for all.
Every year from 2021 until the end of the decade, winners in the five Earthshots will each receive £1 million after being picked by a judging panel of William and leading figures.
Sir David Attenborough, who has supported the project from the beginning, was interviewed alongside the duke on the BBC and sounded an ominous note.
He said: "Suddenly we actually see the writing on the wall. Suddenly we can actually see coral reef dying. Suddenly we can see that forests are disappearing.
"Suddenly there are real dangers that there may be a tipping point in which the ice caps of the North Pole begin to melt – which it's doing already. People can see it's happening and it's a matter of great urgency now."
Today programme presenter Nick Robinson said Sir David's recent documentary had suggested that society should use fewer fossil fuels and take on a plant-based diet, and he asked William: "I just wonder whether your children are now nagging you to change life a little bit to help the planet?
The duke replied: "Absolutely, Nick, and I think, you know, we all want to do – and we all should do – our bit to help in this progress.
"But the key thing about the Earthshot Prize is that it's that positivity. It's the idea that we need to find solutions to be able to live our lives and enjoy our lives and not feel guilty and bad about some of the things we do."
William admitted to Sky News that Prince George was saddened by Sir David's documentary about extinction, and had told him: "I don't want to watch this any more."
The duke also said he is "struggling to keep the optimism levels going" with his children and worried they will soon realise the true predicament of the planet.