The Duke of Cambridge's ambitious Earthshot Prize will pay out a total of £50 million to winners over the next ten years, as they present solutions to some of the world's biggest environmental challenges.
Announcing new details of the global, Nobel-style awards programme, Prince William said: "urgency with optimism really creates action".
In an interview alongside Sir David Attenborough for BBC Radio 4's Today programme, William will say: "I felt very much that there's a lot of people wanting to do many good things for the environment and what they need is a bit of a catalyst, a bit of hope, a bit of positivity that we can actually fix what's being presented. And I think that urgency with optimism really creates action.
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"And so the Earthshot Prize is really about harnessing that optimism and that urgency to find solutions to some of the world’s greatest environmental problems.
"We believe that this decade is one of the most crucial decades for the environment and by 2030 we really hope to have made huge strides in fixing some of the biggest problems the Earth faces."
Later today he will unveil a global prize council of major names from the worlds of sport, the environment, entertainment, business and philanthropy.
With the backing of a scientific advisory panel, they will pick five £1million winners each year between now and 2030.
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Sir David and William will appear on BBC Radio 4's Today programme
In a video introducing the council later today, the Duke will say: "The plan is to really galvanise and bring together the best minds, the best possible solutions, to fixing and tackling some of the world’s greatest environmental challenges.
"We've got to harness our ingenuity and our ability to invent. The next ten years are a critical decade for change.
"Time is of the essence, which is why we believe that this very ambitious global prize is the only way forward."
The themes for each of the five annual Earthshot Prizes are also announced today in a series of short films. Produced by Silverback Films, the production team behind Sir David Attenborough's latest movie, they are narrated by young environmental activists including Bindi and Robert Irwin.
Winners could be individuals, a group of scientists or activists, businesses, governments and even a city or entire country that best meet the challenges, which are: Protect and restore nature, Clean our air, Revive our Oceans, Build a waste-free world and Fix our climate.
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The Earthshot Prize is William's biggest project to date
Nominations for the prize open on 1 November with an annual global awards ceremony to be held in a different city each year. The first Earthshot Prizes will be presented in London in autumn 2021 over several days, with the aim of celebrating the first 15 finalists like "returning astronauts" in a bid to boost optimism in our ability to repair the planet.
Led by Director Amy Pickerill, the Duchess of Sussex's former Assistant Private Secretary, the Earthshot Prize is launching in partnership with the Royal Foundation, but will become fully independent next year.
Among the Global Alliance Founding Partners backing the project are the Aga Khan Development Network, the Jack Ma Foundation, which was set up by the founder of China's online retail giant Alibaba, and the The Paul G. Allen Family Foundation, created by Microsoft co-founder Paul Allen, who died in 2018. Organisations lending their expertise with the nomination process include WWF, Greenpeace, The Green Belt Movement and Conservation International.
As well as showcasing inspiring new solutions to the world's problems, the Earthshot Prize also aims to raise optimism about humanity's ability to solve big challenges – something that will be measured annually with an Ipsos Mori poll. The BBC will also screen a five-part series about the project ahead of the first awards ceremony.
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The launch comes after two years of work
Billed as the most prestigious environmental prize in history, this is William's biggest project to date and one that will define the next decade of his career. The seeds of the idea were sown during a visit to Namibia, Tanzania and Kenya in autumn 2018, when he met frontline conservation workers and was inspired by their ability to solve the challenges they were facing.
William discussed the idea in December of that year with Sir David Attenborough and others including the Prince of Wales, who has campaigned on the environment since the 1970s.
A source close to the project said: "This is an issue with a long family tradition and that’s something that has given us real power in putting this prize together. Generations of work have come before this."
Others believe the Earthshot Prize comes at a time when William has grown in confidence and in stature on the world stage, with another source adding: "He's not naturally the boldest individual in asserting himself, but what he has clearly realised over the last year because of the people he has spoken to is that he has a global leadership role to play and now is the time to play it.
"It's going to be a huge focus of his work in future."
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