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London(CNN) The inaugural winners of Prince William's Earthshot Prize include the country of Costa Rica, an Indian organization that creates fuel from agricultural waste and a coral farming group in the Bahamas.
The prize, a Nobel-like award founded by the Duke of Cambridge and renowned British naturalist David Attenborough, aims to inspire innovative solutions to the most pressing environmental challenges currently facing the planet.
Each of the five winners walks away with £1 million -- the equivalent of over $1.3 million -- and the promise of "professional and technical support" to scale up their innovations.
Costa Rica won for its scheme to pay local citizens to protect and restore rainforests and local eco-systems, a system that the prize committee credits for having already reversed decades of deforestation.
Indian organization Takachar's innovation was a technology that attaches to tractors and reduces smoke emissions by up to 98% while converting the residue into new products.
Coral Vita in the Bahamas won for its method of accelerating coral regrowth by growing it first on land and then replanting on depleted underwater reefs.
The entire city of Milan was recognized for "Food Hubs" approach to reducing food waste and distributing to the needy food that would be otherwise be wasted by restaurants and supermarkets.
And a Thai, German and Italian group won for its AEM Electrolyser, a "plug and play" module that turns water into emissions-free green hydrogen.
Green hydrogen technology -- which is powered by renewable sources -- already exists, but this module is compact, allowing for as few as one electrolyzer unit or as many as 70 to be fitted within it. That makes it versatile and more accessible to lower-income countries and small businesses.
The winners were announced Sunday at an glittering awards ceremony at London's Alexandra Palace -- in what Kensington Palace called "the most sustainable event of its kind."
"We are alive in the most consequential time in human history -- the actions we choose or choose not to take in the next 10 years will determine the fate of the planet for the next thousand," William said in a short film recorded in the London Eye for the awards ceremony. "A decade doesn't seem long, but humankind has an outstanding record of being able to solve the unsolvable."
William continued that "many of the answers are already out there... but we need everyone -- from all parts of society -- to raise their ambition and unite in repairing our planet."
"The future is ours to determine. And if we set our minds to it, nothing is impossible," he added.
Heir to the British throne and lifelong environmentalist, Prince Charles said he was "proud" of his son, in a statement from Kensington Palace.
"I am very proud of my son, William, for his growing commitment to the environment and the bold ambition of The Earthshot Prize. As a world, we need to come together to inspire, reimagine and build the sustainable future we do desperately need," Charles said.
"Over the coming decade, with future generations in mind, The Earthshot Prize, and its inspirational nominees, will help us find innovative solutions," the Prince of Wales added. "Together, with all those who join us, we have a real opportunity to deliver a brighter future for humanity while restoring harmony between Nature, People and Planet."
Attenborough spoke at the ceremony about the award's importance and his optimism in humanity's ability to tackle the most pressing environmental issues of our time. He praised all 15 of the Earthshot finalists for giving the world hope.
"The natural world on which we entirely depend is declining at a rate faster than at any time since the end of the dinosaurs. We know where this story is heading and we must now write a different ending. This is what The Earthshot Prize was created to achieve. The 15 Earthshot Prize Finalists tonight build optimism by finding innovative and brilliant solutions to the world's challenges, and they give us hope, which, we are told, springs eternal."
Earlier this week, Prince William criticized the billionaire space race, arguing that the world's greatest minds should be more focused on trying to repair the planet rather than traveling to space.
It wasn't the only recent royal rebuke of global climate crisis inaction, with the monarch Queen Elizabeth II was overheard Thursday saying she finds "it's very irritating when they talk but they don't do" while discussing the upcoming COP26 climate conference in Glasgow.
Correction: A previous version of this story said that the electrolyzer converted renewable electricity into green hydrogen. The story has been updated to reflect that green hydrogen is made from the electrolysis of water using renewable power.