Prince William launched the £50 million ($62 million) award to encourage and support the fight against environmental challenges.
“It’s gone better then I’d hoped,” he said on Tuesday, but there was “still a lot of work to do”.
“As we’ve seen today, the Earthshot winners and the finalists bring that inspiration and optimism,” Prince William said during a question session at the Earthshot Prize Innovation Summit.
“And I think we’ve got to hang on to optimism and hope because it is the biggest driver of change, it is the biggest driver of innovation.
“An important part of the prize’s designs and development is not just to provide the solutions, but it’s the factor to make people believe there is hope, and there are people out there doing incredible things that will have a massive impact on our futures.”
The Earthshot Prize aims to discover and scale up groundbreaking solutions to repair the planet and £1 million in prize money will be presented to the winners in five categories, or Earthshots: protect and restore nature; clean our air; revive our oceans; build a waste-free world; and fix our climate.
Among the finalists is Sea Forest, from Australia, which has developed a seaweed-based livestock feed to reduce the planet warming methane emissions from cattle and sheep.
Enso, a British-based company, has created a more efficient electric vehicle tyre, which reduces the harmful particles worn off during travel and extends the range.
Prince William, who is coming to the end of a two-day visit to New York, was asked if he went running in Central Park.
“Yes, I decided to join the hordes of New Yorkers doing their morning routine,” he said.
“It’s wonderful waking up in New York on a sunny morning after the rain we had yesterday, beautiful getting some fresh air this morning.”
Another finalist is a project turning Freetown, the capital of the West African nation of Sierra Leone, into “Tree Town” by empowering communities to plant trees to create green spaces and battle soil erosion and landslides.
Gunnlaugur Erlendsson, founder and chief executive of Enso, said a two-year trial with Royal Mail and parcel delivery firm DPD increased by 10 per cent the distance travelled by vans and reduced tyre pollution by 35 per cent.
“We need to talk about tyres because tyres are problematic for the environment, not just in terms of air pollution, microplastics and waste, but the whole industry is incredibly carbon intensive,” Mr Erlendsson said.
“I want to make absolutely clear we need electric vehicles to be successful because they tackle climate change [but] they do, of course, generate air pollution from tyres like all other vehicles.”
Former New York mayor and business news mogul Mike Bloomberg, a global adviser to Earthshot Prize winners, opened and closed the summit, and fellow speakers included Microsoft co-founder Bill Gates.
“Earthshot is not about yesterday, it is about today and about tomorrow because the climate crisis is no longer some far-off menace – it’s here right now, and the effects are only getting worse,” Mr Bloomberg told delegates.
“The best scientific studies tell us risks of more extreme weather are continuing to rise and so it’s up to us to rise to the occasion and do something about it.
“And Prince William is helping the next generation lead the way by building on his father and grandmother’s dedication to environmental stewardship.”