The Duke of Cambridge surpassed himself when tasked with blue-sky thinking to help save the environment – his idea was out of this world.

When William joined a group of schoolchildren encouraged to think the unthinkable to repair the planet, he came up with getting superheroes to collect the world’s rubbish and carry it into space.

The duke was attending an educational initiative inspired by his Earthshot Prize at Kew Gardens, and was joined by the duchess, the Mayor of London Sadiq Khan, television presenter Steve Backshall and his wife double-Olympic rowing champion Helen Glover.

The Duke and Duchess of Cambridge alongside children from The Heathlands School, Mayor of London Sadiq Khan, right, TV presenter Steve Backshall MBE (2nd left) and Olympian Helen Glover (3rd left) during a visit to the Royal Botanic Gardens, Kew, in south London, to take part in a Generation Earthshot event
The Duke and Duchess of Cambridge alongside children from The Heathland School, Mayor of London Sadiq Khan, right, TV presenter Steve Backshall MBE, second left, and Olympian Helen Glover, third left (Ian Vogler/Daily Mirror/PA)

Each of the famous faces sat at a table with children from The Heathland School, in Hounslow, west London and were encouraged to use objects like drum sticks and an orange, a pile of cardboard and their own brain power to come up with planet-saving solutions.

The tables were also assigned a superhero action figure to inspire them and while Kate had the Invisible Woman from the Fantastic Four, William had Ant Man.

“We just need Ant Man here to help us find some answers,” said the duke as he adjusted the toy’s arm.

The duchess said about her superhero: “Maybe she could make an invisible bubble that no-one can see to protect the planet so no-one can cut down any trees?”

Yusuf Rawn, 12, sat with the duke and said about William’s proposal: “One of the ideas was getting all the superheroes together to lift all the rubbish into space.

The Duchess of Cambridge (Ian Vogler/Daily Mirror/PA)
The Duchess of Cambridge (Ian Vogler/Daily Mirror/PA)

“We thought it was quite interesting, it would work but sadly we don’t have any super heroes.”

The brainstorming educational initiative called Generation Earthshot was inspired by the duke’s environmental Earthshot Prize which is holding its inaugural awards ceremony at the weekend.

In a statement William called on society to inspire “optimism, confidence and enthusiasm” in the next generation to find solutions to protect the earth.

The duke said: “Education is such an important part of protecting our planet.

“We must inspire in the next generation the optimism, confidence and enthusiasm to chase those solutions and to continue building a more sustainable future.

Royal visit to Kew
The Duke Cambridge with the Ant Man figure that his group used to inspire their blue-sky thinking. Ian Vogler/Daily Mirror

“We know that young children already identify the climate as one of their biggest worries, and Generation Earthshot aims to educate and encourage them that together we can find the answers.

“Children can be uniquely creative and I can’t wait to see some of the ideas that are shared with us.”

As he left William told the Mayor of London: “Some ideas my table came up with they’re already being done, and they didn’t even realise.”

Backshall said about the Cambridges: “They were fantastic.

“Encouraging the children to throw out every idea possible.

“It’s the kind of attitude our leaders need if we are to have any chance of making an impact on our climate’s problems.”