The Duke of Cambridge has suggested young people could be the champions of environmental change in homes across the globe.

William’s comment came as he chatted to young activists recognised by a United Nations initiative. He highlighted how the next generation could educate their families about the “environmental impact” of their actions.

Seven young people have been named 2020 Young Champions of the Earth by the UN Environment Programme (UNEP) and William told them they could “easily be in the mix” for his Earthshot Prize.

Nzambi Matee, from Kenya, who manufactures sustainable building materials, told the duke it was hard to change the attitudes of older people, although her grandmother had adopted sustainability easily.

She laughed: “If we can convince my grandmother not to use plastic bags, we can do anything.”

The duke agreed, saying the next generation did not have to start ambitious projects like the seven recognised by the UN to “do their bit”.

He added: “If every young person educates their family on the environmental impact they are having, that in turn is making a difference, and changing the tide, and creating that momentum.”

William launched his ambitious £50 million Earthshot Prize project in the autumn with his Royal Foundation and it aims to recognise solutions, ideas and technologies that “repair the planet”.

UNEP is a global alliance partner of the duke’s project and shares its mission to incentivise change and inspire the public to safeguard the natural world.

Among the Young Champions of the Earth are an engineer who turns plastic rubbish into paving stones and an activist fighting to save endangered salmon. All will receive more than £7,000 in seed funding and tailored training to help scale up their ideas.

As the group told the duke about their various initiatives during a video call on Wednesday, he said he was “hugely honoured” to speak to such “brilliant young people doing such fantastic things”.

He added: “There’s a lot of opportunity in the environmental space. If young people have a tiny bit of that passion – that you have clearly shown a lot of – then there’s a really good opportunity to find your feet and find a way and do good in the environmental world.

“You are the shining lights of that movement and that interest. It allows people to see your path, your journey and go ‘do you know what, I want some of that, I can do that, I’ve got some ideas too.’”

William told the group about his Earthshot Prize explaining that it had been launched to “bring hope and optimism back to the environment debate” and to “try and encourage change through hope and action rather than pessimism and despair”.

“Why do you think the optimism part, which I felt very strongly about, is so important?” he asked.

Lefteris Arapakis, from Greece, who co-founded an organisation that teaches sustainable fishing, said the pandemic had “changed everything”.

He added: “I am from a family of fishermen and every year for the last 20 years we get less fish, my family has less and less of everything.

“Personally, I believe that we can make the change, because if we don’t believe that, we can just give up. It’s our only choice. Optimism is our main weapon against the climate crisis.”