The event, in Downing Street on Monday, was held in advance of the UN Climate Conference, COP26, which starts in Glasgow on Sunday night.
School children from around the UK were invited to put their hopes and fears for the climate in a nationwide appeal by the Hartlepool Mail and its sister titles.
Scottish schoolboy Lucas wanted to know whether world leaders would listen to them at OP26, when they gather in his country next month.
The prime minister admitted it was “touch and go” whether world leaders would commit to the actions the Earth needs.
But he was hopeful: “There’s a lot of peer pressure at the summit and I think that people feel that they want to follow the example of their friends and their neighbours, and that will have a good effect on the outcome, I hope.”
Olivia Devaney from County Down joined the Downing Street press conference live via video link.
She wanted to know what Boris Johnson could do to protect marine life from plastic getting into the ocean.
He said that recycling wasn’t the answer because it “didn’t begin to address the problem".
"You can only recycle plastic a couple of times," he said.
"And what you’ve got to do is stop the production of plastic, stop the first use of plastic.”
Other young questioners asked why the UK is not treating the climate as an emergency in the same way as the Covid pandemic and how children could be encouraged to eat less meat.
See the First news page in the Mail on page 11 for more from the prime minister’s Downing Street press conference with children.