BORIS Johnson has joked about feeding humans to animals in a bid to solve the climate crisis.

Burping cows and meat-free lasagne recipes were also discussed when the Prime Minister assembled children to pose their questions at a Downing Street press conference.

The budding inquisitors, aged between eight and 12, also gave Johnson key points to take up with world leaders at the COP26 climate summit, which starts in Glasgow on Sunday.

Olivia, a seven-year-old appearing virtually from County Down, said she uses a reusable water bottle and plastic-free toothbrushes, and asked the Prime Minister what he will do to make sure others use less plastic.

Johnson posited using a reusable toothpaste dispenser as well, adding: "That's a development we need to encourage - we need to have municipal toothpaste, something or other, we'll work this out later."

He went on to describe recycling as a "red herring", saying production of plastic itself is crucial to saving the planet.

Appearing alongside him, WWF UK chief executive Tanya Steele told Johnson reduction is key but said recycling is also needed.

Downing Street later insisted that the Prime Minister wants the public to continue recycling, as the Recycling Association accused him of having "completely lost the plastic plot".

Johnson asked Steele what she thinks of rewilding, the process of promoting the recovery of natural habitats to encourage the restoration of native species.

"I think we need to bring nature back," she said, arguing that 97% of the mass of mammals on Earth is made up of humans and domestic animals.

"Just 3% is left for the wild," she added.

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The Prime Minister said the situation is "so sad" and added a suggestion to rebalance the disparity: "We could feed some of the human beings to the animals."

Steele suggested "a vote later and ask if there's any candidates", before telling Johnson: "Certainly we need to take our responsibilities seriously."

The Prime Minister's official spokesman later told journalists in Westminster that the idea was "not to be taken seriously".

Johnson welcomed one student's suggestion of more electric school buses as a "brilliant idea" before discussing the problem of agriculture producing greenhouse gases.

"Cows burp a great deal and emit gases – we have to encourage them to stop burping," Johnson said, suggesting that would make them "more polite cows".

He suggested "feeding them seaweed", which is thought to reduce cattle's methane expulsion.

Asked what sacrifices he would personally make to reduce global heating, Johnson did not give a straight answer.

But he said he recommended people "stop using hydrocarbon cars", adding: "I used to ride everywhere by bicycle, which was a wonderful life."

With cutting down on meat consumption essential to reducing the climate crisis, the Prime Minister predicted "in the future we will move away from eating as much meat".

Science, he argued, is already developing effective meat substitutes "that are very like meat".

"You won't be able to tell the difference between a bio-engineered hamburger - I'm serious - and a real hamburger," he added.

Steele recommended using beans as a substitute but Johnson misheard.

"Beets? I wouldn't put beetroot in a lasagne," he said.