Attenborough, one of the world’s most influential wildlife broadcasters, said Britain’s move last month to become the first G7 country to commit to a goal of net zero carbon emissions by 2050 could help galvanize broader international action.

“It’s a tough target. It's not an easy statement to have made, and it's going to cost money,” Attenborough told a hearing of parliament’s Business, Energy and Industrial Strategy Committee. “It's actually a practical commitment, and I hope to goodness that we can achieve it and stick by it.”

Attenborough, who has become increasingly outspoken about risks posed by the climate crisis in recent years, added: “It’s absolutely essential that it should be done … if we’re going to avoid massive social unrest.”

Attenborough had earlier told the hearing that he drew hope from an upsurge in environmental activism by a younger generation aware that they would bear the brunt of climate impacts as the crisis worsened in coming decades.

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"The problems in 20-30 years are going to be major problems that are going to cause great social unrest, changes in what we eat, how we live," Attenborough said.

"The most encouraging thing I see is that the electorate of tomorrow is already making their voice very, very clear."

Attenborough, the man behind the Planet Earth and Blue Planet documentaries, also said that the environmental impact of air travel should be factored into ticket prices.

“If you cost that, you would see that the tickets are extraordinarily cheap,” he said.