In his strongest comments yet on global heating, the prime minister laid bare the devastating consequences of the world failing to agree action at the looming Cop26 summit.
“It will be the people in the audience, it will be your generation, young people, who are left to deal with the consequences if we should fail,” he told the event in Milan.
“Because a child born in 2020 will endure seven times as many extreme heatwaves and twice as many droughts as their grandparents.
“Hundreds of millions of you are facing rising seas, failing crops, burning forests and ever-more ferocious storms. Daily challenges that lead to lost opportunity.
“Your future is being stolen before your eyes. I saw the protestors earlier on – and, frankly, you have every right to be angry with those who aren’t doing enough to stop it.”
However, Mr Johnson insisted it was not too late for the world to pull back, adding: “We know what needs to be done, we just have to get on with it.
“It’s a big task, one that will ask a lot of absolutely everybody. But change on the scale we need is perfectly possible.”
At Cop26, from 1 November, the government hopes to “keep alive” the ambition, in the 2015 Paris Agreement, to keep the post-Industrial Revolution temperature rise to 1.5 degrees, to avoid runaway climate change.
However, Mr Johnson has been boosted by Joe Biden’s increase in funding to developing countries to help them adapt to climate change and lower their own emissions.
And China – although it is yet to announce a carbon-cutting target for 2030 – has announced it will no longer fund coal-powered energy generation abroad.
Mr Johnson painted a rosy picture of change underway in the UK, although his own climate advisers have warned he is way off track on attempts to achieve ‘net zero’ emissions by 2050.
“When I was a child, something like 80 per cent of the UK’s electricity was generated by burning coal,” he said, in a video message.
“Even as recently as 2010, we got 10 times more electricity from fossil fuels than from renewables.
“Yet today, as I speak to you, most of the electricity consumed in the UK comes from clean green sources. Our carbon emissions are barely half what they were in 1990.
“And coal, which was once the undisputed king of our energy mix, now accounts for less than two per cent of our electricity – a number that will hit zero within the next couple of years.”
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