By Marie Jackson
image source, Getty Images
It is time for humanity to grow up on climate change, Boris Johnson has said in a speech to the United Nations in New York.
The world is approaching a "critical turning point" and countries must finally take responsibility for the destruction we are inflicting on the planet and ourselves, he said.
His speech comes ahead of the COP26 climate summit in Glasgow in November.
The PM has used his US visit to push leaders for action on climate change.
Some 100 world leaders are expected to attend the meeting at the UN General Assembly.
Mr Johnson attempted to strike a humorous note in his speech, saying Kermit the Frog had been wrong when he sang It's Not Easy Bein' Green.
He also referenced Sophocles, the writer of ancient Greek tragedies: "If you imagine that million years as the lifespan of an individual human being - about 80 years - then we are now sweet 16.
"We have come to that fateful age when we know roughly how to drive and we know how to unlock the drinks cabinet and to engage in all sorts of activity that is not only potentially embarrassing but also terminal for ourselves and others.
"In the words of the Oxford philosopher Toby Ord 'we are just old enough to get ourselves into serious trouble'."
Amid the metaphors, the prime minister made a series of calls for action to the general assembly members, including:
'We missed our cue'
The prime minister concluded his speech with a plea for leaders to do right by the next generations.
"If we keep on the current track then the temperatures will go up by 2.7 degrees or more by the end of the century.
"And never mind what that will do to the ice floes: we will see desertification, drought, crop failure, and mass movements of humanity on a scale not seen before, not because of some unforeseen natural event or disaster but because of us, because of what we are doing now.
"And our grandchildren will know that we are the culprits and that we were warned and they will know that it was this generation that came centre stage to speak and act on behalf of posterity and that we missed our cue and they will ask what kind of people we were to be so selfish and so short sighted."
At COP26, leaders from 196 countries will be asked to agree action to limit climate change and its effects, like rising sea levels and extreme weather.
A recent report from UN scientists warned that global temperatures have risen faster since 1970 than at any point in the past 2,000 years.
Between the UK and the US leaders, there are markers of a relationship in good health.
Remember, on the way to the US Mr Johnson put the chances of achieving his goal of a cheque for $100bn to fight climate change by next month as just "six out of 10".
President Biden's announcement this week, was not something No 10 was sure would happen at this stage.
It takes the UK a long way to meeting that that total, and officials hope the American vow will unlock other finance from other nations.
Remember too how, so often on big foreign trips, a slight, or a stumble can send things into a terrible spin - Gordon Brown's attempt to see President Obama which ended awkwardly in a kitchen and Donald Trump grasping Theresa May's hand.
And of course, Mr Johnson himself is not exactly a stranger to a gaffe or a glitch. But as I write, shortly before he and the press pack fly back there hasn't been any major slips or surprises - at least not that we know about yet.