French President Emmanuel Macron has told fellow world leaders that the battle against climate change is being lost.
Speaking at the One Planet Summit in Paris, Mr Macron said the 2015 Paris climate accord was in a fragile state after President Donald Trump pulled the US out in June.
"We're not going fast enough, there lies the tragedy," Mr Macron said.
"We've committed to limiting the temperature rise to 1.5 degrees Celsius, and if we carry on along this path, we're heading towards 3 or 3.5.
"When I say that we're losing the battle, I would like you to realise that of the countries represented here, 5, 10 or 15 of them won't exist anymore in 50, 60 or 100 years.
"It's as simple as that."
Mr Macron emphasised that the need for action was now.
"The urgency is permanent and our generation's challenge is to act, act faster and win this battle against time, and to put in place concrete measures that will change our countries, our societies, our economies.
"So that our children and maybe even ourselves can choose our future and not suffer through global warming."
Leonardo DiCaprio, Bill Gates in attendance
Politicians from around the world attended the summit in Paris to discuss the issues relating to global warming.
Celebrities Leonardo DiCaprio and Arnold Schwarzenegger were also there, as well as well-known philanthropists Bill Gates and Richard Branson.
The summit marks two years since the landmark climate accord was signed in the French capital.
And Mr Macron was quick to take aim at the US President's decision to opt out of that agreement.
"There have been attempts and decisions to leave this accord. It's very bad news," he said.
"If we're here today, it's because many have decided not to accept the US Federal Government's decision to pull out of the Paris Agreement."
California Governor Jerry Brown echoed his comments.
"The rest of the world is very serious about climate change. The vast majority of scientists are also very serious about climate change," Mr Brown said.
"So I'd say now it's time for President Trump to do what he can. And if he can't then get out of the way, don't try to resurrect coal and don't try to kill solar."
World Bank says it will stop financing oil and gas by 2019
A dozen international projects were announced at the summit.
They included a program for eight US states to develop electric cars, investment funds for hurricane-hit regions, and money to help farmers adapt to climate change.
World Bank president Jim Yong Kim announced the organisation would stop financing oil and gas projects by the end of 2019.
He also promised billions to help reduce greenhouse gas emissions.
The climate summit, which concluded today, came on the same day the US National Oceanic and Atmospheric Administration released its annual Arctic Report Card.
It found that the Arctic had notched up its second warmest year in recorded history.