French President Emmanuel Macron issued a stark warning on climate change at a summit in Paris on Tuesday, telling world leaders "we are losing the battle" against global warming.
"We're not moving fast enough, that's the problem," Macron told the One Planet Summit called to boost the 2015 Paris climate accord, which US President Donald Trump has renounced.
"We must all act because we will all be held to account," Macron told the gathering on an island in the River Seine, adding: "We cannot say we did not know."
Dozens of world leaders and hundreds of ministers, company bosses, and environmentalists attended the meeting held two years to the day since 195
nations sealed the Paris Agreement on curbing emissions.
The absence of the US was keenly felt at the talks, which focused on boosting investment in green energy and divesting from fossil fuels.
Speaking ahead of the summit Macron said he was hopeful Trump would reconsider his decision to take the US out of the climate pact.
"I'm not ready to renegotiate but I'm ready to welcome him if he decides to come back," he told US broadcaster CBS, adding: "I'm pretty sure that my friend President Trump will change his mind in the coming months or years."
Two years ago to the day, US secretary of state John Kerry shared in the cheers and champagne in Paris as world powers sealed a landmark global climate accord.
Returning to the French capital Tuesday for a follow-up summit, he cut a bitter and disappointed figure.
The United States' commitment to fighting climate change -- something both Kerry and former president Barack Obama hoped would be a key part of their joint legacy -- was reversed in June when Donald Trump announced he would withdraw America from the Paris pact.
The lack of American leadership in tackling what Obama had termed "an existential threat", was plain to see at the One Planet Summit in the French
capital Tuesday where more than 50 world leaders and dozens of ministers met for talks.
Only Trump and Syrian president Bashar al-Assad were not invited. The American government was represented by the second-ranked diplomat in the Paris embassy who appeared nowhere on the official programme of events.
"It's very disappointing, it's worse than disappointing, it's actually a disgrace when you consider the facts, the science, the common sense, all the
work that's been done," Kerry told AFP when asked for his thoughts on the US absence.
The 74-year-old stressed Tuesday that Trump's rejection of the Paris Agreement amounted to more than just a waste of the Obama administration's intensive diplomatic efforts -- seen by environmentalists as compensating for Washington's decision in 2001 to withdraw from the global Kyoto climate accord.
"It's 26 years of work that's being dishonoured by people who don't even understand the science," Kerry complained.
Pending a radical about-turn, a high-profile delegation of American entrepreneurs, city leaders, and campaigners underlined in Paris that they
were the only hope for the US meeting its target of cutting greenhouse gas emissions by at least 26 percent from 2005 levels by 2025.
"We can't wait for the White House to wake up. We in America are operating from the grassroots," California governor Jerry Brown, who has become a
leading advocate for emission-cutting efforts, told a panel discussion.
Like other Americans, from Microsoft billionaire Bill Gates to former New York mayor Michael Bloomberg and ex-California governor Arnold Schwarzenegger, Brown lamented the US president's unilateral decision that has isolated Washington and angered allies.
"We have a climate denier in the White House who says climate change is a hoax," Brown said.
Kerry holds out some hope that his hard-fought climate diplomacy might still bear fruit.
Asked whether the US could still meet its emissions-curbing target, he replied: "I think it's possible, yes."