After a year of ever more extreme weather and continually rising global temperatures, it’s no wonder this year’s UN climate summit has been called – once again – the “last-chance saloon”.
Yet swaggering out through its swing doors goes president-elect Donald Trump.
The timing of his election win, with its promise to withdraw the US from the global climate process, couldn’t be worse.
Next year is forecast to exceed 1.5 degrees of warming for the first time – something the Paris Agreement is designed to prevent from becoming the norm.
Despite that and nearly 30 years of talks, man-made emissions of greenhouse gases are still rising.
Yet just a handful of nations have committed to cut them enough to prevent close to three degrees of warming by the end of the century.
So does America’s sudden departure, at this most precarious of moments, spell disaster?
Under previous administrations, the US was a major diplomatic force at the talks – brokering significant concessions from more recalcitrant states, including the world’s largest polluter, China.
It also set ambition, adopting carbon-cutting pledges and domestic policies like the Inflation Reduction Act (IRA) that sent a powerful message to others that if the US saw a future beyond fossil fuels, everyone could.
As the largest shareholder in the World Bank, the US was also seen as key to brokering a new deal to finance the green transition in poorer countries: the main objective of the COP29 talks in Azerbaijan.
Now, although its negotiating team heading to Baku still serves President Joe Biden‘s agenda, it has lost its diplomatic leverage. In less than three months, they will all be out of a job.
Will the departure of the US galvanise other leaders – threatened by increasingly right-leaning electorates at home – to scale back their ambition too?
Or even follow its lead and ditch the “woke” jamboree of school-shy teenagers, indigenous groups and NGOs some have long perceived the UN climate talks to be?
Not likely – at least according to Jonathan Pershing, former president Barack Obama‘s then-climate envoy.
Mr Trump tried to reverse US climate policies when he last won control of the White House and it didn’t come to much, argues Mr Pershing.
“Even with the shock, not a single other country followed the United States in withdrawing from the Paris Agreement,” he says. “I don’t think anyone will this time either.”
His optimism stems from the fact the MAGA (Make America Great Again) movement can ignore climate realities, but not economic ones.
Despite a campaign slogan of “Trump Digs Coal,” more coal-fired power plants closed under Mr Trump’s last administration, for example, than under the climate-friendly one of Mr Obama.
Alternatives to fossil fuels, like wind and solar power, are increasing in popularity and decreasing in price, a trend forecast to continue.
This is the case even more so among America’s competitors like China which, according to Mr Pershing, saw 40% of its GDP last year come from shifting to clean technologies.
“The idea that they would forego that growth just because the US has withdrawn seems not only implausible but highly, highly, unlikely,” he said.
That may be the analysis from COP insiders. However, international agreements have long lagged behind the urgency of the climate crisis.
The talks about to start in Baku were supposed to accelerate action.
Instead, negotiators will arrive knowing that 72 million Americans voted for Mr Trump. It’s unlikely his denial of climate change was a major factor in their decision – but nor was it enough to deter them.
His administration’s plans may turn out to be just another bump along the road towards an inevitable zero-carbon future.
But any climate scientist will tell you that even the slightest delay on that journey is disastrous – and more than half of America just signalled it has no interest in going faster.