The world’s landmark Paris Agreement is “more fragile” than it has ever been and disagreements risk “imploding” it, the UK’s climate ambassador has warned.

The seminal treaty obliges countries to produce regular plans on how they will cut greenhouse gas emissions in order to slow climate change.

Since it was signed in 2015, predicted levels of global warming have fallen, the cost of wind and solar have plummeted and net zero targets have proliferated.

But the Paris Agreement is “more fragile now than it has been in the nine years up to now”, the UK’s new climate envoy Rachel Kyte said yesterday evening.

She added: “Certain countries push back on Paris because it’s too effective, in some respects. And then you’ve got countries who are saying it’s not effective enough.”

“It would be bizarre, if those two [things] came together and Paris found itself with not enough friends”, she said at an event hosted by the Overseas Development Institute thinktank.

This week vulnerable island countries like Vanuatu, frustrated by glacial climate action, have taken their case to the International Criminal Court in a bid to hold polluting countries more accountable under the Paris Agreement.

On the opposite end of the spectrum, other countries think the treaty allows for too much meddling in their own affairs, said Ms Kyte.

They perceive the Paris Agreement as “beginning to lean into their kitchen and start looking over their shoulders while they’re making the soup”.

Ms Kyte – who took up the new role of top UK climate diplomat in September – did not name any countries.

But some Gulf States and India have hit back at accusations their national climate plans aren’t ambitious enough.

“So this is at risk of imploding the agreement... if you put the two together, Paris itself is quite fragile,” she said.

Her warning comes after a difficult time for global climate efforts, including the annual COP summits that produced and make progress on the Paris Agreement.

Last month, a group of climate heavyweights warned COPs were “no longer fit for purpose” and should be reformed.

Donald Trump is expected to pull the US out of the Paris Agreement when he takes office next month. His re-election has already had a “softening” effect on climate ambition in other countries, Ms Kyte said.

“I think it is important to recognise that Paris is working. [But] it is not working well enough.”

She said it’s “not that there’s some kind of fundamental flaw in the Paris Agreement”, but that every country needs to step up and “deliver the ambition” in it by producing more ambitious climate plans, which are due next year.

Under Paris, countries agreed to limit warming to no more than 2C, and ideally 1.5C, above levels before industrial times.

But current plans limit warming only to around 3C, the United Nations warned recently.

While this could still be catastrophic, it is better than the 4C the world was on course for before the Paris Agreement was struck.

Last month countries at the COP29 climate talks in Azerbaijan, agreed to channel $300bn a year to developing states to help them tackle climate change.

The figure is far short of the $1.3trn needed, fuelling concerns countries won’t be able to afford to come up with ambitious enough plans next year.