The report underlines the scale of the task facing world leaders who head to Belém in northern Brazil next week for the COP30 climate gathering.

Ten years after the Paris climate pact was agreed in 2015, the efforts of countries to restrict the rise in global temperatures are under renewed scrutiny.

Every signatory agreed to submit a new carbon-cutting plan every five years, which would cover the next decade.

But only 64 countries managed to put a new pledge in place this year, despite many extensions of the deadline. These represent around 30% of global emissions.

In addition, the UN's review includes statements from China and the EU on their future plans made at Climate Week in New York in September.

Taken together, the efforts mean that global emissions of carbon dioxide should fall by around 10% by 2035.

However, scientists say that such a drop is nowhere near enough to keep the rise in temperatures under 1.5C.

To keep that goal alive will require steep cuts in greenhouse gas emissions, up to 57% by 2035, according to the UN last year.

"This report shows that we are going in the right direction but too slowly," said Laurence Tubiana, CEO of the European Climate Foundation, often referred to as a key architect of the Paris Agreement.

"It is essential to acknowledge the missing national pledges and confront the persistent gap between ambition and actual implementation."

The 1.5C limit, agreed at Paris, has long been seen as the threshold of very dangerous warming.

In 2018, scientists outlined the massive benefits to the world of keeping the rise under 1.5C as compared to allowing them to rise to 2C. Passing 1.5C include more frequent and intense heatwaves and storms, increased damage to coral reefs and growing threats to human health and livelihoods, UN scientists have said.

However, that limit was breached in 2024 for a whole year for the first time.

UN leaders are increasingly accepting the fact that the threshold will be breached permanently by the early 2030s at current rates.

Climate plans don't limit dangerous warming, UN says ahead of COP