Obama, who was US leader in 2015 when the landmark accord was struck, said the world needed to "step up" its emissions-cutting pledges and work together to limit global temperature rises.

"We have not done nearly enough to address this crisis," he told delegates in Glasgow. "We are going to have to do more and whether that happens or not to a large degree is going to depend on you."

In the six years since the Paris deal -- which seeks to limit global heating to between 1.5 and 2 degrees Celsius -- planet-warming greenhouse gas emissions have continued to mount, and an assessment last week said that carbon pollution will rebound this year to pre-pandemic levels.

"By some measures the agreement has been a success," Obama said. "(But) we are nowhere near where we need to be yet."

But he admitted that "some of our progress stalled" when his successor Donald Trump chose to unilaterally withdraw the US from the Paris deal.

President Joe Biden re-joined the accord when he took office.

He said that China and Russia -- whose leaders skipped a high-level segment in Glasgow last week attended by more than 120 heads of state and government -- have shown a "dangerous lack of urgency" on climate commitments.

"Most countries have failed to be as ambitious as they need to be," he said.

"We need advanced economies like the US and Europe leading on this issue but you know the facts. We also need China leading on this issue and India leading on this issue," said the former president.

He said the world was undergoing a "moment when international cooperation has waned".

"But there is one thing that should transcend our day to day politics and normal geopolitics. And that is climate change."

The US is history's largest polluter but plans to achieve carbon neutrality by 2050.