The world is "failing to get a grip" on climate change, the UN warned on Tuesday, as an assessment of climate pledges shows only minor progress on reducing emissions this decade.

In a report released just weeks before high-stakes negotiations on limiting global warming, the United Nations climate change organisation said the world was not acting with sufficient urgency to curb greenhouse gas emissions.

With temperatures soaring and 2023 expected to become the warmest year so far in human history, scientists say the pressure on world leaders to curb planet-heating greenhouse gas pollution has never been more urgent.

The UN found that combined climate plans from nearly 200 nations would put the world on a path for 2030 carbon emissions just two percent below 2019 levels.

That is far short of the 43 percent fall that the UN's IPCC climate panel says is needed to limit warming to the Paris deal target of 1.5 degrees Celsius (2.7 degrees Fahrenheit) since the pre-industrial era.

"Every fraction of a degree matters, but we are severely off track. COP28 is our time to change that," said UN Climate Change chief Simon Stiell.

He called for climate talks in Dubai this month to mark a "clear turning point" for a world already wracked by increasing floods, heatwaves and storms.

Scientists have warned that humanity is dangerously close to blowing past the 1.5C global heating limit, risking intensifying impacts. (AFP)