Earth to warm up to 2.9C even with current climate pledges: UN

The world's emissions-cutting pledges are nowhere near enough to curb the effects of climate change, with Earth on track for warming a potentially catastrophic 2.9C (5.2F) this century, the United Nations has warned.

The UN Environment Programme (UNEP)'s annual Emissions Gap report, published on Monday, assesses countries' promises to tackle climate change against the action needed.

This year is expected to be the hottest in human history.

"The world is witnessing a disturbing acceleration in the number, speed and scale of broken climate records," UNEP said.

The report found the world faces between 2.5C (4.5F) and 2.9C (5.2F) of warming above preindustrial levels on current commitments if governments do not take more aggressive climate action.

At that level of warming, scientists predict the world could pass several catastrophic points of no return, from the runaway melting of ice sheets to the Amazon rainforest drying out, and leave vast swathes of the planet essentially uninhabitable for humans.

UN Secretary-General Antonio Guterres called for "dramatic climate action" at the COP28 climate talks, which begin in Dubai on November 30.

He likened the emissions gap to a canyon.

"Leaders can't kick the can any further. We're out of road," he said, condemning a "failure of leadership, a betrayal of the vulnerable, and a massive missed opportunity".

Guterres said the world "must reverse course" and make a decisive move away from polluting coal, oil and gas.

Time to 'step up'

The 2015 Paris Agreement saw countries agree to cap global warming at "well below" 2C (3.6F) above preindustrial times – with a safer limit of 1.5C (2.7F) if possible.

Nearly 1.2C (2.2F) of global heating so far has already unleashed an escalating wave of deadly hazards – from intensifying hurricanes to floods and deadly heatwaves – across the planet.

UNEP said temperatures had risen above 1.5C (2.7F) for more than 80 days already this year, although the Paris warming thresholds will be measured as an average over several decades.

The report said that planet-warming greenhouse gas emissions must fall by 42 percent by 2030 to hold warming at 1.5C (2.7F).

But even in the most optimistic emissions scenario, the chance of now limiting warming to 1.5C (2.7F) was just 14 percent, it added.

The report said the world continues to pump record levels of greenhouse gases into the atmosphere, with emissions up by 1.2 percent from 2021 to 2022, reaching a record 57.4 gigatonnes of carbon dioxide equivalent. The increase was largely driven by the burning of fossil fuels and industrial processes, it noted.

UNEP chief Inger Andersen said it was crucial that G20 nations – the world's wealthiest economies, together responsible for about 80 percent of emissions – "step up" and lead on reductions but lamented that some were in "snooze mode".

The report said none of the G20 nations had reduced emissions in line with their targets.