Paris (AFP)

This year is "virtually certain" to be the hottest in recorded history with warming above 1.5°C, EU climate monitor Copernicus said on Thursday, days before nations are due to gather for crunch UN climate talks.

The European agency said the world was passing a "new milestone" of temperature records that should be a call to accelerate action to cut planet-heating emissions at the UN negotiations in Azerbaijan next week.

Last month, marked by deadly flooding in Spain and Hurricane Milton in the United States, was the second hottest October on record, with average global temperatures second only to the same period in 2023.

Copernicus said 2024 would likely be more than 1.55 degrees Celsius above the 1850-1900 average.

This does not amount to a breach of the Paris deal, which strives to limit global warming to below 2C and preferably 1.5C, because that is measured over decades and not individual years.

"It is now virtually certain that 2024 will be the warmest year on record and the first year of more than 1.5C above pre-industrial levels," said Copernicus Climate Change Service (C3S) Deputy Director Samantha Burgess.

"This marks a new milestone in global temperature records and should serve as a catalyst to raise ambition for the upcoming Climate Change Conference, COP29."
Meanwhile, average global temperatures have reached new peaks, as have concentrations of planet-heating gases in the atmosphere.

Scientists say the safer 1.5C limit is rapidly slipping out of reach, while stressing that every tenth of a degree in temperature rises heralds progressively more damaging impacts.

Last month the UN said the current course of action would result in a catastrophic 3.1C of warming this century, while all existing climate pledges taken in full would still amount to a devastating 2.6C temperature rise.

In a month of weather extremes, October saw above-average rainfall across swathes of Europe, as well as parts of China, the United States, Brazil and Australia, Copernicus said.

The United States is also experiencing ongoing drought, which affected record numbers of people, the EU monitor added.

Global warming is not just about rising temperatures, but the knock-on effect of all the extra heat in the atmosphere and seas.

Warmer air can hold more water vapour, and warmer oceans mean greater evaporation, resulting in more intense downpours and storms.

Copernicus said average sea surface temperatures in the area it monitors were the second highest on record for the month of October.

C3S uses billions of measurements from satellites, ships, aircraft and weather stations to aid its calculations.

Copernicus records go back to 1940.

But other sources of climate data such as ice cores, tree rings and coral skeletons allow scientists to expand their conclusions using evidence from much further in the past.

Climate scientists say the period being lived through right now is likely the warmest the Earth has been for the last 100,000 years.