2024 'certain' to be hottest year on record: EU monitor

In another grim milestone, 2024 will be the first calendar year 1.5 degrees Celsius hotter than before the industrial revolution when humanity started burning large amounts of fossil fuels.

According to provisional data, Copernicus said the year to date was almost 1.6C warmer than the pre-industrial era, taken as between 1850 and 1900.

Scientists say the risks of climate change increase with every fraction of a degree, and that exceeding 1.5C over a decades-long period would greatly imperil ecosystems and human societies.

Under the Paris accord on climate change, the world agreed to try and keep warming to this safer 1.5C threshold.

Copernicus Climate Change Service deputy director Samantha Burgess said a single year above 1.5C "does not mean that the Paris Agreement has been breached, but it does mean ambitious climate action is more urgent than ever."

Catastrophic warming 

The world is nowhere near on track. In October, the UN said the current direction of climate action would result in a catastrophic 3.1C of warming.

Emissions from fossil fuels keep rising despite a global pledge to move the world away from coal, oil and gas.

When burned, fossil fuels release greenhouse gases that raise global temperatures, with extra heat trapped in the oceans and atmosphere.

Scientists say this warming effect disrupts climate patterns and the water cycle, and makes extreme weather more frequent and ferocious.

2024 saw deadly flooding in Spain and Kenya, violent storms in the United States and the Philippines, and severe drought and wildfires across South America.

In total, disasters caused $310 billion in economic losses in 2024, Zurich-based insurance giant Swiss Re said this month.

Developing countries are particularly vulnerable and by 2035 will need $1.3 trillion a year in outside assistance for their energy transitions and to cope with climate change.

At UN climate talks in November, big historic polluters most responsible for global warming committed to raising at least $300 billion annually by 2035, an amount decried as woefully inadequate.

Exceptional

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

Its 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.

Scientists say the period we are in now is likely the warmest the Earth has been for the last 125,000 years.

Even by these standards, the extraordinary heat witnessed since mid-2023 has sparked scientific debate.

2024 began at the peak of El Nino, a natural phenomenon that drives up global temperatures.

But scientists said El Nino, which ended around the middle of the year, could not alone explain the record-breaking heat in the atmosphere and seas.

Nicolas said the end of El Nino had not proved "a big brake" on global temperatures, and it was still unclear if an opposite, cooling La Nina event would follow.

Robert Vautard, a scientist of the UN's expert climate advisory body IPCC, told AFP that temperatures were starting to fall but "very slowly, and the causes will have to be analysed".

Last week, a study published in the peer-reviewed journal Science suggested a lack of low-lying clouds could be causing less heat to bounce back into space.

A separate paper in May explored the possibility that cleaner-burning shipping fuels were releasing less mirror-like particles into clouds, dimming their reflectivity.

Nicolas said the recent heat was "clearly exceptional" but still within the upper range of the best-available climate projections on global warming.

"As we get more data, we will hopefully better understand what happened," he told AFP.