UN says strong chance average warming will top 1.5C in next 4 years

Tourists use umbrellas to protect themselves from the strong midday sun in a park, during a heatwave in Ronda, Spain, on Jul. 24, 2024. (Reuters/File)
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  • The planet is therefore expected to remain at historic levels of warming after the two hottest years ever recorded in 2023 and 2024
  • 鈥淲e have just experienced the 10 warmest years on record,鈥� said the WMO鈥檚 deputy secretary-general Ko Barrett

GENEVA: The United Nations warned on Wednesday that there is a 70 percent chance that average warming from 2025 to 2029 would exceed the 1.5 degrees Celsius international benchmark.

The planet is therefore expected to remain at historic levels of warming after the two hottest years ever recorded in 2023 and 2024, according to an annual climate report published by the World Meteorological Organization, the UN鈥檚 weather and climate agency.

鈥淲e have just experienced the 10 warmest years on record,鈥� said the WMO鈥檚 deputy secretary-general Ko Barrett.

鈥淯nfortunately, this WMO report provides no sign of respite over the coming years, and this means that there will be a growing negative impact on our economies, our daily lives, our ecosystems and our planet.鈥�

The 2015 Paris climate accords aimed to limit global warming to well below 2C above pre-industrial levels 鈥� and to pursue efforts to peg it at 1.5C.

The targets are calculated relative to the 1850-1900 average, before humanity began industrially burning coal, oil and gas, which emit carbon dioxide (CO2) 鈥� the greenhouse gas largely responsible for climate change.

The more optimistic 1.5C target is one that growing numbers of climate scientists now consider impossible to achieve, as CO2 emissions are still increasing.

The WMO鈥檚 latest projections are compiled by Britain鈥檚 Met Office national weather service, based on forecasts from multiple global centers.

The agency forecasts that the global mean near-surface temperature for each year between 2025 and 2029 will be between 1.2C and 1.9C above the pre-industrial average.

It says there is a 70 percent chance that average warming across the 2025-2029 period will exceed 1.5C.

鈥淭his is entirely consistent with our proximity to passing 1.5C on a long-term basis in the late 2020s or early 2030s,鈥� said Peter Thorne, director of the Irish Climate Analysis and Research Units group at the University of Maynooth.

鈥淚 would expect in two to three years this probability to be 100 percent鈥� in the five-year outlook, he added.

The WMO says there is an 80 percent chance that at least one year between 2025 and 2029 will be warmer than the current warmest year on record: 2024.

To smooth out natural climate variations, several methods assess long-term warming, the WMO鈥檚 climate services director Christopher Hewitt told a press conference.

One approach combines observations from the past 10 years with projections for the next decade (2015-2034). With this method, the estimated current warming is 1.44C.

There is no consensus yet on how best to assess long-term warming.

The EU鈥檚 climate monitor Copernicus believes that warming currently stands at 1.39C, and projects 1.5C could be reached in mid-2029 or sooner.

Although 鈥渆xceptionally unlikely鈥� at one percent, there is now an above-zero chance of at least one year in the next five exceeding 2C of warming.

鈥淚t鈥檚 the first time we鈥檝e ever seen such an event in our computer predictions,鈥� said the Met Office鈥檚 Adam Scaife.

鈥淚t is shocking鈥� and 鈥渢hat probability is going to rise.鈥�

He recalled that a decade ago, forecasts first showed the very low probability of a calendar year exceeding the 1.5C benchmark. But that came to pass in 2024.

Every fraction of a degree of additional warming can intensify heatwaves, extreme precipitation, droughts, and the melting of ice caps, sea ice and glaciers.

This year鈥檚 climate is offering no respite.

Last week, China recorded temperatures exceeding 40C (104 degrees Fahrenheit) in some areas, the United Arab Emirates hit nearly 52C (126F), and Pakistan was buffeted by deadly winds following an intense heatwave.

鈥淲e鈥檝e already hit a dangerous level of warming,鈥� with recent 鈥渄eadly floods in Australia, France, Algeria, India, China and Ghana, wildfires in Canada,鈥� said climatologist Friederike Otto of Imperial College London.

鈥淩elying on oil, gas and coal in 2025 is total lunacy.鈥�

Davide Faranda, from France鈥檚 CNRS National Center for Scientific Research, added: 鈥淭he science is unequivocal: to have any hope of staying within a safe climate window, we must urgently cut fossil fuel emissions and accelerate the transition to clean energy.鈥�

Arctic warming is predicted to continue to outstrip the global average over the next five years, said the WMO.

Sea ice predictions for 2025-2029 suggest further reductions in the Barents Sea, the Bering Sea, and the Sea of Okhotsk.

Forecasts suggest South Asia will be wetter than average across the next five years.

And precipitation patterns suggest wetter than average conditions in the Sahel, northern Europe, Alaska and northern Siberia, and drier than average conditions over the Amazon.