A global average temperature that exceeds 1.5°C above pre-industrial levels would mean that the planet temporarily grows hotter than the limit specified by the Paris climate agreement.
The WMO report says there is a 66% chance that the annual average global temperature will exceed 1.5°C above pre-industrial levels for at least one year between 2023 and 2027.
"It's the first time in history that it's more likely than not that we will exceed 1.5°C," Adam Scaife of the U.K.'s Met Office, who worked on the report, toldReuters.
As Common Dreams reported Monday, climate scientists are currently observing trends in the Pacific Ocean that appear "very much like the 1997 and 2015 early stages of a Super El Niño," in which very high temperatures would be recorded near the equator.
El Niño events occur roughly every five years, and the one that appears to be forming now is likely to make at least one of the next five years the warmest on record. The El Niño event that occurred in 2016 contributed to 2016, 2019, and 2020 being the hottest years on record so far.
The WMO report said there is a 98% chance that the upcoming five-year period as a whole will be the warmest in recorded history. There is a 32% likelihood that the five-year mean temperature will exceed the 1.5°C threshold.
Although the breach of the 1.5°C limit is expected to be temporary, Taalas warned that this El Niño event could signal a new pattern.
"This report does not mean that we will permanently exceed the 1.5°C level specified in the Paris Agreement which refers to long-term warming over many years. However, WMO is sounding the alarm that we will breach the 1.5°C level on a temporary basis with increasing frequency,” said Taalas. "This will have far-reaching repercussions for health, food security, water management, and the environment. We need to be prepared."
Scientists and heat experts have begun calling on officials to prepare communities with cooling stations, access to air conditioning equipment, and other measures to cope with the hot weather El Niño is expected to bring.
Prior to 2015, the chance of the annual global average temperature crossing the 1.5°C threshold was "close to zero," according to the WMO. Between 2017 and 2021, scientists recorded a 10% chance.
"Global mean temperatures are predicted to continue increasing, moving us away further and further away from the climate we are used to," said Dr. Leon Hermanson, a Met Office scientist who led the report.
The report noted that warming in the Arctic is "disproportionately high," which has threatened the collapse of a crucial ocean current system and disrupted weather patterns in the northern hemisphere.
Climate writer Andy Rowell called the WMO's report both "heartbreakingly terrifying and predictable" as the fossil fuel industry and policymakers refuse to heed the warnings of scientists and energy experts, who say the continued extraction of oil and gas have no place on a pathway to avoiding the 1.5°C warming limit.
"This report must be a rallying cry to intensify global efforts to tackle the climate crisis," Doug Parr, chief scientist at Greenpeace U.K.,
told Reuters.
