The world faces a 50% chance of warming 1.5°C above pre-industrial levels, if only briefly, by 2026, the World Meteorological Organization (WMO) said on Monday.
This does not mean that the world would cross the long-term warming threshold of 1.5°C, which scientists have set as a ceiling to avoid catastrophic climate change.
But a year of 1.5°C warming could offer a taste of what crossing that threshold would be like in the long term.
“We are getting significantly closer to temporarily meeting the lower Paris Agreement target,” WMO Secretary-General Petteri Taalas said, referring to climate agreements adopted in 2015.
The probability of exceeding 1.5°C for a short period has increased since 2015, with scientists estimating a probability of 20% in 2020 and revising that of last year to 40%. Even a year of 1.5C warming can have disastrous effects, such as the destruction of many of the world’s coral reefs and shrinking Arctic sea ice cover.
In terms of the long-term average, the average global temperature is now about 1.1°C warmer than the pre-industrial average.
“Loss and damage associated with or exacerbated by climate change is already occurring, some of it likely to be irreversible for the foreseeable future,” said Maxx Dilley, deputy climate director at WMO.
World leaders pledged, as part of the 2015 Paris Agreement, to prevent the breach of the long-term threshold of 1.5C – measured as a multi-decade average – but so far they have not failed to reduce emissions that contribute to global warming. Today’s activities and current policies put the world on track to warm by about 3.2°C by the end of the century.
“It’s important to remember that once we hit 1.5C, the lack of science-based emissions policies means we will experience worsening impacts as we approach 1. 6 C, 1.7 C and every increase in warming thereafter,” said Kim Cobb, a climatologist. at the Georgia Institute of Technology in Atlanta.
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