A warming of more than 1.5 °C could accelerate the melting of the polar ice caps
Sebnem Coskun/Anadolu Agency/Getty Images
It is now “more likely than not” that the world will shortly exceed the 1.5C target for climate change within five years, according to UK Met Office meteorologists.
There is a 66 percent chance that in at least one year from 2023 to 2027, the average global temperature will rise more than 1.5°C above pre-industrial levels, the Met Office said in an analysis prepared for the United States. UN World Meteorological Organization (WMO). .
This would be the first breach of a threshold set to avoid the worst effects of global warming.
In 2015, countries under the Paris Agreement pledged to limit any global increase in average temperatures to “well below” 2°C and to aim for no more than 1.5°C warming.
Warming beyond that lower threshold threatens to destroy the world’s coral reefs, trigger the unstoppable melting of polar ice caps and doom small island nations to rising sea levels.
A single year of warming of more than 1.5 °C would not officially exceed the Paris target. That would only happen if the temperature rise continues for a few decades.
But it would be a clear, worrying signal that the world is on track to exceed the temperature target, he said Adam Schaaf at the Met Office in a briefing with reporters.
“We are now really within range of a temporary exceedance of 1.5°C for the annual average. That’s the first time in human history that we’ve been this close,” he said. “It shows that we are getting very, very close to the Paris threshold.”
The probability of a temporary short-term exceedance of 1.5°C has been steadily increasing since 2015, when the probability was estimated to be close to zero. By 2022, the Met Office suggested there was a “50-50” chance of warming exceeding 1.5°C in any of the five years from 2022 to 2026.
Rising greenhouse gas emissions and an expected shift to an El Niño weather pattern later this year make an exceedance of 1.5°C now even more likely, the Met Office said.
El Niño and La Niña are terms used to describe fluctuations in the Earth’s climate system caused by changing sea surface temperatures in the equatorial Pacific Ocean.
After three years of La Niña, which has a cooling effect on global temperatures, the US National Oceanic and Atmospheric Administration said earlier this month that there is a 90 percent chance that El Niño conditions will develop by the end of the year.
A strong El Niño could temporarily raise the average global temperature by 0.3°C, on top of the warming already caused by greenhouse gas emissions.
“A warming El Niño is expected to form in the coming months and this, combined with human-induced climate change, will push global temperatures into uncharted territory,” WMO Secretary General Petteri Taalas said in a statement.
Even if the temperature does not exceed the 1.5°C threshold, it is almost certain that the world will experience record warming over the next five years.
The currently warmest year we have seen is 2016, when the average temperature was 1.28°C above pre-industrial levels. There is a 98 percent chance that this record will be broken by the end of 2027, according to the Met Office.
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