Madrid. The first summer on record in which virtually all Arctic sea ice melts, a feared milestone of global warming, could occur as early as 2027.
For the first time, an international research team, including University of Colorado (CU) Boulder climatologist Alexandra Jahn and Céline Heuzé of the University of Gothenburg in Sweden, used computer models to predict when the first day might occur. no ice in the northernmost ocean. An ice-free Arctic could significantly affect Earth’s ecosystem and climate by changing weather patterns.
The first day without ice in the Arctic will not change things drastically
Jahn said.
But it will show that we have altered one of the defining characteristics of the natural environment in the Arctic Ocean, which is that it is covered in sea ice and snow year-round, through greenhouse gas emissions.
The findings were published in Nature Communications.
As the climate warms due to increasing greenhouse gas emissions, sea ice in the Arctic has disappeared at an unprecedented rate of more than 12 percent each decade.
In September, the NSIDC (National Snow and Ice Information Center) reported that this year’s Arctic sea ice minimum (the day with the least amount of frozen seawater in the Arctic) was one of the lowest recorded since 1978.
At 4.28 million square kilometers, this year’s low was above the record low seen in September 2012. But it still represents a marked decline compared to the average coverage of 6.85 million square kilometers between 1979 and 1992.
When the Arctic Ocean has less than a million square kilometers of ice, scientists say the Arctic is ice-free.
Previous projections of Arctic sea ice change have focused on predicting when the ocean will be ice-free for a full month. Jahn’s previous research suggested that the first ice-free month would almost inevitably occur and could happen in the 2030s.
Since the first ice-free day is likely to occur before the first ice-free month, we want to be prepared. It is also important to know what events could lead to the melting of all sea ice in the Arctic Ocean.
said Heuzé, who estimated, together with Jahn, the first ice-free day in the Arctic using the results of more than 300 computer simulations. They found that most models predicted that the first ice-free day could occur within nine to 20 years after 2023, regardless of how humans alter their greenhouse gas emissions. The first day without ice in the Arctic Ocean could occur within three years.
It is an extreme scenario, but a possibility based on the models. In total, nine simulations suggested that an ice-free day could occur in three to six years.