Science Editorial.- The image of the Arctic completely free of sea ice in summer could occur sooner than expected: in 2027, according to new research that warns of accelerating melting times in the journal Nature Communications.
An international team of researchers led by climatologists Alexandra Jahn (University of Colorado Boulder) and Céline Heuzé (University of Gothenburg in Sweden) have used computer models to predict when the first ice-free day could occur in the northernmost ocean.
An ice-free Arctic, as scientists have warned for decades, could significantly affect the Earth’s ecosystem and climate by changing weather patterns.
“The first day without ice in the Arctic will not change things radically, but it will demonstrate that we have altered one of the defining characteristics of the Arctic’s natural environment due to greenhouse gas emissions,” says Alexandra Jahn in a statement.
To conclude that the Arctic will be ice-free within three years, the researchers projected the first ice-free day using the results of more than 300 computer simulations.
They found that most models predicted that the first day without ice could occur between nine and twenty years after 2023, regardless of how greenhouse gas emissions evolve.
But the authors have seen that there are a series of extreme weather events that could melt two million square kilometers or more of sea ice in a short period of time: an unusually warm autumn first weakens the sea ice, followed by a winter and a spring warm temperatures in the Arctic that prevent the formation of sea ice.
When the Arctic experiences such extreme warming for three or more years in a row, the first day without ice could occur in late summer.
Based on these latter variables, nine simulations suggested that an ice-free day could occur within three years, or at most within six.
However, the researchers warn that all is not lost and that in their models they have seen that a drastic reduction in emissions could delay the disappearance of ice in the Arctic and reduce the time that the ocean remains ice-free.
“Any reduction in emissions would help preserve sea ice,” Jahn emphasizes.
A blue Arctic
As the climate warms from increasing greenhouse gas emissions, Arctic sea ice has disappeared at an unprecedented speed of more than 12% each decade.
Last September, the National Snow and Ice Data Center in Colorado reported that the day with the least amount of frozen seawater in the Arctic was one of the lowest on record since 1978: 4.28 million square kilometers, the lowest this year was above the historical low observed in September 2012.
That minimum marks a decline compared to the average coverage of 6.85 million square kilometers between 1979 and 1992.
When the Arctic Ocean has less than one million square kilometers of ice, scientists consider the Arctic to be ice-free.
Previous studies by the same team tried to predict when this ocean will be completely ice-free for a full month, concluding that this would occur in the 2030s.