The Arctic Could Have Its First ‘Ice-Free’ Day by as Early as 2027
In a new study, scientists used climate models to predict the alarming milestone
The first summer on record in which practically all of the sea ice in the Arctic melts could occur much earlier than previously expected. In a new study, scientists warn that the ever-increasing greenhouse emissions may bring us closer to an ice-free Arctic by the end of the decade.
The new research, published on Tuesday in Nature Communications, suggests that rapid ice loss is associated with strong winter and spring warming, and warns that a transition to an Arctic Ocean with less than one million square kilometers of ice—a condition known as "ice-free"—in the summer could have cascading effects.
“The climate models show that unless we can stay below 1.5 degrees Celsius globally in the climatological average, which is becoming less and less likely every month basically, it’s guaranteed that we will see ice-free conditions this century,” says Alexandra Jahn, an atmospheric and oceanic sciences researcher at the University of Colorado Boulder and study co-author, to the Independent’s Julia Musto.
In the Arctic, September sea ice has shrunk by a rate of more than 12 percent each decade since 1979. This year, it reached near-historic lows over the summer and its minimum extent on September 11, according to NASA and the National Snow and Ice Data Center (NSIDC). Using satellites and climate models, scientists have been able to track sea ice changes and measure their impacts—these range from losses in polar habitat to implications for local Arctic communities.
According to NASA, the difference in ice cover this year compared to the average from 1981 to 2010 represents an area larger than Alaska.
Past studies have focused on the first ice-free month, or ice-free summer. This new study focuses on the first ice-free day. Using past research showing that the first ice-free month could occur by the 2030s, Jahn wondered when the first ice-free summer day would happen, according to a statement.
“Because the first ice-free day is likely to happen earlier than the first ice-free month, we want to be prepared,” says Céline Heuzé, a climatologist at the University of Gothenburg, in the statement. “It’s also important to know what events could lead to the melting of all sea ice in the Arctic Ocean.”
Scientists Jahn and Heuzé projected the first ice-free day using computer simulations. In most models, regardless of greenhouse gas emissions, the first ice-free day could occur within nine to 20 years. In the earliest model, it could be between 2027 to 2030.
If the first ice-free day does occur in the next few years, it might lead to an ice-free period of between 11 to 53 days, per the study. The average was an ice-free period of 27 days, meaning that an ice-free day could in fact turn into an ice-free month. August and September were the most likely months for such conditions to happen.
That scenario doesn’t guarantee that that ice-free day will happen in 2027. “It’s definitely a very unlikely event,” Jahn tells E&E News’ Chelsea Harvey. “We’re looking at the outer edge of what could happen.”
A series of extreme weather events could lead up to that ‘ominous milestone.’ For instance, a warm fall could weaken sea ice and a warm winter and spring could prevent it from forming. If these weather events happen three years in a row, or more, that could lead to an ice-free day late in the summer.
"When we reach ice-free conditions then the majority of the Arctic Ocean, 94 percent of it, will have no ice anymore," Jahn tells the Independent. “So, we’re going from a white Arctic Ocean to a blue Arctic Ocean.” She adds that shift illustrates the way anthropogenic-caused changes affect the natural environment.
Even though the outlooks seem negative, the scientists point out that if we stick to the 1.5 degree celsius of global warming, “ice-free days could potentially still be avoided.” Thus, making climate action even more important.
If we miss that target and stick to 1.6 degrees, Jahn tells E&E News, “that will be a great achievement and will definitely have a big impact on how the Arctic will look like in the second part of the 21st century.”