This Grim Arctic Milestone Is Only Years Away

If the Arctic were a color, it would be white. But not for long, apparently. Scientists say to expect a "blue Arctic" in summer months within a decade as emissions from the burning of fossil fuels continue to warm the planet, melting Arctic sea ice. Researchers used climate models to predict changes in sea ice coverage, finding the Arctic could experience its first "ice-free" days within a few years, "up to 18 years sooner" than indicated by other projections, Earth.com reports.

The study defines "ice-free" as when the area of ice covering the Arctic Ocean drops below one million square kilometers—"in which case the Arctic would be mostly water," per the Guardian. Under a low-emission scenario, ice-free conditions are predicted between August and October by 2100. Under a high-emission scenario, such conditions are expected between May and January, a period of nine months extending into winter. "This would transform the Arctic into a completely different environment, from a white summer Arctic to a blue Arctic," says lead study author Alexandra Jahn of the University of Colorado Boulder, per the Guardian.

Under every emissions scenario, the Arctic is expected to see its first "ice-free" days between the late 2020s and the 2030s, likely between late August and early September. The September average is currently about 3.3 million square kilometers of sea ice, per Earth.com. But September sea ice is shrinking at a rate of 12.2% per decade, according to NASA. Consistently "ice-free" Septembers are now expected between 2035 and 2067, depending how quickly greenhouse-gas emissions are curbed, according to the study published Tuesday in Nature Reviews Earth ­­& Environment.

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But "even if ice-free conditions are unavoidable, we still need to keep our emissions as low as possible to avoid prolonged ice-free conditions," says Jahn. The loss of sea ice will accelerate warming in the Arctic "by reducing the reflective snow and ice cover," per Earth.com. It will also further threaten wildlife dependent on sea ice. If there's some good news, it's that Arctic sea ice could return even if it's lost completely. "If we can then figure out how to take CO2 back out of the atmosphere in the future to reverse warming, sea ice will come back within a decade," Jahn says. (More Arctic sea ice stories.)