The Arctic’s warming trends are ‘truly unprecedented’

Every day seems to be Horrible Climate Change News Day. We learn of major airports that are going to be underwater because of sea level rise, a chunk of sea ice the size of India melting in the Antarctic, and glaciers cracking from the inside out. Today’s depressing news comes from a report on the Arctic’s warming trends. The report, sponsored by the US National Oceanic and Atmospheric Administration, found that unprecedented warm air over the Arctic caused extensive melting of sea ice, as well as land-based ice and snow in Greenland.

The so-called Arctic Report Card showed a few new “records” this year: the minimum extent of Arctic sea ice from mid-October to late November was the lowest since satellite observations began in 1979. In the North American Arctic, spring snow cover in May fell to the lowest levels since satellite observations began in 1967. And the average air temperature over land this year was also the highest on record, representing a 6.3-degree Fahrenheit increase since 1900. The reports was released today at the annual American Geophysical Union fall meeting in San Francisco.

The higher temperatures are in part due to especially warm air coming from the south during this year’s winter, the report says. And that’s where things get scary. Shrinking sea ice and glaciers used to be a thing of the summer, but now that trend is carrying over into the winter months, says Jeremy Mathis, director of NOAA’s Arctic Research Program. “The pace of change that’s happening in the Arctic ... is truly unprecedented,” he says.

The result is that the Greenland ice sheet, the second largest ice sheet in the world, continues to lose mass. Scientists estimate that if all the ice in the Greenland ice sheet melted, sea levels would rise about 20 feet. Melting sea ice and glaciers also feed into a vicious cycle that’s causing the Arctic to warm up on average twice as fast as the rest of the world. That’s because the Arctic is supposed to be covered by a white surface of sea or land ice, which reflects sunlight back into the atmosphere. But as ice shrinks, dark ocean and land is exposed, which absorbs sunlight, leading to higher temperatures.

“It’s a feedback loop that leads to this warming effect that we’ve seen,” Mathis says.

The consequences of these warming trends go beyond melting ice and snow. Retreating sea ice causes more sunlight to reach the ocean and that leads to blooms of algae and other marine plants. That can have consequences in the food chain animals in the area rely on to survive — for the entire Arctic ecosystem.

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Warmer temperatures are also causing sub-Arctic species to move north. One example is the masked shrew, a small mole-like mammal that lives in the forests just below the Arctic tundra, in Alaska and Canada. These animals — and their parasites — are now spreading north, making life harder for another type of shrew typical on this area, the barren ground shrew. This is changing what wildlife looks like in the Arctic.

All these changes in the region will affect the world in way we don’t fully comprehend yet. Scientists are just now starting to understand the connection between destabilizing Arctic climate and extreme weather events. Seal level rise and coastal erosion are only some of the consequences of the warming trends described in the Arctic Report Card.

“The Arctic is going to touch the life of every single American, whether directly or indirectly,” Mathis says, “and I think that impact is going to grow over time.”