After shrinking to a shocking record low at end of winter, Arctic sea ice staged a modest comeback this summer

By Tom Yulsman | September 20, 2017 12:03 pm

But despite claims to the contrary, one warmish summer in the Arctic does not repeal the long-term trend of human-caused warming

This visualization shows how the extent of Arctic sea ice has evolved through time. The animation begins when the ice reached its wintertime maximum extent on March 7, 2017, and it ends on September 13, 2017, when the ice shrank to its minimum extent for the year. (Source: NASA Scientific Visualization Studio/Helen-Nicole Kostis)

This visualization shows how the extent of Arctic sea ice has evolved through time. The animation begins when the ice reached its wintertime maximum extent on March 7, 2017, and it ends on September 13, 2017, when the ice shrank to its minimum extent for the year. (Source: NASA Scientific Visualization Studio/Helen-Nicole Kostis)

Arctic sea ice has staged something of a short-term turn-around this summer.

The underlying long-term warming of the region, caused by our emissions of heat-trapping greenhouse gases, has not abated. But relatively cool and cloudy weather in the high north during summer caused the sea ice to shrink less extensively than in some recent years.

When the ice reached its minimum extent for the year on September 13th, it turned out to be eighth lowest in the 38-year record of satellite observations, according to a preliminary analysis released yesterday by the National Snow and Ice Data Center.

This is especially noteworthy because the melt season began in March with sea ice at a record low for that time of year, thanks to unusually warm temperatures in winter that had caused sea ice to expand very sluggishly. But then the weather shifted.

Another factor was at work too: Relatively warm winter temperatures had enhanced snowfall onto the ice in parts of the Arctic. That slowed its summertime melt-out.

Even so, the minimum ice extent reached on September 13th was 610,000 square miles below the 1981 to 2010 median extent for that day – an area equivalent to about one sixth of the total area of the United States.


Source: NSIDC (with added labeling)

In the graph above comparing eight years of minimum Arctic sea ice extents, have a close look at 2012, 2016 and 2007. These are the three years with the lowest Arctic ice extents on record. As it turns out, those years brought unusual weather conditions, including strong summer storms that beat up the ice cover, helping to accelerate melting.

Conditions were different this year. Persistent low atmospheric pressure at sea level in the central Arctic this summer resulted in cooler than average temperatures. And the counterclockwise pattern of winds around the low pressure system tended to spread the sea ice over a larger area, according to the NSIDC.

“How much ice is left at the end of summer in any given year depends on both the state of the ice cover earlier in the year and the weather conditions affecting the ice,” says Claire Parkinson, senior climate scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, quoted in an agency sea ice update. “The weather conditions have not been particularly noteworthy this summer. The fact that we still ended up with low sea ice extents is because the baseline ice conditions today are worse than the baseline 38 years ago.”

Arctic sea ice extent for the month of August has been declining at a rate of 10.5 percent per decade since 1978. (Source: NSIDC)

Arctic sea ice extent for the month of August has been declining at a rate of about 10 percent per decade since 1978. (Source: NSIDC)

It all adds up to this: Some years the fickleness of weather helps bring dramatic, record-setting lows to Arctic sea ice, and in other years, not so much. But over the long-term, despite up and down wiggles, the trend line is undeniably clear – as the graph above shows.

So don’t believe any claims you may hear that this summer’s modest, short-term comeback somehow means there is no long-term trend of human-caused warming in the Arctic. Nothing could be further from the truth.

  • jimgrot

    re. “The underlying long-term warming of the region, caused by our emissions of heat-trapping greenhouse gases, has not abated” that was stated ‘matter-of-fact-ly’ all citations for that please; which greenhouse gas, CO2 or water vapor (clouds-fog)?

    • Tom Yulsman

      The idea that certain gases in the atmosphere would trap heat was first worked out by Joseph Fourier in 1820. In laboratory experiments in 1859, John Tyndall identified several gases that could do just that, including water vapor and carbon dioxide. And then in 1896 Svante Arrhenius demonstrated the key role of CO2 in determining Earth’s equilibrium temperature. So the climatic effect of adding CO2 to the atmosphere is actually a matter of simple physics that have been well known for more than 200 years. And the predictions made by Arrhenius have been borne out by observations. Whether you want to believe it or not, these are basic, undeniable facts.

    • So Patriotic, It Hurts

      Water vapor is a feedback, and any that we emit is used in balance as it returns to earth. We emit CO2, methane, and other greenhouse gasses which are forcings.

      No citations needed to something people who read science know. No time to keep restating the obvious.

  • OWilson

    “The underlying long-term warming of the region, caused by OUR emissions of heat-trapping greenhouse gases, has not abated”

    Well perhaps it’s about time to demand accountability from those that are most vocal about the problem!

    I have a very low carbon footprint, I sort and recycle my own refuse.

    But the loudest voices, the silk stocking socialists, limousine liberals, Leo di Caprio, Lady Ga Ga, Indiana Jones, and the Hollywood crowd, politicians Heinz-Kerry, Al Gore, with their multiple mansions, autos, private planes and yachts, put me to shame.

    Perhaps it’s not so much “OUR” emissions that are killing the planet, but “THEIRS”? :)

    Maybe it’s time to bring them to justice!

    • Mike Richardson

      You get to the Dominican Republic by kayak or sailboat (not that those poor folks haven’t suffered enough lately)? Just asking? :)

      • OWilson

        I’m there as we speak.

        Sharing their pain! :) Irma, Jose, now Maria, then, X10% According to NOAA!

        Helping out a little!

        And you?

        But no, I didn’t get here like Obama and the Hollywood crowd, on a Spielberg or Branson multi million dollar yacht with a a crew of servants the size of a small town.

        But thanks for asking!

        • Mike Richardson

          Amazing you have internet access and time to bother with political comments with all the work that must need doing. I’m sure they’ll appreciate such commentary and the victim blaming, if you’re actually there and consistent in your behavior. I’ll see about sending money, as I did for the Harvey survivors (and as so many of those folks you deride have done). Yes, Irma, Jose, Maria — and now Wilson. My heart truly goes out to those poor people in their suffering.

          • OWilson

            Yes, ain’t this new fangled tecchology wonderful!

            The power has been going off and on for two days and the internet has been intermittent.

            I’ve been stuck inside for almost two days, but with gas and water for coffee, and sardines and the occasional internet, I’m fine!

            I got caught in it the first day, with no transportation on the roads.

            Fortunately we don’t have your socialist voters looting and pillaging at the first opportunity, and I was taken in by locals.

            Here, people help and protect each other, in emergencies. They don’t shoot first responders :)

            That’s why I’ll be living here as soon as I can wrap up my affairs in Canada.

            Today, we’ll be out helping with the clean up and counting our blessings!

            Looks like I won’t be enjoying that year round skiing in California, though, that has everybody but the Global Warmers happy!



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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