New analysis: global sea ice suffered major losses in 2016

By Tom Yulsman | January 7, 2017 2:47 pm
sea ice

A visualization of Arctic sea ice during March of 2016. The red line marks the long-term average extent of ice. On this date, sea ice reached a record low wintertime maximum extent. It was the second straight year that a record low was set in winter — a highly unusual event. (Source: NASA Goddard’s Scientific Visualization Studio/C. Starr)

The extent of sea ice globally took major hits during 2016, according to an analysis released yesterday by the National Snow and Ice Data Center.

At both poles, “a wave of new record lows were set for both daily and monthly extent,” according to the analysis.

In recent years, Arctic sea ice has been hit particularly hard.

“It has been so crazy up there, not just this autumn and winter, but it’s a repeat of last autumn and winter too,” says Mark Serreze, director of the NSIDC.

In years past, abnormal warmth and record low sea ice extent tended to occur most frequently during the warmer months of the year. But for the past two years, things have gotten really weird in the colder months.

In 2015, Serreze says, “you had this amazing heat wave, and you got to the melting point at the North Pole on New Years Eve. And we’ve had a repeat this autumn and winter — an absurd heat wave, and sea ice at record lows.”

Lately, the Southern Hemisphere has been getting into the act. “Now, Antarctic sea ice is very, very low,” Serreze says.

From the NSIDC analysis:

Record low monthly extents were set in the Arctic in January, February, April, May, June, October, and November; and in the Antarctic in November and December.

Put the Arctic and the Antarctic together, and you get his time series of daily global sea ice extent, meaning the Arctic plus Antarctic:

sea ice

During 2016, the global extent of sea ice tracked below the 1981 to 2010 average. In the graph, the horizontal axis shows the month of the year, aligned with the first day of the month. The vertical axis is the extent of sea ice globally in millions of square kilometers. (Source: NSIDC)

As the graph shows, the global extent of sea ice tracked well below the long-term average for all of 2016. The greatest deviation from average occurred in mid-November, when sea ice globally was 1.50 million square miles below average.

For comparison, that’s an area about 40 percent as large as the entire United States.

The low extent of sea ice globally “is a result of largely separate processes in the two hemispheres,” according to the NSIDC analysis.

For the Arctic, how much might humankind’s emissions of greenhouse gases be contributing to the long-term decline of sea ice?

sea ice

The relationship between September sea ice extent (1953 to 2015) and cumulative CO2 emissions since 1850. Grey diamonds represent individual satellite data values; circles are pre-satellite era values; the solid red line shows the 30-year running average. The dotted red line indicates a linear relationship of 3 square meters per metric ton of CO2. (Source: D. Notz, Max Planck Institute for Meteorology via NSIDC)

The graph above, based on data from a study published in the journal Science, “links Arctic sea ice loss to cumulative CO2emissions in the atmosphere through a simple linear relationship,” according to an analysis released by the NSIDC last December. Based on observations from the satellite and pre-satellite era since 1953, as well as climate models, the study found a linear relationship of 3 square meters of sea ice lost per metric ton of CO2 added to the atmosphere.

That’s over the long run. But over a shorter period of time, what can be said? Specifically, how much of the extreme warmth and retraction of sea ice that has been observed in autumn and winter of both 2015 and 2016 can be attributed to humankind’s emissions of greenhouse gases?

“We’re working on it,” Serreze says. “Maybe these are just extreme random events. But I have been looking at the Arctic since 1982, and I have never seen anything like this.”

  • OWilson

    Any news on record Northern Hemisphere snow cover?

    Something must be limiting the global average temperature anomaly to 0.24 degrees, over the 38 year NOAA Satellite record.

    • dlr100

      The trend in the satellite data is higher than 0.24 degrees over 38 years….see Spencer and Christy – “Global climate trend since Nov. 16, 1978 [of] +0.12 C [0.22F] per decade”, so the nearly +0.46 C[+0.84F] over 38 years – nearly double of what you say.*jWQItsqnIhOfIdnp.jpg

      • OWilson

        This is January, 2017.

        You chart is a year out of date. The current chart is available at:

        Why do you people have to do this kind of stuff?

        • cgs

          Your link does not work (at least I get a “403 forbidden page”). Can you repost it a different way?

          • OWilson
          • cgs

            Thanks, but for some reason now, you image actually shows. Maybe I just needed to refresh the page.

            But anyway, for starters, you’re not reading the graph correctly. You’re looking at the last data point of monthly temperature and only reporting it’s deviation from 0.

            Spencer creates a 13 month running average which is better to look at since we know that temperatures on the Earth cycle through a complete period in about that time.

            Looking at the full change in that average from 1979 to now one gets at little more than 0.7C change.

            But really one wants to fit a line to this data and look at the slope. It’s about 0.0122 C/year, which over 38 years = 0.46C.

          • OWilson

            It’s a public chart.

            You can read anything you want into it. Have fun!


          • Dano2

            Brave poster won’t own up to its inability to read charts.



        • Dano2

          Show everyone how big your thinks are:

          What does the ‘.24 deg. C’ denote on the chart?

          OK, all: holding our breaths in 3…2…1…pffffffffffffffthwp!



          • OWilson

            Most folks with a brain can read the legend for themselves.

            Warmers are somewhat challenged to keep up!

            You’re welcome :)

            And now you’re done here!

          • Dano2

            Make a think. Show how big your thinks are.

            Tell us what that number means, and why you think your chart does something that dlr100’s chart does not.

            No prancing, no deflecting.



        • dlr100

          See Global Temperature Report: February 2017

          The calculation of temperature change in lower troposphere dataset over 38 year time span remains unchanged from my first post, at +0.12 C per decade, which would be far greater than your “0.24” total over 38 years – nearly double at .46 C

          The statement in my original post remains correct.

    • Dano2
      • OWilson

        With respect, old data doesn’t quite make it here, as I pointed out to the other poster, no matter how much of it you post! :)

        This thread starts with the question, “Any NEWS on (record snow cover in the Northern Hemisphere?)”

        • Dano2

          The trend for NH snow cover is down.

          If you want to pretend that snow cover for part of one year is a new trend, that hit to your integrity and credibility is on you.



          • OWilson

            No you made that up. I was looking for “news”.

            Never mentioned “trends”.

            Now go and talk to Mikey, he misses you and talks your language.


          • Dano2

            Nice prance to deflect from your disingenuous implication.

            I’ll take those points on offer:

            o Weather event somewhere disproves AGW [15 points]




  • Skrotpriser

    Thank You for sharing this article with us



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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