Dana1981 asked in EnvironmentGlobal Warming · 10 years ago

Naval Postgraduate School concludes the Arctic will be effectively ice free by 2016 - thoughts?

In a recent presentation, the Naval Postgraduate School concluded that at the end of summer, by the year 2016 (plus or minus 3 years), the Arctic will be effectively 'ice free'. They define 'ice free' as more than an 80% drop from the 1979-2000 summer volume baseline.

They conclude that some sea ice above Greenland and Eastern Canada may survive into the 2020s, but the Arctic at this point will be effectively ice free. This projection is based on a combined model and data trendline focusing on ice volume. Here's the presentation:

http://soa.arcus.org/sites/soa.arcus.org/files/ses...

This by the way is decades ahead of the IPCC report projections, which put an ice free Arctic at the latter part of the 21st century in the A1 high emissions scenario.

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/a...

What are your thoughts on these data and projections?

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  • 10 years ago
    Best answer

    6 years seems rather radical to me - let me read the link though, and I'll post more....

    Edit:

    This is very interesting. I was unaware that oceanic heating had this much of an effect on sea ice so as to accelerate the melting by such rates. It will be interesting further to see how this model will impact further predictions, and if these conclusions will be accepted in coming months.

    @Trevor:

    While I find the information you have posted to be very insightful, I'd like to point out a few things that may be of significance.

    First off, the presentation by the NPS based most of the findings off of ice *volume*, not extent. 2007 may have been the year for record low extent, but as was stated in the presentation, and as can be shown by NASA:

    http://www.nasa.gov/images/content/365871main_eart...

    ice volume has been decreasing at rather alarming rates, lower in 2008 than 2007, and if we trust the NPS, since the NASA graph stops in 2008, lowest in 2009. Actually, according to measurements as recent as May 30 from Washington University, sea ice volume is lowest this year (since the negative anomaly has also increased in magnitude).

    http://psc.apl.washington.edu/ArcticSeaiceVolume/i...

  • Trevor
    Lv 7
    10 years ago

    Hi Dana,

    My own impression is that 2016 is somewhat over pessimistic. I can see how the authors of the paper have arrived at this hypothesis but in doing so they seem to be overtly focussed on obtaining a worse case scenario.

    Their prediction is based primarily on extrapolation of the linear trend from the 1995-2007 instrumentally observed and modelled data. My immediate concern is why a paper written 3 months ago would need to incorporate modelled data. I could understand the use of models if the data used were reconstructed or projected but they are using a timescale for which instrumentally recorded data are available.

    That said, the instrumental record is quite close to Kwok’s data although not quite as dramatic, removing the modelled component would change the projected date from 2016 to 2018.

    Another major concern I have is why they stopped at 2007, the paper was written in March 2010 so should have included the more recent data. Had they done that the graph would have taken on a very different appearance. 2007 was the year of record low sea-ice extent, there was something of a recovery in 2008 and 2009. With the more recent data included, the linear trend is significantly lessened and the sea-ice loss projected for 2016 ±3 years would be delayed until 2024 ±4 years.

    Further, I would question why they chose to start at 1995. They should have used data for the period 1980 to 2009 or based their projections on anomalies against an historical base-period mean.

    Here’s what I consider to be a more realistic projection. I’ve used data for the last 30 years, the data are up until yesterday and rather than apply a linear trend I’ve applied a polynomial one and projected 80 years forward http://www.flickr.com/photos/trevorandclaire/46772...

    If this graph is correct then by 2029 we could see the first ice-free summer in the Arctic. Using the criteria stipulated by the authors of the report then an 80% decline against the 1979-2000 baseline would occur in 2025 (the 1979 to 2000 mean being 8,813,599km², 20% of which is 1,762,720km²).

    I’ve used JAXA IJIS data as this is updated in real time, other data sets measure sea-ice extent differently so the numbers, whilst similar, aren’t identical. However, the projections for the future are the same give or take about 10% either way.

    It will be worth running the figures again in a few months time so as to include the data for summer 2010. It’s looking more likely than ever that we’ll see a record low ice extent this year. Should this be the case then the slope will increase and the projections may come to fruition sooner. Here’s the latest Arctic sea-ice graph, if you looked at my earlier graphs you’ll note that this one now includes projections beyond the end of summer and a ‘zoom’ feature http://www.flickr.com/photos/trevorandclaire/46766...

  • 10 years ago

    Nobody has mentioned that the Navy has been hiding ballistic missile submarines under Arctic ice for 50 years. Even one month of ice-free or substantially reduced ice conditions has profound implications for nuclear deterrence strategy.

    Flossie - your computer problem was that it wanted to finish loading a 5 meg pdf file. If you get frantic about trying to make it stop, you will generally cause a crash. If you don't have the patience for the download to finish, take the computer off-line for a few seconds and close the window or tab the pdf is loading in. You evidently don't have a high-speed internet connection.

    EDIT Jim z's answer is an excellent example of an inability to see other viewpoints. The Naval Postgraduate School, not surprisingly, writes from a Naval strategic viewpoint. If your job is to hide a nuclear submarine, or to order others to hide a nuclear submarine, on the high seas, then ice that is within the territorial waters of another nation (Greenland or Canada) doesn't exist for your purposes. Including that ice in estimates of remaining ice coverage would be extremely misleading from a strategic perspective. Estimating the predictability of Arctic sea-ice, by scientific means, has been a part of the Navy's job since there has been a Navy. They aren't doing it by right, they're doing it by responsibility.

  • Sharon
    Lv 4
    4 years ago

    Yes, the quadratic trend is clearly a good fit for the Arctic sea ice data. I don't see any reason why it won't continue and lead to a largely ice-free Arctic in the summer by around 2016.

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  • 10 years ago

    Of course I agree with them Dana

    From one year ago

    http://answers.yahoo.com/question/index;_ylt=Ahk7j...

    Edit: I do believe that Jim missed the significance of why the navy would be interested in an ice free ocean no matter how long it is ice free. Any tea partying neocon with more than three teeth should recognise that the Arctic Ocean, being small compared with other oceans is easily crossed by a warship in just a couple of days. That is of course assuming that the tea partier in question knows that the Arctic Ocean is more than just a name of an air freshener scent that they spray in the trailer to make it smell “perdy” for Christmas visitors, like the repo man (I hear it’s good for masking the smell of boiled squirrel that spilled over on the hot plate last thanksgiving).

    For an organisation like the US navy, navigability of that ocean becomes a concern even if small amounts of ice remain. For the more brainy neocons it opens up a whole new reason to manufacture fear in the voting population and sign billions of dollars in weapons contracts for the navy.

  • JimZ
    Lv 7
    10 years ago

    I hope you know that the Arctic won't be ice free for more than a month at the most. It is disingenuous to suggest otherwise but I see you have some fellow alarmists here that are eager to jump on any boat, just as long as it is sinking or melting. Your definition, as well as the Navy's isn't effectively ice free or practically ice free or anyway you want to put it. If there is ice there, it isn't ICE FREE. Do words still have meanings or do you get to change the meanings any time it is convenient? My final extremely obvious point that I shouldn't have to make is who thinks that the Naval Postgraduate School has the authority to declare what ice free means or the psychic abilities to forcast the future?

  • Miles
    Lv 4
    10 years ago

    My question is,what will the feed back be as permafrost releases methane, and open waters absorb more heat.Could the global warming actually speed beyond predictions

  • 10 years ago

    Dana, we might not see eye to eye, but leading people to that so-called website is not amusing. It has taken me ten minutes to get my computer working again, as I said, not amusing.

  • 5 years ago

    YES.......The Lord is coming soon!!

  • 10 years ago

    Medieval warming period here we come. Greenland will again live up to the Viking's hype.

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