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Sea Ice Extent Trends

February 19, 2015

By Paul Homewood




NOAA have this chart of annual Arctic & Antarctic sea ice extents. It is a pity they have no global picture, but while Antarctic ice has been growing in the last decade, it appears that Arctic has stabilised since 2005.


We get hung up about Arctic sea ice when it is at minimum in September. This is illogical.

If we are concerned about albedo, we should be looking at the summer equinox.





Last year, while Arctic ice was 675,000 sq km below average in June, in the Antarctic during December it was 1,552,000 sq km above average.


If there was a “global cooling scare”, I wonder which set of data they would be showing us?

  1. manicbeancounter permalink
    February 19, 2015 12:40 pm

    When evaluating trends in Arctic sea ice trends, there is always a problem of no data prior to 1979. We cannot tell on this basis alone if the recent temperature rises are unprecedented over longer time scales. However, the reduction in sea ice extent over the last 35 years is roughly in line in a consistent rise in temperatures recorded by weather stations around the Arctic sea. This is why the cluster of consistent adjustments that appeared to eliminate the early twentieth century warming period is important. Previous warm phases would provide circumstantial evidence of a previous sea ice minimum.

  2. Bloke down the pub permalink
    February 19, 2015 12:52 pm

    ‘it appears that Arctic has stabilised since 2005’

    When I look at this graph of Arctic sea ice extent, I see some distinct break points. Up till about 1998, it varies about a flattish trending mean. From then until 2007 there is less variation, but a declining trend. For the next six years there’s a period of greater annual variation, which I put down to the reduced sea ice cover being more vulnerable to changes in wind direction either spreading the ice over a greater extent or pushing it out of the Arctic altogether. From 2013 onwards the variability is reduced and the trend so far would appear to be rising, a mirror image of the ’98-’07 period. While past performance is not an indicator for future trends, I would not go spending my winnings too early if I’d bet on the Arctic ‘death spiral’.

  3. February 19, 2015 3:40 pm

    Thanks, Paul.
    I don’t understand the public attention to Arctic Sea Ice extent, now 10% bellow its 1979 maximum and 5% bellow its 1981-2010 mean. -3.2% per decade. For a scientist, this is interesting, but for the public? Maybe they fear sea level rise to be caused by sea ice melting?
    We must help educate by showing the facts of nature.

  4. rah permalink
    February 19, 2015 4:06 pm

    And yet to this day we hear the warmist Bozos Like Bill Nye going on about how the Arctic ice pack is melting and the media, like the good little transcribers they are, uncritically repeating their rubbish.

  5. February 19, 2015 4:14 pm

    That 1979 Arctic ice was high when the satellite observation era began is not a cherry pick. Just a coincidence. There is much qualitative and some quantitative evidence beforehand going back to about 1920 in Canadian, Danish, and Russian observations and ice maps. This shows a roughly 60 year cycle now heading back toward more ice. See essay Northwest Passage. The overreliance by the CAGW meme on the coincidence will come back to bite as hard or harder than the pause.
    See also Wyatt and Curry’s stadium wave paper, which Mann tried but failed to rebut on methodological grounds.

    • A C Osborn permalink
      February 19, 2015 4:56 pm

      Rud, as mkelly says the Satellite era did not start in 1979, it started in 1974, but used different Satellites and Camera systems.
      The re-analyis of those years show that there was much less Ice in 1974.
      But of course that does not fit the warmist narrative and so is never shown.

    • mkelly permalink
      February 19, 2015 8:52 pm

      Rud, did you use the link and look at the evidence?

  6. February 19, 2015 6:24 pm

    it is globally cooling
    who else but me is there that figured this out from the results?

    • February 20, 2015 10:52 am

      A possible scenario ? That there is a cycle of increasing ice, more albedo, and an actual fall in temperatures (which the data collector people cover up with fudging cos they know “temperatures can’t really be falling” and the climate truth is so important it needs a helping hand.)

  7. KTM permalink
    February 19, 2015 10:32 pm

    Antarctic sea ice is a pretty good reflection of what albedo will be like near the bottom of the planet, but the top of the planet’s albedo would be a combination of Arctic sea ice and snow/ice cover on land as well. June in particular seems to have the most dramatic decrease in NH snow extent over time of any month.

    I certainly don’t see any acceleration or “death spiral” in the data though.

    • February 19, 2015 11:32 pm

      Don’t forget that the Antarctic sea ice tends to sit at much lower latitudes than the Arctic, and therefore has a higher albedo.

  8. Paul2 permalink
    February 20, 2015 10:22 am

    Fear not the women are coming:

    ……Mary Robinson, the first female president of Ireland, and now an international gender advocate in the climate change negotiations.

    Who knew?

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