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Is Antarctica Getting Warmer?

September 1, 2013
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By Paul Homewood

 

According to climate models, temperatures at the poles should be increasing faster than anywhere else as greenhouse gases increase. Climate4You describe the reasons for this:-

 

  • Firstly, atmospheric carbon dioxide (CO2) has its greatest absorption of infrared radiation (IR) at sub-zero temperatures, as its absorption bands lie in the 12-16 micron wavelength band, corresponding to the wavelength of strongest IR surface emission from polar ice and snow. At higher temperatures, the typical wavelength of the strongest IR surface transmission is less than 12 microns, and therefore less affected by CO2. At temperatures near the average surface temperature of the Earth (c. 15°C), the strongest emission wavelength is around 10 microns, a wavelength which is largely unaffected by greenhouse gases. This is the so-called `radiation window’ of the atmosphere where IR radiation from the surface escapes freely to the space.

  • Secondly, by far the most powerful atmospheric greenhouse gas is water vapour. Water vapour shares many overlapping absorption bands with CO2 and therefore an increase or decrease in atmospheric CO2 has limited effect on the overall rate of IR absorption in those overlapping regions, if water vapour is present in sufficient quantity. In the Polar Regions , the air is dry due to prevailing low temperatures, allowing CO2 to exert a much greater influence than would be possible in warmer and moister air masses at lower latitudes. Here water vapour saturates the absorption wavebands to the point where changes in CO2 have little effect. In addition to the enhanced greenhouse effect, Arctic climate is influenced by a powerful positive feedback mechanism, the temperature-albedo feedback, tending to amplify any initial temperature change. Rising temperatures will usually increase melting of snow and sea ice, reducing surface reflectance, thereby increasing solar absorption, which raises temperatures, and so on. Conversely, if climate cools, less snow and ice melts in summer, raising the albedo and causing further cooling as more solar radiation is reflected rather than absorbed.

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    According to a report by the World Meteorological Organisation in 2007

    The model runs for the IPCC’s Fourth Assessment Report suggest that, with an increase in greenhouse gases of 1 per cent per year, annual mean surface temperatures in the Antarctic sea-ice zone over the 21st century
    would increase by 0.2-0.3°C per decade.
    There would be a corresponding decrease in the extent of sea ice. Large parts of the high interior of the Antarctic would experience surface temperature rises of more than 0.3°C per decade.

       

    So what has been happening to temperatures in Antarctica in recent decades?

     

    First, let’s have a look at the UAH satellites, that cover 60S to 85S. Since satellites began monitoring temperatures in 1979, there has actually been a small but declining trend (see green line).

     

    image

    http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc_lt_5.6.txt

     

    Climate4you also provide a chart of HADCRUT temperatures, going back to 1957. There was a slight increase leading up to the early 1970’s, but since then, temperatures have been flat.

     

    image

    http://www.climate4you.com/index.htm

     

    So we now have:-

    • Declining temperatures
    • Increasing sea ice
    • Advancing glaciers
    • Increasing ice sheet mass.

    On every count, the models and predictions of the IPCC and WMO have failed.

    Meanwhile, alarmists tie themselves into ever more complicated knots, trying to explain record levels of Antarctic sea ice on global warming!

    4 Comments
    1. Brian H permalink
      September 1, 2013 4:11 pm

      The line about open water at the poles absorbing more solar irradiation is half-baked. At those angles of incidence, it is a fairly minor effect, whereas the emission is always direct.

      IAC, the deep cold of the driest South Pole highlands invalidates any “projection” of maximized CO2 OLR blockage.

      • September 1, 2013 5:25 pm

        Yes, Brian.

        I’ve always believed that much more heat will be lost from evaporation then gained from irradiation.

    2. Dorian Jaubert permalink
      September 1, 2013 5:04 pm

      May the cooling of Antarctica be the beginning of a cool period at the world scale ?
      Do you think that it can result of the weakness of solar activity ? in which case, in view of the predictions for the cycles 25 and following, we can reasonably say the cooling will go on for several decades.
      Of course, it’s not the only climate factor to take into account, but because of the important role of the Antarctica on the Earth climate, it seems to me that the solar hypothesis to expalin its cooling is worth to be studied.
      In all the cases, the cooling of Antarctica does not match with any of the IPCC’s models, and the warmists must seriously question themselves.

    3. September 2, 2013 12:13 am

      The alarmists are sure feeling the heat at the moment… if you’ll pardon the expression (perhaps I should say the squeeze, or uncomfortable, or scared witless – you know what I am saying).

      I find it fascinating that the diehards are still insisting. In 50 years time, when a deep chill is upon us, they’ll still be insisting it’s temporary and that the globe is really warming, and if we don’t get the chill, but it mellows out again, they’ll be screaming the end is nigh.

      They called it a warming trend when it was only 8 years, now they say a cooling trend has to be 30 (having advanced from their original statement that it had to be 15 years). When we reach 30, they’ll be insisting on 50. Why don’t we go back and insist on that original 8 being 15, not 30, no 50 before it can count? Wouldn’t that mean the whole premise can be chucked out now?

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