Friday, September 21, 2012
"Brainiac" Goops Screw It Up Again on Antarctic Sea ice
Comparison images of Arctic (top) and Antarctic sea ice changes for summer minimum and wniter maximums. (From National Snow and Ice Data Center)
I think perhaps there ought to be a law of some kind preventing those who've never taken a physics course from commenting on climate science. It would be nice to have such laws, because then they couldn't use the "free speech" nonsense to justify spreading crappola.
I'm referring, of course, to some recent blogs which castigate "NPR" data (instead of going to NOAA or the NSIDC) to claim that Antarctic sea ice is "growing" and hence global warming is a hoax or over-stated. Of course this is gibberish, because if one examines the actual data disclosing temperature increases globally, we are in deep doodoo - adding nearly 2.0 watts/m^2 per year to the solar insolation because of global warming.
Several common errors are made by these GOOPr naysayers:
1) They commit an error of omission, namely ignoring the critical land ice contribution and focusing only on sea ice. This is a common error made by those who rush into areas for which they have little or no preparation. In Antarctica, sea ice nearly entirely melts away during the S. hemisphere summer but is extensive in the winter.
2) They fail to distinguish the two forms of ice: Antarctic land ice is actually stored ocean water that once fell as precipitation. Sea ice, meanwhile, is ice which forms in salt water (sea water) mainly during the winter months.
3) They fail to distinguish Arctic from Antarctic ice cover and hence the relative importance of each. Arctic sea ice while its cover fluctuates, does remain all year round (so far anyway) and hence provides a reflective surface to increase albedo. (proportion of reflectance back into space).
This is precisely why ARCTIC sea ice is more important for Earth's energy balance because when it melts the albedo more rapidly decreases, exposing dark terrain which absorbs more solar radiation which is then trapped by the CO2 blanket. By contrast, the melting of Antarctic sea ice each summer largely leaves the energy balance unchanged. Meanwhile, the accumulation of Antarctic SEA Ice - some 26 gigatons a year - is not enough to adjust the energy balance away from global warming or to compensate for lost LAND ice (see below)
There are two ancillary environmental factors that lead to Antarctic sea ice growing which have nothing to do with the idea that global warming is refuted:
i) Because of suppression of choloro-flourocarbons in the atmosphere, ozone levels have dropped over the Antarctic causing stratospheric cooling and fiercer winds which lead to more open water freezing.
ii) The Southern Pacific-Southern Atlantic (bordering Antarctica) is experiencing increased rain and glacial runoff altering the pH and altering the composition leading to less mixing between cold and warm waters. As we know a decrease in sea water pH (from 'freshening' via melting ice from glaciers) decreases the saturation rate of sea water relative to CaCO3 - this can actually lead to the release of CO2 from the oceans (See: Eos (Vol. 83, No. 34), from August 20, 2002, ‘Progress Made in Study of Ocean’s Calcium Carbonate Budget’)
Let's return to the land ice issue: Recent studies by Chen et al, Wingham et al, Rignot et al, show Antarctic land ice losing from 100 to over 300 gigatonnes per year. Even reckoning in added sea ice at 26 gigatonnes per year, this is not enough to offset the net LOSS of ice, of at least 74-75 gigatonnes/yr.
It certainly appears that the nattering conservo nabobs who're trying to use "growing" Antarctic ice as a cudgel to "disprove" global warming either need to go back to school and take a physics course, or better yet leave material that they don't grasp out of their blogs!