Quote:
Originally Posted by Kullat Nunu
Incredible. If they're right, this is really bad news. Just recently the "alarmist" IPCC predicted that this could happen in 2050-2100. The Arctic Ocean with its reflective ice has acted as cooler; if the ice is gone, the ocean becomes a heater because dark ocean absorbs solar energy effectively. Warmer Arctic may in turn change the jet streams in the northern hemisphere, which leads to major changes in rain patterns. Droughts, floods, and such.
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The situation is more complicated than that.
The entire Arctic lies in the negative energy flux high latitudes, meaning of course that the annual average heat energy lost to space is higher than insolation. A reduction of sea ice does reduce albedo and increases absorbtion, but it also increases radiation loss to space.
The high latitudes are where the excess heat energy absorbed at low latitudes is radiated to space to maintain the global heat budget. This heat is transported poleward by ocean currents and atmospheric circulation. By raising arctic sea surface temperatures some 40 degrees Kelvin, blackbody radiation is increased. Exposure of arctic surface water also increases downwelling, reducing the temperature of ocean bottom water.
My point is that the heat energy to melt Arctic sea ice is coming from lower latitudes. The exact consequences of an increase in exposed Arctic sea surface on the global heat budget is not yet known. This could well be a negative feedback responsible for holding the measured temperature increases below the predictions.