Scientists Warn of Rising Oceans From Polar Melt – NYTimes.com: … Implications
Scientists Warn of Rising Oceans From Polar Melt – NYTimes.com:
Studies published in the journals Science (here) and Geophysical Research Letters (here) magazine find that the antarctic is melting, probably at a very very fast pace. The terms “beyond the point of no return” and “unstoppable” are used to describe the collapse of this glacial area in Antarctica. How long it will take is harder to predict.
This really scares the bejeebers out of everyone. Let me summarize a few reasons why this is bothersome:
* It seems that arctic (north) should be shrinking a little and the antarctic (south) should be expanding if there were no human factors influencing such. So the shrinking/melt-off in the south would/should have to overcome this tilting effect of the earth, and then some. (This “effect” is something for people far smarter than I to explain.)
* The north pole is now becoming more navigable, longer in the summer as the ice sheets melt off. China, for example is planning to navigate through a north passage for 3 months a year and avoid bringing oil from Russia through the Suez Canal, essentially cutting the trip in half (and maybe making twice 6-months worth of oil runs.
* The melt off in the north pole is not as worrisome in terms of direct ocean level rise because much of the ice is over water, so the conversion from ice in the north pole to water is not a big deal related to ocean rise (although the resulting warming of the oceans from more heat absorption and less glacial reflection definitely is).
* The antarctic is mostly over land. The melting of the Antarctic glaciers results directly into a rise in the sea levels.
* Combine that with apparent acceleration effect, as the glaciers melt, they move faster and faster, accelerating the depletion process.
* Thermal expansion. As ocean and land become exposed by the melting ice sheets, the ocean, land and air all become warmer. In the case of the oceans, water expands. If the average dept of the oceans are 2 miles, the oceans levels should rise at about 2 feet for every increase in (water) temperature of 1 degree Centigrade.
At this rate, the best case by the IPCC of 2 degrees C increase in global warming has got to be very unlikely. The worst case scenarios of business as usual (BAU) of 3 to 4 degrees or more seem to be the most likely… The 4 degree increase would result in about 9 feet (or 3 yards) increase in sea levels.
That means that by the end of the century, water-front cities will have new waterfront. Venus and New York will be new shapes and sizes. The Florida Keys will be less than half their current size.
Some of us would argue that Business as Usual is not working so well, especially if you care much about your grand kids and great grand kids.
Keywords: Antarctica, Arctic, business as usual, glaciers, Global Warming, IPCC, North Pole, sea levels, thermal expansion,
