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> Extensive satellite monitoring began in the 1990s and, within a decade, evidence emerged that the ice sheet was already starting to speed up, retreat and dest
by godshatter 9y ago
> Extensive satellite monitoring began in the 1990s and, within a decade, evidence emerged that the ice sheet was already starting to speed up, retreat and destabilize. Since then, the rate at which some of the glaciers are dumping ice into the ocean has tripled. More than 100 billion tons are lost every year.
I have a pet peeve about large numbers being thrown about without context. 100 billion tons of ice lost every year is a large number. How many tons of ice are in the whole of the ice sheet? 30M km^3 * 0.239913 mi^3/km^3 * 3.82 Gt/mi^3 = ~27.5 million gigatons. So that gives us about 275,000 years at current rates before the ice sheet is gone.
I got the 30M km^3 from here: https://www.sciencedaily.com/terms/antarctic_ice_sheet.htm https://www.sciencedaily.com/terms/antarctic_ice_sheet.htm and other conversions from here: http://www.sealevel.info/conversion_factors.html http://www.sealevel.info/conversion_factors.html
- blondie9x 9y agoIf the whole ice sheet disappears, we disappear.
- cmurf 9y agoI don't see the correlation. The disappearance itself doesn't seem to be the problem, but the accumulation of consequences of even the process of it disappearance that are the problem; not least of which is the cost of adaptation.
- blondie9x 9y agoIf it disappears sea level would rise significantly. Therefore we would disappear because most of our civilization would be effected that lives around sea level.
- lambdadmitry 9y agoThat's a non-sequitur right there. It's not like the entire Antarctica melts in a year or two; in the worst case, it's multi-decade process. It's pretty easy to adapt to such change; we (obviously) built cities before and can do that again.
- godshatter 9y agoAt the time scales we are talking about, our cities can ooze away from the sea slowly just by abandoning property that is currently flooding. The sea is rising at around 3mm / year, which is about a foot a century. Even if we multiplied this ten-fold, that's still only about an inch and a quarter a year we'd have to cope with. We'd have to raise some levies, abandon some property, and maybe update some other infrastructure. Not great, but not the end of the world.
- givinguflac 9y agoSure, but that's assuming a linear rate of decay, which it has not and will not be. There's a tipping point well before your theoretical limit. Ice breaks up and slides into the ocean quite a long time before it all melts.
- deleted 9y ago[deleted]
- tlb 9y agoA billion tons is a cubic kilometer, maybe easier to visualize how tiny a part of Antarctica that is.