Interesting. Obviously if some place is still below freezing all year round (i.e. the bulk of East Antactica), global warming can easily increase ice mass due to increased snowfall. But I’d thought decrease in total ice mass was pretty well-established.
The amount lost in the Arctic is about a factor of 3 larger than the net gain in Antarctica, and West Antarctica as a subset of antarctica is losing ice on the net in a way that is likely to accelerate in the future. Also apparently Antarctica has been gaining ice on the net for 10,000 years according to the source, and it’s a case of recent loss rate increases not yet balancing this normal gain rate.
Further quote from the article:
“If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they’ve been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years—I don’t think there will be enough snowfall increase to offset these losses.”
A late follow-up. I read an article on the study, and it turns out that the difference from previous estimates (which basically all showed a decrease in antarctic ice mass) comes from an interesting place. Everyone agrees on the height change in East Antarctica. But the studies that got a net decrease assumed that the change in height was due to recently increased snowfall, in which case the extra height will have the density of snow. This new study that gets a net mass increase assumes that the change in height is actually part of a long-term mass rebound from the last minimum, and if that’s true then the density profile of the Antarctic ice sheet should be roughly constant, and the extra height will have the density of ice, which is ~3x that of snow.
I think the disagreement over this shows how big our error bars are.
Interesting. Obviously if some place is still below freezing all year round (i.e. the bulk of East Antactica), global warming can easily increase ice mass due to increased snowfall. But I’d thought decrease in total ice mass was pretty well-established.
The amount lost in the Arctic is about a factor of 3 larger than the net gain in Antarctica, and West Antarctica as a subset of antarctica is losing ice on the net in a way that is likely to accelerate in the future. Also apparently Antarctica has been gaining ice on the net for 10,000 years according to the source, and it’s a case of recent loss rate increases not yet balancing this normal gain rate.
Further quote from the article:
A late follow-up. I read an article on the study, and it turns out that the difference from previous estimates (which basically all showed a decrease in antarctic ice mass) comes from an interesting place. Everyone agrees on the height change in East Antarctica. But the studies that got a net decrease assumed that the change in height was due to recently increased snowfall, in which case the extra height will have the density of snow. This new study that gets a net mass increase assumes that the change in height is actually part of a long-term mass rebound from the last minimum, and if that’s true then the density profile of the Antarctic ice sheet should be roughly constant, and the extra height will have the density of ice, which is ~3x that of snow.
I think the disagreement over this shows how big our error bars are.