问题是没有实际应用的请求答案。因此而不是改善一些假设的计算,我将描述问题,希望使困难提供了一个真正的答案一个时间框架清晰。第一:“极地冰”南极洲位于极位置和由multi-km厚厚的冰层。北极被海冰覆盖,除了小冰川和格陵兰岛,这不是位于南极极地位置等于。必须记住,南极洲是circulation-wise孤立于其他行星环极环流,在th esea和大气,情况不满足在北极。因此术语极地冰非常模糊,应该避免。最好是直接谈论的对象。第二:格陵兰岛和南极冰盖如不是一张停滞不前的冰,它有自己的动力和可随时间变化取决于强迫和变化迫使. .格陵兰岛冰川在很大程度上是基于土地但出口,终止在海里。虽然通过这些增加了质量损失损失,格陵兰岛的大部分质量得失是通过表面质量平衡(积雪-消融,融化)。 Antarctica is a different beast since East Antarctica is largely land based while West Antarctica is to a large extent sitting on ground below (in places several km) below sea level. Te latter situation is more unstable since the ice could disintegrate by calving (loss through ice berg formation), a process which is potentially much quicker than surface melt (of which there is currently very little in Antarctica). So one part of Antarctica is much more unstable than the other. Now, several other processes are at play. Ocean currents are sen to produce massive amounts of submarine melt on both Greenland outlet glaciers as well as on the sea-terminating edges of Antarctica. In places, circulation models estimate up to equal loses by calving an submarine melt. This occurs at the same time as there is hardly any surface melt to speak of. So calculating mass loss by surface melt is clearly a lost cause when calving and submarine melt dominate. Finally, in this still simplified picture, the dynamic response of the ice sheets to changes in forcing is not well understood. This means we do not know *how* unstable East Antarctica really is. That Antarctica will totally disappear seems very unlikely any time soon and time frames of 10^3-10^4 years is a minimum. Greenland, not being a polar ice sheet is more sensitive in that as it loses mass it is also on average lower in altitude, experiencing more melt. There appears to be a point of no return for Greenland, under which elevation the ice sheet would not be able to recuperate unless the climate cooled significantly. Again the time to melt off the ice is long. despite the seemingly slow increase in sea level, much infra structure in the coastal environments is threatened by only dm to m changes in ea level so the 66.1 m quoted from IPCC is not something that will happen in a life time but that does not mean the rates are not already problematic. As a PS, I will add some relevant references once I am back home in case someone misses them at the moment.
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