要多久才能融化所有的极地冰?-地江南体育网页版球科学堆栈交换江南电子竞技平台 最近30个来自www.hoelymoley.com 2023 - 03 - 31 - t18:10:46z //www.hoelymoley.com/feeds/question/684 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/684 11 要多久才能融化所有的极地冰? ravenspoint //www.hoelymoley.com/users/357 2014 - 05 - 01 - t15:05:32z 2019 - 03 - 13 - t05:15:23z 说,如果所有的极地冰等都融化,海平面将上升66米。

这需要多长时间?< / p >

Transporting incredible amounts of heat energy to the poles and injecting it into the ice, a good insulator, so that it melts must be very, very slow. The Netherlands, London, and all the rest will be long gone for other reasons, I imagine, long before it could be completed.

I am looking for an order of magnitude minimum under which it is provably impossible for the ice to all melt any faster. Wild and crazy assumptions are welcome, so long as they err on the side of making the ice melt faster than it would in reality - that way the estimate will always be a minimum.

//www.hoelymoley.com/questions/684/-/687#687 6 要多久才能融化所有的极地冰? ravenspoint //www.hoelymoley.com/users/357 2014 - 05 - 01 - t17:44:56z 2014 - 05 - 01 - t18:51:02z 我们需要一些数字。< / p >

Antarctic ice is about $2\,\mathrm{km}$ thick.

enter image description here

Let's replace this with a $1\,\mathrm{km}$ blanket of ice equivalent insulator. In this case, if the mean air temperature ( currently -57C ) rises to $10\,^{\circ}\mathrm{C}$, then energy arrives at the bottom of the blanket ( where I assume the temperature has risen to 0 celsius and the pressure has fallen to 1 atmosphere ) at the rate of ... $0.02\,\mathrm{W/m^2}$.

Antarctica is $14 \times 10 ^{6} \,\mathrm{km}^2$ so we are able to deliver energy at $3\times 10 ^7\,\mathrm{W}$

$$\frac{6 \times 10 ^ {24}}{3 \times 10 ^ 7} = 2 \times 10^{17}\,\mathrm{s} \approx 7 \times 10^{9} \mathrm{years}$$

I think we can all relax!

//www.hoelymoley.com/questions/684/-/688#688 10 北极的冰要融化多久? 大卫Hammen //www.hoelymoley.com/users/239 2014 - 05 - 01 - t18:28:29z 2014 - 05 - 01 - t19:02:59z 别这么轻松,ravenspoint。< / p >

The Laurentide ice sheet at its maximum extent was larger than the Antarctic ice sheet is now. The bulk of that ice sheet melted in two pulses of 2000 years each, separated by the ~1000 year long Younger Dryas. During the first pulse, the Laurentide lost 5400 km3 of ice pear year. During the second pulse, it lost ice at an even faster clip, 5600 km3 of ice pear year.

Source: Dyke, A. S. (2004), "An outline of North American Deglaciation with emphasis on central and northern Canada" in Quaternary Glaciations- Extent and Chronology, Part II, p. 373-424, J. Ehlers and P. L. Gibbard, eds, Elsevier.

You want a SWAG, so I'll use 5000 km3 per year. That's just 5000 years for the Antarctic ice sheets to melt. The Laurentide ice sheet was able to melt quickly because a good chunk of it was outside of the polar circle. That's not the case for the Antarctic ice sheet, so this 5000 years most likely is an overly aggressive estimate.

//www.hoelymoley.com/questions/684/-/690#690 16 北极的冰要融化多久? 彼得很 //www.hoelymoley.com/users/81 2014 - 05 - 01 - t18:43:32z 2014 - 05 - 01 - t19:29:29z 这个问题要求一个没有实际应用的答案。因此,与其改进一些假设的计算,我将描述这个问题,并希望能够清楚地说明为一个时间框架提供一个真实答案的困难。第一个:“极地冰”南极洲位于极地,由厚达数公里的冰盖组成。除了较小的冰川和格陵兰岛之外,北极被海冰覆盖,格陵兰岛的极地位置与南极洲不同。人们必须记住,在海洋和大气中,南极的环流与地球上的其他地方是隔离的,这是北极所没有的情况。因此,极地冰这个术语是非常模糊的,应该避免使用。最好是直接谈论对象。< / p >

Second: an ice sheet such as Greenland and Antarctica is not a stagnant sheet of ice, it has its own dynamics and which can change over time depending on forcing and change in forcing.. Greenland is largely land based but with outlet glaciers that terminate in the sea. Although mass loss through these have seen an increase in loss, much of the Greenland mass gain and loss is through surface mass balance (snow accumulation minus ablation, melt). 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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