This newish paper in The Cryosphere, by Sole et.al., seems to be a decent stab at analysing mass balance changes in the Greenland Ice Sheet and suggesting an explanation.
By their calculations, marine terminating glaciers are thinning much faster than land terminating ones. But they are, mostly, definitely thinning; this should come as no surprise to readers of the literature.
Their broad conclusion is that recent changes in the GrIS probably have most to do with changes in the surrounding ocean conditions. One of the more interesting suggestions they make is that, once marine terminating glaciers lose contact with their outlets (shame there’s no timeframe), the GrIS is unlikely to contribute much to sea level rise (sort of obvious, but worth noting).
Skumtics needn’t bother atarting to infer anything from this: the GrIS contribution to sea level rise is small, and anyway, sea level rise, in spite of the attention of the media, is not likely to be the most significant consequence of climate change. For this, I’d suggest drought and famine are likeliest contenders, closely followed by political instability and climate migration.
Good to see Stoat staying on the case: I think I probably share his POV on this subject, with less scientific basis. Note, following the comments I made in response to the posts by Antony Watts, that current sea ice anomaly is around -1 million km2; I’m optimistic that my predictions back then might be cashed in by March.
I’m currently framing a bet I would be willing to put money on. More later when I have done so.
Finally, thank you to all 41000 viewers who, by accident or design, have hit my page. Given my lowly estate and somewhat inconsistent blogging habits, it’s more than I ever imagined. I hope of you have got something from these pages. Best wishes 🙂
Old man in a cave 
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January 20, 2009 at 4:28 pm
Eric Hacker
From memory, I recall that the Greenland geology is like a ring of mountains around a depressed plain. The depression is well below sea level due to the weight of the ice sheet. There are likely glacial outlets that will never to cease to be marine terminating.
I could be wrong, and don’t have time to research. I believe I saw the Greenland geology pictures from links on Realclimate.
June 6, 2009 at 1:40 am
Aaron Lewis
I must remain the loyal opposition.
Sole et al. does not address the temperature of the ice. This is critical because the mechanical behavior of ice, and hence ice dynamics are very nonlinear with respect to temperature. While elevation can sometimes be a proxy for temperature, heat advection and heat release as water falls through fractures in the ice can disrupt the correlation.
Some of the glaciers terminate in deep fjords that extend inland. Ice contact with salt water in the fjord can create a halo-density pump that will move sea water into the bottom of the fjord and fresh water out of the top of the fjord. If the ice will not come to the sea, the sea will come to the ice.
New modeling of the effects of an ice free Arctic suggest increased precipitation on the East Coast of Greenland. When, ice gets rained on it melts. Worse, when moisture condenses out of the air onto the ice, it melts a lot of ice.
This the first June that I have seen water vapor over Greenland emitting at 270K see (http://discover.itsc.uah.edu/amsutemps/AAT_Browse.php?chan=03&satnum=15&aord=a)
From the above, I consider it very likely that we will see very rapid ice loss from Greenland as we lose Arctic Sea ice cover. I expect that beach goers around the world will be able to eyeball changes in sea level due to Greenland Ice sheet decay within a decade of having a seasonally ice free Arctic Ocean. Since, I expect a seasonally ice free Arctic Ocean within a decade, I am talking about detectable with the naked eye sea level changes from Greenland within 20 years. These sea level changes would be in addition to any sea level changes form Antarctica, permafrost melt, and glacier melt. Together, these could result in economically significant impacts within 20 years.