The high priest of the hotheads is NASA’s James Hansen, who preaches that, unless we dial back to 350ppm, we will lose, within a hundred years’ time, the vast majority of Greenland’s ice, which will raise sea levels about 20 feet. Hansen has testified that he thinks this could happen within a hundred years.
The hothead theory is that the ice on that gigantic island is much less stable than previously thought, and that with a tad more warming, lakes will form in the summer, drain thousands of feet down to the bedrock, and lubricate the flow to the ocean. It quickly melts, submerging a lot of Florida and Manhattan. The Washington Monument becomes an island.
Greenland has 10,000 feet of glacial ice above sea level, which is about 1/4 of the density of the granite underneath it. In order to maintain isostatic equilibrium, the ground underneath the ice sheet must be depressed about 2,500 feet in the center. In other words, the land surface of Greenland must be somewhat bowl shaped.
Additionally, Greenland has large mountain ranges which block the movement of deeper ice. The point being that the ice sheet can not slide off into the ocean as a block – because things don’t slide uphill and they don’t slide through mountain ranges.
Greenland’s glaciers move towards the ocean because snow builds up in the interior (above the mountain tops) and the excess weight causes the ice to flatten and spread outwards.
Hansen is often described by the press as the world’s greatest climatologist.
Does ice cream slide out of a bowl? Only if its made with Helium II.
Steve, I assume you’ve seen this:
http://news.ninemsn.com.au/world/274814/wwii-plane-recovered-in-greenland
Shows that several hundred feet of snow/ice have accumulated there in Greenland in the last 60 years.
-Scott
I’ve written about that. The fact that the plane is covered does not mean that the thickness of the ice has increased, as the ice spreads laterally in the form of glaciers calving into the ocean. In oreder for ice to accumulate, the gain of snow would have to be greater than the amount of melt, evaporation and calving combined.
Regardless, if several hundred feet of snow/ice has formed over 60 years, then the amount due to melting/sublimation is still minimal, even if calving contributes a ton (and apparently much more).
So I see it as:
Addition = Snow
Subtraction = Melt+Sublimation+Calving
Because calving is apparently the dominant mechanism (because the observation I mention shows melt and sublimation to be far behind the added snow), that indicates that Greenland should be nowhere close to losing it’s ice, as calving is likely proportional (to some extent anyway) to the added snow.
-Scott
Hotter summers may not be as catastrophic for the Greenland ice sheet as previously feared and may actually slow down the flow of glaciers, according to new research. It’s worse than we prevously thought!
http://www.nature.com/nature/journal/v469/n7331/abs/nature09740.html
Hansen doesn’t have a clue about the way glaciers behave:
http://icecap.us/images/uploads/OllierPaine-NoIceSheetCollapse-AIGNewsAug.2009.pdf
Here’s a map of Greenland as if it had no ice:
http://commons.wikimedia.org/wiki/File:F1_large2.JPG
It looks to me like big lakes would form – if all that ice could be melted. And that is a big if; there would need to be a tremendous amount of Global Warming to melt that amount of ice. And with Global Warming on hold the last decade, it looks to me like concern over Greenland’s ice are a distant fantasy problem and not worth worrying about.
5 to 10 degrees C, and it would have to remain that way for several thousand years … not gonna happen!
Send Charlie Sheen there with 3 girls and a truck load of Scotch and watch him drink all that ice
Well, once a gatoraide bottle slid out of my freezer and fell on the the floor. That is highly credible scientific evidence that Hansen may be on to something! Maybe I can get a grant to perform further studies.
As long as you indicate your study has to do with global wamring, the money will flow like water from a melting glacier 🙂 .
It depends on the angle of the glacier, not the temperature. Why do different glaciers move at different speeds? They just pick a fast moving glacier in Greenland and model it for the whole island. The centre of the island is actually quite low too, some below sea level. If you look at Greenland without any ice, it’s actually like a big horseshoe.
http://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Topographic_map_of_Greenland_bedrock.jpg/461px-Topographic_map_of_Greenland_bedrock.jpg will ice slip into the centre LOL