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A picture from satellite data highlights the increase in summer melts in Greenland's ice sheet over the decade between 1992 and 2002  (Source: CIRES and CU Boulder)
Greenland's melt is increasing and continues a series of record setting years

Yesterday, DailyTech covered shocking allegations by an esteemed sea-level expert that the IPCC modified climate data and committed other violations in an attempt to falsely portray accelerating sea level rising.  If true, perhaps the IPCC should have learned to be more patient.

Greenland's melt is accelerating, according to a new study published as part of long-ongoing research at the Colorado University at Boulder on climate change.  In 2007, the summer melt record was surpassed by 10%.  CU Boulder notes that record breaking melts are nothing new to Greenland; the last 20 years have brought 6 record melts, with record melts in 1987, 1991, 1998, 2002, 2005 and 2007.

The base cause is clearly a surface air temperature rise.  Since 1991, extensive data shows that temperatures over Greenland's ice sheet increased approximately 7 degrees Fahrenheit on average.

The report by CU Boulder seemed objective and balanced in its observations.  It helpfully noted that the ice level actually had increased slightly at higher elevations due to increased snowfall over the past decade, however, it noted that this increase was not enough to offset the sharply escalating melting.

Professor Konrad Steffen, director of the Cooperative Institute for Research in Environmental Sciences which headed the study, gave a presentation on his team's research to the American Geophysical Union held in San Francisco from Dec. 10 to Dec. 14.  The paper that the presentation is based on, titled "Melt season duration and ice layer formation on the Greenland ice sheet," was published in the peer-reviewed Journal of Geophysics Research and is available here (PDF).

At the presentation, Professor Steffen put the melt in context saying, "The amount of ice lost by Greenland over the last year is the equivalent of two times all the ice in the Alps, or a layer of water more than one-half mile deep covering Washington, D.C."

Professor Steffen explained how his team used Defense Meteorology Satellite Program's Special Sensor Microwave Imager aboard several military and weather satellites to map the melt.  Professor Steffen supplemented this data with polled data transmitted via satellite from 22 stations on the Greenland ice sheet known as the Greenland Climate Network, which he and the University personally maintain.

Lubrication from the melting is one important factor that is speeding up the melt, as explained in Professor Steffen's research.  He stated, "The more lubrication there is under the ice, the faster that ice moves to the coast.  Those glaciers with floating ice 'tongues' also will increase in iceberg production."

If global warming critics or believers hope to use the melt as a quick smoking gun to prove sea level change, they shouldn't hold their breath.  Greenland is slowly and steadily contributing 0.5 mm of world sea level in melt water a year.  If all of Greenland's ice sheet melted, it is estimated that it would raise the global sea levels 21 feet, but for now it is just gradually raising them with time. 

However, deep tunnels in the ice known as moulins are speeding the rate at which water is evacuated into the sea.  With record melts, glacier lubrication, and these tunneling phenomena Professor Stephen expects the current yearly sea level contribution of 0.5 mm/yr to quickly rise.

He thinks that IPCC may have missed the boat on both ends -- overestimating sea level rise now, and underestimating future sea rise for the remainder of the century.  Professor Steffens has publicly stated that based on his understanding of Greenland's current melting process that sea level rise will significantly beat the estimates for 21st century sea level rise made by the IPCC Panel held in 2007.

Professor Steffens works for CIRES, which is a joint venture of CU Boulder and the National Oceanic and Atmospheric Administration (NOAA).  He and his team will continue to provide a voice of scientific reason in the global debate over whether melting is increasing or decreasing, with his team's diligent analysis of melting in Greenland.



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Anyone else notice...
By Terberculosis on 12/13/2007 2:12:36 PM , Rating: 2
quote:
Since 1991, extensive data shows that temperatures over Greenland's ice sheet increased approximately 7 degrees Fahrenheit on average.


quote:
Lubrication from the melting is one important factor that is speeding up the melt, as explained in Professor Steffen's research. He stated, "The more lubrication there is under the ice, the faster that ice moves to the coast.


Am I the only one who sees a problem with claiming that increased air temperature is causing lubrication under the ice sheet? Did I miss something. Last time I checked, Ice was not especially water permiable... so how does the air temperature rising and melting the ice on top translate to lubrication beneath the ice?

I am aware that the ice probably isnt a single sheet, but at the same time, the ice has seen spring thaws for millions of years, and would likely already have well defined chanels to get rid of the melt water.

My 0.013707 EUR




RE: Anyone else notice...
By masher2 (blog) on 12/13/2007 2:43:31 PM , Rating: 2
Ice under extreme pressure melts at a lower temperature than normal. So its possible in theory that the higher air temperatures have raised the temperature under the sheet to a point that, while still below 0C, is now high enough to enable melting.

However, in my opinion, below-surface heating, such as the magma upwelling mentioned elsewhere in this thread, seems a more likely candidate.


RE: Anyone else notice...
By ChuckNash on 12/13/2007 4:33:21 PM , Rating: 2
Looking at those images you included in the article, you really think an upwelling of magma is more likely that global warming to cause the observed melting? If magma was the main cause, wouldn't the melting have a totally different profile, one more focused around the upwelling?


RE: Anyone else notice...
By masher2 (blog) on 12/13/2007 5:07:36 PM , Rating: 2
If you heat the center of an ice sheet, it won't melt in the center...heat will flow to the edges, where melting will commence.

In any case, I didn't mean to suggest that *all* the melting was due to magma upwelling, just for the liquid water beneath the ice sheet, which is acting as a lubricant and speeding the melting process.


RE: Anyone else notice...
By Rovemelt on 12/14/2007 12:16:46 PM , Rating: 2
That's funny, because you didn't seem to think magma moving under the earth could cause a change in the length of day measurements (which you linked to ocean level rise), otherwise you would have told us of this fact in your previous blog.


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