Greenland Melting to Ring
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.