Researchers at Copenhagen University have completed a study that has both good and bad news regarding the ice cover in Greenland. They studied the layers of ice that go back as far as 120,000 years and have come to the conclusion that the ice cover appears to have the ability to survive a warmer climate better than anyone hoped it would, but on the other hand, they also found that there are changes happening that will happen much faster than has been thought. These happenings have the possibility of making the seas in the world rise faster than has been anticipated.
For example, they found that the ice stream, which is ice that moves through the inland ice, much like a river through a mountain pass. This is also the ice that forms icebergs at the mouth, a process called calving. They found that in just two to three years, the speed of a particular ice stream had almost doubled. What this means is that they have greatly underestimated the changes that will result because of the large amounts of ice that flow away and become icebergs and thereby leave the ice sheet every year.
The research also showed that the inland ice has the ability to cope with the warmer climate that Greenland is experiencing must better than the researchers models had previously indicated.
They are now in the process of up dating their base of information for the models. One factor that they are going to use is how the ice moved some 120,000 years ago during a period known as the Eem Warm Period when the average temperature was actually a little warmer than it is now. By using measurements such as the amount of oxygen in the ice core, they were able to determine that this warm period actually lasted for many thousands of years.
By using DNA samples that they collected from under the ice cover, they discovered that the last time Greenland was all bare ground was about 400,000 years ago. They combined these findings and have come up with a model that shows the fact that a good amount of the inland ice can still be around even during a longer period of warmer whether than they have experienced in the modern era.
We are rapidly approaching the same levels that existed during the Eem Period, so therefor the research that is being done now is about something that may be a fact of life relatively soon.
The purpose behind doing research on the inland ice is that it is possible to see what kind of impact the earlier warm periods had to the ice and compare those results to the models to calculate what the future ice cover might look like. If the model fits in with the Eem Period, then they can rely on the model to show the near future.
The lead researcher on the project is Dorthe Dahl-Jensen, a professor at the Niels Bohr Institute at Copenhagen University.
Source: Swedish Research Council. http://www.vr.se/