I was reading a report about a presentation at the American Geophysical Union (AGU) meeting in San Francisco last week. Lora Koenig, a glaciologist at the National Snow and Ice Data Center (NSIDC) led a group that found the way ice is melting on the Greenland Ice Sheet changed during the 1990s. The principle means of melting used to be glaciers calving off into the sea. What Koenig's group found is that, while the glacial flow continues, melt ponds have now become the dominant means of mass loss. The ice will melt during the summer and forms bodies of water that range from small ponds to large lakes. This water finds ways to get through the ice and rivers of melt water form. Some of these ponds are even staying liquid through the winter with a layer of insulating snow on top. This provides a jump start on the next melt season. Additionally, the conditions have changed to allow even more melt water to run off. The top layer of snow used to absorb a lot of melt water, but it has now absorbed so much in some places that it is saturated and freezes solid. Since the snow can no longer absorb the melt water, the water flows over the surface and eventually goes into the sea.
So, if the climate isn't changing, as the denier industry wants us to believe, then why is the means of melting changing on something as large as the Greenland Ice Sheet?