The New York Times is reporting today that continued acceleration of the rate at which the Greeland ice sheets are melting have scientists scrambling for answers. In particular, a combination of changes have the glaciologists particularly concerned. They say the accumulation of meltwater on the surface of the ice in the form of ponds and streams absorbs as much as four times more heat than the lighter colored ice thereby accelerating the rate at which the surface melts.
Additionally, this meltwater eventually finds its way to bedrock where it appears to ever so slightly lubcricate the surface between ice and rock thereby facilitating more rapid shifting of the ice towards the ocean. A third factor in the trifecta is the breakup of huge semi-submerged clots of ice that typically block narrow fjords. As these blockages are cleared that accelerates the flow of the frozen glacial rivers.
While there is still a tremendous amount about this cycle that remains unknown, what is clear is that the best estimates to date have fallen far short in terms of the speed at which these rare environments are changing. Although questions remain about how much of these changes are cyclical and how much are due specifically to man-originated global warming it is imperative that we gain a more complete understanding of these events so that we can take whatever steps we must to ameliorate any damage we’ve caused before the situation becomes so critical that massive changes come about as a result of our negligent handling of our environment.