Goodbye, Greenland Ice Sheet

A few months ago I had dinner with a climate scientist at JPL (Jet Propulsion Laboratory, in Pasadena, CA) whose job is using cutting-edge technology to measure the size and health of the Greenland Ice Sheet.  In keeping to my policy in such situations, I did very little talking, and a great deal of listening. 

To abbreviate a much longer explanation, determining the area of an ice sheet is a piece of cake; it can be done with terrific accuracy using satellite images.  The problem is that this data alone doesn’t get us very far; the thickness, and size of the internal gaps occupied by air or flowing water, all of which vary greatly from one spot to another, are far more important factors.  Of greatest importance is the flow of water under the surface; the greatest melting of a glacier happens deep within its interior, making the observation of this process – and thus the assessment of the glacier’s health – extremely difficult.

The article linked here doesn’t go into all this too much, but it does suggest that the process by which we are saying goodbye to a significant part of the Greenland Ice Sheet is happening far faster than we had thought.