As a glaciologist I must correct misreading of the literature. No one at NASA or anywhere else is noting that the WAIS or Greenland Ice Sheet is disintegrating. They are both showing signs that it may happen, but not that it is happening. In your link Hansen (not a glaciologist) strongest statement is "The detection of recent, increasing summer surface melt on West Antarctica (Nghiem et al 2007) raises the danger that feedbacks among these processes could lead to nonlinear growth of ice discharge from Antarctica." That is the point, could lead to non-linear response, which equates to disintegration in WAIS, no such statement is made for Greenland. There is no statement or data that suggest it has led. The observed changes are very short term on the order of a decade and these ice sheets respond on much larger time scales. The contributiion of these ice sheets to sea level to date has been small, again indicating disintegration has not begun. This NASA points explains well what is observed. Note there also is a GE tour of Jakobshavns. Glacial quakes-Jakobshavns