NASAs Ice, Cloud and Land Elevation Satellite (ICESat) generated recently published data showing “that all latitudes of the Greenland ice sheet are affected by dynamic thinning â€“ the loss of ice due to accelerated ice flow to the ocean” as well as evidence of “extensive thinning in Antarctica, affecting the ice sheet far inland.”
This is, of course, bad news when it comes to the magnitude of sea level rise to expect in response to climate change. Most analyses of sea ice focus on area covered, not on the potentially more meaningful figure of total ice volume. In addition to raising concern about sea level rise, melting icesheets produce a positive feedback effect as darker surfaces are exposed to sunlight. They also risk disrupting ocean currents where salinity is an important driver.
More information is in Nature: “Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets.”