August 16, 2006
|Greenland's Melt Speeding Up||Environment|
The meltdown of Greenland's ice sheet is speeding up, satellite measurements show.
Data from a US space agency (NASA) satellite show that the melting rate has accelerated since 2004.
If the ice cap were to completely disappear, global sea levels would rise by 6.5m (21 feet). [...]
Estimated monthly changes in the mass of Greenland's ice sheet suggest it is melting at a rate of about 239 cubic kilometres (57.3 cubic miles) per year.
This figure is about three times higher than an earlier estimate of the mass loss from Greenland made using the first two years of Grace measurements. [...]
"Acceleration of mass loss over Greenland, if confirmed, would be consistent with proposed increased global warming in recent years," the authors wrote in Science. [...]
The group's findings agree remarkably well with a study released earlier this year that used data from other satellites to estimate mass changes in the Greenland ice. [Emphasis added]
The Greenland melt is important not just because it will cause sea-levels to rise (if one can say "just" about something that significant) but also because it is likely to trigger other changes with even more far-reaching effects. Chief among these is disruption of the North Atlantic currents that warm the UK and Western Europe. Besides which, the accelerating melt is evidence that global warming generally is accelerating. Feedback loops are strengthening, in a self-reinforcing process that may spin out of control, finally reaching equilibrium in a world very different from the one we know.