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.
But, then the article goes on to say
This would amount to a contribution to global sea level rise from Greenland of about half a millimetre (0.02 inches) each year.Now, my 20th hig school reunion is this weekend, so I'm reminded of the big ugly box I went to about 180 days out of the year for two years. They had a little class there they liked to call 'Physics.' And in Physics, we learned that accelerating phenomena don't proceed at constant rates. Remember the little triangle to show how much ground an accelerating car covered?
I think we need a new estimate of when the sheet will be gone.