Even less consensus

Quick, someone call ExxonMobil and tell them to write an article:

Greenland's glaciers are melting into the sea twice as fast as previously believed, the result of a warming trend that renders obsolete predictions of how quickly Earth's oceans will rise over the next century, scientists said yesterday.

All those scientists were wrong! Ooops, but it's in the opposite direction that the propagandists want you to believe. Booman has it right.


Update: That was fast! Someone at ExxonMobil TCS daily had an article ready to go! (Imagine that):

Why would Science publish this paper with no reference to Johannessen's earlier paper showing that Greenland is accumulating ice at a rate of about 5.4±0.2cm/year? Johannessen even used data from some of the same satellites. What's more, Johannessen used real data and Hanna et al., cited by Rignot, used a model of surface melt.

Not true. ScienceMag did include that relevant piece of information. Here, from the "Perspectives" section of that same issue:

Satellite and airborne radar and laser altimeter data sets complete the picture of a changing Greenland Ice Sheet. Above the 2000-m contour, representing 70% of the ice-sheet surface, elevations increased by a mean of 5 to 6 cm year-1 (11, 12). These values were based on satellite radar altimeter data acquired between 1992 and 2003 (11, 12), and are greater than those reported previously from more scattered airborne evidence (13). The pattern of change was variable, however, with growth of 10 to 20 cm year-1 in southwest and parts of east Greenland and negative values of 25 to 30 cm year-1 in some lower-elevation western areas in particular (11, 12). By contrast, peripheral thinning of the ice sheet was recorded, exceeding 1 m year-1 close to the coast, often associated with outlet glaciers (13). The thinning was due to changes in ice flow, in addition to enhanced melting. However, parts of southern Greenland appear to be thickening even close to the ice margin, perhaps resulting from increased coastal precipitation (12).

Taking the new evidence on the acceleration of ice-sheet outlet glaciers together with estimates of increasingly negative surface mass balance (7) yields, according to Rignot and Kanagaratnam (2), a contribution from the Greenland Ice Sheet of more than 0.5 mm year-1 to global sea-level rise, over two-thirds of which is derived from flow acceleration. This new information on velocity change more than doubles previous estimates of losses from the ice sheet to the global ocean (6, 7). Future monitoring of the velocity structure of the ice sheet, especially above 70°N where acceleration to date has been limited, is required. It is also necessary to understand better the nature and distribution of precipitation over Greenland. Increased accumulation in the ice-sheet interior, and even in some coastal areas, could offset losses attributable to surface melting at lower elevations (12). Existing and forthcoming satellites will continue to measure ice-surface elevation and any shifts in the rates of surface melting and accumulation. In a warming world, it is likely that the contribution to sea-level rise from Greenland is set to grow further, assuming that the observed acceleration in outlet-glacier velocities is sustained, with possible increases in precipitation providing the only prospect of short-term amelioration.

The Science article recorded south-of-70 ice flows. Patrick Michaels of ExxonMobil TCS daily, wants to generalize isolated precip measurements over all of Greenland:

Consider what would have happened had the latest study included the ice and snow gains observed by Johannessen (and ignored the losses modeled by Hanna et. al.). Johannnessen's increase of 5.4cm/year averaged over Greenland converts to about 75km3/year. Rignot and Kanagaratnam could have subtracted Johannessen's gains. If they had done so, the total volume of ice loss from Greenland would only have become positive during the last 5 years, totaling 17km3 in 2000 and 92km3 in 2005. This translates to a sea level rise contribution of 0.04mm in 2000 and 0.23mm in 2005 -- values much less dramatic than those they published.

It might turn out that he's right, which is why more studies need to be done. Precisely what Science Mag says.