As mentioned elsewhere in my posts, I generally agree with, and greatly respect the work that Hansen and Sato are doing to convey the risks of abrupt SLR to the community of concerned parties; including the following exerpt from: "Update of Greenland Ice Sheet Mass Loss: Exponential?" 26 December 2012 by James Hansen and Makiko Sato:
"Iceberg cooling effect. Exponential change cannot continue indefinitely. The negative feedback terminating exponential growth of ice loss is probably regional cooling due to the thermal and fresh-water effects of melting icebergs. Temporary cooling occurs as icebergs and cold fresh glacial melt-water are added to the Southern Ocean and the North Atlantic Ocean.
As a concrete example, Fig. 9 shows the global temperature change in simulations with GISS modelE (Schmidt et al., 2006; Hansen et al., 2007c) with and without the melting iceberg effect. GHGs follow the A1B scenario, an intermediate business-as-usual scenario (IPCC, 2001, 2007; see also Figs. 2 and 3 of Hansen et al., 2007b). Ice melt rate is such that it contributes 1mm/year to sea level in 2010, increasing with a 10-year doubling time; this melt rate constitutes 0.034 Sv (1 Sverdrup = 1 million m3 per second) in 2065 and 0.1 Sv in 2080. Half of this melt-water is added in the North Atlantic and half in the Southern Ocean.
By 2065, when the sea level rise (from ice melt) is 60 cm relative to 2010, the cold fresh-water reduces global mean warming (relative to 1880) from 1.86°C to 1.47°C. By 2080, when sea level rise is 1.4 m, global warming is reduced from 2.19°C to 0.89°C. These experiments are described in a paper in preparation (Hansen, Ruedy and Sato, 2011), which includes other GHG scenarios, cases with ice melt in one hemisphere but not the other, and investigation of the individual effects of freshening and cooling by icebergs (the freshening is more responsible for the reduction of global warming). Note that the magnitude of the regional cooling is comparable to that in 'Heinrich' events in the paleoclimate record (Bond et al., 1992), these events involving massive iceberg discharge at a rate comparable to that in our simulations. Given that the possibility of sea level rise of the order of a meter is now widely accepted, it is important that simulations of climate for the 21st century and beyond include the iceberg cooling effect.
Detailed consideration of the climate effects of freshwater from ice sheet disintegration, which has a rich history (Broecker et al., 1990; Rahmstorf, 1996; Manabe and Stouffer, 1997), is beyond the scope of our present paper. However, we note that the temporary reduction of global warming provided by icebergs is not likely to be a blessing. Stronger storms driven by increased latitudinal temperature gradients, combined with sea level rise, likely will produce global havoc. It was the prospect of increased ferocity of continental-scale frontal storms, with hurricane-strength winds powered by the contrast between air masses cooled by ice melt and tropical air that is warmer and moister than today, which gave rise to the book title "Storms of My Grandchildren" (Hansen, 2009)."
I have attached Hansen & Sato (Dec 2012)'s Figure 9 showing the severity of the influence of temperature change from the polar ice mass loss the they are projecting (note my projected ice mass loss occurs faster for WAIS, and a little bit slower for GIS, than they project). Not only will this cooling and freshening of the adjoining ocean water create storms, and alter ocean currents due to changes in the AABW, but there can also be a feedback effect on more ice mass loss as in the case that I am proposing for the Weddell Sea Embayment marine ice sheet.