Currently, only Greenland’s SMB is lessening (Bamber et al. and Shepherd et al., 2012). Greenland run-off is given by Bamber et al. as 416 Gt/yr ≅ 0.013 Sv. Fig. 13.9 in the AR5 (Church et al., 2013) indicates that R   is expected to increase. If we assume a linear melt rate increase (during the 21st century), we obtain 1.3·10-21.3·10-2 mm/yr2, or a time-dependent rate of (converted with Table 3) equation(1) R(t)=0.013+(2.96·10-4·t)Svfor Greenland’s run-off R.

The variable t is the number of years since 2000. Run-off is a forcing to be applied to (Greenland’s) coastal selleck inhibitor grid-cells in the model used. A simulation of Greenland’s run-off also shows a linear progression ( Mernild and Liston, 2012). The projection of R is shown in Fig. 2. The value of 0.013 Sv is assumed to be the value appropriate for hydrological balance and does not contribute http://www.selleckchem.com/products/Docetaxel(Taxotere).html to any rise in sea-level. Here we give prescriptions for ice discharge in the scaling regions that we distinguish. The initial rate is presumed to be balanced before the epoch (t≡0t≡0), while the excess value forms the additional imbalance. The initial rate is model-specific, we will address this issue below in A.2. The time index t is to be the number of years

since 2000 in all expressions that follow. Greenland i. The northern glaciers and—in particular—Jakobshavn Isbræ are expected to show a fourfold increase in their rate of the retreat

by 2100 ( Katsman et al., 2011). Their behaviour is the same in the east and south (see below), except that these termini are not expected to retreat to above sea-level and in the north retreat does not stop during the 21st century. A fraction of 0.18 of the current mass loss is allocated to these regions on the basis of recent mass loss values (see Rignot and Kanagaratnam, 2006 for an overview for Greenland glacial mass loss), Atorvastatin equation(2) Dni(t)=69.5·3104(t+4)+1Gt/yr.The total sea level rise is 10 cm by 2100. Greenland ii. A doubling of the rate of retreat of the eastern and southern tide-water glaciers by 2050 followed by a return to the balanced rates of 1996 (with 0.21 the fraction of 1996 mass loss, see Table 1) gives, equation(3) Dnii(t)=81.7·1/54·(t+4)+1t⩽501t>50Gt/yr. Greenland iii. We use the updated values from IPCC’s fifth assessment report ( Church et al., 2013), instead of the fourth ( Meehl et al., 2007) which was used in Katsman et al., 2008 and Katsman et al., 2011. An increase of Greenland’s discharge D   (without the two tidewater glacier areas discussed above) by 2100 is expected due to enhanced run-off caused by a 4 K global-mean atmospheric temperature rise Katsman et al., 2008. The effect is assumed to give an increase of sea-level rise of 0.21 mm/yr for each degree the local temperature increases; this was the increase observed during the period 1993–2003 ( Katsman et al., 2011).