6.4.3.4 What Is the Long-Term Contribution of Polar Ice-sheet Derived Melt Water to the Observed Globally Averaged Rate of Sea Level Rise?

Models of postglacial RSL history together with Holocene observations can be employed to assess whether or not a significant fraction of the observed globally averaged rate of sea level rise of about 2 mm yr^–1 during the 20th century can be explained as a long term continuing influence of the most recent partial deglaciation of the polar ice sheets. Based upon post-TAR estimates derived from geological observations of Holocene sea level from 16 equatorial Pacific islands (Peltier, 2002; Peltier et al., 2002), it appears likely that the average rate of sea level rise due to this hypothetical source over the last 2 kyr was zero and at most in the range 0 to 0.2 mm yr^–1 (Lambeck, 2002).