Though the polar ice caps store sufficient water to raise sea level by ~65 m (IPCC 2007), the expected sea level rise due to global warming is much less and is expected to develop over millenia rather than centuries. Up to the year 2100, the IPCC suggests that sea level rise will be only 18-76 cm depending on models and emission scenarios (IPCC 2007), which is similar to the ~20 cm of sea level rise observed during the twentieth century. As a result, sea level rise during the twenty-first century is likely to be a significant problem only for a limited number of highly vulnerable localities.
Over the long term, sustained high temperatures may lead to irreversible declines in the Greenland and/or Antarctic ice sheet. During the previous interglacial period, 120 kyr ago, sea level is estimated to have been 4-6 m higher due to orbital variations that caused greater solar heating at the poles than today (Overpeck et al. 2006). A total ablation of the Greenland ice sheet would correspond to a 7 m sea level rise (IPCC 2007). Though this process may proceed at only ~30 cm/century, the temperatures required to begin the decline may be only 1.9 to 4.5 °C, similar to the 1.1 to 6.4 °C of warming expected to occur by 2100 (IPCC 2007).
This map is based on the SRTM30 PLUS digital elevation model. Like all space based elevation models, SRTM30 contains errors of several meters, especially in areas of complex terrain (Rodriguez et al. 2006). Hence, while broad qualitative features should be relatively reliable, one should not rely upon data such as these for small scale or precise details unless they have been confirmed by ground based observations.