Global warming is causing sea levels to rise, primarily due to loss of land-based ice masses and thermal (steric) expansion of the world oceans. Sea level does not rise in a globally uniform manner, but varies in complex spatial patterns. This chapter reviews projections of the individual contributions to sea-level rise. These are used to assemble a mid-range scenario of a 0.70 ± 0.30-m sea-level rise over the twenty-first century (based on the SRES A1B scenario) and a high-end scenario of 1.10 m. The sea-level projection was regionalised to the Baltic Sea area by taking into account local dynamic sea-level rise and weighting the components of the sea-level budget by their static equilibrium fingerprint. This yields a mid-range Baltic Sea sea-level rise that is ~80 % of the global mean. Ongoing glacial isostatic adjustment (GIA) partly compensates for local sea-level rise in much of the region. For the mid-range scenario, this equates to a twenty-first century relative sea-level rise of 0.60 m near Hamburg and a relative sea-level fall of 0.35 m in the Bothnian Bay. The high-end scenario is characterised by an additional 0.5 m.
Note: This chapter has been superceded by newer probabilistic sea level projections using AR5 as the foundation. Please refer to this paper for more up to date information.
Grinsted, A. (2015). Projected Change—Sea Level. In Second Assessment of Climate Change for the Baltic Sea Basin (pp. 253-263). Springer International Publishing.