The Sea Level Rise Module

Abstract

Undoubtedly sea level rise is potentially one of the most threatening consequences of the greenhouse phenomenon. Nearly one-third of the world’s population, including many of the world’s largest cities, lives within 60 km of a coastline. Even a sea level rise of 1 meter would have a tremendous influence on habitation patterns, causing large-scale migrations of millions of people. Nevertheless the relation between a global temperature change and global sea level rise is not yet clear, and our knowledge of processes causing sea level rise is still deficient. Although on a large time scale geological processes are of crucial importance, on a relatively small time scale of centuries, three dominating causes of sea level rise are distinguished in the sea level rise module: thermal expansion of ocean water, melting of mountain glaciers, and the reaction of land ice. These causes associated with the greenhouse issue explain only a part of the basic sea level trend. Next to these anthropogenic causes, there are other factors which should be taken into account when studying the sea level rise. First, the internal variability of the climate system, regarded as all climatic fluctuations which are not related to anthropogenic activities or to changes in isolation of the earth (Oerlemans, 1982). Second, the systematic changes on long time scales. In this study only the latter are assumed to form the unexplained part of the basic trend, although it could be possible that climate variability is also related to the unexplained part of the basic trend.