One of the dominant manifestations of climate change is sea level rise. NOAA estimates that "since 1992, new methods of satellite altimetry (the measurement of elevation or altitude) indicate a rate of rise of 0.12 inches per year". In addition, NASA calculates that average sea level rise is 3.41 mm per year and that sea level rise is directly caused by the expansion of water as it warms and the melting of polar ice caps. Both of these changes are dependent on global warming and thus climate change. Sea level rise is especially threatening to low-lying island nations because seas are encroaching upon limited habitable land and threatening existing cultures. As Stefan Rahmstorf, a professor of Ocean Physics at Potsdam University in Germany notes "even limiting warming to 2 degrees, in my vi