The puzzle of global sea-level rise

Global sea level (GSL), a potent indicator of climate change and key observational constraint on the climate model, is discussed. Different ways to measure sea level over a number of years are also presented. It is observed that measurement of rate of sea level rise over the past century requires modeling of the behavior of Earth's crust over the past 20,000 years. The analysis suggests that the true global rate of secular GSL rise is closer to 2 mm/y which implies that the great polar ice sheets on Antarctica and Greenland are losing mass at a net rate that contributes 1 mm/y to the global value.