[NIGS LECTURE SERIES] Sea level rise and associated changes in surface temperature and the ice sheets


Among the most profound impacts of climate change is sea level rise since a large proportion of global population resides in coastal areas. The rate of sea level rise was for a long time estimated to be around 2 mm/year but in recent years the rate as measured by more advanced techniques, including the use of satellite radar altimeter systems, has increased to 3 mm/year. Much of the increase has been attributed to  the warming of the oceans and mass loss in the glaciers and ice sheets. The heat content of the oceans upo 700 m in depth and the global average of sea surface temperatures have been increasing significantly but the main concern has been the vulnerabilities of the Greenland Ice Sheet and the West Antarctic ice sheet which have a combined sea level equivalence of more than 13 meters. Recent studies have indicated changes in the stability of the ice sheets and glaciers that would make it possible for the rate of sea level rise to be a lot faster than the current rate. Also, the rate of warming in the Arctic has been observed to be three-times that of global warming rate in part because of ice-albedo feedback. Such warming has already resulted in dramatic changes in sea ice and snow cover and would make the Greenland ice even more vulnerable . An assessment of impacts especially in coastal areas, including those in the Philippines, will be presented.