Global Warming and the Future Sea Level Rise due to Ice Sheet Change

Research Project , Research Report 2002

Ayako Abe-Ouchi Center for Climate System Research, The Univ. of Tokyo
Fuyuki Saito Center for Climate System Research, The Univ. of Tokyo
Akimasa Sumi Center for Climate System Research, The Univ. of Tokyo(Research Partners)
Heinz BLATTER ETH Institute for Atmospheric and Climate Science, Switzerland

Abstract

Numerical experiments using a coupled ocean- atmosphere climate model and ice sheet model are performed in order to predict the change of glaciers and sea level rise. The coupled model was run under the scenario of 1% per year increase of atmospheric CO2which gives doubling CO2in 70 years and quadrupling of CO2in 140 years. By doubling the CO2, the air temperature over Greenland increased by 3 to 4 degree Celcius which has an effect to melt the ice sheet and raise the sea level by about 3 meters in several hundred years at least, while the warming over the Antarctica does not result in the sea level rise since the increase of precipitation compensates the melting of the ice for sea level change. The sea level rise due to Antarctic ice sheet seems to become effective when the CO2is quadrupled and the air temperature over Antarctica reaches 7 to 8 degree Celcius. The estimation of the effect of global warming upon the ice sheet change and sea level rise is larger than the former results published by ETH and U-Tokyo, CCSR, which will be the future task to investigate. Since the remained unknown that is due to the fast-flow ice stream process and the ice shelf process should be investigated for better prediction, a work to develop a next generation ice sheet model to take into account the higher order stress effect in the ice sheet model was launched and cooperatively carried out between Univ. of Tokyo and ETH this year.

Keywords:

Global warming, sea level change, ice sheet, climate model, ice sheet model