Past Evaluation and Future Projection of Sea Level Rise Related to Climate Change Around Japan

Using new sea level data on 71 points on Japan's coast during 1966-2003 in which crustal movement is eliminated from tide records, we evaluate long-term oceanic-origin sea levels and project sea level rises (SLR). We classify Japan's coast into seven regions of about 100 km(2) by applying cluster analysis to the sea level data. For western Japan, we propose a linear regression model enabling us to predict sea levels based on sea surface temperature (SST). SLR are projected for the 21st century using our linear regression model to SSTs of 10 coupled general circulation models (CGCMs), based on the SRES A1B scenario of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. The mean SLR in western Japan in the 21st century is 12 cm, almost the same as the SLR around Japan's coast predicted dynamically by CGCMs. We found that the SLR predicted by our linear regression model is high in the western Japan, particularly at about 17 cm/century in western Kyushu.