Climate Change and Sea Level Rise : A Review of the Scientific Evidence

Abstract

Sea-level rise (SLR) due to climate change is a serious global threat: the scientific evidence is now overwhelming. The rate of global sea level rise was faster from 1993 to 2003, about 3.1 mm per year, as compared to the average rate of 1.8 mm per year from 1961 to 2003 (IPCC, 2007); and significantly higher than the average rate of 0.1 to 0.2 mm/yr increase recorded by geological data over the last 3,000 years. Anthropogenic warming and SLR will continue for centuries due to the time scales associated with climate processes and feedbacks, even if greenhouse gas concentrations were to be stabilized. This paper reviews the scientific literature to date on climate change and sea level rise. There appears to be a consensus across studies that global sea level is projected to rise during the 21st century at a greater rate than during the period 1961 to 2003 and unanimous agreement that SLR will not be geographically uniform. Ocean thermal expansion is projected to contribute significantly, and land ice will increasingly lose mass at an accelerated rate. But most controversial are the mass balance loss estimates of the Greenland and Antarctic Ice Sheets and what the yet un-quantified dynamic processes will imply in terms of SLR. Recent evidence on the vulnerability of Greenland and west Antarctic ice sheets to climate warming raises the alarming possibility of SLR by one meter or more by the end of the 21st century.