Subscribe
Prev | Table of Contents | Next
Science
Vol. 321 no. 5894 pp. 1340-1343
DOI: 10.1126/science.1159099
  • Report

Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise

  1. S. O'Neel3
  1. 1 Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA.
  2. 2 Department of Geosciences, University of Montana, Missoula, MT 59812, USA.
  3. 3 Scripps Institution of Oceanography, University of California San Diego, San Diego, CA 92093, USA.
  1. * To whom correspondence should be addressed. E-mail: pfeffer{at}tintin.colorado.edu

Abstract

On the basis of climate modeling and analogies with past conditions, the potential for multimeter increases in sea level by the end of the 21st century has been proposed. We consider glaciological conditions required for large sea-level rise to occur by 2100 and conclude that increases in excess of 2 meters are physically untenable. We find that a total sea-level rise of about 2 meters by 2100 could occur under physically possible glaciological conditions but only if all variables are quickly accelerated to extremely high limits. More plausible but still accelerated conditions lead to total sea-level rise by 2100 of about 0.8 meter. These roughly constrained scenarios provide a “most likely” starting point for refinements in sea-level forecasts that include ice flow dynamics.

  • Received for publication 14 April 2008.
  • Accepted for publication 18 July 2008.