Recent work with airborne laser altimetry has shown that thinning glaciers and icefields in Alaska, Yukon, and NW British Columbia have contributed about 52 +/- 15 km3/yr water equivalent, on average, to rising sea level from the mid-1950’s to the mid-1990’s. This is equivalent to about 7-12 % of the mean annual rate of sea-level rise estimate by the IPCC during the past century.

It is of interest to estimate the role of melting glaciers on sea level in the future as the overall climate warms. To examine this question, an interdisciplinary study is being conducted that employs dynamical downscaling using a regional climate model (MM5) to connect future GCM scenarios to a glacier mass balance model. Dynamical downscaling (MM5 forced with NCEP reanalysis) provides temperature and precipitation information to force a glacier mass balance model. In a warmer climate, it is not necessarily the case that warmer temperatures will lead to enhanced melting since changes in precipitation patterns can also impact glacier mass. This research explores whether the predominantly negative balances are due to increased ablation or decreased snowfall in the observed record and how will this ratio could change in the future.