Glaciers of the Canadian Rockies and their response to global climate change

Abstract

This study investigates the interactions between carbon dioxide, climate, and glaciers of the Canadian Rockies under a relatively conservative IPCC emission scenario for the 21st century through the use of the PSU/NCAR MM5 mesoscale model (MM) nested within the Princeton GFDL global atmosphere-ocean model. A simple model of orographic precipitation is developed and indicates that if relative humidities change little in a warmer climate the Rocky mountains will experience substantially larger precipitation increases than the global average, despite a weakening midlatitude jet. Furthermore, a simple energy balance model indicates that the elevation of equilibrium net snow accumulation in the Rocky mountains rises steadily through the 21st century. Precipitation increases at high elevations offset increases in melt, particularly in 2050 but also evident at some isolated high elevations in 2100.