Swiss glacier recession since the Little Ice Age: Reconciliation with climate records

Abstract

Since the culmination of the Little Ice Age, Alpine glaciers have been in a state of general retreat. The present study, focusing on the Swiss Alps between 1850 and 1973, seeks to relate the concomitant rise in equilibrium-line altitudes (ELAs) to recorded climate shifts. The approach taken involves the development of a regression model, but differs from most other studies in that the relationship of (midlatitude) ELAs to climate is examined at a resolution such that regional values are treated as individual data-points. Although such a treatment implies loss of resolution at small scales, a coherent relationship between climate and ELA is nonetheless obtained, due in large part to the primary control exercised by temperature, as well as the relatively wide range of ELAs included in the regression dataset. The derived relationship is applied to observed Swiss climate shifts, and is found to predict a secular rise in ELA somewhat greater than that observed. It is hypothesized that the difference represents climate change that had not yet been expressed by changes in glacier morphology. Copyright 1999 by the American Geophysical Union.