I’ve written at some length (and with some enthusiasm) about Phil Mote’s work on declining western snowpack. Here’s an interesting counterpoint:
We conclude that only about one third of the gages exhibit significant trends with time but over half of the gages tested show significant relationships with discharge. Therefore, runoff timing is more significantly correlated with annual discharge than with time. This result differs from previous studies of runoff in the western USA that equate linear time trends to a response to global warming. Our results imply that predicting future snowmelt runoff in the northern Rockies will require linking climate mechanisms controlling precipitation, rather than projecting response to simple linear increases in temperature.
The suggestion here seems to be that precipitation variability, rather than temperature trend, explains a lot of what we’ve been seeing.
, J. T. Harper, and M. C. Greenwood (2007), Significance of trends toward earlier snowmelt runoff, Columbia and Missouri Basin headwaters, western United States, Geophys. Res. Lett., 34, L16402, doi:10.1029/2007GL031022.