Now, if tailpipe emissions are truly changing the climate, the automobile may get rid of snow entirely. But despite periodic snowy spells, Cascades and Olympics glaciers have been mostly in retreat the past century. Jon Riedel, a National Park Service geologist studying glaciers in the North Cascades, calculates they've advanced for only about 20 of the last 100 years, receding the rest of the time. Some have started advancing again just since 1998, due to good snowpack years, but Riedel projects the long-range pattern will be continued shrinkage. This could cause future problems for fish because glaciers provide most of their meltwater after the snowpack has been exhausted, keeping streams full in the crucial late-summer months.
Glaciers grow when winter snowfall exceeds summer snow melt and decline when the opposite occurs.
While Washington is the most heavily glaciated of the contiguous 48 states, once-famous features such as the Paradise Ice Caves on Mount Rainier have simply disappeared. Scott Pattee of Mount Vernon is a water-supply specialist for the federal Natural Resources Conservation Service, an agency that operates 54 automated climate stations and 100 manual ones in Washington to measure snowpack. Weight is more revealing than depth. In Western Washington the water depth in the snowpack can equal 30 percent to 50 percent of the snow depth. That's why skiers call it Cascade concrete.