I believe Koppes' City Club talk omitted much data:
No global warming for the past 17 years!
Mount Baker glaciers advanced to Little Ice Age (1300-1915) positions during the 1880-1915 cold period, then retreated upvalley during the 1915-1945 warm period (with no significant increase in carbon dioxide). During cooling from 1945-1977, glaciers readvanced farther downvalley than their 1947 positions during maximum carbon dioxide emissions after 1945! Glaciers retreated again from 1978-1998 and as climate warmed
Climate in Washington since 1998, has cooled, not warmed. Since 1998, winters (December to February) cooled at a rate of minus 13 degrees per century, springs (March through May) cooled minus 7.8 degrees per century, and summers cooled minus .5 degrees per century, according to NOAA.
Koppes' claim that "here and almost everywhere else in the world, the mountain snow accumulations that feed the glaciers are dwindling" is not true -- five of the six snowiest years in the northern hemisphere occurred since 2003, according to NOAA. Since 1997, snow-water equivalent in Washington's snowpack has increased, not declined as Koppes claimed (Snotel data).
Koppes conclusions were based on small cirque glaciers, totally ignoring massive glaciers on Cascade volcanoes, which have much more glacial ice that tells a very different story.
Considering all of these easily confirmed facts omitted by Koppes , I believe her conclusions are badly flawed and not scientifically defensible.