(Introduction To Geology And Societal Impacts) Movie reflection

After watching the movie "Chasing Ice". Explain why glaciers are considered "Canaries in the Coal Mine" in the context of climate change and a warming earth.   How will disappearing glaciers and rising snow levels in the Cascades affect the lives of Washingtonians living near this mountain range (think about from the perspective of urban dwellers on the west side of the range versus agricultural communities on the east side of the range)?  Think about the timing of water needs in Washington state.