Climate change means not only changes in temperature, but changes in precipitation. These precipitation changes are especially important in arid regions like the American West. There is reason to be concerned about the future of Western climate, according to the latest report from ScienceNow:
The Rocky Mountains have lost an unusual amount of springtime snowpack over the past 30 years or so. During that interval, the average springtime snowpack—the accumulated snow that piled up during the previous winter—is the lowest it has been since the early 20th century and has been comparably low for only three extended intervals during the past 800 years, according to a new study of tree-ring records. The recent decline in snowpack, experts say, presage a panoply of ill effects, from an increased number of wildfires to a reduced water supply from major rivers.
As the report points out, the repercussions could be serious:
The impact goes far beyond disappearing ski slopes and scenic vistas. Between 60% and 80% of the water slaking the thirst of 70 million people and nourishing three of North America’s largest rivers—Columbia, Colorado, and Missouri—comes from snowmelt.
The fact that these changes are already happening is not a good sign, since we can expect more climate change yet to come. It’s not like the West has a lot of extra water to act as a cushion. Due to agricultural needs and rapid urban growth, the current water supply is mostly spoken for. In the short run, groundwater can fill the gap, but aquifers recharge slowly, especially in dry areas, so that’s only a temporary solution. We need to start serious contingency planning now.
Addendum: More Droughts. After I posted this, I saw a story in Climate Wire about the situation in Europe:
One of the driest spring seasons on record in northern Europe has sucked soils dry and sharply reduced river levels to the point that governments are starting to fear crop losses and France, in particular, is bracing for blackouts as its river-cooled nuclear power plants may be forced to shut down.