Most of Earth's major river systems are fed by mountain snowpack; the Rockies (photo), the Andes, the Alps and the Himalayas are among the primary sources. Snow depths build during the colder months and meltwater is released as the weather warms. The highest peaks retain snow throughout the year.
One wonders how global warming will affect this simple but vital process. No doubt, the snow line will rise and freshwater storage will diminish over time but the transition will likely be erratic. As occurred in California last winter, energized storm systems may produce record snowfall in some regions while others experience snow droughts. Mountain glaciers continue to recede and their release of water will gradually diminish. In addition, as the snow line ascends, heavy mountain rains will lead to downstream flooding.
While the uncertainties confront us and we attempt to slow (if not reverse) climate change, we must also focus on water conservation, freshwater recycling and ecological means of water storage. Cycles of heavy mountain snow are temporarily reassuring but they should not lead to complacency.
