Glaciers Melting Faster Than Expected
Environmental researchers around the globe are finding that glaciers are melting faster than previously expected. While this melting will have little impact on the global stage (Garry Clarke, professor emeritus of glaciology at the University of British Columbia in Vancouver, Canada, estimates, that if all of western Canada’s glaciers were to melt away, the oceans would rise by less than 6.6 millimeters (a quarter-inch)), glacial melting has long been recognized as a sign of warming global trends and has the potential to significantly alter local water supplies.
Glaciers act as nature’s reservoirs, collecting and storing freshwater during the winter months and slowly releasing it during the warm season. Many of the world’s great rivers are tied to the glaciers of their mountainous neighbors. The Rhine would not exist without the snowy Alps and the Ganges would dry without the glaciers of the Himalayas. If mountain glaciers disappear, the streams and rivers that they feed will be forever altered; flows will decrease, peak seasons will change, and water temperatures will rise.
According to Michel Baraer, of McGill University, Montreal, Canada, even the total volume of runoff will change because glacial ice keeps the water locked away in a form in which it does not easily evaporate.
Thus, even if annual precipitation remains the same in mountain regions, less of the water will make it to the lowlands, evaporating back into the atmosphere instead. The building of dams, reservoirs, and other water control systems will only exacerbate the problem of evaporation by slowing the flows and increasing the exposure to sunlight. The efficiency of storing freshwater in glaciers cannot be matched by human engineering.
Increased glacial melting will mean the inevitable arrival of peak water followed by a steady progression towards regional water shortages. According to Rick Lovett of National Geographic News, much of South America, with its high mountains and tropical sunshine, appears to be particularly vulnerable to climate-induced glacial shrinking. We have yet to see how peoples and governments chose to respond to water shortages, but as glacial melting continues to accelerate around the world, the consequences will be unavoidable.
Source: National GeographicThis entry was posted by in Environment, To Learn, Water Resources and tagged climate change, glacial melting, glacier, global warming, rivers, water resources.