Thursday, April 24, 2014
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RECEDING: Warming temperatures lead to the melting of glaciers and ice sheets. The total volume of glaciers on Earth is declining sharply. Glaciers have been retreating worldwide for at least the last century; the rate of retreat has increased in the past decade. Only a few glaciers are actually advancing (in locations that were well below freezing, and where increased precipitation has outpaced melting).
Graphic courtesy of NOAA
The melting responsible for disappearing ice is caused by climate change, aka global warming, which is actually happening regardless of how cold it was at your house last night. In the last 10 years, temperatures have risen about 5 degrees Fahrenheit on the Greenland ice sheet. The warming might be part of a long-term climate cycle, but it is almost certainly influenced by a steep rise in carbon dioxide levels unknown in the last half-million years. Corresponding to the steep rise is the fact that at the same time, humans have been pouring carbon dioxide and other greenhouse gases into the atmosphere at high rates. It is practically certain the three kinds of rise are linked.
This might all be at worst a shrug – so what? – or at best a chance to make a pot of money, which is the way Gov. Paul LePage, ever the optimist, sees it. The trouble is, there’s trouble ahead and trouble behind. If the glaciers keep melting, within 100 years sea level will rise by about 3 feet. Worldwide, about 100 million people live within 3 feet of sea level. One hundred years is headed like a freight train straight at you, me and everybody else, whether we turn two good eyes toward it or not. If in some future future all the glaciers melt, then sea level will rise 200 feet. Meanwhile, mountain glaciers are melting now. A billion people in Asia alone depend on Himalayan glaciers for water. When their drinking water runs dry and their homes are under the ocean, what will happen?
Take my advice, you’re better off not thinking about it. Here in the woods of Troy, the key environmental question is not how billions of people in Europe and Asia will get drinking water, but if or when the ice sheet is going to melt. Those are just two completely different things. That and driving the car over the brook, and along the ice. When you come around the bend, you know it’s the end.
Dana Wilde lives in Troy. His writings on the Maine woods are collected in “The Other End of the Driveway,” available from Booklocker.com and online book sellers. Backyard Naturalist appears the second and fourth Thursdays each month. You can contact him at firstname.lastname@example.org.