Dear “Earth Talk”: What are the
implications for Montana’s Glacier National Park if the glaciers
there keep melting?
— Oliver Ryan, New York City
The glaciers for which Glacier National Park is named
are melting away as a result of increasing global temperatures in recent
decades, attributable most likely to global warming. A century ago,
Grinnell Glacier, once the park’s largest, covered almost 440 acres.
Today it has shrunk to just a quarter of that size. Many of the glaciers
are gone altogether: According to the Sierra Club, the number of glaciers
in the park has dropped from around 150 in 1850 to approximately 35 today.
Most of the glacier loss in the park has occurred
since the late 1960s, when global-warming trends began to intensify. Park
scientists are now worried that if nothing is done to curb global warming,
by the year 2030 there may not be a single glacier left in Glacier National
Park.
Glaciers form when huge ice sheets build up under
snow that has slowly accumulated over time. As the snow cover mounts, the
intense weight compresses the delicate snowflakes beneath the surface,
gradually changing them into the ice grains that make up glaciers. During the last Ice Age, some
glaciers were a mile thick, covering huge swaths of the Earth and carving
out much of the topography we know today through their slow and grinding
movements.
The warming of the Earth that occurred at the end of
the last Ice Age — and which melted glacial ice from pole to pole
— was a natural phenomenon that took place over thousands of years.
Today, the carbon dioxide emissions generated over just the last
half-century from industrial and automotive sources could, say scientists,
lead to an equivalent amount of glacial melting within just decades, not
millennia.
This process could put plants and animals, which have
adapted to certain living conditions over time, in deep trouble as their
habitat characteristics shift right under their feet, fins, and roots. And
Glacier National Park will be no exception. For example, the lack of
glaciers and snow pack there could eliminate avalanches, which perform a
valuable ecosystem function by knocking down forested stands to make way
for new growth in meadows. The berries that are prevalent in these meadows
are a major nutrition source for the grizzly bears that call the park home.
Without avalanches and the meadows they create, the park’s already
stressed grizzly population could suffer a drastic decline.
Beyond such ecological implications, no one knows how
a glacierless Glacier National Park might play to tourists doing their
grand Western tours. If the number of visits to the park and therefore the
region were to drop significantly, the local economy — now dependent
on tourism revenue — could suffer debilitating losses. After all, who
would visit a place called Glacier if there were no glaciers to see?
For more information: Sierra Club,
www.sierraclub.org/globalwarming/articles/glacier.asp; Glacier National
Park, www.nps.gov/glac/.
Send questions to “Earth Talk” in care of E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881, or e-mail earthtalk@emagazine.com.
This article appears in May 26 – Jun 1, 2005.
