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September 2007

National Parks Report Card

We surveyed more than 40 scientists, conservationists, and professional adventurers, then ranked the 15 parks that are most in peril from climate change.

From melting permafrost to disappearing icefields, this Alaska park is literally vanishing before our eyes.
In 1794, when George Vancouver sailed up the Inside Passage, there was no Glacier Bay: The rivers of ice extended all the way to the coast. A hundred years later, John Muir called it “icy wilderness unspeakably pure and sublime.” Now? It’s still beautiful, but far less frozen. If you come here to paddle, you’ll find fewer tidewater glaciers; if you come here to hike, you’ll tread on less and less tundra. “Temperatures are climbing twice as fast here as anywhere else in the U.S.,” says Mark Wenzler, director of Clean Air programs for the National Parks Conservation Association. “Alaska is our ground zero for climate change.”

The rising mercury causes what the Wilderness Society’s Don Barry calls the “double whammy” of glacier shrinkage and sea-level rise. A recent University of Alaska Southeast study found that 95 percent of the region’s glaciers are thinning, but that’s just the tip of the proverbial iceberg: The Muir Glacier has retreated more than 13 miles since 1941.

Glacier Bay is most at risk among southeast Alaska’s parks because it’s at a low elevation, making its ice more sensitive to rising sea level and temperatures. Since the late 18th century, the Glacier Bay Icefield has lost 6.2 trillion pounds of ice. All that frigid meltwater causes stream temperatures to drop and stream channels to shift, affecting the reproduction of salmon, among other species. Glacier-dammed lakes may burst open, flooding the vegetation and wildlife below with water and sediment. As the ice thins, it ceases to weigh down on the landscape–and the land actually rises. This phenomenon is known as land-surface uplift (or, technically, isostatic rebound), and the resulting sea-level change–driven by the earth instead of the water itself–dries up marshes, driving out sedge grasses, Canada geese, and migrating birds such as the pipit and longspur.

Away from shore, Glacier Bay’s permafrost is melting, causing tundra ponds, the pools of surface water that sit on ice, to drain away. “It’s like pulling the stopper out of the bathtub,” says Jim Stratton, the NPCA’s Alaska regional director. “You can actually see dirty rings on the new shorelines that are formed.” One study projects that 90 percent of Alaska’s tundra may be gone by 2100. Most ironic? Permafrost normally serves as a carbon sink, storing CO2 in its ice–but when it melts, it becomes a carbon source, releasing CO2 and methane and adding more greenhouse gas to the environment.

At age 12, on the first of his 217 ascents up the famed Northwest volcano, Peter Whittaker poked around the Paradise Ice Caves, as the massive, aquamarine nostrils at the snout of Paradise Glacier were known. These days, not only are the caves MIA–the entire glacier is pretty much gone. “And it happened in my lifetime,” says Whittaker, a Rainier guide for more than 25 years. “That’s the scary part.”

Two-thirds of Rainier’s other glaciers are retreating, including the park’s second-largest, Nisqually, which has withdrawn nearly a mile since 1912. The ice’s disappearance leaves huge, ugly scree fields, and has a cascade effect that affects the rest of the park. As a glacier recedes, it leaves more gravel on the moraines; rain washes that gravel down drainages, filling streambeds and sometimes causing creeks to jump off course. This is normal–unless the process accelerates unnaturally, which happens when there’s an increase in rain falling on snow. That’s happening more frequently. Greg McCabe, a Denver-based USGS climatologist, reported in a March 2007 study that high-elevation rain is melting more and more snow in the West. Case in point: Last November, a freakish storm dumped 18 inches of rain on Rainier in 36 hours. Rivers leaped onto highways; campgrounds were swept away.
It left a frightening vision of what the park could become: trails washed away, massive retreat of glaciers, trees rising into alpine areas and choking out wildflower meadows, more giant storms and destruction. Mountaineers are already seeing climate change in the altered rock features on Rainier’s flanks. “Since I know the mountain so well, these changes are already obvious to me,” says Whittaker. “Soon it’ll be clear to everyone else.”

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