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September 2007

The Impact of Climate Change on Florida’s Everglades, Alaska’s Wrangell-St. Elias

What do Florida's Everglades and Alaska's Wrangell-St. Elias have in common? Both face uncertain futures as temperatures rise.

“We know well enough that there’s likely to be a higher sea-level rise than the IPCC was willing to project,” says Martin Truffer of the University of Alaska’s Geophysical Institute. “They are trying to be cautious and conservative. But their conclusions lag behind the latest findings.”

Kimball, a hydrologist by training, appropriately spends much of his time worrying about water. Aside from what a three-foot sea level rise would do to the Everglades–where more than 60 percent of the landmass is less than three feet above sea level–Kimball has plenty of other stuff to worry about. “We’re still rebuilding our infrastructure from Wilma and Katrina. We’ve got coastal erosion, we’ve got people barreling around in powerboats in the wilderness areas. We’re losing the tidal flats, the rich estuaries, entire ecosystems. We’ve got algae blooms, we’ve got droughts and brush fires, we’ve got an explosion of invasive species.”

“Floods, fires, pestilence,” says Stuart Pimm, a Duke University conservation ecologist who studies bird populations in the Everglades. “It’s almost biblical, isn’t it?”

To get a comprehensive view of the effects of climate change on Wrangell-St. Elias, I had to contribute to it, by taking a flight in a single-engine Cessna with Millen and pilot Don Welty of Wrangell Mountain Air.

We take off from McCarthy’s airstrip and fly southeast, on a course that veers past nine of the 16 highest mountains in North America. Even on this hazy day, we can see into the Yukon, over the massive ice fields to Mt. Logan, at 19,550 feet the second-highest peak on the continent. Dumbstruck by the sprawl of snow-covered summits, I write in my notebook: “This, finally, is what possibility is all about.”

We pass over the spectacular Bagley Icefield, which extends east and west beneath us to both horizons, filling the valleys with age-old ice and snow. Out of the Bagley flow the huge Bering, Malaspina, and Hubbard Glaciers and a dozen other smaller ice masses.
Recently released studies by the USGS report that the Bagley is losing mass; another study found that 98 percent of Alaska’s glaciers are either retreating or thinning. From high above, there is no obvious sign of human impact. But when we come in low, we can see the evidence in the details passing beneath us. Following the suggestion of Wrangell’s land manager/geologist Danny Rosenkrans, Welty takes us over Young Creek, where swaths of once-permafrosted slopes have fallen away, leaving huge gouges in the streambank and dumping tons of silt into this tributary of the Copper River, the spawning ground of Alaska’s most prized salmon, the Copper River reds.

“Man, is that lake low,” Welty remarks as we pass over Berg Lake. “In the mid-’80s, the lakeshore was three-quarters of the way up to those spruce trees,” he says, pointing to the southwest side of the lake. In the Copper River Basin, more than half of the small lakes and ponds have disappeared since 1950, as the hard-frozen lakebeds have thawed, allowing water to seep through where it was once contained by ice. These bodies of water provide breeding habitat for millions of waterfowl and shorebirds that winter in southern regions of North America. More ominously, the drying landscapes absorb more heat and release more CO2 into the atmosphere as the carbon stored in the soil decomposes, further contributing to atmospheric warming.

Welty skims over hundreds of acres of spruce trees that appear to have been scorched by fire. The grayish skeletons that blanket the hillsides are what remains after an invasion by spruce bark beetles. The beetles have infested Alaskan forests in the past, but what makes the most recent die-off unusual is the vastness of the area affected–more than 2.3 million acres.

“At first,” says Millen, “people didn’t get that the spruce die-off and global warming were related.” But biologists have now confirmed that longer and warmer summers have allowed the beetles to flourish. The mean temperature in the Wrangells has increased 7°F over the past 30 years, and recent winters have seen warm spells that have brought unprecedented highs in the 40s in December and January.

After zigzagging through notches in the mountains, we reach the coast. Welty takes us to Icy Bay, which broke out of the ice ages only a century ago. We circle for minutes, looking for an iceberg-free spot of beach. “I’ve never seen so much free ice in the bay,” Welty says, before bouncing the plane down with impressive precision. We get out and walk toward the tongue of the Yahtse Glacier, which is shedding chunks of ice with thunderous splashes.

“You look at these massive things from the air and you’d think they’re permanent,” Welty says. “But a lot of them are retreating fast. Year after year, I can see it changing.”

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