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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.

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The Everglades under water? Glacier and Rainier with no ice? If these sound like nightmare scenarios, consider this: Your backcountry is changing. And if global warming matches even conservative forecasts, your most prized wild places will be drastically altered–or worse. To determine which parks face the most peril, we surveyed more than 40 scientists, park personnel, conservationists, and professional adventurers, then pored over dozens of studies. Here, ranked in order of threat level, are the parks in which climate change, left unchecked, will cause the greatest damage to the terrain and scenery you treasure most.

A New Map of the World

Topos have long been a staple of safe backcountry travel. But they’ve failed to keep up with a changing planet.

By Bruce Barcott

During a recent bushwhack through the Alakai Swamp on the Hawaiian island of Kauai, my companions and I walked straight off the map. The Alakai is a gloriously dismal place, soggy and foggy and tangled with lehua trees, sword ferns, and eye-scratching brush. Our only guide was a USGS topo quad published at least two hurricanes prior to our arrival. Deep into our journey, our machete growing duller with every mile, we took a GPS reading and found our map had gone haywire. The paper showed a flat, swampy plain. Our eyes saw steep ridges and valleys. For a few seconds, the world spun in a swirl of disorientation and mild panic. Psychologists have a term for this: Cognitive dissonance brought on by a disconfirmed expectancy. Out in the field, we had our own way of putting it: We’re on our own, boys.

The world is now in the process of walking off the map. Global warming is changing the landscape beneath our feet. As you’ll learn in these pages, some glaciers are shrinking and others are disappearing entirely in alpine parks like Denali, Glacier, and Rainier. In the Rockies, the Cascades, the Alaska Range, and the Sierra, treeline marches steadily uphill. It’s one thing to talk about that in theory, quite another to encounter it on the ground.

In Wrangell-St. Elias National Park, the maps show the northern lobe of the Bremner Icefield as a continuous ice sheet; yet members of a BACKPACKER team that hiked it instead found themselves on a lateral moraine bench, looking down hundreds of vertical feet to a series of silt deltas and large, quarter-mile-long lakes set in talus where the ice should have been. Coastlines are also changing, as the marine shoreline creeps ever inland. Stronger hurricanes reshape the Gulf Coast, and a rising sea threatens to swallow whole swaths of the Everglades.

As a backcountry traveler, I came of age in a world of absolutes. The rules were simple and few. Take extra food and water. Be ready for weather. When in doubt, check your map and compass. My companions and I consulted our trusted USGS topos like fundamentalists reading Scripture. The maps translated a chaotic mess of landscape into a beautiful language of thin contour lines and soft green, blue, and brown hues. The maps were almost always perfect and right.

Now they are turning into antiques. We’ll eventually see a new generation of updated topos, but it may take a good long while, and in the meantime we’re stuck with maps that grow more obsolete by the day. Our great field guides remain locked in time as the landscape around us moves on.

That day in the Alakai Swamp, we were forced to abandon our GPS coordinates and rely on our senses. We made our own way across the terrain, counting on eyes and ears to get us safely back home. As climate change remakes the landscape, that experience will become more common. Perhaps we can learn from the wildlife around us. Many biologists are expecting a gradual, massive wildlife migration–a poleward trek, as rising temperatures push existing ecosystems away from the equator. Researchers have already seen a northward shift in the winter range of birds around Cape Cod. Australia plans to establish a 1,700-mile wildlife corridor along its eastern coast to facilitate the movement of animal refugees driven south by global warming. Animals maintain their own sense-driven maps, and their cartography is shifting, too.

It’s unnerving to walk off the map. The compass and GPS assure us that we know where we are and we know where we’re going. At this point in history, we know where we are. We don’t know where we’re going. Or rather, we don’t know where the planet is going. Terra incognita is returning.


Expect a massive decline in bird and marine life this century, plus the submersion of many Wilderness Waterway campsites.

Of all the global warming computer models out there, the ones that show coastal Florida swamped by rising seas are among the hardest to digest. The animations look like a cinematic apocalypse, not cold, hard reality. But the math is simple enough. “Sixty percent of the park is less than 3 feet above sea level,” says superintendent Dan Kimball. And researchers are predicting that oceans could swell anywhere from 7 inches to several feet by 2100. In worst-case scenarios, “the Everglades are gone,” says Don Barry, executive vice president of the Wilderness Society and Assistant Interior Secretary under Bill Clinton. Even in less gloomy forecasts, the Glades, which form the largest protected mangrove ecosystem in the Western Hemisphere, will be seriously disrupted, the changes dramatically altering wildlife, fishing, and paddling.

A laundry list: Mangroves, which act as natural dikes that keep out swarms of sea water, may not be able to grow fast enough to keep up with the rising sea level. Warmer water could bleach coral reefs, effectively killing the ecosystems they create. Florida panthers and West Indian manatees could lose their habitats, as could rare pinelands. Hurricanes, which may occur more often, will bring higher storm surges that bloat the park with seawater.

Most notably, higher seas will assault the park’s freshwater environments, creating brackish marshes that push out species like American crocodiles and the endangered Cape Sable seaside sparrow. “The River of Grass should be flowing north to south,” says Jonathan Ullman, the Sierra Club’s regional representative. “With sea-level rise, it will start flowing south to north.” If that happens, says Harold Wanless, a University of Miami geologist, channels could turn into mangrove-choked creeks and brackish ponds–and campsites and chickees on the Wilderness Waterway could be inundated with saltwater.

A number of new projects–including the $11 billion Comprehensive Everglades Restoration Plan–are in the works to correct past engineering and water-flow blunders. But no repair project can save the Glades if sea levels rise several feet.

It’s not just the ice: The park could lose its trout streams and wildlife, too.

It isn’t easy being a climate-change poster child. Glacier staffers have endured years of gallows humor arising from the park’s eventual loss of its namesake features. A typical recent example: The National Environmental Trust started a glib publicity-generating web campaign to rename Glacier. The worst part, of course, is that it’s true: In 1850, there were 150 glaciers; that number is now closer to 27. A 2003 article in BioScience by Dan Fagre, an ecologist at the USGS Northern Rocky Mountain Science Center (see page 23), projects glacial extinction here by 2030. Of the park’s 84 watersheds, 18 have less than 1 percent of their glacial cover remaining–which makes Glacier the ultimate canary in the coal mine.

Changes are already on display for hikers. On the Grinnell Trail to the retreating Grinnell Glacier, the vistas are emptier, except for the upward-creeping treeline. But it’s not just about the dramatic “before” photos and the altered aesthetics of snowless summits. Glacial retreat has dire consequences because it makes for earlier spring runoff–no small thing when you consider that Triple Divide Peak is the headwaters of the Columbia, Missouri, and Saskatchewan River systems. On the middle fork of the Flathead River in March 2007, researchers measured the highest flow for that month in recorded history. Glaciers naturally shrink in summer, but when they start melting in February, that’s a problem. “We’ll start seeing streams warm up, then go ephemeral,” says Leigh Welling, director of Glacier’s Crown of the Continent Research Learning Center. Stream insects are highly sensitive to changes in water temps; if they perish, species like bull trout, whose eggs are also vulnerable to warm water, will see a critical food source disappear.

Perhaps the most catastrophic consequence of all this is the potential for longer fire seasons, with bigger and hotter burns. Experts say it’s already happening, because there’s less stream flow and water in the soil. Since 1987, the Western wildfire season has increased an average of 78 days, and the time lapse from discovering to controlling a fire has risen from 7.5 days to 37.1. In 2003, 145,000 acres burned in the park. And much of Glacier’s vegetation, such as old-growth cedar and hemlock, doesn’t rejuvenate after an aggressive blaze. “That wet, lush, cool habitat might not come back,” Thompson says.

As for the caribou, grizzly and other iconic mammals? They’ll likely head north to Canada’s cooler Waterton Park, leaving Glacier a mere echo of its former self. The mountains will remain–but not all that came with them. “That,” says Barry, “is the tragedy.”


Expect starker, emptier views and sketchier alpine routes as the most glaciated region in the Lower 48 passes its tipping point.

This park’s South Cascade Glacier has been more closely monitored than Alex Rodriguez’s fantasy stats. Ed Josberger, head of the USGS Ice and Climate Project in Tacoma, tracks its winter growth (with snow) and summer shrinkage (with melting). The oceanographer, who also follows Alaska’s Wolverine and Gulkana Glaciers (in the Kenai Mountains and Alaska Range, respectively), says all three have fluctuated historically. What worries him now? “They’re all retreating at the same time,” and have been since 1989. “That says to me that we have a bigger global problem.”

The 318 glaciers in North Cascades make up about 60 percent of the land covered by ice in the Lower 48. But the park has lost 46 percent of its coverage since 1900, says Andrew Fountain, a professor of geology at Portland State. And the Rocky Mountain Climate Organization reports that total ice mass has decreased by 80 percent. Many glaciers here are below 6,000 feet, in just-under-freezing air temps–which means they’re particularly vulnerable. With a 4°F rise, 75 percent of NCNP’s remaining ice could vanish over 40 years. South Cascade Glacier’s nose is receding 56 feet a year in places.

With less ice, summer stream levels will drop. Scientists say that glaciers historically provided NCNP streams with about half of their late-summer flow. In the Thunder Creek drainage, levels have dropped 31 percent, threatening salmon spawning. Thunder is also a major tributary of the Skagit River Watershed, the only one in the nation that contains all Pacific salmon species. So the threat to biodiversity extends to the entire Puget Sound ecosystem. Scientists have identified 1,600 plant species and 3,000 fungi in eight distinct zones here–more than any other national park. In a warmer climate, temperate evergreen forests would slowly spread into subalpine zones, altering the habitat for that flora.

These changes will create real safety issues for explorers, like outdated park topos and sketchier alpine routes. Years ago, the famous Ptarmigan Traverse–a route from Cascade Pass to Dome Peak–involved more glacier travel and less technical scrambling. “The mountaineering could get more difficult,” Josberger says, “with fewer chances to bail.”


In five years, this Arizona park’s iconic cacti will face a huge new fire threat.

“What we have here is the first unhinging of a major American ecosystem,” says Julio Betancourt, a paleoecologist with the University of Arizona’s Desert Laboratory. He means the climate-related expansion of an insatiable neotropical plant called buffel grass, introduced in south Texas in the 1940s and now taking over Southwest parks like Saguaro.

What’s so bad about buffel grass? It usurps the space, nutrients, and water that saguaro cacti, nicknamed “desert monarchs,” need to survive, and it will eventually turn the cactus forest along the Hugh Norris Trail and other routes into endless prairie. Though it’s been around for decades, this 4-foot-tall grass only started spreading quickly in the mid-1980s, when winter and spring temps in the Sonoran Desert started rising. According to a recent Intergovernmental Panel on Climate Change (IPCC) report, future rain patterns might shift in the Southwest, creating even more advantageous conditions for the invasive plant.

Buffel grass is highly flammable, and thrives in post-fire conditions. “These deserts haven’t been flammable in 10,000 years,” says Betancourt. There used to be plenty of space between cacti and scrub vegetation, making it hard for flames to spread. Now, the grass fills those spaces. If the saguaros burn, they may never come back. “In as little as five years, southern Arizona will be converted to a fire-prone grassland,” Betancourt says.

This all comes at a time when the desert can ill afford to lose water. Richard Seager, a scientist at Columbia University’s Lamont-Doherty Earth Observatory, recently published a study in Science analyzing 19 computer models that all forecast a permanent drought by 2050, and a 15 percent drop in surface moisture. Similar conditions, he says, led to the Dust Bowl. “It might not necessarily be warmer,” says Betancourt, “but it will be much more dry.” That’s more bad news for the saguaro, which need summer monsoons to germinate. Add in the area’s building boom–”Saguaro was founded as a wilderness park, and now it’s a suburban park,” says Luther Propst, executive director of the Sonoran Institute–and the cacti have nowhere to migrate from their present sky-island habitat. “If we don’t get control of this fast,” Betancourt warns, “the parks in southern Arizona are dead meat.”


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.”


This park holds the planet’s largest stand of virgin red spruce and the southernmost vestige of Ice Age boreal forest. In fact, more tree species exist in the Smokies than in all of Europe, and more wildflower species (1,660) than in any other national park. There are 27 species of salamander. “It’s in between a lot of zones, with a lot of niche species at the end of their ranges,” says Don Barry. “It’s a great barometer for how global warming is affecting the richness of our wildlife–and it might give us signals about the bigger picture.”

Which is why researchers targeted the park for a huge, 100-plus-university study to catalog its species. Scientists predict that if CO2 levels double from 1961-1990 levels, as the IPCC models predict they will by the middle to end of this century, 16.7 percent of the park’s mammal species won’t survive, including the southern red-back voles and northern flying squirrels. A 3.6°F temperature increase, which could happen by the end of this century at current rates, could eliminate more than a third of native trout, which need cold, quick streams. Trees will begin migrating upward, seeking cooler temperatures; they’ll eventually overtake the Smokies’ iconic balds, along with species like the pygmy salamander that can only survive there. And what about the trees not near balds, with nowhere else to go? Species like the red spruce and the Fraser fir, which have already declined by 15 percent, won’t tolerate hotter, drier days, and their numbers will continue to plummet.


Because it’s so high–the main entrance is at 9,000 feet, and 11 percent of its area is open tundra–this Colorado park hasn’t seen the same glacier and snowfield retreat as Glacier and North Cascades. But spring runoffs are still starting earlier every year. With a 3.6°F temperature rise, they’ll arrive three to four weeks earlier than they do now; a 7.2°F spike will push them six to eight weeks ahead of schedule (the IPCC predicts the planet will warm 2.5°F to 10°F by 2100). On the plus side, the hiking season will be much longer. “This year, the Loch Vale Trail was snow-free in mid-May,” Baron says of the route from Glacier Gorge Junction to the Loch. “I remember walking on snow in early July. So we’re now seeing examples of what the future will be like.”

But that’s a silver lining in a rather dark cloud: fire danger. Some experts predict that for every degree Fahrenheit of warming, the park’s treeline could rise 250 to 300 feet, with savanna woodland replacing boreal forest and limiting tundra to isolated patches. A 9°F rise could eliminate all tundra. Already, krummholz–the stunted trees that hug the ground at treeline–are advancing, and will eventually wipe out many of RMNP’s open ridges and classic Colorado vistas. And the famous high-alpine wildflowers? John Harte, who’s spent 14 years artificially warming plants and soil with heat lamps at the Rocky Mountain Biological Laboratory in Gothic, CO, predicts that in 50 to 100 years the vivid displays could look more like lower-elevation sagebrush fields.


Thanks to naturalist Joseph Grinnell, who spent decades observing Yosemite–filling out 13,000 pages in his journal and collecting 20,000 specimens–we have a detailed catalog of what the park looked like 90 years ago. Now researchers from Berkeley are painstakingly re-surveying the ground he covered. Here’s what’s changed: Species are climbing higher to stay in cooler alpine conditions. American pikas, which used to be common at 7,800 feet, now only live above 9,500–and soon may have nowhere to go. Trees normally held at bay by a short growing season and a heavy snowpack are sneaking into signature meadows like Tuolumne. The trend may well continue: Several recent studies have concluded that 70 to 90 percent of the Sierra snowpack could disappear by the end of the century–meaning its renowned waterfalls will disappear far earlier every season, or become less spectacular.


California’s popular desert park has astonishing diversity: 700 plant species and 200 bird species, not to mention desert tortoises and bighorn sheep. But the most obvious climate-related threat is to the park’s eponymous tree. Kenneth Cole, a climate scientist with the Colorado Plateau Research Station in Flagstaff, warns that if warming trends continue, 90 percent of the park’s Joshua trees will be gone by 2100. Though they’re desert species, they need winter freezes to flower, and warm winters evaporate the moisture the trees need for survival. “The southernmost Joshua tree populations are perched at a critical threshold of high winter temperatures, and aren’t found in areas with temperatures above these limits,” Cole says. Since Joshua tree forests can only migrate about 32 feet a year, they won’t be able to shift north fast enough to survive.


All that work restoring grizzly bear populations, and now this: A major source of fat for their hibernation, the whitebark pine nut, is disappearing. Warming temps have allowed the mountain pine beetle, usually frozen out of the trees’ terrain, to thrive. In some areas, like Avalanche Ridge, the pests have started eradicating entire forests. And tree species with higher resistance to climate change–like the lodgepole pine–are displacing whitebarks. There’s also the ever-present threat of massive wildfires, à la 1988; long-term Western drought, early runoff, and hot summers all increase the chances of park-altering conflagrations.


Species exist in a delicate balance in this 45-mile-long island park, and that balance is increasingly out of whack. Scientists at the Isle Royale Institute have been studying wolves and moose for 50 years, and their latest findings are grim: In 2002, more than 1,000 moose lived here; now there are 385. As deciduous trees replace conifers like balsam firs–a common phenomenon in the Midwest as rising temps push out boreal forests–the moose lose their food supply. With milder springs, ticks multiply to such levels that they lead to anemia and hair loss in moose. With hotter summers, moose lose their appetites and thus their strength for winter. When their numbers drop, wolves hunt the hares on which red foxes depend, and eventually both predators run out of food. University of Michigan researchers forecast that if the mercury keeps rising, the moose population will crash between 2025 and 2040–with wolves following suit in the two ensuing decades.


Comprising five islands off the coast of Santa Barbara, CA, this park is threatened both above and below the waterline. Up on terra firma, trees such as the bishop pine can’t tolerate higher temperatures, and other vegetation–which holds dunes in place, keeps soil from drying, and prevents eroding drainages called arroyos from forming–could die off. If the dunes become active, “the islands could look like a bloody desert,” says Daniel Muhs, a USGS geologist. As ocean temps spike, marine invertebrates may begin migrating north, and the rich, upwelling currents off California’s coast could become less productive, with fewer organisms at the bottom of the food chain. Of course, sea-level rise could have a huge effect on land: As beaches erode, seals and sea lions lose their habitat; sea cliffs would get undercut, and thus retreat; and sea caves will flood.


In 2000, fires burned more than a third of this Colorado archeological wonder, closing it for three weeks. In 2002, another 2,600 acres burned, destroying staff housing and shuttering the park for two more weeks. Counting three other big blazes, more than half of this park has burned in the last seven years. The piñon-and-juniper forests take three centuries to regenerate. And because it’s small (52,000 acres), surrounded by development, and situated atop a self-contained plateau, its tree species–like the piñon pine–have nowhere to migrate when temperatures rise. A study by the Rocky Mountain Climate Organization found that high temps and drought could eventually eliminate Mesa Verde’s forests.

15. Wrangell-St. Elias

In a June 2007 report by the NPCA, Mark Wenzler describes flying over hundreds of acres of what looked like charred spruce trees in this Alaska park. “The grayish brown skeletons,” he discovered, “were the remains of a spruce bark beetle invasion.” Millions of Alaska trees have been killed because the bug is suddenly thriving in a changing climate. As in Glacier Bay, tundra is disappearing, taking caribou herds with it. Wrangell-St. Elias is also home to famed Copper River salmon, which might not withstand warmer water–or the loss of closed-basin tundra ponds, which have decreased by half in the Copper River Basin.

Phased Out: Don’t expect updated national park topos to arrive in stores any time soon.

So your map is obsolete, and you want the new one? Sorry. The USGS stopped doing updates in the early 1990s. “The old ones were expensive because there were a lot of artistic components,” says Kari Craun, director of the USGS’s National Geospatial Technical Operations Center. “Updating those maps in that same style would be cost-prohibitive.” The good news: The agency is working on a prototype that combines elements of the old topos with high-resolution satellite imagery, like on Google Earth. Look for those models by late 2008.

The bad news? Maps will be updated according to federal criteria, not your need to walk in the woods. The Atlantic seaboard comes first, because of the urgent need for information during hurricane season. The worse news: Because of staff reductions, the USGS now relies heavily on state and county data, especially from transportation and zoning agencies. That means sparsely developed areas get low priority. Fortunately, the Forest Service maps 193 million acres of forest and grassland, and it’s among the most active surveyors out there.

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