Climate change puts parks at risk
by: Paul Nussbaum 2 July 2006
Natural preserves may lose distinctive features.
GLACIER NATIONAL PARK, Mont. - Global warming is erasing the glaciers from Glacier National Park and the Joshua trees from Joshua Tree National Park, and may turn the Everglades into the Neverglades.
Many national parks, created as preserves of the best or the most or the last, are especially vulnerable to climate change. Already-fragile park environments are often at special risk because of their location at high elevations and latitudes or along coasts.
Faced with this threat, unimagined when it was created in 1916, the National Park Service will be hard-pressed to meet its legal obligation to conserve the parks' natural and historic wonders "unimpaired for the enjoyment of future generations."
"At some parks, you might lose the key species that Congress intended to be protected," said Michael Soukup, associate director of the Park Service for natural resource stewardship and science in Washington. "We've been looking at this for a number of years, and we're starting to look at it much more seriously."
"Managers will have choices to make, where to put their money and what to do," said Leigh Welling, director of the Park Service's Crown of the Continent Research Learning Center at Glacier National Park, Mont., and national coordinator of the Park Service's 17 research centers. "We want to promote informed decisions... . The public has to be involved in answering the question: 'What do you want to save?' "
A changing climate will affect the parks' animals, plants, landscapes, historic artifacts and visitors. Uncertainties abound about exactly how individual parks will be reshaped by global warming, but park scientists say change is inevitable.
Among the chief concerns:
Habitat loss. Warming climates will force animals and plants to move uphill or northward in search of hospitable homes. From the Great Smoky Mountains to Rocky Mountain to Yellowstone to Denali, those at the limits of their range or unable to move quickly enough will vanish from the parks.
Rising sea levels. By 2025, sea levels in the Chesapeake Bay area are projected to have risen by eight inches and in south Florida by five inches. By 2100, south Florida seas are predicted to be 20 inches higher. Many coastal parks, such as Everglades, Assateague, Cape Cod, Fire Island and Biscayne will see more erosion and flooding, and salt water will invade freshwater marshes, changing the nature of the parks and their inhabitants. Rising water can also jeopardize low-lying historical sites such as Jamestown in Virginia and Jean Lafitte National Historical Park near New Orleans.
Precipitation changes. Parks will become wetter or drier, depending on location, and moisture may arrive as rain, rather than snow, altering local water cycles. Different plants and animals will thrive. Forest fires will likely occur more frequently in drier parks, such as Yellowstone, Rocky Mountain, and Glacier.
Changing migration patterns. Migrating birds appear to be arriving and nesting earlier in some parks as the climate warms. If their patterns fall out of synch with the insects on which they feed, they and their fledglings may not survive.
"Climate change is the greatest single threat to our national parks," said Stephen Saunders, a former Interior Department official in charge of fish, wildlife and parks during the Clinton administration. "There will be changes in nearly every national park unit, and in some, they will be huge and sweeping and profound."
Saunders is now president of the Rocky Mountain Climate Organization and is cowriting, with the Natural Resources Defense Council, a report on the effects of climate change on national parks in the western United States.
More than 270 million people a year visit the nation's 390 national parks, and some park managers are taking the opportunity to inform Americans about global warming, though not as aggressively as critics would like.
"We're not pushing any political message; we're not telling visitors to call their senators or representatives," said Shawn Norton, director of a Park Service program to make parks more "climate friendly" and the public more aware of the effects of climate change. "Advocacy is a fine line to walk... our responsibility lies in making sure visitors understand the impacts and what they can do."
"We're a very small agency with a potentially high impact," said Soukup, the associate Park Service director for science. "We have an obligation to take advantage of those teachable moments."
Glacier National Park is a perfect classroom, because with its easily identifiable receding glaciers it is a laboratory for measuring and predicting the changes.
There are only 27 glaciers left of the 150 that were here in 1850, at the end of the "little ice age" and the beginning of the current warming trend. At the present rate of warming, park scientists say, all the glaciers will be gone by 2030.
"Glaciers are an icon for climate change," said Daniel B. Fagre, an ecologist with the U.S. Geological Survey's Global Change Research Program at the park. "They're symbolic of change across ecosystems. They don't adapt, and they're an easy-to-identify physical phenomenon.
"People can get it: Ice melts when it gets warm. It's a teachable phenomenon."
What happens along with the vanishing glaciers is also instructive:
Snowpacks are melting two weeks earlier than they did 50 years ago. More precipitation arrives as rain instead of snow. Less glacial water feeds streams and lakes. Warmer waters mean fewer trout and other aquatic creatures that depend on cold water. Less snow means drier summers and falls, increasing the likelihood of fires.
Alpine meadows, which depend on heavy winter snowpacks, give way to forests. Animals and plants that flourish in meadows - mountain goats and bighorn sheep and marmots and butterflies - are replaced by forest wildlife.
The towering cedar-hemlock groves along Avalanche Creek, where 500-year-old stands of 100-foot-tall trees are remnants of an earlier, cooler climate, are likely to be replaced by other species, such as lodgepole pine.
Mountain pine beetles advance in warmer climates, which means fewer white bark pines, which means fewer pine nuts and army cutworm moths, two favored foods of the grizzly bears that roam Glacier.
Those cascading effects represent "a pretty fundamental shift in how the ecosystem works," Fagre said.
Similar ecological chains of events are playing out at national parks around the nation as the climate warms. (Since 1900, Glacier National Park's average summer temperatures have increased by about 1.8 degrees Fahrenheit.)
At Joshua Tree National Park, in the deserts of southern California, at least 90 percent of the Joshua trees are projected by researchers to be gone in the next century, as winters warm.
"The area will be hotter, the range will move northward, and Joshua trees don't propagate very quickly," said Deborah DeMeo, the California desert field representative of the National Parks Conservation Association. "The Joshua tree needs colder winters, and by making winters warmer, the Joshua tree won't survive."
In the Everglades, natural barriers are being lost as sea levels rise, and if the water rises faster than protective mangrove trees can keep up, much of the freshwater Everglades will disappear, replaced by saltwater wetlands and shallow bays.
South Florida's sea level has risen about 12 inches since 1846, and global warming is predicted to accelerate the trend. By 2100, the Park Service and Environmental Protection Agency predict, south Florida seas will be 20 inches higher than in 1990.
In Southeastern Pennsylvania, Valley Forge National Historical Park and Hopewell Furnace National Historic Site are home to 22 bird species whose numbers have been dwindling, including the osprey, Louisiana water thrush, wood thrush, and cerulean warbler. Climate-change-induced alterations to vegetation at the parks may mean further declines of the birds.
At many parks, managers have begun to identify natural "vital signs" to indicate how the health of the parks is changing.
Because national parks are so new (Yellowstone, created in 1870, was the world's first), there is little precedent for accommodating the demands of preservation to the imperatives of an ever-changing climate.
And the uncertainties about the extent of future change and all its causes make it even harder for park managers and visitors to cope.
There is no doubt that earth's temperatures and sea levels have risen in the past 150 years. An increase in heat-trapping gases in the atmosphere, such as carbon dioxide and nitrous oxide, are believed responsible for much of the increase.
The full extent of human responsibility for the increase is still a matter of political - and to a much smaller degree, scientific - debate. Scientists generally believe that the burning of fossil fuels in vehicles, factories and homes is responsible for most of the increase in greenhouse gases - and temperatures. There have been warmer periods in Earth's history, but not during human civilization, said Fagre, of the Global Change Research Program at Glacier National Park.
"The last time anything like this happened was at least 160,000 years ago," Fagre said. "We're entering new terrain. This is a human issue because we'll be affected and because we're having an effect. This is the first time we've had our fingers on the thermostat.
"We're simply pushing the system and we'll be affected by it in a way that hasn't happened before."