As the U.S. government shutdown goes into its 10th day, a work-around to save the country from defaulting on its debt may be in the works with a temporary hike in the nation's borrowing limit. Even still, the partial shutdown of the government, including national parks, is likely to continue. Here the U.S. Capitol looms in the background of a sign on the National Mall reminding visitors of the closures to all national parks due to the federal government shutdown in Washington.
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Yosemite Valley destinations are closed to drivers; as the sign indicates, travelers must exit the park by way of the El Capitan Bridge Crossover.
A sign announces the closure of the Yellowstone National Park in Wyoming.
Though Old Faithful continues to spout off in Yellowstone National Park, the famous geyser is off-limits to tourists.
Due to the government shutdown, the Statue of Liberty and Ellis Island have been closed to visitors.
A National Parks policeman walks past a sign after the Lincoln Memorial was sealed off from visitors in Washington, Oct. 1, 2013. During the last shutdown 17 years ago, government workers were furloughed for 6 days in November and then again from Dec. 16, 1995 to Jan. 6, 1996. Barricades were then, as they are now, placed around national monuments, such as the Lincoln Memorial.
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A park ranger secures a road at the entrance to Mount Rushmore National Memorial on Oct. 1, 2013 in Keystone, South Dakota.
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A sign in the lobby of the Ronald Reagan Presidential Library in Simi Valley, Calif., warns visitors that the library is closed due a government shutdown. While the government-funded library is closed, outdoor areas where a piece of the Berlin Wall (in background) is located and Air Force One, are privately funded and remain open to the public.
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A board informs visitors of the closing of the Suresnes American Cemetery and Memorial, west of Paris, on October 1, 2013. The famous D-Day cemetery for American soldiers in Normandy, France, is also closed.
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U.S. Park Police move barricades into place around the World War II Memorial in Washington to prevent people from entering the monument on the National Mall. After a confrontation was caught on video between a park ranger and Texas Republican Rep. Randy Neugebauer, during which Neugebauer told the park ranger she should be ashamed for closing the memorial, park rangers have taken to wearing badges that read: "I Am Not Ashamed."
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A U.S. Park Police officer assists Park Service employees in closing down the Martin Luther King (MLK) Memorial on the National Mall Oct. 1, 2013 in Washington, D.C.
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The USS Constitution in Boston, is closed to onboard visitors because of the federal government shutdown.
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Visitors take pictures of the outside of the San Francisco Maritime National Historical Park on Oct. 1, 2013 in San Francisco, Calif.
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Park Ranger Dylan Moe stands guard as the sun sets at the entrance to Joshua Tree National Park to prevent any tourists from entering, in Joshua Tree, Calif., on Oct. 2, 2013.
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Access to Switzer Picnic Area is prohibited in the Angeles National Forest on Oct. 2, 2013 in the San Gabriel Mountains, northeast of Los Angeles, Calif.
An unidentified biker rides past the barricades and sign at the entrance to Rock Creek Park in Chevy Chase, Md. The road, Rock Creek Parkway, which runs through the park, is a major thoroughfare for motor vehicles and bicycles between the Maryland suburbs and downtown Washington, D.C.
America’s national parks receive harmful, accidental fertilization from air pollution. A recent study identified how this unwanted dose of nitrogen nutrients harms plants and disrupts aquatic environments in 38 U.S. national parks.
Much of this accidental fertilization comes from ammonia that evaporated from agricultural chemicals and livestock urine, according to the study published in Atmospheric Chemistry and Physics. Power plant and vehicle emissions also contribute nitrogen in the form of nitrous oxides.
These nitrogen-containing gases enter the atmosphere, then fall back to earth in rain water or through other means.
“When we apply fertilizer in the United States, only about 10 percent of the nitrogen makes it into the food,” said lead author Daniel J. Jacob of Harvard University in a press release. “All the rest escapes, and most of it escapes through the atmosphere.”
Once that nitrogen escapes into the environment, it damages ecosystems.
In the east, the unwanted fertilizer most seriously affects the hardwood trees, such as oak, in Great Smoky Mountains National Park. The trees start to suffer when nitrogen input reaches 3 to 8 kilograms per hectare each year. However, the forest now receives far more than that, at 13.6 kilograms per hectare each year.
On the other side of the nation in Washington’s Mount Rainier National Park, nitrogen input levels have reached 6.7 kg/ha/year. Lichens, the base of the ecosystem, start to suffer when levels reach 2.5 to 7.1 kg/ha/year.
In bodies of water across the nation, excess nitrogen alters the acidity of the waters and fuels explosions of algae growth.
Controlling the environmental effects of accidental over-fertilization from air pollution poses a legal challenge, noted Jacob.
“Air quality regulations in the United States have always focused on public health, because air pollution leads to premature deaths, and that’s something you can quantify very well. When you try to write regulations to protect ecosystems, however, the damage is much harder to quantify,” said Jacob. “At least in the national parks you can say, ‘There’s a legal obligation here.’”
The government has an obligation to maintain the national parks we all share. This gives regulatory agencies a legal foundation for fighting nitrogen air pollution.
IMAGE: Looking up into Redwoods and Rhododendron on a foggy morning in the Lady Bird Johnson area of Redwoods N.P., California. (Darrell Gulin/Corbis)