Environment of the United States

The environment of the United States comprises diverse biotas, climates, and geologies. Environmental regulations and the environmental movement have emerged to respond to the various threats to the environment.

Biota

With habitats ranging from tropical to Arctic, U.S. plant life is very diverse. The country has more than 17,000 identified native species of flora, including 5,000 in California (home to the tallest, the most massive, and the oldest trees in the world). [cite web|author=Morse, Larry E., et al.| url=http://biology.usgs.gov/error.html | title=Native Vascular Plants | publisher = U.S. Dept. of the Interior, National Biological Service|work=Our Living Resources| accessdate=2006-06-14Citation broken|date=December 2007] More than 400 mammal, 700 bird, 500 reptile and amphibian, and 90,000 insect species have been documented. [cite web| url=http://biology.usgs.gov/error.html | title=Our Living Resources | publisher = U.S. Dept. of the Interior, National Biological Service| accessdate=2006-06-14Citation broken|date=December 2007] Wetlands such as the Florida Everglades are the base for much of this diversity. The country's ecosystems include thousands of nonnative exotic species that often harm indigenous plant and animal communities.

Many plant and animal species became extinct soon after first human settlement, including the North American megafauna; others have become nearly extinct since European settlement, among them the American Bison and California Condor. [ [http://www.cpluhna.nau.edu/Biota/megafauna_extinctions.htm Pleistocene Megafauna Extinctions] ]

Climate

. Its comparatively generous climate contributed (in part) to the country's rise as a world power, with infrequent severe drought in the major agricultural regions, a general lack of widespread flooding, and a mainly temperate climate that receives adequate precipitation.

Following World War II, the West's cities experienced an economic and population boom. The population growth, mostly in the Southwest, has strained water and power resources, with water diverted from agricultural uses to major population centers, such as Las Vegas and Los Angeles. According to the California Department of Water Resources, if more supplies are not found by 2020, residents will face a water shortfall nearly as great as the amount consumed today. [ [http://www.globalpolicy.org/ngos/role/policymk/conf/2002/0827water.htm A World Without Water -Global Policy Forum- NGOs] ]

Geology

The lower 48 states can be divided into roughly five physiographic provinces: the American cordillera, the Canadian Shield, the stable platform, the coastal plain, and the Appalachian orogenic belt.

Environmental law and conservation

The Endangered Species Act of 1973 protects threatened and endangered species and their habitats, which are monitored by the U.S. Fish and Wildlife Service.

In 1872, the world's first national park was established at Yellowstone. Another fifty-seven national parks and hundreds of other federally managed parks and forests have since been formed. [cite web| url=http://home.nps.gov/applications/release/Detail.cfm?ID=639 | title=National Park Service Announces Addition of Two New Units | publisher = National Park Service|date=2006-02-28| accessdate=2006-06-13] Wilderness areas have been established around the country to ensure long-term protection of pristine habitats. Altogether, the U.S. government regulates 1,020,779 square miles (2,643,807 km²) , 28.8% of the country's total land area. [cite web| url=http://johnshadegg.house.gov/rsc/Federal%20Land%20Ownership--May%202005.pdf | title=Federal Land and Buildings Ownership | publisher = Republican Study Committee|date=2005-05-19| accessdate=2006-06-13] Protected parks and forestland constitute most of this. As of March 2004, approximately 16% of public land under Bureau of Land Management administration was being leased for commercial oil and natural gas drilling; [cite web| url=http://www.iht.com/articles/2007/05/27/bloomberg/bxbeer.php | title=Abuse of Trust: A Brief History of the Bush Administration’s Disastrous Oil and Gas Development Policies in the Rocky Mountain West | publisher = Wilderness Society | date=2007-05-28| accessdate=2007-06-11] public land is also leased for mining and cattle ranching.

Environmental issues

As with many other countries there are a number of environmental issues in the United States. Topical issues include the Arctic Refuge drilling controversy and the Bush Administration stance on climate change.

Protected areas

The protected areas of the United States are managed by an array of different federal, state, tribal and local level authorities and receive widely varying levels of protection. Some areas are managed as wilderness while others are operated with acceptable commercial exploitation. By international definitions, the United States had 7448 protected areas, not counting marine areas, as of 2002. These protected areas cover 578,000 square miles (1,500,000 km²), almost 16% of the land area of the United States. [1] This is also one-tenth of the protected land area of the world. U.S. marine protected areas cover an additional 347,000 square miles (900,000 km²) with varying levels of protection.

ee also

*Timeline of major U.S. environmental and occupational health regulation
*National Conservation Exposition

References

United States topic
title = Environment of the United States by political division
prefix = Environment of