Editing Environment of the United States

{{Use mdy dates|date=March 2018}}
[[File:LocationUSA.png|right|thumb|The United States is part of [[North America]].]]
The '''[[environment (biophysical)|environment]]''' of the '''[[United States]]''' comprises diverse biotas, climates, and geologies. This diversity leads to a number of different distinct regions and geographies in which human communities live. This includes a rich variety of species of animals, fungi, plants and other organisms. 

Because of the strong forces of economic exploitation and industrialization, humans have had deep effects on the ecosystems of the United States, resulting in a number of environmental issues. 

Since awareness of these issues emerged in the 1970s, environmental regulations and a growing [[environmental movement]], including both [[climate movement]] and the [[environmental justice]] movement have emerged to respond to the various threats to the environment. These movements are intertwined with a long history of conservation, starting in the early 19th century, that has resulted in a robust network of protected areas, including 28.8% of land managed by the Federal government.

== Biota ==
[[File:A map of North America's bioregions, improved from the previous.jpg|thumb|400px|Bioregions of Northern America, according to one scheme.]]
{{Main|Fauna of the United States|Flora of the United States}}

=== Animals ===
There are about 21,717 different species of native plants and animals in the United States.  More than 400 mammal, 700 bird, 500 reptile and amphibian, and 90,000 insect species have been documented.<ref>{{cite journal |url=https://pubs.er.usgs.gov/publication/70148108 |title=Our Living Resources |year=1995 |publisher=U.S. Dept. of the Interior, National Biological Service |doi=10.5962/bhl.title.4172 |last1=Laroe |first1=Edward T. }}</ref> Wetlands, such as the Florida [[Everglades]], are the base for much of this diversity.  There are over 140,000 invertebrates in the United States which is constantly growing as researchers identify more species.  Fish are the largest group of animal species, with over one thousand counted so far.  About 13,000 species are added to the list of known organisms each year.<ref>[https://www.currentresults.com/Environment-Facts/Plants-Animals/number-of-native-species-in-united-states.phpCurrentResults.com Number of Native Species in United States]{{Dead link|date=January 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

=== Fungi ===
Around 14,000 species of fungi were listed by Farr, Bills, Chamuris and Rossman in 1989.<ref>Farr, D.F, Bills, G.F., Chamuris, G.P. and Rossman, A.Y. "Fungi on Plants and Plant Products in the United States". 1252 pp., APS Press, St Paul Minnesota, USA, 1989</ref> Still, this list only included terrestrial species. It did not include [[lichen]]-forming fungi, fungi on dung, freshwater fungi, marine fungi or many other categories.  Fungi are essential to the survival of many groups of organisms.

=== Plants ===
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 [[Sequoia sempervirens|tallest]], the [[Sequoiadendron giganteum|most massive]], and the [[Bristlecone pine|oldest]] trees in the world).<ref>{{cite book |last1=Morse, L. E., Kartesz, J. T., & Kutner, L. S. |title=Our Living Resources: a report to the nation on the distribution, abundance, and health of US plants, animals and ecosystems |date=1995 |publisher=US Department of the Interior, National Biological Service |location=Washington, DC |pages=205–209 |url=https://books.google.com/books?id=-a3HjWpMWuMC |chapter=Native vascular plants}}</ref> Three quarters of the United States species consist of flowering plants.

=== Human impacts on biota ===
The country's [[ecosystems]] include thousands of nonnative [[exotic species]] that often harm indigenous communities of living things. Many indigenous species became extinct soon after first human settlement, including the [[Pleistocene megafauna#North America|North American megafauna]]; others have become nearly extinct since European settlement, among them the [[American bison]] and [[California condor]].<ref>{{cite web |url=http://www.cpluhna.nau.edu/Biota/megafauna_extinctions.htm |title=Pleistocene Megafauna Extinctions |publisher=Cpluhna.nau.edu |access-date=January 31, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100308123523/http://cpluhna.nau.edu/Biota/megafauna_extinctions.htm |archive-date=March 8, 2010 }}</ref> Many plants and animals have declined dramatically as a result of massive conversion and other human activity. 

== Climate ==
{{Main|Climate of the United States}}
[[File:US 50 states Köppen.svg|thumb|350px|[[Köppen climate classification|Köppen climate types]] of the US]]  The U.S. climate is temperate in most areas, tropical in [[Hawaii]] and southern [[Florida]], polar in [[Alaska]], semiarid in the [[Great Plains]] west of the [[100th meridian west|100th meridian]], Mediterranean in coastal [[California]] and arid in the [[Great Basin]].  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]], cities in the southern and western region experienced an economic and population boom. The [[population growth]] in the [[Southwestern United States|Southwest]], has strained water and power resources, with water diverted from agricultural uses to major population centers, such as [[Las Vegas, Nevada|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 scarcity|water shortfall]] nearly as great as the amount consumed today.<ref>[http://www.globalpolicy.org/ngos/role/policymk/conf/2002/0827water.htm A World Without Water -Global Policy Forum- NGOs] {{webarchive|url=https://web.archive.org/web/20070712174955/http://www.globalpolicy.org/ngos/role/policymk/conf/2002/0827water.htm |date=July 12, 2007 }}</ref>

The United States mainland contains a total of seven distinct regional climates.  Those include high elevation Northwestern region, the Pacific Northwest, the High plains, Midwest/Ohio valley/New England, Mid Atlantic/Southeast, Southern region, and Southwestern region.  Each region contains different states and has their own climate and temperatures throughout the year.<ref>[http://traveltips.usatoday.com/regional-climates-united-states-21675.html Regional Climates in the United States] March 21, 2018 USA Today</ref>

== Geology ==
{{excerpt|Geology of the United States|paragraphs=1-2}}

== Environmental law and conservation ==
{{Main|United States environmental law}}
The nation's major [[environmental law]]s were enacted between 1969 and 1980:
* [[National Environmental Policy Act]] (1969)
* [[Clean Air Act (1970)|Clean Air Act]] (1970)
* [[Federal Insecticide, Fungicide, and Rodenticide Act]] (1972)
* [[Clean Water Act]] (1972)
* [[Endangered Species Act]] (1973)
* [[Safe Drinking Water Act]] (1974)
* [[Resource Conservation and Recovery Act]] (1976)
* [[Toxic Substances Control Act]] (1976)
* "[[Superfund]]" Act (1980)

The Endangered Species Act of protects [[threatened species|threatened]] and [[United States Fish and Wildlife Service list of endangered species|endangered species]] and [[Protected areas of the United States|their habitats]], which are monitored by the [[U.S. Fish and Wildlife Service]].

===Protected areas===
[[File:US National Marine Sanctuary global system map.gif|right|300px|thumb|United States National Marine Sanctuaries]]
{{Main|Protected areas of the United States}}
The United States maintains [[national park]]s as well as other preservation areas, such as the Florida Everglades. There are more than 400 protected sites spread across 84 million acres but very few are large enough to contain ecosystems.

In 1872, the world's first national park was established at [[Yellowstone National Park|Yellowstone]]. Another fifty-seven national parks and hundreds of other federally managed parks and forests have since been formed.<ref>{{cite web |last1=Baker |first1=Maverick |title=10 Ways Humans Impact the Environment |url=https://interestingengineering.com/10-ways-humans-impact-the-environment |website=interestingengineeering.com |access-date=March 24, 2018 |date=2016}}</ref> [[Wilderness area]]s 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&nbsp;km<sup>2</sup>), 28.8% of the country's total land area.<ref>{{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=May 19, 2005 |access-date=June 13, 2006 |url-status=dead |archive-url=https://web.archive.org/web/20100524171319/http://johnshadegg.house.gov/rsc/federal%20land%20ownership--may%202005.pdf |archive-date=May 24, 2010 }}</ref> 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;<ref>{{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=May 28, 2007 |access-date=June 11, 2007}}</ref> public land is also leased for mining and cattle ranching.

== Environmental issues ==
{{excerpt|Environmental issues in the United States}}
===Climate change===
{{Excerpt|Climate change in the United States}}
== Conservation ==
{{excerpt|Conservation in the United States}}



== See also ==
* {{portal-inline|Environment}}
* {{portal-inline|United States}}

* [[Ecotourism in the United States]]
* [[Environmental movement in the United States]]
* [[List of Superfund sites in the United States]]
* [[National Conservation Exposition]]
* [[National Environmental Information Exchange Network]]
* [[Timeline of major U.S. environmental and occupational health regulation]]

== References ==
{{reflist|2}}

== Further reading ==
* {{Cite book |publisher=Grey House Pub |isbn=978-1-78034-241-2 |last=Neimark |first=Peninah |author2=Mott, Peter Rhoades |title=The environmental debate a documentary history, with timeline, glossary, and appendices |location=Amenia, N.Y. |date=2011 }}<!--| access-date = February 17, 2013-->
* Reed, Daniel. 2009. [http://ecommons.txstate.edu/arp/291/ Environmental and Renewable Energy Innovation Potential Among the States: State Rankings]. Applied Research Project. Texas State University.
* Tresner, Erin. 2009. [http://ecommons.txstate.edu/arp/293/ Factors Affecting States' Ranking on the 2007 Forbes List of America's Greenest States]. Applied Research Project, Texas State University.

== External links ==
* [https://web.archive.org/web/20110410084724/http://www.pewtrusts.org/our_work_category.aspx?ID=110 Environment] at the [[Pew Charitable Trust]]

{{Environment of the United States by political division}}
{{North America topic|Environment of}}

[[Category:Environment of the United States| ]]