Portal:Environment/Selected article

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The layout design for these subpages is at Portal:Environment/Selected article/Layout.

  1. Add a new Selected article to the next available subpage.
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[edit] Selected articles list

Selected article/1           view - talk - edit - history

Global mean surface temperature anomaly 1850 to 2006 relative to 1961–1990
Global warming is the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. An increase in global temperatures can in turn cause other changes, including sea level rise, and changes in the amount and pattern of precipitation resulting in floods and drought. There may also be changes in the frequency and intensity of extreme weather events, though it is difficult to connect specific events to global warming.

Other effects may include changes in agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors.

Most national governments have signed and ratified the Kyoto Protocol aimed at combating greenhouse gas emissions.

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Selected article/2           view - talk - edit - history

An average of several samples of δ18O, a proxy for temperature, for the last 600,000 years
100,000-year problem is a discrepancy between the climate response (as measured by proxies for the temperature and extent of glaciations) and the forcing from the amount of incoming solar radiation, or insolation, which has little power on a 100,000 year (100 ka) timescale.

Due to variations in the Earth's orbit, the amount of insolation varies with periods of around 21,000, 40,000, 100,000 and 400,000 years. This is recognised as a key factor in the initiation and termination of ice ages.

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Selected article/3           view - talk - edit - history

Attribution of recent climate change
Climate change refers to the change of Earth's global climate or in regional climates over time. These changes can be caused by processes internal to the Earth, external forces (e.g. variations in sunlight intensity) or, more recently, human activities.

In recent usage, especially in the context of environmental policy, the term "climate change" often refers only to changes in modern climate, including the rise in average surface temperature known as global warming. In some cases, the term is also used with a presumption of human causation, as in the United Nations Framework Convention on Climate Change (UNFCCC). The UNFCCC uses "climate variability" for non-human caused variations.

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Selected article/4           view - talk - edit - history

Eutrophication is apparent as increased turbidity in the northern part of the Caspian Sea, imaged from orbit.
Eutrophication refers to an increase in the primary productivity of any ecosystem. It is usually caused by the increase of chemical nutrients, typically compounds containing nitrogen or phosphorus. It may occur on land or in water.

In aquatic environments, enhanced growth of choking aquatic vegetation or phytoplankton (that is, an algal bloom) disrupts normal functioning of the ecosystem, causing a variety of problems such as lack of oxygen in the water for fish and shellfish to survive.

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Selected article/5           view - talk - edit - history

Thick particles in the atmosphere can reflect back the sunlight. Photo taken by NASA's Aqua satellite
Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in 1950s. It is thought to have been caused by an increase in particulates such as black carbon in the atmosphere due to human action.

Global dimming has interfered with the hydrological cycle by reducing evaporation and may have caused droughts in some areas. Global dimming also creates a cooling effect that may have partially masked the effect of greenhouse gases on global warming.

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Selected article/6           view - talk - edit - history

Participation in the Kyoto Protocol: dark green indicates countries that have signed and ratified the treaty, yellow indicates those that have signed and hope to ratify it, and red indicates those that have signed but not ratified it.
Kyoto Protocol is an amendment to the United Nations Framework Convention on Climate Change international treaty on climate change, assigning mandatory emission limitations for the reduction of greenhouse gas emissions to the signatory nations. It works on an emission allowance scheme. Countries that meet their emission reduction target are given quotas while countries who do not meet their targets have to purchase the quotas, thus rewarding countries that follow this treaty.
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Selected article/7           view - talk - edit - history

Advancing sand dunes.
Desertification is the degradation of land in arid, semi arid and dry sub-humid areas resulting from various climatic variations, but primarily from human activities. A major impact of desertification is biodiversity loss and loss of productive capacity, for example, by transition from grassland dominated by perennial grasses to one dominated by perennial shrubs.

A number of solutions have been tried in order to reduce the rate of desertification and regain lost land. Leguminous plants, which extract nitrogen from the air and fix it in the soil, can be planted to restore fertility. Stones stacked around the base of trees collect morning dew and help retain soil moisture. Artificial grooves can be dug in the ground to retain rainfall and trap wind-blown seeds. Windbreaks made from trees and bushes to reduce soil erosion and evapotranspiration was widely encouraged by development agencies from the middle of the 1980s.

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Selected article/8           view - talk - edit - history

Sources that create acid rain
Acid rain or acid precipitation commonly used to mean the deposition of acidic components in rain, snow, dew, or dry particles. Acid rain occurs when sulfur dioxide and nitrogen oxides are emitted into the atmosphere, undergo chemical transformations and are absorbed by water droplets in clouds.

Acid rain is defined as any type of precipitation with a pH that is unusually low. Acid rain accelerates weathering in carbonate rocks and accelerates building weathering while destructing rivers, streams, and forest because many organisms cannot tolerate the unusually low pH.

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Selected article/9           view - talk - edit - history

Pied Currawong, an invasive specie in Australia
Invasive species are widespread non-indigenous species. It can be damaging to the local ecosystem as invasive species compete resources with local species. Most of the time the non-native species cannot survive in the new environment and died out. However, there is a chance that they managed to survive and no natural predator in the new environment. This can wipe out local species as the population of the invasive species increases, thus affecting biodiversity.
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Selected article/10           view - talk - edit - history

Renewable energy commercialization involves a broad, diverse array of technologies, including solar photovoltaics, solar thermal power plants, solar heating and cooling systems, wind power, hydroelectricity, geothermal, biomass, and ocean energy systems. The current status of these different technologies varies considerably. "First-generation" technologies are already mature and economically competitive, "second-generation" technologies are market ready and are being deployed at the present time, and "third-generation" technologies require continued R&D efforts in order to make large contributions on a global scale.
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Selected article/11           view - talk - edit - history

Ozone depletion describes two distinct, but related observations: a slow, steady decline of about 4 percent per decade in the total amount of ozone in Earth's stratosphere since around 1980; and a much larger, but seasonal, decrease in stratospheric ozone over Earth's polar regions during the same period. The latter phenomenon is commonly referred to as the ozone hole.
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Selected article/12           view - talk - edit - history

Air pollution is a chemical, particulate matter, or biological agent that modifies the natural characteristics of the atmosphere. The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.
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Selected article/13           view - talk - edit - history

Dioxins, which are members of the family of halogenated organic compounds, build up primarily in fatty tissues over time (bioaccumulate), so even small exposures may eventually reach dangerous levels. In 1994, EPA reported that dioxin is a probable carcinogen, but notes that non-cancer effects (reproduction and sexual development, immune system) may pose an even greater threat to human health. TCDD, the most toxic of the dibenzodioxins, has a half-life of approximately 8 years in humans, but at high concentrations, the elimination rate is enhanced by metabolism.
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Selected article/14           view - talk - edit - history

Acid mine drainage (AMD), or acid rock drainage (ARD), refers to the outflow of acidic water from (usually) abandoned metal mines or coal mines. However, other areas where the earth has been disturbed (e.g. construction sites, subdivisions, transportation corridors, etc.) may also contribute acid rock drainage to the environment. In many localities the liquid that drains from coal stocks, coal handling facilities, coal washeries, and even coal waste tips can be highly acidic, and in such cases it is treated as acid rock drainage.
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Selected article/15           view - talk - edit - history

Nuclear fallout is the residual radiation hazard from a nuclear explosion, so named because it "falls out" of the atmosphere into which it is spread during the explosion. It commonly refers to the radioactive dust created when a nuclear weapon explodes. This radioactive dust, consisting of hot particles, is a kind of radioactive contamination. It can lead to contamination of the food chain. Fallout can also refer to the dust or debris that results from the nuclear explosion.
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Selected article/16           view - talk - edit - history

Waste, rubbish, trash, garbage, or junk is unwanted or undesired material. "Waste" is the general term though the other terms are used loosely as synonyms, they have more specific meanings. Rubbish or trash are mixed household waste including paper and packaging; food waste or garbage (North America) is kitchen and table waste; and junk or scrap is metallic or industrial material. There are other categories of waste as well: sewage, ash, manure, and plant materials from garden operations, including grass cuttings, fallen leaves, and pruned branches.
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Selected article/17           view - talk - edit - history

Soil conservation is a set of management strategies for prevention of soil being eroded from the earth’s surface or becoming chemically altered by overuse, salinization, acidification, or other chemical soil contamination. The principal approaches these strategies take are choice of vegetative cover, erosion prevention, salinity management, acidity control, encouraging health of beneficial soil organisms, prevention and remediation of soil contamination and mineralization.
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Selected article/18           view - talk - edit - history

An oil spill is the unintentional release of liquid petroleum hydrocarbon into the environment as a result of human activity. The term often refers to marine oil spills, where oil is released into the ocean or coastal waters. Oil can refer to many different materials, including crude oil, refined petroleum products (such as gasoline or diesel fuel) or by-products, ships' bunkers, oily refuse or oil mixed in waste. Spills take months or even years to clean up.
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Selected article/19           view - talk - edit - history

Pollinator decline is based on observations made at the end of the twentieth century of the reduction in abundance of pollinators in many ecosystems worldwide. Pollinators participate in sexual reproduction of many plants, by ensuring cross-pollination, essential for some species, or a major factor in ensuring genetic diversity for others. Since plants are the primary food source for animals, the reduction of one of the primary pollination agents, or even their possible disappearance, has raised concern, and the conservation of pollinators has become part of biodiversity conservation efforts.
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Selected article/20           view - talk - edit - history

Bottom trawling (known in the scientific community as Benthic trawling) is a fishing method which involves towing trawl nets along the sea floor, as opposed to pelagic trawling, where a net is towed higher in the water column. Bottom trawling can be carried out from one vessel or two vessels fishing cooperatively. It is practiced from a very wide range of fishing vessels, starting with small motor boats powered by engines of several tens of horsepower and up to large ocean-going trawlers, up to 100 m long, and powered by engines of several thousand horsepower.
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[edit] Nominations

Feel free to add featured, top or high importance articles about Environment to the above list. Other Environment -related articles may be nominated here.

Added. -- Alan Liefting talk 02:05, 5 September 2007 (UTC)