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Friday, July 9, 2010

Environmental engineering

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Environmental engineering is the application of science and engineering principles to improve the environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites.

Environmental engineering involves water and air pollution control, recycling, waste disposal, and public health issues as well as a knowledge of environmental engineering law. It also includes studies on the environmental impact of proposed construction projects.

Environmental engineers conduct hazardous-waste management studies to evaluate the significance of such hazards, advise on treatment and containment, and develop regulations to prevent mishaps. Environmental engineers also design municipal water supply and industrial wastewater treatment systems as well as address local and worldwide environmental issues such as the effects of acid rain, global warming, ozone depletion, water pollution and air pollution from automobile exhausts and industrial sources.At many universities, Environmental Engineering programs follow either the Department of Civil Engineering or The Department of Chemical Engineering at Engineering faculties. Environmental "civil" engineers focus on hydrology, water resources management,bioremediation, and water treatment plant design. Environmental "chemical" engineers, on the other hand, focus on environmental chemistry, advanced air and water treatment technologies and separation processes.

Pollutants may be chemical, biological, thermal, radioactive, or even mechanical. Environmental engineering is a diverse field, which emphasizes several areas: process engineering, environmental chemistry, water and sewage treatment (sanitary engineering), waste reduction/management, and pollution prevention/cleanup.

Thursday, July 8, 2010

Deforestation

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Deforestation
It is impossible to overstate the importance of humankind's clearing of the forests. The transformation of forested lands by human actions represents one of the great forces in global environmental change and one of the great drivers of biodiversity loss. The impact of people has been and continues to be profound. Forests are cleared, degraded and fragmented by timber harvest, conversion to agriculture, road-building, human-caused fire, and in myriad other ways. The effort to use and subdue the forest has been a constant theme in the transformation of the earth, in many societies, in many lands, and at most times. Deforestation has important implications for life on this planet.

Just think, originally, almost half of the United States, three-quarters of Canada, almost all of Europe, the plains of the Levant, and much of the rest of the world were forested. The forests have been mostly removed for fuel, building materials and to clear land for farming. The clearing of the forests has been one of the most historic and prodigious feats of humanity.

About one half of the forests that covered the Earth are gone. Each year, another 16 million hectares disappear. The World Resources Institute estimates that only about 22% of the world's (old growth) original forest cover remains "intact" - most of this is in three large areas: the Canadian and Alaskan boreal forest, the boreal forest of Russia, and the tropical forest of the northwestern Amazon Basin and the Guyana Shield (Guyana, Suriname, Venezuela, Columbia, etc.)

Today, forests cover more than one quarter of the world's total land area, excluding polar regions. Slightly more than 50% of the forests are found in the tropics and the rest are temperate and boreal (coniferous northern forest) zones.

For millennia, humankind has influenced the forests, although much of the impact has been relatively minor. Today, the impact is enormous. Deforestation is expanding and accelerating into the remaining areas of undisturbed forest, and the quality of the remaining forests is declining. Today we examine global patterns in deforestation, assess the human and ecological costs of forest loss, and discuss some of the steps that can help to rectify this alarming situation.