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sabato 28 settembre 2013


Environmental problems can be found all over the world, and they affect land, water and air.
These problems include deforestation, soil erosion, damage to ecosystems and reductions in biodiversity. Other problems are climate change, damage to the ozone layer, urban pollution, and acid rain.

One of the biggest enviromental problem is deforestation. In the Amazon forest in particular, trees are cut to provide more land for agriculture. This is threatening the survival of many animal species, for example the jaguar. In Borneo and Sumatra the orang-utan is under threat for the same reason.
Deforestation in Amazon forest
Deforestation can also lead to soil erosion, infact trees stabilize the soil with their roots, reduce the intensity of rainfall that hits the ground, and help soils retain moisture. Deforestation on hill and mountain sides can lead to flooding, as water is then able to run unimpeded down the slopes, and can also result in disastrous mudslides.

Air Pollution
Air pollution affects the atmosphere, oceans, lakes, rivers, and also land. Many human activities release toxic chemicals substances into the air or into water, which can go on to damage the environment or cause ill health in people.
A very important problem is depletion of the ozone layer: this layer absorbs ultraviolet light, but the release of chemicals known as chlorofluorocarbons, used in aerosol sprays, damages this layer, and potentially increasing exposure of humans, animals and plants to dangerous levels of ultraviolet light. These chemicals have been banned in the USA and Canada, but many other countries are still using them. 
Air pollution can also take the form of tiny particles. Many combustion processes, such as wood and coal fires, wood stoves, and the burning of fuel in cars produce minute particles of carbon, in the form of soot and smoke. These may affect climate, by reducing the transparency of the atmosphere, and may contribute to respiratory problems in people.

Water Pollution
Water pollution occur through the release of industrial waste, for example from mining and metal refining activities, into streams and rivers. A variety of toxic metals can affect aquatic and marine life and may accumulate in the food chain, becoming a threat to humans. Another major source of water pollution is fertilizers, which can be washed into rivers and lakes from farmland.
Nitrates and phosphates, present in fertilizers, and essential for plant growth, can also promote uncontrolled multiplication of algae in lakes. This reduces water quality and oxygen levels, and may kill fish.

Climate change
One of the biggest environmental problems is due to carbon dioxide (CO2) which is produced in huge quantities by the burning of fossil fuels, for example by cars, industrial processes, and airplanes. It traps heat in the Earth’s atmosphere, and is the most important “greenhouse” gas. Increased levels resulting from human activities are thought to be raising air and ocean temperatures across the planet, a phenomenon known as “global warming” or “climate change.”
Climate change consequences
Climate change may also have a drastic effect on agriculture due to changes in temperature and rainfall. Many crop plants may be unable to adapt to drier or wetter conditions. It may also be that warming of the oceans will lead to more frequent, and more severe, hurricanes.

Possible solutions
Solutions to many of these problems would require action by governments across the globe, for example, to reduce burning of fossil fuels and develop renewable energy resources. Ordinary people, however, can make their own contributions; for example, cutting down on car journeys helps reduce levels of carbon dioxide, nitrogen oxides and soot.
Companies can play a role by using teleconferencing facilities so that employees do not have to travel to meetings, and allowing staff to work online from home.
People can also help in many small ways, such as minimizing their use of garden fertilizers, not using them when rain is forecast, picking up litter and rubbish that might harm wildlife, and properly disposing of harmful chemicals.

(Complete informations here)

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