02-03-2013, 03:58 PM
Natural Resources:Vital and Invaluable
Natural Resources.ppt (Size: 1.93 MB / Downloads: 25)
Forests
A forest is any area with a lot of trees. There are forests all over the world. The type of forest varies depending on the location of the forest: for example, there are tropical rain forests, coniferous forests, and deciduous forests.
Forests occur naturally, but they can be affected positively and negatively by human behavior. If a forest is carefully replanted and allowed to grow, it can exist in balance. If the forest is cut down faster than it can grow back, then it will be used up quickly.
Fossil Fuels
Fossil fuels take millions of years to form. They are the product of the fossilized remains of dead plants and animals that have been exposed to the heat and pressure deep within the earth’s crust. There are many types of fossil fuels, such as petroleum (gasoline), natural gas, and coal.
Fossil fuels are arguably one of the most valuable natural resources in modern times. It is estimated that 86 percent of the world’s energy comes directly from burning fossil fuels. Fossil fuels are the source of energy for almost every machine, including the generators that produce electric energy.
Solar Energy
The sun is the closest star to Earth. It brings heat and light to the world. Some areas of the world, such as those closest to the equator, have more sun than others.
The sun’s rays are used for energy by organisms that undergo photosynthesis. Nearly every organism on the planet gets energy through photosynthesis, directly or indirectly. There are also ways that people can utilize the energy that the sun provides.
Wind
Wind power does not make greenhouse gas emissions. It does not directly cause pollution. However, critics of wind power say a large number of windmills could cause problems for animals, especially migratory birds. Some people think the windmills are unattractive.