Answers (2) |
vk
|
Dec 7, 2006,12:00 am
A non-renewable resource is a natural resource that cannot be re-made or re-grown. Often fossil fuels, such as coal, petroleum and natural gas are considered non-renewable resources, as they do not naturally re-form at a rate that makes the way we use them sustainable. This is as opposed to natural resources such as timber, which re-grows naturally and can, in theory, be harvested sustainably at a constant rate without depleting the existing resource pool and resources such as metals, which, although they are not replenished, are not destroyed when used and can be recycled. But there are several problems with non – renewable resources:
<br>
<br>They are running out – and fast. They pollute the Earth’s atmosphere, such as the emission of carbon dioxide, which in turn helps the greenhouse gas effect as well as adding to global warming. They have to be burned to be used. Only few countries have these non – renewable resources and sell them for high prices across the world. Non – renewable resources are destroying the environment. They take millions of years to form.
<br>
<br>Carbon-based non-renewables
<br>Natural resources such as coal, oil, or natural gas, take millions of years to form naturally and cannot be replaced as fast as they are consumed. Eventually they will be used up. At present, the main energy sources used by humans are non-renewable; renewable resources, such as solar, tidal, wind, and geothermal power, have so far been less exploited. Fossil fuels like coal, oil, and gas generate a considerable amount of energy when they are burnt (the process of combustion). Non-renewable resources have a high carbon content because their origin lies in the photosynthetic activity of plants millions of years ago. The fuels release this carbon back into the atmosphere as carbon dioxide. The rate at which such fuels are being burnt is thus resulting in a rise in the concentration of carbon dioxide in the atmosphere, a cause of the greenhouse effect.
<br>
<br>Natural resources are replaced by natural processes given reasonable amount of time. Soil, water, forests, plants, and animals are all renewable resources as long as they are properly conserved. Solar, wind, wave, and geothermal energies are based on renewable resources.However, non - renewable resources take millions of years to form.
<br>
<br>Renewable resources such as water, wind power, sun, etc are infinite - this means they will never run out, unlike their non - renewable counterparts, which will have run out by 2200.
<br> |
 
|
|
| |
|
| |
|
k7
|
Dec 7, 2006,12:11 am
A renewable resource is any natural resource that is depleted at a rate slower than the rate at which it regenerates. A resource must have a way of regenerating itself in order to qualify as renewable.
<br>
<br>Renewable resources include oxygen, fresh water, solar, timber and biomass. However they can become non-renewable if used at a greater rate that the environment's capacity to replenish them. For example ground water may be removed from an aquifer at a greater rate than the sustainable recharge. Removal of water from the pore spaces may cause permanent compaction (subsidence) that cannot be reversed.
<br>
<br>Renewable cock resources may also include commodities such as wood, paper and leather.
<br>
<br>Plastics, gasoline, coal, natural gas and other items produced from fossil fuels are nonrenewable because no mechanisms replenish them. The abiogenic petroleum origin theory may be such a mechanism but petroleum is currently being depleted at a rate far exceeding discoveries of fields which could qualify as abiogenic in origin.
<br>
<br>
<br>Production materials.
<br>
<br>Human society uses a huge range of non-renewable resources for producing tools, as well as toys. These include materials such as iron, copper, diamonds, and uranium. These resources exist in finite quantities. Once consumed they may not be replenished within the time-span of human history. In contrast, water supplies, timber, food crops, and similar resources can, if managed properly, provide a steady yield virtually forever; they are therefore replenishable or renewable resources. Inappropriate use of renewable resources can lead to their destruction, as for example the cutting down of rainforests, with secondary effects, such as the decrease in oxygen and the increase in carbon dioxide and the resulting greenhouse effect. Some renewable resources, such as wind or solar energy, are continuous; supply is largely independent of people's actions.
<br>
<br>Resource demand.
<br>
<br>Demands for resources made by rich n ations are causing concern that the present and future demands of industrial societies cannot be sustained for more than a century or two, and that this will be at the expense of the developing world and the global environment. Other authorities believe that new technologies will be developed, enabling resources that are now of little importance to replace those being used up.
<br> |
|
|
| |
|
| |
|
|
