Wednesday, June 4, 2008

CAUSES OF GLOBAL WARMING



What causes global warming?
Many things cause global warming. One thing that causes global warming is electrical pollution. Electricity causes pollution in many ways, some worse than others. In most cases, fossil fuels are burned to create electricity. Fossil fuels are made of dead plants and animals. Some examples of fossil fuels are oil and petroleum. Many pollutants (chemicals that pollute the air, water, and land) are sent into the air when fossil fuels are burned. Some of these chemicals are called greenhouse gasses.
We use these sources of energy much more than the sources that give off less pollution. Petroleum, one of the sources of energy, is used a lot. It is used for transportation, making electricity, and making many other things. Although this source of energy gives off a lot of pollution, it is used for 38% of the United States’ energy.
Some other examples of using energy and polluting the air are:
Turning on a light
Watching T.V.
Listening to a stereo
Washing or drying clothes
Using a hair dryer
Riding in a car
Heating a meal in the microwave
Using an air conditioner
Playing a video game
Using a dish washer
When you do these things, you are causing more greenhouse gasses to be sent into the air. Greenhouse gasses are sent into the air because creating the electricity you use to do these things causes pollution. If you think of how many times a day you do these things, it’s a lot. You even have to add in how many other people do these things! That turns out to be a lot of pollutants going into the air a day because of people like us using electricity. The least amount of electricity you use, the better.
When we throw our garbage away, the garbage goes to landfills. Landfills are those big hills that you go by on an expressway that stink. They are full of garbage. The garbage is then sometimes burned. This sends an enormous amount of greenhouse gasses into the air and makes global warming worse.
Another thing that makes global warming worse is when people cut down trees. Trees and other plants collect carbon dioxide (CO2), which is a greenhouse gas.
Carbon dioxide is the air that our body lets out when we breathe. With fewer trees, it is harder for people to breathe because there is more CO2 in the air, and we don’t breathe CO2, we breathe oxygen. Plants collect the CO2 that we breathe out, and they give back oxygen that we breathe in. With less trees and other plants, such as algae, there is less air for us, and more greenhouse gases are sent into the air. This means that it is very important to protect our trees to stop the greenhouse effect, and also so we can breathe and live.
This gas, CO2, collects light and heat (radiant energy), produced by the sun, and this makes the earth warmer. The heat and light from the sun is produced in the center of the sun. (The sun has layers just like the earth.)






Increment of the greenhouse gases.

Human activity has been increasing the concentration of greenhouse gases in the atmosphere (mostly carbon dioxide from combustion of coal, oil, and gas; plus a few other trace gases). There is no scientific debate on this point. Pre-industrial levels of carbon dioxide (prior to the start of the Industrial Revolution) were about 280 parts per million by volume (ppmv), and current levels are greater than 380 ppmv and increasing at a rate of 1.9 ppm yr-1 since 2000. The global concentration of CO2 in our atmosphere today far exceeds the natural range over the last 650,000 years of 180 to 300 ppmv. According to the IPCC Special Report on Emission Scenarios (SRES), by the end of the 21st century, we could expect to see carbon dioxide concentrations of anywhere from 490 to 1260 ppm (75-350% above the pre-industrial concentration).



FOREST DESTRUCTION CREATS MORE HEAT:
Trees play a unique role in the global carbon cycle. They are the largest land-based natural mechanism for removing CO2 from the air. (CO2 is also removed by the oceans and ocean organisms.)
Trees are able to store a large amount of CO2 in their structures. An acre of forest will absorb about 10 times the CO2 amount absorbed by an acre of crop land or grassland. One tree absorbs about 13 pounds of CO2 per year, and each one acre of forest absorbs about 2.8 tons of CO2. However, when trees are burned, the carbon locked in the structure is released into the air in the form of CO2. Today, the shrinking world forests are not able to absorb all the CO2 created by human beings while burning fossil fuels. Everyday over 5500 acres of rain forest are destroyed, and over 50 million acres are destroyed every year. Global CO2 levels rise approximately 0.4 percent each year, to levels not experienced on this planet for millions of years. Planting more trees and reducing timber cuts world-wide will help restore the imbalance, and perhaps buy time as ways are found to reduce world greenhouse gas emissions.



POPULATION GROWTH CONTRIBUTES TO GLOBAL WARMING.
The intellectual powers that we enjoy has enabled us to make effective use of technology and thereby changed the environment. Technology is partly responsible for explosive population growth and responsible for the resulting damage to Earth's resources. The industrial revolution caused a rapid increase in the Population growth, as oil and gas fuels were exploited for our use. There is a clear link between the problems of global warming and overpopulation, as increases in CO2 levels follows growth in population. Presently, we have too many people on Earth, who are using technologies that are destructive for the Earth. We cannot continue to grow, and make use of limited natural resources.

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