Related Sponsors

What Causes Global Warming?

Home » Adventure Travel » Global Warming » What Causes Global Warming?
Posted by Your Guide on October 11, 2006 5:44 AM

Global warming is a result of an increase in the greenhouse effect, which is what keeps the earth warm enough for life to survive. The earth absorbs 70% of the energy from the heat of the sun's rays, and the remaining 30% is reflected back out. The heat that is absorbed by the earth is eventually transferred into other objects that reflect the energy back out into space. However, not all of the energy reaches outer space. Some of it is blocked by things in the atmosphere, such as carbon dioxide, methane gas, and water vapor. When the energy is blocked, it is reflected back down to earth. Since more heat and energy are coming in than are going out, the earth's atmosphere remains warmer than it is in outer space. The greenhouse effect happens naturally, as a result of the substances that are naturally found in the atmosphere. However, since the Industrial Revolution, we have been putting more and more substances into the atmosphere, which causes more of the earth's radiated energy to be reflected back down to the earth.

Carbon dioxide is one such substance that blocks the radiated energy from outer space. Carbon dioxide is a colorless gas that is a by-product of the combustion of organic matter. The atmosphere naturally contains less than .04 percent of carbon dioxide. Most of this was put there as a result of volcanic activity. Unfortunately, today's human activities are also pumping significant amounts of carbon dioxide in to the atmosphere. So much so that the increase in carbon dioxide is considered one of the primary factors in global warming. Carbon dioxide absorbs infrared radiation, which makes up most of the earth's escaping energy, and more energy consumption by the atmosphere means an increase in the planet's temperature. According to the Worldwide emissions report, the carbon emissions worldwide increased from 1 billion tons in 1900 to about 7 billion tons in 1995.

Another important greenhouse gas is nitrous oxide. Although human activities are not releasing as much nitrous oxide as carbon dioxide, nitrous oxide absorbs about 270 times as much energy than carbon dioxide does. Nitrous oxide is released in part because of the large amounts of nitrogen fertilizer used on crops, and also because it too is a product of combustion. Methane gas is another substance important to the greenhouse effect. It occurs naturally as a result of the decomposition of organic material, but it is also produced by several man-made processes. Methane can be produced by extracting it from coal, from the digestive gases of large herds of livestock, from the bacteria in rice paddies, and from the decomposition of garbage in landfills.



Next Page: Is Global Warming Really a Problem?

Related Articles