Greenhouse Effect The Greenhouse Effect is a term for the role the atmosphere plays in warming the earth s surface. Infrared rays are trapped by the earth s atmosphere, keeping the earth warm and habitable. Acting as a pane of glass, methane, carbon dioxide, nitrogen oxide and CFCs trap the heat in. As infrared radiation travels through the atmosphere, much of it is absorbed by atmospheric gases such as carbon dioxide, methane, nitrous oxide, and water vapor. These gases then re-emit infrared radiation, some of it striking the earth. Other gases such as nitrogen oxide and man made gases called fluorocarbons get caught in the atmosphere as well.
The absorption of infrared energy by the earth and the atmosphere maintains a temperature range on earth that is hospitable to life. Without the greenhouse effect the earth would be a frozen planet with an average temperature of 0 F and -18 C. The amount of carbon dioxide in the atmosphere, in the last hundred years, has increased 28% and could rise by more than 40% in the next hundred years. Nitrogen oxide is the key element of smog. The EPA has required 22 states to reduce local levels of nitrogen oxide. The compound, produced by power plants, cars, and other sources, contributes significantly to the formation of ground level ozone.
This affects us locally in Maine especially during the summer. Maine is seeking to strengthen the pollution controls in neighboring states. According to the EPA, New Hampshire has three of the dirtiest power plants in the East. Emissions from Massachusetts and New Hampshire are probably the most important in determining whether Maine has clean air. States should meet the EPA pollution caps for nitrogen oxide by using tighter controls on electric power plant smokestacks, but each state will have to decide how to achieve the emission reductions. A number of international efforts have been initiated to decrease greenhouse-ga emissions.
The most recent effort occurred in 1997, when representatives from 160 countries met in Kyoto, Japan to negotiate an agreement to reduce worldwide emissions of greenhouse gases. This agreement is known as the Kyoto Protocol. It obligates 38 industrialized nations to reduce emissions of six greenhouse gases. Specifically, by 2012, emissions must be an average of about 5% below the level the 1990 emissions. The United States, which is responsible for about 20% of the global emissions, pledged to reduce its emissions to 7% below 1990 levels, while the European Union pledged to reduce it s emissions to 8% below 1990 levels. One hundred million years ago the Cretaceous was the warmest period we have knowledge of.
There was so much carbon dioxide in the air that the oceans rose many feet. North America was flooded and split apart into two pieces. The temperature then was more than 15 greater than the average temperature today. The global temperature has been increasing steadily, but slowly.
Since 1980 the temperature has risen 0. 4 F and 0. 2 C. Scientists predict that if the same amount of gas is put into the atmosphere by the year 2030, the temperature will be rising as much 0. 9 F and 0. 5 C or more per decade.
Some scientists attribute the rise to natural fluctuations in the level of carbon dioxide; others attribute it to the burning of fossil fuels, such as oil, gas and coal. The slash and burn clearing of tropical forests may also be a contributing factor. Overall, the global temperature could rise anywhere from 5-9 degrees in the next 50 years. This warming increase would alter climates throughout the world, affect crop production, and cause sea levels to rise significantly.
If this happens, millions of people will be adversely affected by major flooding. With the melting of polar icecaps, the sea level will rise 1-3 feet resulting in flooding of small islands, shallow rivers and coastal cities. The Everglades in Florida would be almost, if not totally, wiped off the map. The animal life there would have to move northward across very dry land, which they would not be able to endure for long.
With the hot temperatures spreading northward and southward, tropical disease will spread with it. Diseases that were originally in Mexico will perhaps occur in the Carolinas or Vermont. These new diseases will be difficult to deal, causing many more deaths and illnesses than before. The flooding will result in the construction of more dams; cities to be rebuilt and the shortage of food will cause prices to go up.
Financially, the greenhouse effect is very serious. The Topex satellite has been collecting information on the changes of temperatures across the globe, sea levels, and the amount of gases emitted into the atmosphere. Everyday the satellite makes 500, 000 measurements, each at a different place on earth. Measurements are all made between 66 N and S latitudes. Scientists believe that the tilt of the earth s axis changes to tilt the opposite way in a ten -thousand year cycle. While going through this cycle it will change the climate of areas.
Right now, it is moving in a pattern that the sun will be close to North America during the winter. Seasons become more extreme when the opposite happens. This controls the cycle of ice ages. When volcanoes erupt they send clouds of dust into the air, blocking sunlight and causing the earth to cool off more.
Oceans are known to absorb CO because of the ocean currents and the action of plankton. There is some evidence that there is naturally rapid climate change between the Ice Age, which confuses the whole global warming and idea. As detrimental as the greenhouse effect may seem, life depends on it. Mars has a very thin atmosphere with a weak greenhouse effect.
Its surface is much colder than the Earth; in fact it is frozen. Venus has an intense greenhouse effect. Its atmosphere is thick with carbon dioxide and other gases that trap the heat. Venus surface is much hotter than the Earth s hot enough to melt lead. Without our greenhouse effect, the Earth s heat would be lost directly into outer space and life on Earth, as we know it, would end.