The atmosphere is something that is around us everyday, but do we really think about the changes that occur in it. It isn't that we just aren't paying attention, but more of the fact that it is hard to notice slight changes over long periods of time. Everyday gases are released into the air by all living material. The gases in the air are used for many important things. For example, hydrogen is released by volcanoes, which can give energy to the cell; photosynthesis has evolved to take the gas carbon dioxide and create food and release oxygen; nitrogen is a gas used in our air, oceans, and solid earth, as an essential part of living things. Carbon dioxide is also involved in processes wh ...view middle of the document...
The greenhouse gases are carbon dioxide, methane, oxygen, nitrogen, ozone and water vapor, as well as other atmospheric gases. These greenhouse gases cause the greenhouse effect by capturing and absorbing solar energy. For without the greenhouse effect, the planet would be inhospitable to life because the surface temperature of earth's surface would be cooler by 63 degrees F (Roleff 12). This world mean the average temperature would be 19 degrees C which causes the earth to be barren (Bilger 23).Many scientists believe that the increase in temperature is caused by humans. The greenhouse effect increases because of the burning of fossil fuels such as natural gases, oil, and coal. These cause more heat to be trapped in the atmosphere than needed. Carbon dioxide is the most important gas that humans have affected. It has increased by nearly 30% since 1700 because of human destruction's (Roleff 18). The amount of fossil fuels we burn each year has increased dramatically. Between 1850 and 1950 60 million tons of fossil fuels were burned. Now the world burns at least five billion tons of fossil fuels each year. This means that we are adding between 15 and 20 billion tons of carbon dioxide into the atmosphere every 12 months (Firor 50). This is causing a steady increase of carbon dioxide into our air.Another way humans increase the amount of carbon dioxide is by deforestation. Huge numbers of trees are cut down each year to clear land for farming and building. The rain forest are really needed because they absorb carbon dioxide and release oxygen into our atmosphere. Also, when trees decay or are burned, the carbon dioxide that was absorbed is put back into the air. George M. Woodwell and KilapartiRamakrishan said, "Deforestation is the second biggest source of carbon dioxide, . . . only the burning of oil, coal, and gas produce more, . . . If [global warming] is to be slowed, the world must not only stop cutting and burning large forests, but replace the many millions of acres that have been destroyed." (Roleff 13). Deforestation is most severe in the tropical regions where the rain forests grow. Most of the rain forests are around developing countries. The people of these countries have to find a way to get land, buy food, and get money. The only way they know how is to go into these forests and clear land to create more space for farms.More recently, the amount of rain forests destroyed each year is causing attention. Thirty-three acres of rain forest are chopped or burned down every minute, and up to 25% of the world's species will be extinct by the next century (Bilger 36). The great plains that we have now were once one enormous forest before the Europeans settled. It is said that if deforestation continues at its current rate, all of the world's forests could be destroyed within only a few decades. It is very important that we stop destroying our forests and replant what has been destroyed.Another cause of global warming is El Nino. F...