Global Warming
Global Warming is thought to be caused by the Greenhouse effect, a buildup of CO2 (carbon dioxide) in the atmosphere that holds heat close to the earth. Ultimately, the heat causes changes in temperatures and weather patterns. While part of the cause of global warming can be attributed to the buildup of CO2, this simplistic explanation certainly is not the whole story. Our automobiles and other vehicles release carbon dioxide which holds heat in the atmosphere and all living animals and bacteria release CO2 during respiration, so the atmospheric buildup of CO2 arises as a result of automobile emissions and animal respiration. By contrast, plants consume CO2 during respiration and release oxygen that animals breath in, so the Greenhouse effect is actually the result of a distortion of the cycle of CO2 and O2 (molecular oxygen) in the atmosphere.
A look at our worldwide deforestation reveals that in the Amazon alone, each year we are losing an area of forestation the size of the state of Massachusetts. Not only is this causing a greater buildup of CO2 in the atmosphere, but it is dramatically altering our global rainfall and weather patterns. Perhaps 25 to 35 percent of the earth’s rainfall occurs over or arises from the Amazon. While we are losing this much tropical forest each year in the Amazon alone, we are certainly losing at least that much or more each year throughout the world due to urban expansion and sprawl, and this dramatically alters the cycle of CO2 and O2 in the atmosphere. Increasing the atmosphere CO2 level increases plant growth, but as we eliminate plants (trees in particular), there are fewer plants to grow faster in response to the increased levels of CO2 in the atmosphere.
Carbon dioxide arises from combustion, fermentation and breathing and is consumed by plants. In plants photosynthesis gives rise to O2 whereas in animals the Krebs Cycle gives rise to CO2. Thus, planting more trees, slowing urban sprawl and reducing combustion that arises from auto emissions are three steps that can combine to reduce atmospheric CO2. Two of these processes involve either planting trees or slowing deforestation. These steps should reduce CO2 levels by altering the CO2 –O2 cycle.
Reference
Krogh, David Krogh (2004). Biology: A Guide to the Natural World, 3 edition. New Boston, MA: Addison-Wesley.
