Greenhouse Gases and their Effects: Full Original Essay:- LINK
Earth’s atmospheric GHG constituents are: Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), and Flourocarbons (typically chlorofluorocarbons (CFCs), and hydrofluorocarbons (HFCs)). This paper focuses mainly on CO2, the largest contributor (See Fig1).
Not long ago physicists discovered a simple equation regarding incoming power (light waves) from the Sun: Power in = power out.(iii) Earth is in a radiation power balance with the Sun. Power comes in from the sun, some energy is stored in Earth’s surface and atmosphere, and then infrared radiation (IR) radiates out to space. When Earth’s atmosphere is devoid of GHGs, there is good drainage of power-out from the Earth. But when GHGs are added, it restricts power from exiting; thereby building pressure and temperature until power-out equals the incoming power (See Fig2).
If GHGs failed to exist in Earth’s atmosphere Earth’s surface temperature would be colder than temperatures during an ice age. With roughly 200 parts per million (ppm) of CO2 in the atmosphere, Earth’s temperature would roughly be freezing (350F). Clearly, we need GHGs in the atmosphere to sustain our life on Earth, but excessive GHG saturation generates negative effects. From the Industrial Revolution until the end of the 20th century CO2 in the atmosphere increased by 30%, likely because of humans. Humans contribute to CO2 when they burn fossil fuels for: heating their homes, driving their cars, turning on lights, manufacturing goods, and transporting those goods. If CO2 production keeps apace, the average global temperature could increase 10.4° F, by the end of the 21st century.(iv) An increase in temperature holds potential consequences for forests, such as slower tree growth. According to Stan Wullschleger, “…a tree may experience reduced growth because of an inadequate supply of nutrients. Also, because leaf pores tend to close under drought conditions to hold in what little water the tree has, the tree’s uptake of photosynthetic CO2 will be reduced, further slowing its growth.” (v) Reducing a tree’s CO2 intake will force humans to find another means by which to covert CO2 into oxygen (see Fig3 for a causal loop diagram showing the relationship between CO2 and forests).
Fossil fuels, rich in carbon because they are primarily made up of decayed plants from millions of years ago, combine carbon with oxygen to form CO2, when they are burned. (vi) The process of deforestation results in fewer plants available to convert CO2. The problem of CO2 production rate, therefore, begins to grow exponentially because as deforestation adds to the total CO2 in the atmosphere, simultaneously the only known CO2-converter is depleted. Once in Earth’s atmosphere CO2 contributes to the greenhouse effect for fifty to two hundred years. Understanding this relationship between CO2 and forests is of great importance because it is estimated that deforestation is responsible for 25% of global CO2 emissions. ii If humans can significantly reduce deforestation, then the resulting greenhouse effect can plausibly be manipulated before irreversible damage occurs.
One obvious option may jump out: plant MORE forests and green plants to offset any greenhouse effect resulting from humankinds’ addiction to fossil fuels. Unfortunately soil erosion and urbanizations prevent reclaiming land to use for planting forests. According to EarthTrends.com, the original amount of forest area in the U.S. as a percentage of total land area was: 53.5%; as of 1996 the current amount of forest area in the U.S. as a percentage of the original amount is 60.2%. This means in roughly 200 years the U.S. wiped out 40% of its forests.(vii) To give you an idea of the amount of forest destroyed, the U.S. (50 states and D.C.) is 9,161,923 square miles (sq/mi) of land; 53% (4,855,819 sq/mi) originally was forest. Today, however, remains 2,913,491.5 sq/mi of forest.