Greenhouse gases and society

Greenhouse Gases and Society
by Nick Hopwood and Jordan Cohen 
    Greenhouse gases naturally blanket the Earth and keep it about 33 degrees Celsius warmer than it would be without these gases in the atmosphere.  This is called the �Greenhouse Effect�.  Over the past century, the Earth has increased in temperature by about .5 degrees Celsius and many scientists believe this is because of anincrease in concentration of  the main greenhouse gases:  carbon dioxide, methane, nitrous oxide, and fluorocarbons.  People are now calling this climate change over the past century the beginning of �Global Warming.�  Fears are that if people keep producing such gases at increasing rates, the results will be negative in nature, such as more severe floods and droughts, increasing prevalence ofinsects,  sea levels rising, and Earth's precipitation may be redistributed.  These changes to the environment will most likely  cause negative effects on society, such as lower health and decreasing  economic development.  However, some scientists argue that the global warming we are experiencing now is a natural phenomenon, and is part of Earth's natural cycle.  Presently, nobody can prove if eithertheory is correct, but one thing is certain; the world has been emitting greenhouse gases at extremely high rates and has shown only small signs of reducing emissions until the last few years.  After the 1997 Kyoto Protocol, the world has finally taken the first step in reducing emissions.

The Greenhouse Effect
    The "greenhouse effect" is the heating of the Earth due to the presence of greenhousegases.  It is named this way because of a similar effect produced by the glass panes of a greenhouse.  Shorter-wavelength solar radiation from the sun passes through Earth's atmosphere, then is absorbed by the surface of the Earth, causing it to warm.  Part of the absorbed energy is then reradiated back to the atmosphere as long wave infared radiation.  Little of this long wave radiation escapesback into space;   the radiation cannot pass through the greenhouse gases in the atmosphere. The greenhouse gases selectively transmit the infared waves, trapping some and allowing some to pass through into space. The greenhouse gases absorb these waves and reemits the waves downward, causing the lower atmosphere to warm.(www.eb.com:180)

Diagram to help explain the process of global warming andhow greenhouse gases create the "greenhouse effect"
www.eecs.umich.edu/mathscience/funexperiments/agesubject/lessons/images/diagrampage.html

Greenhouse Gases

This graph shows the distribution of GHG in Earth's atmosphere. Carbon Dioxide is clearly the majority.
www.abcnews.com/sections/us/global106.html
 
Carbon Dioxide
       Carbon Dioxide (CO2) is a colorless, odorless non-flammable gas andis the most prominent Greenhouse gas in Earth's atmosphere.  It is recycled through the atmosphere by the process photosynthesis, which makes human life possible. Photosynthesis is the process of green plants and other organisms transforming light energy into chemical energy.  Light Energy is trapped and used to convert carbon dioxide, water, and other minerals into oxygen and energy rich organiccompounds.  (Encyclopaedia Britannica Volume 25)    Carbon Dioxide is emitted into the air as  humans exhale,  burn  fossil fuels for energy, and deforest the planet.  Every year humans add over 30 billion tons of carbon dioxide in the atmosphere by these processes, and it is up thirty percent since 1750 (www.envirolink.org/orgs/edf/sitemap.html).    An isolated test at Mauna Loa in Hawaii revealedmore than a 12% (316 ppm in 1959 to 360 ppm in 1996) increase in mean annual concentration of carbon dioxide. Mauna Loa, located in Hawaii,  is the worlds largest volcano at 40,000 cubic km and 4,170 meters above sea level.  (Encyclopedia Britannica Volume 27) .  Ice core samples have also shown a dramatic increase in carbon dioxide levels.  Drilling deep into glaciers and polar ice caps and...