All too often, when one hears the term “global warming” they envision the disastrous manipulation of global climate by the human race, or some far-fetched hoax invented by wild environmentalists. Global warming is a real and very natural environmental phenomenon that has occurred on our planet for billions of years. Global warming is frequently and falsely used to describe the relatively rapid “global climate change” occurring on Earth when it in fact refers to a specific process known as the “Green House Effect.” In this day and age, considering recent concerns over the rapid and unnerving changes in global climate, every human being should understand exactly what the term global warming really means and the specific, environmental process that influences it.
The green house effect is a process that regulates temperature on the surface of the planet, keeping it warm enough for life to survive. What many people don’t realize is that global warming is crucial to the existence of life on Earth and without it, our planet would be a ball of ice with an average temperature of -18 °C rather than the current 15 °C. The green house effect occurs in the Earth’s atmosphere where various gas molecules, some of which are known as “Green House Gases” (GHG), float around freely. These GHG molecules are special because of their ability to capture and hold heat, which influences and maintains temperature on the Earth’s surface. Carbon dioxide, Water Vapor, Methane, and Nitrous Oxide are all GHGs that have this unique ability. Some of the GHG are more powerful than others in that they are able to trap greater amounts of heat.
Here is a very basic, step-by-step description of the Greenhouse Effect:
- The sun radiates energy, two thirds of which are absorbed by the Earth’s surface and atmosphere while the other third is reflected back into space.
- In order to maintain a balance of energy, most of what was absorbed by the Earth’s surface is reradiated back into the atmosphere in the form of infrared radiation (heat)
- GHG molecules absorb this reradiated heat, keeping it trapped in the atmosphere, warming the planet and contributing to global warming [iv].
The amount of GHG molecules in the atmosphere will affect the amount of heat being [v] trapped, therefore altering the temperature on Earth. GHG is naturally added to the atmosphere mainly through volcanic eruptions, variations in solar luminosity, evaporation of water, and the excretions and exhalation of animals (humans included). GHG is naturally removed from the atmosphere and contained by what is referred to as a GHG “sink.” The major sinks on Earth include forests, which absorb GHG throughout the process of photosynthesis, and oceans, which absorb GHG throughout the process of ocean acidification [vi].
Humans intensify global warming by adding to the greenhouse effect mainly through farming and burning of fossil fuels. If a farming operation is livestock based, managing a large group of animals demands lots of fossil fuel to generate energy and produces a tremendous amount of GHG-heavy waste. Farming rice paddies in particular generates a tremendous amount of the GHG methane because methane is natural byproduct of the rice plant [vii][viii]. The largest amount of GHG is fed into the atmosphere through the combustion (burning) of fossil fuels in order to generate electricity and fuel transportation. The gasoline you pump into your car has the phenomenal ability to produce energy however as it fuels your engine, large quantities of the GHG carbon dioxide are released through your tailpipe which then float up into the atmosphere and hang there, waiting to capture more heat. Prior to the 20th century, average global temperature maintained a stable fluctuation, never varying more than 0.4 °C. Since the early 1920s, after the height of the industrial revolution when the use of fossil fuels like coal and petroleum were on the rise, global temperature increased steadily to be 0.4 °C higher than the pre-20th century average [ix].
Currently we lack any human induced direct removal of GHG from the atmosphere yet we continue to tamper with the natural systems that remove it naturally. Deforestation, particularly that of the rainforest, contributes directly to an increase in atmospheric GHG and in turn, global climate change because the vegetation is no longer there to absorb the GHG [x]. There have been numerous attempts world-wide to regulate humanity’s excessive contribution to global warming and the greenhouse effect, including the drafting of the Kyoto Protocol, the Copenhagen Accord and the Inter-Governmental Panel on Climate Change. Many countries including the United States and China are hesitant to commit to certain regulations that would require them to limit their GHG emissions because it would have a direct and negative impact on their ability to produce and export commercial goods.
Global warming is real and it is normal, but human behavior has caused it to intensify. At this rate, scientists hypothesize severe consequences [xi] including a dramatic rise in sea level and tremendous biodiversity loss. Diminishing humanity’s contributions to the greenhouse effect will require dramatic changes in the way we conduct ourselves, along with significant government involvement to regulate these changes. Still, there is no way of knowing exactly what the consequences of an intensified greenhouse effect on our planet will be and whether the world’s governments will truly rise to the challenge. Either we will just sit back and wait to see what comes of global warming, or we can start making some serious changes to quell it.
For more information regarding the efforts to slow global climate change, please consult the following:
[i] 2012. The Greenhouse Effect. National Geographic. Retrieved Electronically June 15th 2012 <http://environment.nationalgeographic.com/environment/global-warming/gw-overview-interactive/>
[ii] Mitchell, J.F.B The “Green House Effect” and Climate Change. American Geophysical Union. Reviews of Geophysics 27 116-122, 1989
[iii] Jacob, Daniel J. Introduction to Atmospheric Chemistry. Chapter 7: The Greenhouse Effect Princeton, NJ: Princeton UP, 1999. Retrieved Electronically June 15th, 2012 <http://acmg.seas.harvard.edu/people/faculty/djj/book/bookchap7.html>
[iv] IPCC Fourth Assessment Report: Climate Change 2007. What is the Greenhouse Effect? Retrieved Electronically June 15th, 2012 <http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-1-3.html>
[vi] Environmental Literacy Council 2008. Sources and Sinks. Retrieved Electronically June 15th, 2012 http://www.enviroliteracy.org/article.php/439.html
[vii] Graham, Sarah. Rice Paddy Methane Emissions Depend on Crops’ Success. Scientific American. 2002. Retrieved Electronically June 15th, 2012 <http://www.scientificamerican.com/article.cfm?id=rice-paddy-methane-emissi>
[ix] Le Treut, H., R. Somerville, U. Cubasch, Y. Ding, C. Mauritzen, A. Mokssit, T. Peterson and M. Prather, 2007: Historical Overview ofClimate Change. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
[x] Yadvinder Malhi, J. Timmons Roberts,Richard A. Betts, Timothy J. Killeen, Wenhong Li, and Carlos A. Nobre Climate Change, Deforestation, and the Fate of the Amazon. Science 11 January 2008: 319 (5860), 169–172.Published online 29 November 2007 [DOI:10.1126/science.1146961]
[xi]Climate Change Synthesis Report: Summary for Policy Makers 2007. Retrieved Electronically June 15th, 2012 <http://timeforchange.org/effects-of-global-warming-by-region-ipcc-2007>