Heat of Global Issue Rises

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By Ben Tambaschi, Staff Writer Hey, it’s a new Fall semester – another year almost over- and Earth is still getting warmer. On Sept. 23, the onlinejournal Science published research confirming sea level increases dueto Antarctic glacial melting. So, it’s time for me to trot out mybiannual “Global Warming 101” column.

Global warming is due to excessive accumulation of heat trapping(greenhouse) gases such as carbon dioxide, nitrous oxide and methanein Earth’s atmosphere. The volume of these gases, which occurnaturally in the atmosphere, has been greatly increased by emissionsfrom automobiles, factories and power plants in industrializednations.

Climate change poses many diverse threats to the biosphere. In itsGlobal Warming Web page (www.yosemite.epa.gov), our very ownEnvironmental Protection Agency posts predictions of: Increases insea level, changes in precipitation causing droughts and floods,altered forests and crop yields, decreased water supply anddetrimental effects on human health, animals and ecosystems.

In light of the Bush administration’s unwillingness to participatein world environmental protocol – defeat of greenhouse gasreducing legislation in Congress and general apathy toward globalclimate change on the part of politicians and civilians alike- it is more than ever the burden of the scientific communityto expose the threat looming over the world. Hard facts and solidevidence must be presented to those who are skeptical, and the costs- economic and human – must be made known to those whoare uninterested or ignorant.

Long term data collection, over years or even decades, is key tothe efficient and accurate study of greenhouse gases in theatmosphere. Hard evidence illustrates what the extrapolations of amathematical model based on a small amount of data cannot. Climatemodeling is subject to certain deficiencies and limitations, whichare often exploited and misused by critics of climate science tominimize and trivialize the impact of global warming. Because dailyclimate fluctuates, long-term study helps to minimize variability andgive a more accurate picture of significant climate trends. Thus,while modeling is useful in some regards, the importance ofwidespread, long-term data collection is of paramount importance.

San Diego State’s Global Change Research Group (GCRG) currentlymaintains several field stations that gather Carbon-flux data, whichrepresents the exchange of carbon dioxide between plants and theatmosphere. By the process of photosynthesis, plants absorbatmospheric carbon dioxide and fix carbon in the form of glucose.When plants respire (essentially, the reverse of photosynthesis),glucose is broken down and the plant releases carbon dioxide.Photosynthesis is greatest when the plant is subject to the mostphotons available from the sun. Midday is typically the time whenplants can fix the maximum amount of carbon, but it is also duringthe midday hours that the air temperature is at a maximum. Increasesin air temperature cause plants to close stomata (gated openings onthe undersides of the leaves) in an attempt to conserve moisture.When stomata are closed, gas exchange does not occur between theplant and the atmosphere, and thus, carbon is not absorbed by theplant. Carbon flux is dramatically affected when plants do not absorbatmospheric carbon during their peak times of photosyntheticactivity.

The data collected by organizations such as GCRG demonstrates atrend that, once induced, can be seen as self-perpetuating -increased carbon in the atmosphere creates higher air temperatures;higher air temperatures cause less carbon to be absorbed by plants,and in turn, yields even more carbon in the atmosphere.

Historically, plants have maintained a balance between the amountof carbon fixed by photosynthesis and carbon released by respiration.Simultaneously, plants have acted as sinks for carbon released byother organisms and the physical environment. With today’s excessesand continual increases of atmospheric carbon, it is likely thatEarth’s plants will not be able to process the burden laid upon them.If we hope to re-balance Earth’s carbon cycle that has been sodramatically altered in the last century, we must decrease industrialand automobile emissions of carbon dioxide. Furthermore, there needsto be a decrease in deforestation and the use of wood products,cleared ares need to be re-planted with species of vegetation thathave high capacities for sinking carbon.

We all need to conserve and spread the word. Get Involved. Checkout Dr. Walter Oechel’s Climate Change Research Group at www.sci.sdsu.edu/GCRG.

– Ben Tambaschi is a biology and religious studies senior.

– This column does not necessarily reflect the opinion of TheDaily Aztec. Send e-mail to letters@thedailyaztec.com.Anonymous letters will not be printed – include your full name, majorand year in school.