PDS APES 8th Period 2009-10

*Note: This is a guest blog post by Coco in 5th period since I forgot to name a scribe.

Last Friday, we discussed the origins of global warming. However, climate change is a more accurate term since some regions are cooling, not warming.

First off, it must be established that not all greenhouse gases, like water vapor, CO2, CH4 and N2O are “bad.” In fact, without the natural greenhouse effect earth would be very cold, thus uninhabitable, but the natural greenhouse effect makes the Earth warm enough to sustain life. Essentially, when solar radiation reaches Earth’s surface, some is absorbed by land and water, but a good portion is reflect as infrared radiation. Greenhouse gases trap IR, causing warming in the troposphere. Take a look at this diagram:

http://www.ncrlc.com/01-GCC_imgs/figure03.jpg

However, there are several anthropogenic, or human-caused increases in greenhouse gases, such as fossil fuel use, deforestation, and agriculture. This “unnatural greenhouse effect” contributes to global warming, whose effects include but aren’t limited to an increase in average temp, glacier retreats, and severe weather events like hurricanes due to higher ocean temps. However, global warming gets political when people feel forced to relinquish their Hummers on the bases of hypothetical “what if” situations surrounding global warming, such as rising sea levels and their resulting population shifts. So when did all the hype about anthropogenic causes of climate change begin?

Origins of Climate Change:

It’s important to note that Al Gore didn’t invent “Global Warming.” In reality, research on the relationship between increased CO2 levels from the Industrial Revolution and higher temperatures began in 1896 by chemist Svante A. Arrhenius. For more on the history of climate change research, see http://www.npr.org/templates/story/story.php?storyId=10307560.

One important chemist, Charles Keeling, is known for his study of temperature and CO2. His results yielded the Keeling Curve, which “launched the current debate over what to do about rising greenhouse gas levels.”

http://sio.ucsd.edu/keeling/images/Keeling_Curve.jpg

Today, research illustrates with near certainty that average temperatures in the troposphere are increasing. But as for the debate over whether climate change exceeds the natural cycle of warming and cooling, or if human activity is causing climate change, many argue that more research is needed before any decisive conclusions are formed. As with all scientific questions, the question of why the Earth is warming falls somewhere on the spectrum of certainty. In order of least to greatest certainty are: hypothesis, theory, and finally law. With increased data and observation, a hypothesis can either be supported or refuted.