An Experiment in Lowering my Carbon Footprint - Part 3

In my last post, I discussed the amount of CO₂ I prevented from being released into the atmosphere by increasing the thermostat setting in my house during the summer months in Dallas, Texas. I won't say it was a breeze to do; however, I am pleased by my results and by how much energy I saved.

In researching for my post, I discovered some interesting facts about US power consumption.

In 2007, the energy demand from the entire United States was 4.157 x 10¹² kWhrs; this includes energy used in transportation, utility electricity generation, residential and commercial and for industrial purposes. The total amount of energy demand for electricity generation was 2.5 X10¹² kWhrs. The types of fuel used to generate electricity in the US is provided below:

Breakdown of 2007 Energy Generation
Fuel Type	Energy Generated	Percent of Total
Coal	2.02 MWhrs	48.5%
Gas	0.9 MWhrs	21.2%
Nuclear	0.8 MWhrs	19.4%
All Other Sources	0.44 MWhrs	10.52%

Other sources of energy include that derived from solar, wind, biomass, hydroelectric among others.

The total amount of CO₂ released in 2007 from all sources was 2.5M metric tons (tonnes) or 2.7M tons. The largest contributor to this is from the generation of electricity and burning coal releases more CO₂ than oil or natural gas.

President Obama while attending the UN Climate Summit in Copenhagen, Denmark proposed a target reduction in US greenhouse gas emissions by 17% below 2005 levels by 2020. In order to maintain a somewhat pleasant lifestyle, I'll have to find additional ways in which to reduce my carbon footprint as I won't maintain the thermostat setting I used in my summer experiment in future summers.

In future posts, I'll share my thoughts on some of the ideas I came up with to lower my carbon footprint. I'm also going to start tracking my monthly energy consumption to see how effective my actions are and I'll share them periodically.

So why is reducing CO₂ in the atmosphere such a big deal? For most of pre-industrial humanity, the level of CO₂ in the atmosphere was approximately 275 parts per million (ppm); this is a ratio of the number of CO₂ molecules to all other molecules in the atmosphere. As we started to burn coal and oil to create energy, the amount of CO₂ in the atmosphere started to rise. Scientists have estimated the amount of CO₂ currently in the atmosphere to be 390 ppm and rising roughly 2 ppm per year. They have also stated that we need to curtail our activities and bring the number to a sustainable 350 ppm.

Most of the sunlight emitted from the sun is in wavelengths shorter than 4 μm, which pass through the atmosphere and gets either absorbed or reflected by the earth. When reflected from the earth, the wavelengths are stretched longer than 4 μm and the heat energy gets absorbed by the CO₂ molecules in the atmosphere. When a molecule of CO₂ absorbs heat energy, it goes into an excited and unstable state; to become stable again, it releases this energy. Some of the heat energy will fall back to the earth and some gets released into space.

If the amount of CO₂ in the atmosphere increases, the amount of reflected heat energy increases, which results in temperature increases. This is called the greenhouse effect and is similar to sunlight warming the interior of a car that has all its windows closed.

There are many things being done to combat this starting from greater use of renewable energy to generate electricity; higher gas mileage for cars; energy efficiency initiatives to name just a few. There are many initiatives being implemented at the local, state and national levels by many countries. I believe if we all work together, we can have combat climate change and at the same time intelligently meet our energy needs going forward.