[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2013/07/EW-07-09-13-Greenhouse-Gases.mp3|titles=EW 07-09-13 Greenhouse Gases]
Greenhouse gases are responsible for our planet having the mild temperatures that make life as we know it possible. The most important ones – water vapor and carbon dioxide – have historic stable levels that are a result of a fine balance among various environmental processes on land and sea.
The dramatic rise in carbon dioxide levels seen over the last 150 years is widely attributed to human activities, foremost of which is the burning of fossil fuels. But which human activities contribute the most to greenhouse gas emissions?
The Environmental Protection Agency compiles data on this topic for the United States. In this country, generating electricity is the biggest culprit, accounting for a third of all emissions. Following close behind is transportation, which produces 28% of the emissions. The third largest contributor is industry, whose consumption of fossil fuels results in 20% of greenhouse gas emissions. So these big three account for more than 80% of all emissions.
The remainder of the man-made greenhouse gases in the U.S. come from our homes and offices (at 11%) and from agriculture (at 8%). Agricultural greenhouse gases include methane from livestock and anaerobic fermentation, nitrous oxide from fertilizers, and carbon dioxide from decomposition of organic soils. On a global basis, with populations on the rise, greenhouse gas emissions from agriculture are rapidly increasing and are in fact catching up with those from transportation.
As we seek to gain control of surging greenhouse gas emissions, we cannot limit our attention to electricity and transportation. All aspects of our daily lives are part of the problem.
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Web Links
Sources of Greenhouse Gas Emissions
http://www.epa.gov/climatechange/ghgemissions/sources.html
Photo, taken on March 19, 2008, courtesy of Lingaraj GJ via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.