Greenhouse Gas Emissions

A guy I met at work told me that according to some source greenhouse gas emissions from automobiles were negligible compared to other sources. According to this executive summary of a report by the EPA, that is not the case. The report measures greenhouse gas sources and sinks and gives an equivalent to trillions of grams of carbon dioxide.

The total was 6,639.7 for the U.S. as of 2009, but since the forests are expanding we have a sink of 1015.1 and a net value of 5624.6. By far the largest source of emissions is fossil fuel combustion, which makes up about 83% of all greenhouse gas emissions. Chief among the sources of emissions is carbon dioxide, and the chief source of that would be the use of fossil fuels. Transportation was second only to electricity generation as a source of emissions. These two made up about 26% and 32% of total greenhouse gas emissions respectively. Industrial emissions make up about 11%. Residential and commercial uses make up 5% and 3% respectively.