Leon Zedillo ,
2007 , p . 22 . During the previous decade , industrial sector emissions ,
such as transportation , accounted for more or less one-third of overall
energy-related emissions of CO2 (U .S . Office of Energy Markets and End
Use , 2005 , p . 17 . In the United States , approximately 98 percent of
CO2 emissions are instigated by the burning of fossil fuels , and
automobiles are the second main source of these emissions , producing
roughly 1 .5 billion tons of CO2 per year (U .S . Office...