Energy and Environment

Consequences of transportation for the human and natural environment (chapter 2, section E)

• Highway vehicles emitted 82% of all transportation carbon dioxide emissions in 2005. [E-2]
• Transportation emitted 54% of the nation's pollution from carbon monoxide, 36% of nitrogen oxides, 22% of volatile organic compounds, and 1.4% of sulfur dioxide in 2006. All of these emissions have declined in the last decade despite a rise in vehicle-miles of travel. [E-3]