Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportation's Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1
2-6
fuels, and the construction and maintenance of transportation infrastructure.
Collectively, emissions from these processes, many of which occur overseas,
increase the U.S. transportation share of global GHGs to about 7 to 8 percent. 33
Most of the domestically produced emissions are included in the industry sector
shown in Figure 2.2. However, providing a transportation life-cycle estimate
provides a broader perspective on the actual impact of transportation on GHGs.
A full discussion of transportation life-cycle emissions can be found in
Section 2.3.
Figure 2.2 U.S. Greenhouse Gas Emissions by End Use Economic Sector,
million metric tons CO2 equivalent
2006
Electric Power
Industry, 2,378,
34%
Industry, 1,372,
19%
Transportation,
2,098, 29%
Commercial,
395, 6%
Residential, 345,
5%
Agriculture, 534,
7%
Source: U.S. EPA (2008). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 to 2006.
When compared with transportation emissions from all countries in the world,
and total world emissions, GHG emissions from the U.S. transportation sector
are put into a global context. International Energy Agency (IEA) data for 2006
show that while the U.S. accounts for 5 percent of the world population, it
accounts for 21 percent of global CO2 emissions, with the U.S. transportation
33 This is based on the conclusion, as discussed in Section 2.3, that lifecycle emissions may
be on the order of 50 percent greater than direct transportation emissions alone.