TRANSPORTATION ENERGY DATA BOOK: EDITION 22 - Center for ...

The transportation sector accounted for more than three-fourths of the nation’s carbon monoxide (CO)
emissions in 1999. Highway vehicles are by far the source of the greatest amount of CO. For details
on the highway emissions of CO, see Table 4.3.
Table 4.2
Total National Emissions of Carbon Monoxide, 1970–99 a
(million short tons)
Source category 1970 1980 1990 1995 1998 1999
Highway vehicles
Aircraft
Railroads
Vessels b
Other off-highway
88.03
0.51
0.07
0.02
11.38
78.05
0.74
0.10
0.06
13.59
58.44
0.90
0.12
0.13
17.04
a The sums of subcategories may not equal total due to rounding.
b Recreational marine vessels.
54.81
0.94
0.11
0.13
19.04
TRANSPORTATION ENERGY DATA BOOK: EDITION 22—2002
52.36
1.00
0.12
0.14
23.87
49.99
1.00
0.12
0.14
23.90
Percent
of total,
1999
51.3%
1.0%
0.1%
0.1%
24.5%
Transportation total 100.00 92.54 76.64 75.04 77.48 75.15 77.1%
Stationary fuel combustion total 4.63 7.30 5.51 5.93 5.08 5.32 5.5%
Industrial processes total 9.84 6.95 4.77 4.61 3.81 3.80 3.9%
Waste disposal and recycling total 7.06 2.30 1.08 1.19 1.14 3.79 3.9%
Miscellaneous total 7.91 8.34 11.12 7.30 9.36 9.38 9.6%
Total of all sources 129.44 117.43 99.12 94.06 96.87 97.44 100.0%
Source:
U. S. Environmental Protection Agency, National Emission Inventory Air Pollutant Emission Trends website
www.epa.gov/ttn/chief/trends (Additional resources: www.epa.gov/oar/oaqps)
Note:
Detailed data tabulations for 2000 have not yet been released. Look for the 2000 Air Quality Trends Report
on the EPA website: http://www.epa.gov/airtrends/reports.html.
Emission estimation methodology changes indicated by shaded areas. Transportation methodologies changed
in 1970, while all others changed in 1990.
4–3