| Source
Classification | Tons of Carbon Monoxide emissions |
|---|
|
| Highway Vehicles - Gasoline
|
47,759,311 |
| Off-highway Vehicle Gasoline, 4-Stroke
|
16,957,102 |
| Off-highway Vehicle Gasoline, 2-Stroke
|
2,506,211 |
| Pleasure Craft
|
2,254,474 |
| Highway Vehicles - Diesel
|
2,230,128 |
| Off-highway Vehicle Diesel
|
1,291,807 |
| Aircraft
|
1,001,978 |
| LPG
|
772,763 |
| Marine Vessels, Commercial
|
138,064 |
| Railroad Equipment
|
128,968 |
| CNG
|
110,591 |
| Marine Vessels, Military
|
138 |
|
