Sources of Ozone Projected in 2017
Due to the dramatic reduction in smog-forming emissions from motor vehicles over several decades, as of 2017 on-road mobile sources contribute just 6.5% of all ozone precursors, down from almost 30% in 1970.
Number 1
By 2025, smog-forming emissions of hydrocarbons and nitrogen oxides from passenger vehicles will have dropped 99.8% since emissions controls began.
Number 2
To place these reductions in context, automakers have reduced ozone faster than other man-made sources have reduced their emissions. On-road vehicles are projected to reduce hydrocarbons by about 96% by 2030, compared to reductions of about 63% from all man-made U.S. sources.
Number 3
Average contributions to U.S. smog-forming emissions
Number 4
Sources of Ozone Projected in 2030
By 2030 more progress will occur, with motor vehicles expected to contribute only 3.3% of all smog-forming emissions.
Average contributions to U.S. smog-forming emissions
Number 5
If only passenger vehicles are considered (not including medium and heavy trucks), their smog-forming emissions are even smaller. By 2030, passenger vehicles (cars and light trucks) are anticipated to contribute only 1.2% of all smog-forming emissions.
Source: Information on this page derived from U..S. EPA. 2013. MOVES (Motor Vehicle Emission Simulator)