Abstract
Over the past 30–40 years, vehicle tailpipe emissions of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HCs) have decreased significantly. Advanced emission after-treatment technologies have been developed for gasoline and diesel vehicles to meet increasingly stringent regulations, yielding absolute emission reductions from the fleet despite increased vehicle travel. As a result of mobile and stationary source emission controls, air quality has generally improved substantially in cities across the US and Europe. Emission regulations (such as Tier 3 in the US, LEV III in California, and Euro 6 rules in the EU) will lead to even lower vehicle emissions and further improvements in air quality. We review historical vehicle emission and air quality trends, discuss the future outlook for air quality, and note that modern internal combustion engine vehicles typically have lower exhaust emissions than battery electric vehicle upstream emissions. As vehicle manufacturers and city officials grapple with questions about future mobility in cities, we raise the question “how low should we go?” for future vehicle criteria emissions. The answer to this question will have profound implications for automotive and fuel companies and for the future economic and environmental health of urban areas.
Highlights
Vehicle emissions affect local and regional air quality
The criteria pollutant emissions generated from fuel combustion by internal combustion engines (ICE) include nitrogen oxides (NO and NO2, together called NOx), hydrocarbons (HC)— known as volatile organic compounds (VOCs) or non-methane hydrocarbons (NMHC), carbon monoxide (CO), and particulate matter of size
Heavy duty vehicle (HDV) emission standards include the Euro VI standards, effective in 2013, and the current US HD standards, fully phased-in as of 2010
Summary
Vehicle emissions affect local and regional air quality. The criteria pollutant emissions generated from fuel combustion by internal combustion engines (ICE) include nitrogen oxides (NO and NO2, together called NOx), hydrocarbons (HC)— known as volatile organic compounds (VOCs) or non-methane hydrocarbons (NMHC), carbon monoxide (CO), and particulate matter of size
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have