A green vehicle or environmentally-friendly
vehicle is a road motor vehicle that produces less harmful impacts to the environment
than comparable conventional internal combustion engine vehicles running on gasoline
or diesel, or one that uses certain alternative fuels. Presently, in some
countries the term is used for any vehicle complying or surpassing the more
stringent European emission standards (such as Euro6), or California's zero
emissions vehicle standards (such as ZEV, ULEV, SULEV, PZEV), or the low-carbon
fuel standards enacted in several countries.
Green vehicles can be powered by alternative
fuels and advanced vehicle technologies and include hybrid electric vehicles, plug-in
hybrid electric vehicles, battery electric vehicles, compressed-air vehicles, hydrogen
and fuel-cell vehicles, neat ethanol vehicles, flexible-fuel vehicles, natural
gas vehicles, clean diesel vehicles, and some sources also include vehicles
using blends of biodiesel and ethanol fuel or gasohol.
Vehicle emissions contribute to the
increasing concentration of gases linked to climate change. In order of significance, the principal greenhouse
gases associated with road transport are carbon dioxide (CO2),
methane (CH4) and nitrous oxide (N2O). Road transport is the third largest source of
greenhouse gases emitted in the UK, and accounts for over 20% of total
emissions, and 33% in the United States.
Of the total greenhouse gas emissions from transport, over 85% are due to CO2
emissions from road vehicles. The transport sector is the fastest growing
source of greenhouse gases.