In the United States, vehicle emissions are responsible for 29% of total greenhouse gas (GHG) emissions with the majority of these coming from light-duty vehicles. To reduce GHG emissions, the U.S. has adopted policies to support the development and deployment of low-carbon fuels and zero emission vehicles (ZEVs—e.g., plug-in hybrid electric vehicles [PHEVs] and battery electric vehicles [EVs]).
Most current policies focus on emissions from vehicle operation only, omitting significant contributions from vehicle production and other parts of the vehicle and energy life cycle.
GHG emissions from vehicle operation and even from operation plus production are almost always lower for EVs than for conventional internal combustion engine vehicles (see Figure). However, as EVs become more efficient, low-carbon electricity becomes more common, and the size of the global EV fleet increases, emissions from production and other non-operation parts of the life cycle become increasingly important.
Researchers at UC Davis studied: (i) the effect of different factors on life cycle emissions; (ii) the impact of excluding life cycle emissions from policies; and (iii) potential strategies that might be used to effectively incorporate life cycle emissions in light-duty vehicle GHG policy. This policy brief summarizes the findings from that project.