The Importance of Passenger Cars for Global Greenhouse Gas Emissions – Today and Tomorrow

Abstract

Worldwide energy use and CO₂ emissions are on a trajectory to double by 2050. Transport is on a similar trajectory. The stock of light duty vehicles could triple. This paper explores scenarios to cut the energy and CO₂ emissions of light-duty vehicles. It is found that deep reductions will require both the widespread adoption of current best available technology, e.g. via measures to maximize their use to improve fuel economy, and the longer-term development and deployment of a range of new technologies such as electric and plug-in hybrid vehicles. A combination of doubling fuel economy (halving fuel intensity) from 2005 levels and strong rates of adoption of new technology vehicles and fuels (e.g. electric and plug-in hybrid vehicles accounting for more than half the vehicles on the road by 2050) could cut oil use and CO₂ emissions by well more than half in 2050, compared to Baseline 2050 levels (and to half of 2005 levels in Europe). However, the changes needed will be dramatic including unprecedented penetration rates for certain key technologies. At the same time, some other trends must stop: those toward ever larger, more powerful cars, and trends in some countries toward ever-greater dependence on the car for all types of trips. And while the emergence of low cost cars can provide mobility to millions of people, society must ask if this is the best way to provide such mobility, rather than (for example) via advanced bus and train systems, and with land use patterns supporting a bigger role for non-motorized transport.