New findings challenge the assumption that drivers should keep a functioning gasoline vehicle until the end of its life before switching to an elective vehicle (EV). Despite the carbon footprint of manufacturing the electric car, the study shows, replacing even a brand-new gasoline vehicle with an EV results in lower lifetime greenhouse gas emissions. In the United States, personal vehicles are responsible for more carbon dioxide (CO₂) emissions than all other forms of transportation combined, including air, rail, water, and commercial trucking and busing. This dominance makes the transition away from gasoline-powered cars, SUVs, and trucks central to climate policy. Battery electric vehicles (EVs) generally produce far fewer lifetime greenhouse gas emissions than internal-combustion-engine (ICE) vehicles, and their climate advantages are expected to grow as electricity grids become cleaner. However, while the emission benefits of choosing an EV over an ICE vehicle during a new vehicle purchase are well established, just when to retire a working gasoline-powered vehicle and replace it with an EV remains an open question. Keeping the gasoline vehicle on the road avoids the additional manufacturing emissions of producing a new EV, but replacing it early could deliver substantial savings because EVs generate far fewer emissions during operation. To address this question, Elliott Campbell and Roland Geyer estimated the life-cycle CO₂ emissions associated with keeping an ICE vehicle in use versus scrapping it early and replacing it with an EV. They conducted life-cycle analyses across a broad range of retirement scenarios and vehicle classes, taking into account variation in powertrain, battery size and manufacturing, electricity sources, and retirement year. According to the findings, replacing a functioning internal-combustion vehicle with an EV can reduce carbon emissions across a broad range of conditions, even when the gasoline vehicle is relatively new. The authors argue that this result makes vehicle scrappage-and-replacement programs a potentially powerful climate policy.
