As countries race to reduce emissions and mitigate climate change, the debate on green vehicles often focuses on fuel efficiency and alternative fuels, such as electricity and hydrogen. A common idea is that the faster the transition is, the better it is for the environment.

Now, a new study of car use in Japan shows that, even with gasoline vehicles, keeping and using cars with good fuel efficiency longer could reduce CO2 emissions significantly more than an accelerated transition to alternative fuel vehicles.

“The faster you replace a car, the more CO2 it emits. It’s no different with electric cars, because when the demand for new cars increases, it shoots up manufacturing emissions,” says Shigemi Kagawa, professor of Kyushu University’s Faculty of Economics and leader of the study.

Car replacement is especially rapid in Japan, where people enjoy longevity but cars do not. The average life expectancy of a car, from its birth in a factory to its end in a scrapyard, is around thirteen years. Moreover, the average length of ownership of a new car by its first owner is seven years.

Read more at Kyushu University

Image: A hydrogen car is parked at a hydrogen station at Kyushu University. (Credit: Kyushu University)