> car ownership
While ownership isn't that important per se, access to a car is vital for many people living where there are no public transport options available. Unless you intend to start relocating people forcibly, we need to maintain some kind of transport ability on the country side.
Of course, but that will be a considerably longer process than desired if we're going to rely on that for reducing emissions. After all, there are always going to be some people living outside cities, and in most cases, public transport would be a waste out here because of the long distances involved and the low population density.
Bring farming machinery into the equation and replacing fossil fuels suddenly becomes far more important than reducing car ownership.
Doesn't have to be run on fossil fuels, though.