Gasoholics Anonymous

I was thinking on my way into work, how strictly should I or anyone else end gasoline (or other fossil oil) use? Should use of it be zero'd or just diminished? Clearly in the context of today's city infrastructure etc (in the U.S.A.) it's going to be nigh on impossible to have zero fossil oil (gasoline) use. Yes there are people who have zero'd their use of fossil oil (gasoline) but should everybody do so?