Looking long-term we are clearly not going to use oil this way for the next billion years. Also, the sun itself will burn out eventually, and the galaxy will grow dim. Not to mention that ultimately all the galaxies except possibly 1000 of them in the local cluster will move out of sight and the ones that are left will be so dark they will be invisible. So how much oil do we need, both right now and in the next few years? 200 years isn't long. We have coal for 500 years. What then? Some say that the generation that will live forever is already living, so we can't assume it won't matter to us.