A better question might be “How much can your changed lifestyle do by itself? Second, how much can it do to influence others. Third question is whether all of the above will make the tiniest sliver of a difference, because it’s hardly likely to.
Attack the real scope of the problem. Pull more carbon out of the air than we put in in the first place. Don’t worry about stuff a little less carbon into the air, worry about taking it out.
That is a horrendously difficult task – we can do it once we can control fusing hydrogen into helium to produce energy, So to make a *real* difference, invest in programs that are working on that.
Oh, and Another Thing 