It's true that really - it doesn't matter. On a geologic timescale, everything we do is happening quickly.
Regardless of how many electric vehicles we put on the road, or how much fuel efficiency we push, every, single, last, drop of gasoline on this planet will be burned in the next ~1000 years. On a geologic timescale whether we burn it all in 50 years or in 1000 it really isn't going to matter.
So basically, we just cross our fingers and hope that by the time we dump all the available CO2 into the atomosphere that's it's not borked to the point that the planet won't recover.
Truly - the only solution we're going to have to global warming is to hope that eventually we just run out of fossil fuels and clean energy is all that's left.