Or, maybe if consumption is reduced too much, we will never run out. If abiogenic origin theories are correct, petroleum is still being produced. If we stop extracting and using it carefully we might again be "Out one day just a shootin' at some food, And up from the ground came a bubblin' crude. Oil that is. Texas Tea."
"Exploiting" petroleum fuels may be the most environmentally conscious thing man has ever done. And since methane is a "greenhouse gas" preventing its natural, uncontrolled venting into the atmosphere by drilling, capturing, refining and combusting, may actually be COOLING the earth.
Bringing to mind the good people of Santa Barbara, California. Nearby denizens prefer to let the oil seep into their world class beach rather than extract it and relieve pressure.
I like where you're headed. This would be a pretty good SciFi novel: the world switches to cheap cold fusion power; all the animal habitat is ruined by oil because nobody remembers how to get rid of it.
Bingo. Let's flesh out a screenplay and split the rights.