You can make a coherent, logical argument for cars that don’t burn gasoline without once mentioning global petroleum supply. You can talk about international relations and the power of gasoline exporters (just read the first three paragraphs of this for a bit of history). You can talk about climate change. You can talk about the health effects of CO2 in the air. But the fact remains that gasoline (or diesel) remains the go-to fuel for almost every passenger vehicle on the planet, so the question of how much black gold is out there is an important one. The answer, though is not so clear.