There's a theory that our economies are so fundamentally dependant on fossil fuels that, if you limit their extraction, you don't get fossil fuels price increases, but rather proportional GDP contraction (as less f.f. means less economic activity overall), and f.f. prices stay roughly the same. The evidence to back this up is the fact that, historically, the correlation between global f.f. extraction and global GDP is pretty much perfect. In other words, economic activity is pretty much about energy expenditure, and energy means pretty much fossil fuels.