Actually it is not that important to current and evolving energy needs because of the available Tar Sands and Shale oil. And as for methane, there are huge amounts just lying about on the deep ocean floorin those little ice nodules, enough that libs are already worrying that efforts to tap that source will Destroy Us All or that Global Warming will melt the nodules and flood the atmosphere with methane that will Destroy Us All.
Tar sands are becoming economical at current oil prices. I'm not sure about the shale oil. It's been talked about for 30+ years, but little seems to have been done with it, which I interpret as it not yet being cost effective. A better current source would be converting coal into more portable liquid or gas derivatives. There is some commercial work on that. Not that the greenies would like that solution; coal produces more CO2 per unit energy. However
#18 points out that CO2 could be considered a resource rather than a pollutant. Just collect it and pump it back down the old wells to harvest more oil. Maybe if we pump down enough CO2 the greenies will start to complain we're starving the trees and causing global cooling instead.