Before the oil runs out: The search for alternatives

Even as conventional oil supplies begin to play out in the U.S., the North Sea, and some other major production areas like Venezuela, the Journal says that the most “realistic” replacements would be other “hydrocarbon resources [such as] oil shale, tar sand, extra heavy oil, and possibly coal liquids.”

Only hydrocarbon sources like tar sands and coal liquids are in great enough supply to supplement regular oil