Dr. Mike Walden, North Carolina Cooperative Extension economist in the College of Agriculture and Life Sciences at N.C. State University, responds:

"Oil shale is rock that when heated to extreme temperatures can produce an oil-like substance that can be suitable for refining into energy products. And the U.S. has large, large supplies of oil shale. In fact, we have more supplies of oil shale than Saudi Arabia does of liquid oil. But there are issues related to turning that oil shale into usable energy. First of all, pollution. The process of taking oil shale into energy creates both air and water pollution. Also the process uses large quantities of water. And then finally, it could take up to a decade once you find the oil shale to get it to market. So with today's technology, we certainly have the potential of seeing substantial energy supplies from oil shale, but it's not a short-run solution."