His reasoning is simple: energy demand is ever increasing, the energy infrastructure is not capable of handling this demand, so prices will go up. There are people who will disagree with him, but Simmons says the myth that the Middle East has unlimited amounts of oil and would continue to be a cheap oil source needed to be dispelled a three decades ago. Once you realize this, he says, and look around the world for other sources of oil, it's easier to realize that Peak Oil is coming.
You can read the interview transcript here or listen to the MP3 file here.
[Source: Financial Sense Newshour via B100Fuel]