I was in New York in the 30’s. I had a box seat at the depression. I can assure you it was a very educational experience. We shut the country down because of monetary reasons. We had manpower and abundant raw materials. Yet we shut the country down.

We’re doing the same kind of thing now but with a different material outlook.We are not in the position we were in 1929–30 with regard to the future.Then the physical system was ready to roll. This time it’s not. We are in a crisis in the evolution of human society. It’s unique to both human and geologic history. It has never happened before and it can’t possibly happen again. You can only use oil once. You can only use metals once. Soon all the oil is going to be burned and all the metals mined and scattered.

M. King Hubbert - Wikipedia