Resources are a function of technology, which in turn is the result of human ingenuity. There's really no inherent limit, considering the way markets develop substitutes (higher prices encourage both conservation and innovation).
After all, man can turn sand into silicon computer chips...it is the technology and the end use, not the natural resource, that matters.
After all, man can turn sand into silicon computer chips...it is the technology and the end use, not the natural resource, that matters.