Yes. To comment on what Gordon was saying, granted that mining has been around for thousands of years, and granted that the tendency of the industry in all its sectors, I would think, but in any event an awful lot of the sectors, is to continue to look for new deposits when they run out of the past ones, that's not going to go on forever. That's quite clear. The resources on the planet are limited. Whether it's going to go on for thousands of years, as it has in the past, or not is the question. With the population of the planet having tripled in the last sixty years, with the consumption of resources having probably increased--and I don't know what the factor is over the last sixty years--something has changed rather radically. We just disagree. I don't think you want to approach the question of copper or oil or zinc as something that's there forever.
He mentioned substitutes too, and given lots of indications, sustainability and the need for substitutes suggests you should start looking for substitutes rapidly. The general tendency is to look for renewables, rather than for more of the same non-renewables.