I disagree. Can you name something we've completely run out of? Believe me, if gasoline costs you $50 a gallon, you'll be walking everywhere by choice. You'l

I disagree. Can you name something we've completely run out of? Believe me, if gasoline costs you $50 a gallon, you'll be walking everywhere by choice. You'll pay $10 for a bus ride and love it. R&D will be in overdrive. This is not the first time human beings have encountered a scarce resource.