Jeremy Grantham says the most valuable and critical resource on earth is phosphorous

Jeremy Grantham says the most valuable and critical resource on earth is phosphorous. Phosphorous cannot be made, only placed. It is necessary for all living things. We are mining it, and it's depleting. If that doesn't give you goosebumps, then you're tougher than me. That is a terrible equation. So I went to the professors, and I said, what's going to happen, and they said, 'Oh, there's plenty of phosphorous.' But what's going to happen when it runs out? We do have a lot, but 85 percent of the low-cost, high-quality phosphorous is in Morocco...and belongs to the King of Morocco. I mean, this is an odd situation. Much, much more constrained than oil in the Middle East ever was and much more important in the end. And the rest of the world has maybe 50 years of reserve if we don't grow too fast.