It's interesting. Demand is up for a heartening reason - because hundreds of millions of people in China and India are now ascending to middle class status, and they want the stuff that comes with that. As always, higher prices will create incentives to both conserve and to innovate - finding ways to substitute less costly inputs and do more with less.
More rapidly than people imagine but still "long term" for purposes of commodity price cycles, birth rates will fall in those places where so many are coming to enjoy more comfortable and secure lives than their previous subsistance level existance provided. In consequence, population will stabilize and even fall. That will create whole new sets of problems. Progress is moving from one set of problems to a better set of problems.