A few years ago I listened to a talk by Lester Brown, founder of the Worldwatch Institute and subsequently the Earth Policy Institute. He was talking about China. The country had an insatiable appetite, he said, that was already driving up the price of cement, steel, and other commodities. One billion times anything, he said, is a big number.

Brown commented on the growing drought in northern China, where the water table was falling dramatically every year. Declining crop yields would send China into world markets to make up the shortfall, he said, and the difference would be more than Canada's annual grain production. World food prices would inevitably rise. This scenario has since been compounded by drought in other countries and the diversion of food crops into the creation of biofuels. Speculation in food commodities has further driven up prices.

Recent food riots in Haiti bear witness to a dramatic global change. The World Bank now forecasts that more than 30 nations will experience social unrest due to the rising cost of food.

Many global resources are being depleted, climate change is deepening global drought, and world population is projected to reach nine billion by 2050. We will compete more and more for scarce resources, and we'll pay more for everything -- including commodities we previously took for granted. Nine billion times anything is a big number.