Last week's Economist carried a feature on a recent wave of farmland purchases in poorer parts of the world. The buyers? Cash-rich emerging markets and Arab oil states looking to insure themselves against future food shortages. And if you think that's just a reaction to last year's stunning spike in prices, think again. The new trend speaks to the impact global warming will have on where food will be produced in abundance in coming decades.

Continue reading Tom's 'The New Rules' column this week at WPR