Global food prices reached record highs early this year, sending millions around the world into poverty and contributing to starvation in East Africa. Many blame the government-subsidized growth in the market for biofuels, such as ethanol. Biofuels are expected to consume 40 percent of this year's corn crop from the world's largest producer -- the United States. Others say commodities speculators caused food prices to ricochet wildly. Europe is considering adopting restrictions on speculation similar to a new U.S. law, but Wall Street is lobbying hard to weaken the American regulations. Perennially high food prices may be the first sign that changing climate is handicapping agriculture. To feed the world's growing population, experts say farmers must double their food output by mid-century -- a tall order to fill without destroying more rain forests and further boosting planet-warming carbon emissions. The solution may be a combination of two warring philosophies: high-tech agriculture and traditional farming methods that are kinder to the environment.