Christian Science Monitor: Not too long ago, corn ethanol was being touted as the energy wave of the future for fighting global warming. It was said to be much better than coal and oil, those carbon-based sources of greenhouse-gas emissions. But lately the drawbacks to this form of energy production have become more obvious, its critics more vocal, its supporters on the defensive. For one thing, there’s evidence that the rush to produce ethanol made from corn is contributing to the recent rise in …