Dear EarthTalk: I thought that putting ethanol in our gas tanks was going help fight climate change, but lately I've heard reports to the contrary. Can you enlighten? -- Bill B., Hershey, PA
Ethanol and similar "biofuels" made from corn and other crops seem like a good idea given their potential for reducing our carbon outputs as well as our reliance on fossil fuels. But recent research has shown that the federal government's push to up production of corn-derived ethanol as a gasoline additive since 2007 has actually expanded our national carbon footprint and contributed to a range of other problems.