Research suggests that in the short run, the production, distribution, and consumption of ethanol will create about 20 percent fewer greenhouse-gas emissions than the equivalent processes for gasoline. In the long run, the result is less clear. If increases in the production of ethanol led to a large amount of forests or grasslands being converted into new cropland, those changes in land use could more than offset any reduction in greenhouse-gas emissions. This presentation will discuss both of these issues in the context of current economic and market conditions with an eye toward future impacts of alternative fuels.