I hate to say I told you so, but two new science articles have made corn-based ethanol, and even more futuristic cellulosic ethanol, seem much less legitimate as an option to combat global warming. Appearing in the prestigious journal Science, both new papers suggest that switching to ethanol will actually add to net greenhouse gasses in the near term (i.e., for at least 100 years if not more). One of the reasons is that clearing more land for biofuels will immediately release a large pulse of carbon into the atmosphere. Moreover, as the pressure to both grow food and fuel mount, more land will be cleared, thereby accelerating such a carbon release. Here are the abstracts for both articles (lead authors were from Princeton University and the Nature Conservancy) and here is some commentary from Grist. The authors are careful to note that producing fuel from the waste stream (i.e., used cooking oil and grease, etc) does not have this drawback.