biofuels yet again

According to Robert Lawrence, a policy should have one defined goal and not try to be a "one stone two mangoes" kind of policy.
More on biofuels-
"In the 1930s, biofuel was touted as a strategy for dealing with agricultural surpluses and low commodity prices.When oil prices were high in the late 1970s, ethanol was seen as a gasoline extender. During the 1990s, ethanol was seen as an aide to combating urban smog in large U.S. cities. As concerns about greenhouse gases intensified in the 2000's, Europe adopted biofuels as a way to reduce emissions. While the United States was concerned about emissions as well, a biofuels mandate was also adopted for national security reasons, namely, concerns about oil imports, and to support Midwestern corn farmers."
He feels that if you look closely,one by one at these goals, you will see that
the policy does not meet any of them really well.
In addition, I think, it will lead to further depletion of water (in the case of corn) and erosion of food security.
Very often, our solutions lead to bigger problems.