To accomplish this about two of every five bushels of corn in the US are diverted from food use to ethanol production.
So, instead of the US feeding people world wide, we starve them.
An estimated 192,000 people could die due to food shortages tied to biofuel production.
More than AIDs, TB and malaria combined worldwide.
Of course, other sources of fuel could replace corn ethanol.
But the EPA, so far on its third 90 day "extension" to evaluate this has yet to decide if its policies are killing people.
There is a shortage of corn due to the US drought in 2012.
This will compound the problem.
I am pretty sure you can't enjoy a cleaner environment if you are dead...
For further details see this article as well as this one.