When will the US stop fooling around with corn based ethanol?

The US agreed at a UN summit to reduce our usage of fossil fuels by 15% and this is how they decided to do it. Even though it has caused even more emissions, is bad for engines, reduces gas mileage, and last but not least, has caused all corn fed food to become more expensive adding to world hunger, our Congress leaves it in place for lack of a better alternative. Hemp would replace use of fossil fuels by a huge percentage but our government has confused it with marijuana; another indication of their stupidity. Byproducts of hemp can be used in making fabrics and plastics that currently use oil, paper as well.