See Iain Murray on the Corner.
If you're determined to both decarbonize and stop sending money to the Middle East then there is but one plausible answer and it isn't a flex fuel mandate (although allowing sugar ethanol imports could be a smal factor). It's improved hybrid/electric technology for automobiles combined with nuclear-generated electricity. The auto manfacturers are moving very quickly on their end, and it would not surprise me if all the storage problems were solved and long-range mostly electric vehicles were the norm by 2020. The technology isn't there yet, though, so mandates are useless. As for nuclear, there's a chance that lawmakers will see its value and override environmentalists like they're doing in Europe. The enviros will, however, put up one heck of a fight on that.
Read the whole thing.
I have his book, The Really Inconvenient Truths: Seven Environmental Catastrophes Liberals Don't Want You To Know About -- Because They Helped Cause Them, but haven't read it yet.