Tax carbon fuels at the source, where they are processed. Distribute the tax money equally among lawful U.S. residents.
Why is this important?
Climate scientist James Hansen proposes a tax on carbon fuels at the source, where the fuel is produced. See http://www.columbia.edu/~jeh1/2009/WaysAndMeans_20090225.pdf. The tax money would be returned to legal U.S. residents to spend as they choose. Prices of carbon fuel would go up, creating an incentive to use less, while the money returned to residents offsets the higher price. Unlike a simple gasoline tax, under which proceeds go to state or federal coffers, this plan compensates residents for the tax they pay, so an excessive burden does not fall on the poor.
