I was going to post int the cap and trade vs, carbon tax thread, but someone already made the points I was going to:
You don't need to choose between the two necessarily.
I think cap-and-trade is more efficient, but it can only really apply to stationary sources like refineries, power plants, factories, etc. Cap and trade works better for them because it creates an incentive to reduce your emissions as much as possible, whereas a tax provides the same incentive to everyone. The factory that can cut emissions 80% has the same incentives as the factory that can cut emissions 40%, it's just inefficient.
For individuals, taxes are the only option to affect behavior directly. But, I wouldn't have a strict carbon tax. I would have something like an environmental externality tax on things like gasoline, electricity from coal plants, cars, etc which factor in all greenhouse gases and some measure of the pollution they cause.
