We depend on market prices to inform us. But market prices are not omniscient and there has been a lively discussion on how to get the prices right when they are not. This is where it gets messy. Carbon taxes, if we ever get them, will be politicized. Domestic politics are not simple and international politics enter when an international commons is involved.
So we get "footprint" math. Today's WSJ has a nice piece on the some of the math involved: "Hate Calculus? Try Counting Cow Carbon". Yesterday's Financial Times included "If you can't measure your footprint, you can't shrink it"
Let's dream for a minute and pretend that policy makers do nothing. Would unplanned change be more benign than what they have cooking? Research on the Environmental Kuznets Curve is suggestive. Trouble is that "curve-bending" is now the new sport among politicians.