Taxing fat

Dave Pannell posts on the Danish fat tax - he argues that it is ineffective, regressive and potentially with high transaction costs. On the plus side, the revenue raised could be used to make it less regressive.
Are there parallels with a carbon tax?

Greg Mankiw argues that a carbon tax is not regressive as the poor use less on carbon than the rich (who own more cars for example). Although presumably proportionally more of their income is spent on meeting basic needs which are carbon related expenditures (like food and heating).

Mankiw and Hansen both argue the regressive element of carbon can be reduced through paying dividends to the poor from the revenue raised.