I would like to attempt to answer Mike's charge (which I agree with) that economists tend to apply simplistic band-aid-like solutions to complex problems. I would argue that a carbon tax is one such overly simple solutions: Is there a social cost to pollution? "Tax it!" say (some)economists. Is there a social benefit to health care? "Subsidize it!" say (some) economists.
Of course the reason many economists are attracted to simple solutions is because 'simple' is the only course of actions their mathematical models allow. When you try to box your science into modelling all behavior as a system of digits, then the only answers you can provide will consist of the same system of digits. It is this failure of the science to incorporate a more holistic method of analysis that begets the simplicity - and why all mainstream economic analysis needs to be tempered with reality checks.