The removal of Penny Wong from the climate change portfolio in favour of Greg Combet provides an opportunity to take stock of where we're at on climate change and what should be the Government's priority.

Opinion is undoubtedly swinging away from an emissions trading scheme toward a carbon tax, and it's been happening both among progressive economists like John Quiggin and right-wing commentators like Michael Stutchbury. A similar change is going on within Cabinet, although the conversion isn't yet complete. A carbon tax isn't as elegant and economically pure as an emissions trading scheme, and not as efficient, but the original debate omitted the simple reality that politicians -- or certainly the politicians we now have -- can't be relied upon to develop a complex policy without allowing every rentseeker in the country to defile it.