Let's assume the science of human induced global warming is roughly true, that there's a correlation between increased carbon and increased global temperatures and we need to do something sensible to manage it. The current Australian government has decided to introduce a carbon tax, it's personal effects can be roughly measured here.
My difficulty is with human nature and while I acknowledge the difficulties of governing in a fallen world surely there are schemes that could be created to reduce greenhouse gas emissions that didn't require a clumsy tax? (What about a radically comprehensive train system and targeting the three dirtiest power stations?) Speaking broadly, some nations, even lovely ones like Russia may simply say "yes we have a carbon tax" while not making any changes. Other nations like say China may say "at this point a carbon tax isn't in our national interest for the next ten years." Australia instead of leading a global revolution is left to hang out to dry economically. Then on a national level a large bureaucratic system is open to fraud and mismanagement. Practically the ideological aim of the carbon tax is negated by it's implementation both globally and locally.
[My prediction is that the carbon tax is here to stay. There'll be some token global scheme and some future global crisis; such as a war or a disaster that reduces emissions and people will assume the scheme has caused the reduction. Then a future conservative government facing a rising cost of living and whatever unpleasantness is on the horizon will nationalise the carbon trading market and reduce the price of carbon.]