The claims, counter claims and responses about the carbon tax are loud and filled with invective. Positions are being stated loudly and with deep emotion, but it's been difficult to make sense of the various positions and analyses regarding the impact of this proposal.



This is not the first time a tax has been used by policy-makers, from Australia and elsewhere in the world, to manage environmental issues. Environmental taxes have been part of the suite of responses used by governments for more than 30 years.



As all the warnings on superannuation funds say: "Previous results are not an indication of future earnings."

But they do provide a useful template and it is also useful, given our current context, to know what claims were made prior to the introduction of those taxes and whether the fears were realised.

Example 1: CFCs

Remember back to the early 1990s, when there was increasing concern about the degradation of the ozone layer due to pollutants.

In order to play our part in meeting international agreements to reduce emissions of harmful chemicals like HCFCs and CFCs, the Australian government legislated a phase out of these substances and instituted a levy (a tax).