THE political stoush over carbon pricing is as divisive as any in recent memory, but the basic idea underpinning the clean energy laws is neither new nor particularly radical.
More than eight years ago, four federal departments advised John Howard's cabinet that an emissions trading scheme was the cheapest way to tackle climate change and give companies an incentive to find cleaner ways to do business.
Further back, it is two decades since the Intergovernmental Agreement on the Environment between Canberra and the states and territories embraced the ''polluter pays'' principle.
In recent years carbon trading has been introduced in the European Union and, on a much smaller scale, in New Zealand.
California plans to start in 2013, with South Korea likely in 2015. Guandong province - a manufacturing stronghold with a population more than five times greater than Australia - is expected to be the first of six Chinese regions and cities to try emissions trading from 2013.
Those acting are only partly driven by concern for the planet. China is as motivated by seizing the economic opportunities in developing clean industries.
Where Australia differs from other countries is the initial scale of its scheme.
Australia also launches into the carbon market when the future of co-ordinated international action looks bleak.
But amid all the uncertainty, the evidence from Europe is that emissions trading is almost the only climate policy to have caused a meaningful cut in carbon dioxide.