Starting a "floating" carbon price one year early is not such a big deal, really. The fact that every political party is screaming about it just proves how twisted the politics of this issue has become.

For Kevin Rudd, it's a way to reboot a debate Labor has been comprehensively losing, and provide businesses and households with some very short term cost relief.

The $3 billion or more the government now has to find in budget savings is the same amount business won't have to pay for carbon permits next year.

And that gets passed through to households in the form of savings of $210 a year for a sole parent on benefits, $300 to $400 a year for average couples with children and $180 a year for an aged pensioner couple, according to helpfully provided Treasury modelling.

But it's a price reduction that would have happened when the system moved into line with international prices one year later anyway. The real impact Labor is hoping for is political.

For the Greens it's an opportunity for product differentiation ahead of an election that's looking very difficult for the minor party.

But Christine Milne's argument that Australia's economic transformation will be somehow fundamentally interrupted by allowing the price to drop to international levels just one year earlier than planned doesn't make sense.

And for Tony Abbott it turns back against him his own successful blurring of the difference between a carbon tax (which Julia Gillard promised not to have) and a floating price emissions trading scheme (which has always been Labor's policy in one way or another, and until Abbott became leader was the Coalition's policy as well). A one year shift in the start of the floating price could never have resulted in front page headlines proclaiming "carbon tax to go" if it hadn't been for Abbott's own hard work decrying the fixed price "tax" for the last three years.

For their very different political reasons both Abbott and Milne are labelling the decision a "fraud" and a "con".

But, putting the politics aside, we actually don't yet have the most important pieces of information to make that judgement.

What we really need to know is whether the government intends to keep the independent Climate Change Authority and listen to its advice about how hard we should be cutting our greenhouse gas emissions.

The domestic discussion has been locked in this senseless, fact-free headbutt of a debate about "axing the tax" for so long, it's been easy to forget that reducing emissions - probably by more than the minimum 5% by 2020 agreed by both major parties - is the point of the exercise. The "tax", the trading scheme and even the Coalition's "Direct Action" are all just different means to get there.

If bringing forward a floating price means we can do more, while imposing lower costs on the domestic economy because the international price is lower than we thought it was going to be, surely that's a good thing.

And if Tony Abbott really thinks he has found a cheaper way to make deep, long term cuts to Australia's emissions than can be achieved by participating in an international market, now would be the time to finally unveil the detail of his Direct Action policy to try to prove it.

If Labor is keeping the climate authority and leaving open the possibility of tougher targets - by far the most important change negotiated by Milne in the deal with Julia Gillard compared with Labor's first emissions trading scheme - are the Greens really going to stand in the way?

Properly assessing Australia's share of the global effort to slow climate change, and then figuring out how we most efficiently do it - that is a really big deal.