With the ground carefully prepared, including selective briefing to the home of climate change scepticism, The Australian, Brendan Nelson and the conservative wing of the Liberal Party have stolen a march on party moderates on linking emissions trading to international action. The extent to which Greg Hunt and Malcolm Turnbull have adjusted their language to accommodate a rightward shift is a giveaway that it is a fait accompli.

The argument that Australia should not have too low a carbon cap until there is international agreement from the major emitters is a sound one, and likely to be adopted by the Government, even if we don’t know what’s in the Godot-like Treasury modelling. The argument that we should do nothing at all until major emitters have signed on to some agreement is indefensible and weak.

It’s weak because it signals the Opposition lacks the confidence to argue on policy detail. The Emissions Trading Scheme and supporting arrangements proposed by the Government are a shocker, with plenty of scope for improvement in areas like encouraging the development of renewable energy and avoiding exploitation of permits by traders. Greg Hunt has been trying to exploit this, but senior Coalition figures evidently figure they lack the firepower to really hurt the Government on this. And emissions trading is an economic reform.

Economics is supposed to be the Coalition’s strong point, but with Turnbull as shadow Treasurer and Peter Costello in his usual Zone of Indecision, they have ceded that ground to the Government. This has been the signal failure of Turnbull’s stint as shadow Treasurer. The bloke is brilliant, but he’s no economist.

It’s weak because the time to do this was three or four years ago when we were still in the early, low-inflation, high-growth phase of the resources boom. The Coalition refused to do anything then, and left it to its successor to implement a scheme at a time of deepening economic uncertainty and stronger inflationary pressures. In effect it is arguing that we should delay further because of the consequences of its own delay.

And it’s weak because it reflects Nelson’s desire to have it both ways, to play populist while pretending that he still has policy credibility. This is the bloke who wanted a 5c a litre excise cut, but didn’t have the guts to argue for a big reduction that would’ve made a genuine difference to petrol prices. This is the bloke who argued the Budget was inflationary, while opposing taxation measures in the Senate. I’m serious about addressing climate change, Nelson wants to say, but I’m not going to do anything. Same old same old.

But given the difficulty that Nelson has had in describing his own position in recent weeks, it’s no wonder he wants a simpler position to put. Trouble is, the wait-for-others approach is no easier to argue. What if President Obama (should such a disaster come to pass) makes an Emissions Trading Scheme or carbon tax his first priority? Will that be enough? What if China takes steps to curb emissions but India doesn’t? What if the Europeans decide to start imposing carbon tariffs on imports from freeriders like Australia?

The new Coalition position — which can be summarised as “Copenhagen or bust” is predicated on some major international agreement being thrashed out next year, and only doing something in the unlikely event that that occurs. Far more likely is that, bit by bit, major emitters start to address abatement measures in a variety of ways that suit their circumstances. At what tipping point does the Coalition say, “yeah OK, that’s good enough for us”?

Not to mention the usual arguments about there being a greater chance of an international agreement if we’re already doing something. Or the responsibility of doing something when we’re one of the biggest per-capita emitters and major carbon dealer to the planet.

And given the indiscipline in Coalition ranks, the ceaseless offering of alternative policies and critical commentary won’t disappear. There’ll be no Coalition unity on the issue, because they can’t keep their mouths shut. Greenhouse denialists like Nick Minchin will continue to maintain that climate change is a myth. Moderates who want serious action will express their disappointment.

The new position will also make it significantly easier for the Prime Minister to portray Labor as the moderate, sensible course between extremists. Rudd has been demonising the Greens as economic vandals, and now the Coalition is happily giving him the evidence to show it is retreating to the sort of flatearther attitude it clung to for most of its years in power. Labor’s proposed emissions scheme isn’t balanced, it isn’t moderate and sensible, but it will look exactly that by the time Brendan Nelson finishes with the issue.

In short, whatever the merits or otherwise of their new policy, the Coalition leadership is kidding itself if it thinks it will make life any easier.