The Opposition Leader's discomfiture in the face of certain large repositories of expertise is a matter of record.

He disapproves of climate scientists, of Australian economists on the whole, and he has no time at all for the work of Treasury officials, which should make things fairly interesting should the public distaste for Julia Gillard bear its probable fruit two years hence, and install Mr Abbott as their lord and master. Awkward.

After several months spent demanding details of the Government's carbon tax, Mr Abbott has not let the details themselves break his stride for a nanosecond. Treasury can predict until it's blue in the face that the cost of living will rise by a modest 0.7 per cent; Mr Abbott doesn't believe it, and campaigns accordingly.

In one sense, he's living the dream. A political campaign that is 100 per cent rhetoric is - to any politician - as a milkshake that is 100 per cent Milo would be to any child. And after all, as Reagan famously told the Republicans in 1988: "Facts are stupid things".

Once you've severed the guy ropes of obeisance to empirical evidence, many happy hours of ballooning lie ahead. Mr Abbott's liberation from such constraints allows him to lead a free-market party while advocating a carbon reduction scheme that is interventionist to its core. Or to deplore, for instance, a goal of reducing Australian emissions by 5 per cent over the next nine years as "crazy", while simultaneously holding that goal as sworn Coalition policy. Last week, when the Leader of the Opposition assured a group of Victorian voters that carbon dioxide was a tricky gas on account of being "weightless", it seemed for a glorious moment as if he was hedging his bets even on the work of Newton.

But Mr Abbott's one-man battle against demonstrable logic has entered a new and compelling phase.

After a long period of ignoring expert opinion where it does not mesh with his own, the Opposition Leader has taken the ambitious next step, and spent this week ignoring himself.

First, he claimed that he had never supported a carbon tax or emissions trading scheme, a proposition for which the contradicting evidence is so plentiful that it seems insulting to list it, although Crikey's Bernard Keane summarised the material recently, formatted entertainingly as a long argument between the Opposition Leader and himself.

Then, he claimed - while in Victoria - that the Coalition's national emissions reductions could be accomplished without touching a hair on the head of any brown coal-fired power stations. This is precisely at odds with his own policy's promise to shutdown at least one brown coal station, and to pay generators to move to gas.

In fairness, no-one can claim that Mr Abbott didn't warn us about this. Twelve years ago, during the republic referendum campaign, he did point out rather forcefully that politicians weren't to be trusted. In the first of two memorable interviews with Kerry O'Brien last year, he warned voters not to believe anything he said unless he put it in writing. In the second, he warned especially that he shouldn't be asked anything much about the internet, seeing as he knew diddly-squat about all that stuff (he is a papyrus-to-the-node kind of guy).

This is why Mr Abbott is a very, very effective Opposition Leader. He pursues his opponent all day, and sleeps soundly at night unhaunted by the ghosts of his own inconsistency. Rather blackly, Mr Abbott's central case against Julia Gillard is that you can't believe a word she says.

Malcolm Turnbull, a man whose own consistency on the topic of carbon pricing borders on the unfashionable, is in trouble today for his speech last night suggesting that people listen to the experts on climate change.

Mr Abbott, when interviewed in 2009 by Tony Jones about his thoughts on climate change, confessed to have read none of the IPCC report and just a bit of the sceptic Ian Plimer's book before arriving at his opinion that climate change was a bit overdone. "I don't claim to have immersed myself deeply in all of these documents," he told Jones. "But look, I think I am as well-versed on these matters as your average politician needs to be."

Mr Turnbull, who has read widely on the subject, delivered a lecture last night in which he encouraged voters to draw reasonable conclusions from empirical evidence, and to listen to the science on climate change.

Everything he said was well-contained within the Coalition's formal policy position. One suspects it was checked and triple-checked so as not to offend a single strand of the party's official position on climate change. And yet the whole thing was deeply, Turnbullishly off-message.

Why? Because on climate change in the Coalition, it's not loyal simply to recite the party's formal policy line. Loyalty demands you deliver the policy with a wink, to show you don't mean it.

Annabel Crabb is the ABC's chief online political writer.