30 May 2007: Peter Shergold delivers a report on a carbon trading scheme to John Howard, who looks at it like a baby he’d prefer not to hold. The report, heavily influenced by resources companies, recommends an emissions trading scheme by 2012, without waiting for an international agreement, but with a low carbon charge. The report sports a lovely picture of the Earth on the cover, because, you know, that’s what it’s really about.

November 2007: With Malcolm Turnbull furiously leaking to save his own seat, the Government goes to the election committed to the Shergold position, a requirement for 15% of electricity by 2020 produced by low-emission sources, including nuclear power and “clean coal”. Labor starts asking voters if they’d like a nuclear reactor in their backyard. Howard declares in his debate with Rudd “I mean, one of the things we have to face about climate change is that there is a cost,” a level of candour to date unmatched by Kevin Rudd.

Dec 2007: Greg Hunt convinces his colleagues and Brendan Nelson to give the “green light” to the Government for its ratification of Kyoto. A relieved Kevin Rudd signs on the dotted line.

23 June 2008: The Opposition uses Question Time to demand that the Government rule out petrol price increases and job losses from an emissions trading scheme.

4 July: The release of the Garnaut draft report. In the morning, the Coalition leadership team agrees on the position of supporting an emissions trading scheme by 2012, unconditional on international agreements, but with a low carbon price in the absence of the latter. Greg Hunt, Malcolm Turnbull and Julie Bishop go out to say exactly that. However, Brendan Nelson later that day declares “there must be a genuinely global response which involves the world’s major emitters – China, India and the United States in particular.” No one spots the difference.

7 July: Nelson meets emissions trading opponent Warwick McKibbin with ex-Howard Government staffers from right-wing consulting firm Concept Economics. He then more boldly declares there should be no emissions trading scheme until big emitters take action, declaring it “economic suicide” to do otherwise. We finally wake up to the fact that Nelson is singing from a different hymn sheet to his colleagues.

8 July: Julie Bishop says the Coalition is committed to 2012. So does Greg Hunt.

9 July: Greg Hunt tells Crikey the Coalition is “rock-solid” on 2012. Nelson promptly repeats that the Coalition won’t do anything without big emitters taking action. Malcolm Turnbull appears on Lateline and, referring to Nelson like a rather slow pupil, says that the Coalition position in support of 2012 has been repeatedly agreed.

10 July: As if chastened by Turnbull, Nelson appears to soften, declaring emissions trading “should occur in the context of us doing everything we possibly can to see that the major emitters, the United States, China and India in particular are committed to action.”

11 July: Nelson writes for The Australian, not merely backing away from 2012, but suggesting an emissions trading scheme may not be appropriate at all. A Coalition policy on dealing with the challenge of global cooling seems imminent. A telephone hook-up with the Coalition leadership group ensues to work out WTF is going on. At a press conference in Launceston, Nelson then repudiates both ideas and restates Coalition policy as an emissions trading scheme by 2012.

26 July: After two weeks of allowing the Government’s Green Paper to be the issue rather than the Coalition, Nelson, evidently feeling limelight deprivation syndrome, has another go, telling The Australian he wants to make an emissions trading scheme conditional on international action. The Australian’s commentators cheer but presciently worry that Nelson will bugger it up. Malcolm Turnbull and Greg Hunt lie doggo on the imminent debate in shadow Cabinet.

29 July: Nelson emerges from shadow Cabinet to painfully articulate a “new” Coalition position that is exactly the same as the old one. An angry Australian complains “but we’ve just written all this stuff on how you won support for a change” and runs it anyway.

30 July: Nelson emerges from a 5-hour joint party room meeting to declare the party “in-principle” supports an emissions trading scheme by 2012. Wilson Tuckey ignores Nelson’s request that he alone put the position and declares that they are no longer wedded to 2012 at all. Nelson goes on the 7.30 Report to declare that the Coalition would “probably” start a scheme by 2012. Kerry O’Brien sinks his teeth into Nelson and doesn’t let go for a full three minutes.

31 July: Senior Coalition figures lament the lack of mobile phone coverage wherever Peter Costello is staying.