Who do you trust, the PM asks. Who do you trust to tackle climate change, not through environmental zealotry but through responsible economic management?

John Howard is the hoped-for answer, and the latest Galaxy polling suggests that more Australians are slowly inclining to that view. But it’s something of a trick question. Howard may well be returned as Prime Minister in this year’s eagerly contested federal election, but he will not not hold that office for the duration of the next parliamentary term. When he will leave is uncertain, but he will certainly be in retirement by the time the Government’s still un-mooted carbon-trading scheme begins in 2012. This is a scheme with no working detail yet, and we may not have that detail before the election. But in all probability it will be a carbon market framed around an emissions target to be announced by Howard’s successor, presumably, sometime in the new Liberal term.

So, who do you trust? Well, who knows?