Andrew Bolt has continued to ask all comers about how the Australian carbon tax will impact on global temperatures, and most people have refused to answer. So he decided to work out his own estimate. Using the calculations of Damon Matthews, who suggests that a tonne of co2-e will change temperatures by 0.0000000000015 degrees, and given that the government plans to reduce our emissions by 160 million tonnes, then Bolt estimates that our carbon tax will change the global temperature by about 0.00024 degrees. Fair enough.
From the other side of the fence, the only person I have seen willing to put their name to an estimate is John Quiggin, who thinks the carbon tax will be 100 times more effective and reduce temperatures (compared to “business-as-usual”) by 0.02 degrees. Quiggin should be congratulated for putting his name to an estimate, and it’s appropriate to note his caveat “as should be pretty obvious, it’s not meant to be precise, and claiming precision would be silly in any case”. Fair enough.