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Warming evidence on shaky ground
letter published in The Australian Financial Review, 3 July 2009

John Quiggin suggests that if the coalition does not support the emissions trading legislation a double dissolution would allow the government to secure its passage with the support of the Greens ("Carbon action gathers global pace", Opinion, July 2).

This assumes continued acceptance of what he calls "the compelling science evidence on climate change". Evidently, he has not caught up with Climate Change Minister Penny Wong’s answers to Senator Steve Fielding’s three questions. These answers suggest that the evidence is now far from compelling.

The published assessment of those answers by four expert Australian scientists reveals why that is the case viz:

• The answers detract from previous arguments that CO2 emissions are the dominant influence on temperatures by acknowledging that natural variability explains the failure of surface temperatures to increase since 1998;
• Ignoring the previous centering of public debate on surface temperatures, they advance a previously unheard of claim that ocean temperatures are the most appropriate single indicator of global warming because "only about 5 percent of warming since 1960 has taken place in the air";
• They fail to explain the difference since 1960 between the apparent respective increase in ocean and surface temperatures – 0.15 and 0.6 of a degree;
• The answers also fail to acknowledge either the recognised paucity of measurements of ocean temperatures before the deployment of Argo buoys in 2002 or the apparent absence of any increase since then; 
• By using dubious proxy reconstructions of ancient temperatures they ignore the abundant historic and geological data showing previous periods of warmings higher than at present.
  

These answers were partly prepared for the minister by ANU Climate Change Institute's Professor Will Steffen, who also helped draft the Synthesis Report of the March scientific congress held in Copenhagen as a precursor to the world conference there in December. That report contains similarly misleading assertions.

It is difficult to believe that this “compelling evidence” could last for long.

Des Moore
Director  Institute for Private Enterprise
South Yarra Vic

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