Garnaut needs critical scan

Letter

Australian Financial Review

29th February 2008

As your editorial "Garnaut turns up the heat" (February 22) says, Ross Garnaut has stunned many with his advocacy of deeper cuts in CO2 emissions than called for by the Intergovernmental Panel on Climate Change (and the government). This reflects his assumption that the very short period of recent faster world economic growth than the IPCC assumes will continue to 2050 and, hence, cause faster growth in emissions and higher temperatures.

However, while Garnaut rightly says climate change policy must begin with the science, he rejects assessments by "some people with relevant scientific credentials" seriously questioning the IPCC conclusion that increased human activity has caused increased temperatures since 1750.

Accordingly Garnaut argues, "it would be imprudent ... to choose to do nothing in the hope that the problem will go away". But he also considers "there is value in expanding the global scientific effort" and foreshadows proposals for expanding Australian research in climate change science.

Unfortunately, Garnaut appears unaware of the seriousness of the critical assessments of IPCC conclusions by highly qualified senior Australian (and overseas) scientists.

These include, first, that the recent global warming is not unprecedented but has occurred in past periods when human activity of the post-1750 kind did not exist; second, widely agreed scientific analysis (acknowledged in successive IPCC reports but not reflected in its conclusions) shows that any warming effect from increased CO2 concentrations diminishes progressively and has already almost stopped (even doubling CO2 concentrations in the 21st century would increase temperatures by only 0.3 of a degree); and, third, models projecting temperature increases based on radiation effects of higher CO2 concentrations take inadequate account of associated offsetting cooling effects.

It would be highly imprudent, to say the least, not to take account of these critical assessments in making policy decisions on reducing CO2 emissions. Accordingly, the Rudd government should institute an independent inquiry into the science comprising non-contributors to the IPCC report.