Warming theories not carved in stone

The Australian

16th April 2008

square brackets show original draft

If the 2020 Summit wants new ideas on climate change, it needs to question the international panel's science, writes Des Moore

The 2020 summit is supposedly designed to allow consideration of views not previously examined by government policy makers. With climate change on the agenda, this should provide an opportunity to question the alleged scientific consensus claiming that increased emissions of greenhouse gases emanating from increased human activity have caused global warming.

The touting of the science consensus claim underpins the advocacy of large reductions in CO2 emissions to prevent temperatures increasing above a further 2 degrees and the assertion of many adverse consequences if that happened.

However, since the last report by the International Panel on Climate Change, many qualified scientists have begun to question its basic science, and even those accepting the science differ widely on emission reduction policies.

While the Stern review advocates early and strong action, well-regarded environmental economist William Nordhaus argues for only modest emission reductions initially, followed by sharper reductions later.

And Australia's Productivity Commission notes that uncertainty continues to pervade the science, geopolitics and economics, describing the Stern review as much an exercise in advocacy as an economic analysis of climate change.

Yet without holding any public inquiry into the science, the federal government aims for a 60 per cent reduction of CO2 emissions by 2050, starting with an emission trading scheme in 2010 that implies some reduction target then regardless of other countries' policies.

And although economist Ross Garnaut has been commissioned to report on emissions trading by September, he basically accepts the IPCC's science and his interim report foreshadows a reduction target for 2020. By contrast, internationally recognised emissions trading expert and Australian academic Warwick McKibbin rightly criticises Garnaut for failing to incorporate into the policy response that most experts in the climate change area acknowledge the science is still uncertain on what the precise target for greenhouse emissions should be.

Given the vast structural changes any emission reduction policy would cause, and the enormous increase in government power, the summit should surely call for more than a report on emissions trading. It is difficult to think of a more important issue facing Australia and the Government.

Account needs to be taken of the many expert analyses post-IPCC, including 400 who signed the minority US Senate report disputing the IPCC view. Also pertinent is the recent major report by the Nongovernmental International Panel on Climate Change (NIPCC) concluding that natural causes are very likely to be the dominant cause of global warming, signed by 23 experts, including two highly qualified Australian scientists.

Even a cursory consideration suggests it is timely to re-examine the situation at the summit, particularly:

* Global warming has occurred in past periods when human activity involving industrial type CO2 emissions did not occur and temperature levels were almost certainly higher. Experts, including scientists, have a history of unrealised doom and gloom predictions;

* Since the last IPCC report, new authoritative research shows about half the temperature increase since 1980 reflects normal heating effects from urban areas. Also, the absence of any increase since 2001, and the fall of 0.6C between January 2007 and January 2008, raises further doubts about the claimed correlation between increases in temperatures and CO2 emissions;

* Indeed, scientific analysis acknowledged in successive IPCC reports shows that incremental warming effects from increased CO2 concentration in the atmosphere diminish progressively with concentration. So, why did the IPCC fail also to acknowledge that this analysis suggests even a doubling of CO2 concentrations in the 21st century would increase temperatures over the rest of the century by only 0.3C?

* Scientific analysis of IPCC modelling used to project temperature increases is seriously deficient in [failing to take] taking proper account of the strong increase in surface evaporation occurring when surface temperatures rise. That surface evaporation includes an offsetting process that acts to limit such temperature rises. Why did the IPCC fail to recognise that larger CO2 concentrations will result in much smaller surface temperature rises than the models produce?

* If there are substantive qualifications to IPCC views, the need for governments to intervene to limit CO2 emissions is much diminished or disappears. Humans readily adapt themselves to different climates (as they do now) and for the present it would be best to rely on adaption;

* Any adoption of an emissions reduction policy by Australia should only be in the context of an effective, comprehensive global agreement.

The summit should call for a detailed public inquiry on both the science and economics of global warming, such inquiry to include experts not directly involved in the IPCC reports.