David Evans “worked for the Australian Greenhouse Office from 1999 to 2005, building the carbon accounting model that Australia uses to track carbon in its biosphere for the purposes of the Kyoto Protocol. He is a mathematician and engineer, with six university degrees including a PhD from Stanford University.” In this recent contribution to ABC Unleashed, linked to his name there, he argues:
On global warming, public policy is where the science was in 1998. Due to new evidence, science has since moved off in a different direction.
The Intergovernmental Panel on Climate Change (IPCC), the UN science body on this matter, is a political body composed mainly of bureaucrats. So far it has resisted acknowledging the new evidence. But as Lord Keynes famously asked, “When the facts change, I change my mind. What do you do, sir?”
Four things have changed since 1998…
This may seem to be one of the more credible interventions on the side of the sceptics on this issue, though the argument that there has been global cooling since 1998 was rather well refuted by Tim Flannery on Q&A last week. Dr Flannery pointed out that 1998 was a record high in global temperature, and that any downward shift since does not affect the overall trend. If you take 1998 as a starting point, in other words, you falsify the general trend. David Evans is revealed to be very much a Usual Suspect by Sourcewatch. For a detailed rebuttal of Evans see The Australian’s War on Science XV by Tim Lambert, a computer scientist at the University of New South Wales.
Tonight’s Four Corners, with supplementary material appearing in the Sydney Morning Herald, is a must see.
Note the box on climate change in the side bar on this blog for related links.
Unleashed now has an answer to Evans, perhaps, in another David — David Karoly, “an ARC Federation Fellow and Professor of Meteorology in the School of Earth Sciences at the University of Melbourne. He was heavily involved in the preparation of the IPCC Fourth Assessment Report, released in 2007. He is a member of the Wentworth Group of Concerned Scientists.” See Climate change science misinformation.
…Global average temperatures have dropped from 2002 to 2008, while carbon dioxide has increased, so carbon dioxide can’t cause long-term warming. This is another false conclusion. There are large natural year-to-year variations in climate. The warming influence due to increasing greenhouse gases is at global scales and cumulative over many years.
At short time scales, natural variability can offset that warming influence and cause short-term cooling. Global average temperatures have fallen over the last six years, due to natural variations, with the warmth in 2002 and in 1998 due to El Niño events and the recent La Niña causing colder temperatures in 2007 and 2008. The long-term warming trend is unequivocal…