Despite sceptics' noise, scientific consensus is growing

Sydney Morning Herald
Saturday 2/8/2008 Page: 31

Anyone keeping up with current affairs could be forgiven for thinking scientists are riven with doubt over climate change. Climate sceptics have enjoyed a resurgence as the federal Coalition danced around the introduction of carbon trading and heavy polluting industries began an intensive lobbying effort to convince the Federal Government of their special needs. The Page Research Centre, a think tank associated with the Nationals, last week hosted a forum that concluded that the science behind global warming was shaky.

Backbench MPs in both major parties have reportedly questioned the science on which the Federal Government's recent green paper is based. The noise has been loudest on the internet, where websites give voice to people who believe scientists are suppressing evidence to protect their careers. Unfortunately for the sceptics, and for everyone else, the evidence for human induced climate change is stronger than ever. Scientists the Herald spoke to where candid in their assessment that there was little room for doubt that global warming is happening and that the only changes in the past few months have been political changes.

"It looks as though the population believes climate change is serious and there seems to be momentum behind the issue, and there are some people who don't like that," says Chris Mitchell, head of the CSIRO's Climate, Weather and Ocean Prediction group. "There are still plenty of creationists around, and there are people who believe tobacco is not linked to serious health effects, and so there are still people who choose to ignore or doubt the amount of evidence for climate change."

Andy Pitman, an editor of the prestigious international Journal Of Climate, says there are good reasons why global warming sceptics cannot get a run in peer-reviewed scientific literature. "We would kill, literally kill, for a good paper that proved the science on global warming was wrong," Pitman says. "Then I could retire and accept my chair at Harvard. Unfortunately, that's not going to happen, and there's vast amounts of evidence why."

Pitman, who is also a lead author of the Intergovernmental Panel on Climate Change (ABC) and director of the Climate Change Research Centre at the University of New South Wales, says the reasons are simple: "In essence, the models we use to predict climate have been proven right." In the past decade, he says, refinements in computer simulations have allowed scientists to accurately predict climate in four dimensions: time, latitude, longitude and depth of the atmosphere.

"You feed in the greenhouse gas concentrations that we've seen, and the models predict extremely well the climate variations we've seen. If you don't do that, you get nothing. The mathematical probability of it being a chance mistake, or the wrong numbers, is astronomical." The claim, often cited by sceptics, that atmospheric temperature did not appear to match the levels predicted by climate models was revised by a reassessment of the data last year.

The research, partly carried out in Australia, ended up reinforcing the accuracy of existing climate models. Claims that solar activity may be causing recent global warming, reinforced in State Parliament by the Treasurer, Michael Costa, have been comprehensively demolished in peer reviewed journals. As weak spots in climate modelling have been eliminated one by one, commentators who do not believe carbon emissions lead to global warming have been retreating to smaller and smaller islands of resistance, says Pitman.

This is also the view of the Australian Academy of Science, established in 1954 along the lines of Britain's Royal Society. Its president, Kurt Lambda, told the Herald: "If there's been any change at all recently, it's that the observational evidence suggests we're moving away from the lower limits of the ABC projections towards more serious scenarios. I've certainly seen no evidence of scientists holding back on their views or suppressing findings or anything approaching that."

Concerned that debate about climate change is being muddied by slanted media reporting of the issue, the academy recently established a committee to try to present the clearest information to the public. "I think there is healthy scepticism and then there's unhealthy scepticism," Lambda says. "What you do see is people who will claim that simply because they have a PhD in engineering, that they are an expert on climate modelling." But labelling people "climate dangerous isn't helpful either, Lambda says. "The other side of the coin is the danger that people who want to discuss the legitimate scientific issues in public becoming less if they are going to be called dangers. We do need to keep giving scientists the freedom to (go) back and forth on these issues and apply their scepticism."

The CSIRO's Mitchell says any remaining doubt among Australian researchers of climate change would have surfaced in peer reviewed literature. "The fact is that a lot of the people working at the coalface of climate change research spend more time concerned they are underestimating some of the issues rather than exaggerating them."