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Rebels of the sun
IT says a lot about the complexity of climate science that we can put a man on the moon but we still can't predict the weather beyond the next few days. The warming of the planet, and man's contribution to this phenomenon, has become the top scientific issue of this generation.
Science by its very nature is an argument. But apparently not this one any more. Yet a minority of scientists are still lining up to challenge the accepted wisdom with their claim that global warming is being principally driven by the sun, not by human activity.

The mainstream view is that an accumulation of greenhouse gases, mostly due to human activity, is trapping too much of the sun's heat within our atmosphere. But the rebels against this dominant view suggest massive variations in the sun's heat radiation are far more influential in warming than accumulating greenhouse gases.

The UN-linked Intergovernmental Panel on Climate Change released the executive summary of the science of its fourth assessment report in February. It reported "90 per cent" certainty among consulted scientists that the 0.6C average temperature increase measured during the 20th century was largely caused by the release of greenhouse gases, mainly from the burning of fossil fuels by industrialised economies. In other words, by humans.

Although the scale of warming predictions had altered little during the preceding six years of research, politicians and mainstream climate-change scientists queued up to declare the argument about human-caused climate change was officially over.

Despite such confidence, hundreds of blogs across the world continue to run charged claims and counterclaims on the internet about the various positions adopted by climate scientists. The scale of the argument is unprecedented and reflects considerable uncertainty. By comparison, there are no blogs debating the validity of the periodic table of elements, for example. ...

...At least one of the 1500 "leading scientists" it quotes as its underpinning authority is also one of its staunchest critics, Richard Lindzen, who is Alfred P. Sloan professor of meteorology at the Massachusetts Institute of Technology. He was a contributing author to this year's fourth IPCC assessment report but remains highly critical of how the panel operates, claiming it is largely a political process underpinned by science, which carefully stage-manages the release of its reports to maximise political impact.

The IPCC made headlines across the world in February with the release of the executive summary of its assessment report, which Lindzen says was severely modified by the political session that writes it and which is now modifying the full scientific report to fit for release in May. "That's a very funny procedure by most standards," he said. "You don't appeal to consensus if you have a scientific argument.

"Very few of the models are independent and they all share certain profound difficulties. They all get clouds hugely wrong and a small change in clouds has a much bigger effect than doubling CO2."

Bob Carter, who is a research professor in marine geology at James Cook University, says there are some excellent scientists involved in the IPCC process and the actual report is likely to be both sound and useful science. But he is even more scathing of the process.

"I think it is probably without precedent in any Western democratic process, the idea that you would publish an executive summary before the report and then openly say that 'we need a few more weeks to work on the report to make sure it is consistent with the executive summary'," he says.

"I don't know how anybody can take them seriously. It's become a religion. I have no doubt that a number of the IPCC supporters genuinely believe. Others know very well that the evidence isn't there, but it suits them to believe. ...

...In his Oscar-winning documentary An Inconvenient Truth, former US vice-president Al Gore's central claim in his description of the science was his correlation of 650,000 years of temperature changes with atmospheric carbon concentrations using polar ice-core samples. Gore described the relationship as complex, but made the most of the theatre, climbing up on a crane to accentuate the scale of the increases in greenhouse gas. But the sceptics point to a paper published in Nature and Science magazines showing the historical relationship between carbon dioxide and temperature has the gas lagging, not leading.

That is, greenhouse gas rises occurred about 800 years later than allegedly matching temperature change, as the warming seas released more gas into the atmosphere and trapped it when cooling.

This doesn't discredit the mainstream theory that present levels of greenhouse gases are still well above historical levels, but it is one of several areas where even mainstream scientists believe Gore appears loose with the science to make his film more dramatic.

The CBC documentary referred to predictions of sea-level rises of up to 24m as a result of climate change. The IPCC predicts rises at worst of about 50cm by 2100. If it's not OK to mislead the public in criticising climate-change science, why is it OK to mislead people in selling it? ...