Friday, May 1, 2009

The sceptic's shadow of doubt

AS MIGHT be expected of a man taking on the world's major scientific academies and governments, Professor Ian Plimer isn't short on confidence.

Two weeks ago, Plimer, an award-winning geologist from the University of Adelaide, published Heaven + Earth, a 500-page argument against the idea that humans can dramatically affect climate.

"Very few people know that the planet changes all the time — that we have these massive cycles driven by forces far greater than human forces — and in many ways it is my job as an educator to say 'look at the big canvas'," he tells The Age.

His book has received glowing endorsements in the conservative press and been embraced by some federal MPs. Queensland Nationals senators Barnaby Joyce and Ron Boswell offered to launch it.

The uncritical publicity and some robust ABC interviews helped push an initial print run of 5000 to 15,000. But the book's thesis has also raised the ire of Australia's most internationally respected climate scientists.

"If the book was handed to me as an assignment in my undergraduate earth science classes, it would have failed— not because I don't agree with the answers, but it doesn't support the answers with sources," says Melbourne University climate change expert Professor David Karoly, who accuses Plimer of using data misleadingly.

It is a debate among scientists — and non-scientists — echoed across the globe. Last weekend, the respected scientific journal Geophysical Research Letters published a paper that, from its first sentence, criticised the media and blogosphere for disseminating persistent — and, it suggests, unscientific — claims that the climate has stopped warming and started cooling. According to that argument, temperatures have fallen since 1998 despite greenhouse emissions continuing to rise. Ergo, global warming and emissions can't be linked.

The paper, by scientists David Easterling, of the United States National Climatic Data Centre, and Michael Wehner, of the Lawrence Berkeley National Laboratory, tackles this contention head on.

They wrote: draw a trend line through the temperatures from 1998 — an abnormally hot year even by the soaring standards of the 1990s, due to El Nino — and 2008, and it is statistically flat. Temperatures plateaued over the decade. But drop 1998 off the graph and the line turns upward. Global warming before your eyes.

The point, Easterling says, is that perspective is everything. When it comes to climate change, a wider lens is needed; "cherry picking" temperatures from a short period to reinforce a point of view can be misleading.

The paper, "Is the Climate Warming or Cooling?", comes at a crucial time in the climate change debate in Australia.

On one hand, the Federal Parliament will this month debate the Government's much-criticised emissions trading scheme. Unless Prime Minister Kevin Rudd bows to the Opposition's demands to redesign the scheme, it seems highly unlikely it will get through the Senate.

On the other, debate about the validity of the climate science, cited to demand an overhaul of the economy, has gained new momentum. Much of this is due to Plimer. Over a coffee on a wintry April morning, Plimer is politely combative, rambling and hard to pin down. Like his book, his conversation is a grab-bag of arguments against human-induced climate change drawn from science and popular debate. It veers here and there, but has three main points.

He explains, at length, that climate is constantly changing due to natural variability (a point no climate scientist disputes). He says climate science lacks scientific discipline, and he is scathing at the use of computer modelling, saying it manipulates and simplifies the tried and trusted scientific process of observation, measurement and experiment.

Crucially, and like Easterling, Plimer says you can't cherry pick when looking at the planet. But his idea of perspective is a little different and, according to his critics, inconsistent. Heaven + Earth repeatedly makes a case that the globe has cooled since 1998, but then argues you can't get an accurate picture of changes by looking at just a decade, or even the 250 years since industrialisation began. You have to look at the geological record over millions of years. This, he contends, has been ignored by the United Nations Intergovernmental Panel on Climate Change, which, he says, has focused solely on the atmosphere.

"Every human living on planet earth, at any time in history, has always thought that these are special and unique times, and I think it is enormous human arrogance to think we have some control of the planet," he says.

Plimer says his book is for the "average punter in the street", who can smell something is wrong in the climate debate but can't put a finger on what. "They're sick of being treated like a fool and having scientists and some quarters of the media pontificate to them," he says.

He has taken this sort of stance before, though not with a position so out of step with the majority view.

He devoted years to disproving creation science, a campaign that led to a book, Telling Lies for God, and a court case when he was sued for defamation after he accused a group of lying about having found the remains of Noah's Ark. He responded by taking his opponent to court under the Trades Practices Act.

He has also written on the perils of non-human-induced climate change, and was awarded the Eureka Prize for the promotion of science for his 2001 book A Short History of Planet Earth. That book warns: "It would not be surprising if sea level rose a few metres over the next century causing untold suffering in low-lying areas such as Bangladesh, Holland, north Germany and many non-coralline islands." Of course, he does not link this to carbon dioxide emissions.

Plimer places human-induced climate change in a similar basket as creation science. He describes it as a fundamentalist religion adopted by urban atheists looking to fill a yawning spiritual gap plaguing the West. That gap, he claims, was filled by environmental groups who latched on to a new means for existence once the Cold War ended and the threat of nuclear annihilation dissipated. Many environmentalists are dismissed as having a romantic view of a less developed past, rather than concern for the future.

In Heaven + Earth, some fierce contempt is reserved for the IPCC, which Plimer says has allowed "little or no geological, archeological or historical input" in its analyses. If it had, it would know cold times lead to dwindling populations, social disruption, extinction, disease and catastrophic droughts, while warm times lead to life blossoming and economic booms — suggesting that global warming, were it happening, should be welcomed.

The IPCC, he says, is a dishonest political organisation hijacked by environmental activists and diplomats to boost trade, encourage protectionism and add costs to competitors.

Some questions Plimer can't answer. His book challenges claims that six of the warmest years since industrialisation were between 1998 and 2006, instead quoting NASA figures that the hottest four years were in the 1930s. He fails to say in the book that this data is for the US alone.

Some of his critics say they are surprised that a former head of the University of Melbourne geology department, with more than 120 published papers to his name, would include unsourced graphs in his book. Asked where he found one graph showing temperatures across the 20th century differing markedly to the data used by the IPCC or the world's leading climate centres, Plimer says he can not recall.

David Karoly, also an IPCC author, says there are other examples of misleading use of data. The first graph in the book contrasts temperature over the past two decades with climate models used by scientists, but averages the models together, removing the variation they factor in.

But what of the book's broader claims?

Matthew England, joint director of the University of NSW Climate Change Research Centre, rejects Plimer's attacks on the IPCC, saying the organisation has always looked at the past, including a chapter on paleoclimatology in each of its reports.

"That is an absolute no-brainer. He shouldn't be getting away with saying the IPCC ignores the past, it's absolutely untrue," he says. "The IPCC includes all relevant information from geology, geophysics, solar processes, oceanography, glaciology, right through to paleoclimate. Every area he claims he is bringing in for the first time is already there."

When Plimer says carbon dioxide levels have been higher than today's for more than 90 per cent of geological history, England says, "he is talking about eras where human civilisation didn't even exist. Records out to 50 million years ago clearly show that whenever carbon dioxide levels were higher than today, the planet was subjected to much higher air temperatures and much higher sea levels — by tens of metres."

Professor Charlie Veron, former chief scientist at the Australian Institute of Marine Science, says every original statement Plimer makes in the book on coral and coral reefs is incorrect. He says many of the contextual diagrams and references used in the book are accurate, but "when it comes to attacking climate change science, Plimer changes tack. We are served up diagrams from no acknowledged source, diagrams known to be obsolete and diagrams that combine bits of science with bits of fiction."

Several scientists argue that Plimer's work hasn't been backed by other scientists. Easterling hasn't read Plimer's book, but his analysis published last weekend also challenges Heaven + Earth. Taking a century-long view, it shows temperatures have flatlined and sometimes cooled for up to two decades at a time due to natural variability — the end of an El Nino, for instance — within a longer warming trend. It backs the IPCC models, and says the warming will continue.

Adam Morton is environment reporter.

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