Christopher Pearson: Science for believers

One of the Radio National world view's more disconcerting features is its enthrallment to apocalyptic science. Sometimes, listening to Fran Kelly discussing the latest portents of global warming, I can almost hear the polar ice melt and rising waters lapping at the front doorstep. No hint of licensed scepticism, no inkling that this may be just one more millennial fantasy, is allowed to obtrude. This is not a radio show. It's a sacramental observance for true believers.

It was while listening to Radio National that I first began to understand Tim Flannery, the director of the South Australian Museum and author of a number of popular science books. Previously I've dismissed him in this column as the P.T. Barnum of his profession, just a showman. But, as his new book The Weather Makers makes plain, he's more shaman than showman, a folk mystic and prophet for the New Age remnant.

Mainstream science is committed to sceptical inquiry, to falsifiable hypothesis and empirical method. Flannery embraces the Gaia principle: that the Earth is a single, planet-sized organism. This mystical theory was first advanced, at least in its modern form, by a mathematician called James Lovelock in 1979. He named it Gaia after an ancient Greek earth goddess.

Flannery hopes to keep a foot in the rationalist camp by suggesting: "Let's use the term Gaia as shorthand for the complex system that makes life possible, while recognising all the while that it may result from chance." From the standpoint of scientific method that is still, at best, a superfluous hypothesis. How does he justify it?

He says: "Does it really matter whether Gaia exists or not? I think that it does, for it influences the very way we see our place in nature. Someone who believes in Gaia sees everything on Earth as being intimately connected to everything else, just as organs are in a body. In such a system, pollutants cannot simply be shunted out of sight and forgotten, and every extinction is seen as an act of self-mutilation. As a result, a Gaian world view predisposes its adherents to sustainable ways of living."

As Dorothy famously remarked to her little dog, as they were swept up on to the yellow brick road: "Toto, I don't think we're in Kansas any more." Consider the solipsistic logic. It matters that Gaia exists not because it's true but because it helps us to conceive of the world and our place in it in what he supposes is a desirable way.

It's an exercise in mystagoguery, justified on instrumentalist grounds. Once swallowed whole, it becomes as immune to argument as the patent falsehood that when, for any reason, a species becomes extinct, humans have somehow mutilated themselves. Species become extinct for many reasons, some quite unrelated to human activity. The idea that all changes to biodiversity are down to human mischief is as hubristic as the notion that we're collectively responsible for changes in the weather.

Bob Carter, a science professor at James Cook University, took The Weather Makers to task the other day for what he called "Mother Earthism". As he says, it's a debilitating affliction involving "a touching belief in the Garden of Eden, the halcyon state of the Earth in times before the wicked Industrial Revolution. This balmy, and barmy, garden existed in a state of existential ecological balance."

While Flannery is indeed a true believer, his general stance is that of a man of knowledge who has satisfied himself that human-generated greenhouse gases threaten our survival and is telling his readers as much as they need to know. Most of the time impending catastrophe is offered simply as the informed consensus view, but sometimes he takes us into his confidence on thorny questions of cognitive dissonance.

The most artlessly comic example occurs halfway through the book. "We must now turn to the key uncertainty that remains in all models: will a doubling of CO2 lead to a 2C or a 5C increase in warming, and can we expect a reduction in this uncertainty in the near future? This is a critical issue not least because the US Government has signalled that it will not reconsider its climate change policy until there is more certainty. Given that almost 30 years of hard work and astonishing technological advances have failed to reduce the degree of uncertainty, we should not be too sanguine about hopes for more precision."

The tone of this admission is so cack-handed and the margin for error so large. What government in its right mind, you may wonder, would commit to spending billions of dollars on the strength of computer modelling so lacking in predictive authority? Doesn't he realise how withering a light this casts on all that Gaian wisdom, not to mention the much-vaunted consensus scholarship and technological ingenuity? Probably not, I suspect.

William Kininmonth is a meteorologist with more than 40 years' experience. In the space of a single column in The Sydney Morning Herald last week he drew attention to three problems with Flannery's argument. First of all, he pointed out that historically the Earth had often experienced naturally occurring extremes of climate. Even so, "the evidence that the climate system may pass some imagined critical point that leads to runaway global warming is not convincing".

Second, he noted that, from a climatological perspective, the influence of CO2 was vastly overrated. "Water vapour is a more powerful greenhouse gas than carbon dioxide and the formation and dissipation of clouds has a bigger impact on the climate."

Finally, "climate is a complex system for exchange and transport of energy, to balance the excess solar radiation of the tropics and the deficit over polar regions. Existing computer models are not able to adequately replicate these essential energy processes, raising serious doubt over their ability to predict future climate."

In ordinary scientific debate, the proponents hammer out the issues and the matter is eventually decided on the force of evidence and argument. If an expert in the field writes an article saying there's nowhere near enough evidence for the case you're trying to make or that, whoops, you're concentrating on the wrong gas or that your computer models don't correspond to observable reality, you reply as best you can. But, for subscribers to catastrophist theories, these days belief apparently supplants the need to engage with your critics.