Ian Plimer has outraged the ayatollahs of purist environmentalism, the Torquemadas of the doctrine of global warming, and he seems to relish the damnation they heap on him.

Plimer is a geologist, professor of mining geology at Adelaide University, and he may well be Australia's best-known and most notorious academic.

Plimer, you see, is an unremitting critic of "anthropogenic global warming" -- man-made climate change to you and me -- and the current environmental orthodoxy that if we change our polluting ways, global warming can be reversed.

It is, of course, not new to have a highly qualified scientist saying that global warming is an entirely natural phenomenon with many precedents in history. Many have made the argument, too, that it is rubbish to contend human behaviour is causing the current climate change. And it has often been well argued that it is totally ridiculous to suppose that changes in human behaviour -- cleaning up our act through expensive slight-of-hand taxation tricks -- can reverse the trend.

But most of these scientific and academic voices have fallen silent in the face of environmental Jacobinism. Purging humankind of its supposed sins of environmental degradation has become a religion with a fanatical and often intolerant priesthood, especially among the First World urban elites.

But Plimer shows no sign of giving way to this orthodoxy and has just published the latest of his six books and 60 academic papers on the subject of global warming. This book, Heaven and Earth -- Global Warming: The Missing Science, draws together much of his previous work. It springs especially from A Short History of Plant Earth, which was based on a decade of radio broadcasts in Australia.

That book, published in 2001, was a best-seller and won several prizes. But Plimer found it hard to find anyone willing to publish this latest book, so intimidating has the environmental lobby become.

But he did eventually find a small publishing house willing to take the gamble and the book has already sold about 30,000 copies in Australia. It seems also to be doing well in Britain and the United States in the first days of publication.

Plimer presents the proposition that anthropogenic global warming is little more than a con trick on the public perpetrated by fundamentalist environmentalists and callously adopted by politicians and government officials who love nothing more than an issue that causes public anxiety.

While environmentalists for the most part draw their conclusions based on climate information gathered in the last few hundred years, geologists, Plimer says, have a time frame stretching back many thousands of millions of years.

The dynamic and changing character of the Earth's climate has always been known by geologists. These changes are cyclical and random, he says. They are not caused or significantly affected by human behaviour.

Polar ice, for example, has been present on the Earth for less than 20 per cent of geological time, Plimer writes. Plus, animal extinctions are an entirely normal part of the Earth's evolution.

(Plimer, by the way, is also a vehement anti-creationist and has been hauled into court for disrupting meetings by religious leaders and evangelists who claim the Bible is literal truth.)

Plimer gets especially upset about carbon dioxide, its role in Earth's daily life and the supposed effects on climate of human manufacture of the gas. He says atmospheric carbon dioxide is now at the lowest levels it has been for 500 million years, and that atmospheric carbon dioxide is only 0.001 per cent of the total amount of the chemical held in the oceans, surface rocks, soils and various life forms. Indeed, Plimer says carbon dioxide is not a pollutant, but a plant food. Plants eat carbon dioxide and excrete oxygen. Human activity, he says, contributes only the tiniest fraction to even the atmospheric presence of carbon dioxide.

There is no problem with global warming, Plimer says repeatedly. He points out that for humans periods of global warming have been times of abundance when civilization made leaps forward. Ice ages, in contrast, have been times when human development slowed or even declined.

So global warming, says Plimer, is something humans should welcome and embrace as a harbinger of good times to come.

jmanthorpe@vancouversun.com