Insufficient proof to condemn the accused, CO2

Earth scientist Ian Plimer has hit a nerve in the debate about the role of carbon dioxide in global warming.

Critics of Ian Plimer’s opinion that mankind’s minuscule contribution to carbon dioxide emissions remains an unproven theory that continues to rely on the discredited belief that 97 per cent of scientists agree that climate change is man-made (Letters, 19/1). It has been shown conclusively that this consensus derives from a handful of surveys and exercises in counting abstracts from scientific papers and articles — most of which have since been contradicted. In fact, scores of prominent climate scientists have questioned the consensus.

Regarded as one of the 20th century’s greatest physicists, Freeman Dyson, said this recently: “The harmful effects of CO2 have been greatly exaggerated ... The people who are supposed to be experts and who claim to understand the science are precisely the people who are blind to the evidence.” Plimer is not among them but his critics are.

Kevin Begaud, Dee Why, NSW

Ian Plimer seems to have hit a nerve. While many of us are sure climate is changing, it may be cooling. After all, even the true believers have changed the term from global warming to climate change. Whatever is going on, the average person in the street knows the whole thing is being exaggerated and that governments are acting on these exaggerations.

Even assuming that increased CO2 is to blame, what can be done? Nothing Australia does can make any significant difference to global CO2 emissions so why aren’t the hand wringers protesting outside the Indian and Chinese embassies instead of making life here increasingly difficult and expensive?

Hilary Mercer, Rockhampton, Qld

May your letters columns be given more space in your august journal. If ever there was a time for robust debate, it is now. You gave respected geologist Ian Plimer the opportunity to present his views on an issue fundamental to understanding why we have hitherto enjoyed the benefits of cheap and reliable access to energy.

He exposed foolish political obstacles denying access to this essential need. There is no scientific evidence that mankind has any influence on tides, sea levels, earthquakes, volcanic eruptions, or asteroid impact, yet social scientists continue to claim attention with newspeak words — sceptics, deniers, scientific consensus — all attempting to supplant science with popular opinion and poll-driven policies underlain by other agendas. Political power and the money trail are clues to this phenomenon.

John McRobert, Indooroopilly, Qld

First, they said that the temperature wasn’t rising anymore, that there was a hiatus. But we don’t hear much about the hiatus anymore. Then they said some temperatures were not accurate and accused the Australian Bureau of Meteorology of doctoring temperature records.

Then they ridiculed some of the computer modelling that was predicting much faster temperature rises than was actually occurring. But recently, more accurate ocean temperature measurements have shown that the modelling is much closer to the measurements.

Now, Ian Plimer is disputing the claim that 97 per cent of scientists agree that humans are contributing to global warming. We will have to wait for some alternative analysis of how this figure was reached to see who is right. Meanwhile, global temperatures, and temperatures in Australia especially, keep rising.

Denialists argue this is a natural cycle. But what if it isn’t and is caused by man-made greenhouse gases? Will our great grandchildren forgive us for bequeathing them almost unbearable temperatures, increased storms and rising sea levels, all because we weren’t willing to forgo a little of our already relatively excessive affluence to reduce greenhouse gases?

Allan Thomas, Lochinvar, NSW

Robert Healy (Letters, 19/1) justifies all geography and science teachers teaching “anthropogenic climate change as a fact” because that’s what he was taught at university and his reading supports this view.

Does it not occur to him that his university lecturers and the texts he reads may be blinkered? He implicitly dismisses Ian Pilmer’s article because Pilmer is a geologist, not a climatologist. I wonder if he gives palaeontologist Tim Flannery such short shrift. I suggest he’d serve his students better by distinguishing between hypothesis and fact and also presenting alternative credible theories to consider.

Tim Noble, Southbank, Vic