A challenge to climate sceptics

There are admittedly a number of factors that muddy the waters when it comes to climate.

• Climategate demonstrated that a number of scientists were behaving badly. That, by itself, is not surprising. It has happened throughout history and will happen again. In that respect scientists are no different to any other group – e.g. Wall Street Bankers. What is shocking is that, like Wall Street Bankers, the misbehaving scientists were not sacked. Phil Jones should not have been allowed to remain on as head of the Climate Research Unit at the University of East Anglia
• Some climate scientists appear to have an exaggerated notion of their ability to forecast the future.
• Some of the policy responses to AGW are nothing short of lunatic. The only thing that I can think of that would be worse than the Gillard Government's go-it-alone carbon tax would be to emulate Europe's carbon trading scheme.
• People most of us would prefer not to be associated with have taken on climate change as a political cause. I really do not like the thought of being on the same side as that recycled Stalinist and anti-Semite, Lee Rhiannon, in any debate.

However most climate scientists are not charlatans. Nor are they Stalinists. They are hard working researchers who are doing their best to understand the likely consequences of adding greenhouse gases to the atmosphere. It is a fiendishly difficult task.

I have admitted freely that some climate scientists have behaved badly and that, for reasons I cannot understand, they keep their posts. But the same is true on the other side. I'll confine myself to one example, Professor Ian Plimer, Professor of Mining Geology at the University of Adelaide.

I used to respect Professor Plimer so I was anxious to read his book, Heaven and Earth - Global Warming: The Missing Science (2009).

What a load of codswallop! There is no other way to describe it. For example, Plimer claims that volcanoes emit more CO2 than human activity. This is news to the United States Geological Survey (USGS) that keeps track of volcanic emissions across the globe. According to their figures volcanic emissions amount to less than 1 per cent of human emissions. Attempts to get Plimer to explain the differences between his numbers and USGS have been to no avail.

Plimer claims that temperatures during the so-called Mediaeval Warm Period (MWP) were higher than today. There were no thermometers around during the MWP. We do not have an accurate temperature record. Temperatures have to be inferred from proxy sources such as tree ring widths. To say that the error bands are large is an understatement.

However the best evidence we have suggests that temperatures today are considerably higher than those prevailing during the MWP. In fact the whole idea of a Mediaeval Warm Period may be something of a myth. Many scientists have pointed these and other errors of fact out to Plimer. His book has been through multiple printings. He has never issued a correction.

Here is what one pundit writing in The Australian, hardly a hotbed of Marxists, had to say about Plimer:

Plimer claims that scientists such as himself, who do not agree with the consensus, are labelled deniers, "yet their scientific doubts are not addressed". Nothing could be further from the truth. All of Plimer's arguments have been addressed ad nauseam by patient climate scientists on websites or in the literature.

So a professor at a leading Australian university continues to disseminate information knowing it to be false. Should he be sacked? What is the scientific consensus with regard to global warming?

Most actual climate scientists are of course of the opinion that continuing to add CO2 to the atmosphere could have severe negative consequences for humanity. Not all of them are of that opinion. But the vast majority are. What about scientists from other disciplines?