After 13 years of writing this weekly column I have become inured to criticism, to which I rarely respond, but the letter by Jim Salinger published on the page opposite on Monday demands a reply.

Typical of patronising PhDs, Dr Salinger labels me a "climate change denier". That is downright dishonest. However, it is understandable considering that those who peddle the CO2-is-the-cause-of-global-warming fallacy rely on pseudo-science which is in itself dishonest.

I am not, and nor are the many, many people - scientific and lay - who agree with me, a climate change denier. We cheerfully admit that our climate is changing. It would be hard not to, since climate change has been happening since the Earth was created.

It might even be warming, at least in some parts of the world, but having just suffered the longest and coldest winter since the 1960s in Rotorua, I have real cause to doubt that it is happening here.

My scepticism grows when I note the fact that the Franz Josef and Fox glaciers are increasing in ice, that the ice melt across the Antarctic during the summer (October-January) of 2008-09 was the lowest ever recorded in satellite history, that western Antarctica has had a major increase in ice lately, and that there are 200-odd peaks in the Himalayas that are increasing drastically in ice and snow.

But you never read in the press of these things for some reason or another, just as we never read any of the copious material available, much of it peer-reviewed, which questions the effect of man-produced CO2 on global warming.

So let's take a look at one of the most recent papers, published last month in Economic Analysis & Policy, the journal of the Economic Society of Australia.

Headed, "Knock, knock: Where is the evidence for dangerous human-caused global warming?", it is written by Robert M. Carter, adjunct research professor in the Marine Geophysical Laboratory at James Cook University, Townsville, and at the University of Adelaide. A geologist, he specialises in palaeoclimatology, stratigraphy, marine geology and environmental science.

In the conclusions to his paper he writes: "To focus on the chimera of human-caused greenhouse warming while ignoring the real threats posed by the natural variability of the climate system itself is self-delusion on a grand scale.

"That human-caused climate change will prove dangerous is under strong dispute among equally well-qualified scientific groups. The null hypothesis, which is yet to be contradicted, is that observed changes in climate or climate-related phenomena are natural unless and until it can be shown otherwise.

"The science of climate change is far from settled. Meanwhile, there is no compelling evidence that human-caused climate change poses a strong future danger."

Professor Carter says no measurable environmental benefits have resulted from actions taken under the Kyoto Protocol, nor can they be predicted to result from CO2 emissions restrictions more generally.

On the other hand, the social and economic "disbenefits" of governments deploying such instruments are reported daily in the media.

"The available scientific data, and proved relationships, do not justify the belief that carbon dioxide emission controls can be used as a means of 'managing' or 'stopping' future climate change," says Professor Carter.

"The projections (which are not predictions) of computer modellers that are now almost the sole basis for IPCC climate alarmism must be assessed against the best available empirical evidence."

He says climate variation has always occurred and always will. Citizens are right to be concerned about the possibly damaging effects of both the warmings and coolings which lie ahead.

"As with most potential natural disasters, however, the appropriate action is to have in place reactive response plans to manage the change when it occurs. Dangerous climate extremes will not be prevented by reducing human carbon dioxide emissions, but - as they occur - should be adapted to using similar response strategies to those applied to other dangerous natural events such as earthquakes, volcanic eruptions, tsunami and sea-level change."

Professor Carter avers that "attempting to 'stop climate change' or, in the present state of knowledge and technology, even to modify it, is an Arcadian fantasy".

He suggests that Australia's Emissions Trading Scheme Bill should be deferred until the completion of a thorough and independent judicial review into alleged human-caused global warming, as assessed against the reality of dangerous natural climate change.

Cutting CO2 emissions, he says, is as likely to harm as to help future climate as judged against a human viewpoint.

"The correct climate policy is one of monitoring climate change as it happens, adapting to any deleterious trends that emerge, and compensating those who are disadvantaged through no fault of their own," Professor Carter says.

Now I don't know about Dr Salinger and his fellow global warming scaremongers, but what Professor Carter has to say makes eminent sense to me.