One cool view of global warming

Canberra academic Professor Don Aitkin presents this skeptical article in the Canberra Times 2 April 2008. Great to see another skeptic speaking out.

One cool view of global warming
By DON AITKIN 03 April 2008 (Canberra Times 2 April)

About a year ago I decided that I should look hard at the issue of Anthropogenic Global Warming the notion that it is we human beings who are responsible for the warming of the earth.

I thought we had immediate environmental problems facing us, including our failure to manage water and our over-dependence on oil , and that we should be dealing with them. Global warming seemed a distraction.

Although it was plain that the learned academies, governments and the UN all seemed to believe AGW was true, what puzzled me was the stridency of the claims that we had to act now. If it was all so obvious, why weren’t our governments acting to save us? What followed were months of discovery and learning.

I think the central AGW proposition can be put like this:

Human activity in burning coal and oil, and clearing forests has put an enormous amount of carbon dioxide into the atmosphere, where it has combined with water vapour to increase global temperatures in an unprecedented way. The evidence that this has occurred is clear-cut, and the increase in temperature will have, according to our computer models, dire effects on the planet. We must change our ways lest catastrophe strike us. It may already be too late.

That led me to find out what I could about the following:

(1) the extent to which the planet is warming;

(2) whether or not such warming is unprecedented;

(3) whether the warming is caused by burning fossil fuels;

(4) the likelihood of polar ice melting in a major way;

(5) the use of computer models in predicting future climates;

(6) the reluctance to admit uncertainty; and

(7) the extent to which we need to change to avoid catastrophe.

Twelve months later the outcome for me is, to say the least, uncertain. But this is what I think one can reasonably say.

Is the planet warming? Maybe. It depends on what measurements you think are relevant. It doesn’t seem to have warmed for the last 10 years. The Intergovernmental Panel on Climate Change says 0.6 of a degree plus or minus 0.2 of a degree over the 20th century. I’m prepared to accept that.

Is the warming unprecedented? Probably not. There is abundant historical and proxy evidence for both hotter and cooler periods in human history.

Is it our fault? Again, maybe. The correlation of increasing warmth with increasing carbon dioxide concentrations is particularly weak; that with solar energy and with ocean movements is much stronger.

Are we likely to see rising sea-levels? Not in our lifetimes or those of our grandchildren. It is not even clear that sea-levels have risen at all. As so often in this domain, there is conflicting evidence. The melting of polar or sea ice has no direct effect.

How reliable are the computer models on which possible future climates are based? Not very. All will agree that the task of modelling climate is vast, because of the estimates that have to be made and the rubbery quality of much of the data.

Given all this, why is there such insistence that AGW has occurred and needs drastic solutions? This is a puzzle, but my short answer is that the IPCC has been built on the AGW proposition and of course keeps plugging it, whatever the data say. The IPCC has considerable clout. Most people shy off inspecting the evidence because it looks like science and must therefore be hard.

The media have been captured by AGW (it makes for great stories), the environmental movement and the Greens love it, and business is reluctant to get involved. Governments simply postpone making the draconian decisions they are urged to make.

What should we do? The current Garnaut inquiry is not of much help, because it too is based on the assumption that AGW is correct. A Royal Commission has been proposed, and I would be in favour of that course of action if the inquiry is run properly.

More generally, I would urge people to find out for themselves, because the issue is important. There are around four million Australians who have been to university. This domain is science, but the questions are straightforward and accessible. I warn that there is a lot of reading!

What we should not do is go down the path of carbon taxes, carbon trading and carbon caps before it is absolutely plain that there is no alternative. Why? At present such measures seem likely to be unnecessary and futile and to lead to rorts.

Professor Aitkin AO, a historian and political scientist, is a member of the Australian Science and Technology Council.

This is a much abridged summary of his address to the Australian Planning Institute yesterday.

3 thoughts on “One cool view of global warming”

  1. It is an interesting compendium of aspects worth to be discussed. But it might help more to find questions to circumstances which can be answered, for example: Who is going to explain the global cooling from 1940 to about 1970? This question has been asked by www.oceanclimate.de as IPCC and others think they have explained enough by claiming that a high concentration of sulphate aerosols in the atmosphere may have had a cooling effect on the climate because they scatter light from the Sun, reflecting its energy back out into space, by industrial activities at the end of the second world war. That is defiantly not the major cause when taking the following reasoning into account:

    The sulphate aerosols relation towards the mid-century global cooling should be checked against three facts, namely
    A. the cooling started with extreme winters in Northern Europe in winter 1939/40; and
    B. the temperatures were low during the winter season, when the effect of sulphate aerosols on sun ray was at the lowest, and thirdly
    C. the pre WWII industrial activities presumably had been much higher than immediately after the end of WWII in 1945.
    D. Actually only since 1950, annual car production has grown fivefold , starting with eight million, today about 40 million cars. Similar figures, if not higher, apply for aviation, electricity production, shipping, etc..

    More important for understanding the global cooling since winter 1939/40 until about 1975 is the impact of the seas and oceans. To understand the extreme cold winters all over Northern Europe from 1939/40 to 1941/42, one has to consider the impact of the North- and Baltic Sea, for the global cooling one should take the North Atlantic and North Pacific into consideration, and what men did do with them during WWII, as thoroughly explained at www.seaclimate.com.

  2. April 2007 hottest April month for many years. April 2008 several inches of snow falls in many parts of UK.
    A one off. Possibly but so is so much of the so called scientific evedence on global warming

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