Quite so: the balance has clearly shifted in favour of scepticism, and those who insist on clinging to the Titanic of AGW will go down to the bottom with it, unmourned and unmissed.

And it's worth pointing out that the alleged 'feedback loop' on which all the hysteria is based has never actually been observed under experimental conditions. You'd think, with tens of billions of dollars sloshing around, that SOMEONE could have found a few bucks to set up a couple of sealed chambers and test their fundamental hypothesis: but no, that was conveniently overlooked.

Keep throwing the deckchairs overboard, folks: you're bound to find something that will float eventually.

Well said Mark. And as you know, the poor forecasting you address is only one of the problems. Other key questions:

1. How come all the "adjustments" to the temperature records in many places (US and NZ are well documented examples) are always in the direction of making the warming worse?

2. It is clear that observed climate changes can result from natural factors, land-use factors (deforestation, urbanisation, agriculture etc) and possibly the effect of anthropogenic CO2 releases. How come we are told that effectively ALL of the changes are caused by CO2, and the impact of natural factors and land-use factors is minimal?

3. Most observers accept that the physics show that a doubling of atmospheric CO2 (if it were to happen) could result in around 1 deg C of warming. However, it is the feedback assumptions that triple the IPCC number to a scary 3.5 deg C. These are just assumptions in a model. Quite a lot of work, and empirical analysis is showing that the feedbacks are likely neutral, or even negative, in which case CO2 caused warming is not really a serious problem.

4. How come the IPCC (which goes on and on about "peer reviewed" literature), accepts so much "grey" literature from WWF, Greenpeace and other green activist organisations?

There is much to question in all this. And particularly the role of the MSM(especially Fairfax and ABC) and the so-called independent Climate Commission of Flannery and Steffen.

But the carbon tax DOES make sense if you are using it as a cover to move society away from fossil fuels that are (in the case of oil) already peaking or that are predicted to peak within two decades (for gas and coal).

The problem with the IPCC is that it is the UN InterGOVERNMENTAL Panel on Climate Change. It is led by economists and, of course, it can only consider scenarios where the developing nations of the world continue on their self-evident path to greater prosperity. To suggest otherwise is simply politically impossible. The IPCC was warned very early on that their scenarios were impossible due to fossil fuel limits but they chose to ignore the science.

Mark Lawson here

Jon J - an excellent point. No one has looked carefully at the feedback issue, one suspects, because they won't like what they find. It is is extraordinary.

Herbert Stencil - quite so. I wasn't going to get into those issues as the article was way too long as it was. But they are worth making.

michael_in_adelaide - I see you've taken up one point I made but unfortunately for your take on the argument, even the environmental movement has dumped the peak oil stuff. It just won't be happening, at least not in the form they thought it would. As for the growth rates of developing countries, undoubtedly it is happening, just not at anything like the rates required for the extreme scenarios.

Curmudgeon, in the world we live in, there are many risks which are hard to see or understand easily.

There are particular characteristics of risk which can cause misunderstandings when communicated, and people do not perceive this information as important ‘‘news’’ which they should react to.

As Stringer and McKie explain (Stringer C, McKie R. African exodus: the origins of modern humanity. London: Pimlico; 1996.), “we are not biological devices newly constructed for the twentieth century, we still have Stone Age bodies, and therefore Stone Age brains, for what is true of our appearance must also be true for our behaviour.

Because of this ‘brain lag’ we are not programmed to perceive certain risk information adequately. One of the characteristics of ‘invisible’ information is that it is ‘hidden from the senses.’ We understand information with our brains by using our primary senses: sight, hearing, smell, touch and taste. Some information that is hidden from the senses, for example radiation risk from a nuclear power station or pesticides in food, would be more difficult to be perceived by human brains than risk information from a fire or approaching cars.”

Additionally, risks are based on how people perceive risk information when it contains ‘time-hidden’ information, hazard and risk change is too slow and the added problem of scale latency, it is very hard for humans to perceive risk information when the scale is too small or too large.

I think these ‘risk’ issues muddy the waters and given the entire uncertainty in climate science, perhaps a more precautionary approach is driving AGW mitigation strategies at the political and scientific levels.

Uncertainty and risk are two issues that humans will always struggle to grapple with. What our new policy is really based on has, I think, yet to be answered. It is certainly not backed by science nor politics or rational empirical evidence as to its effectiveness or usefulness.

Curmudgeon (Mark),

>"None of this is to say that the climate forecasts are actually wrong as such"<

So they might be right. (And a 0.35 degree increase against a 0.4 forecast is not a bad correlation, is it?) As for using back-testing to improve the accuracy of modelling, what alternative would you propose? At least back-testing affords opportunity to identify causative factors and degree of influence, as well as testing the very assumptions you laud.

Any forecast not based on the application of scientific method to unravel the secrets of accumulated data is alternatively based on what? Gut? (or magic?)

>"it is difficult to think of any reason at all to trust either the emissions forecasting or the greenhouse gas concentration scenarios."<

Why? Are population and general living standards not going to increase, and with it a considerable increase in energy consumption - meaning increased emissions (unless the world quickly goes nuclear or 'green')?

>"give(n) the recent history of greenhouse gas concentrations the most extreme scenarios (the only ones often quoted) seem unlikely."<

"Seem" unlikely? So, you're just not entirely convinced, but you're willing to stake the future of humanity on your gut feeling?

>"it is clear no concerted international effort to curb emissions is going to occur in the foreseeable future"<

Wow, the crystal ball must be working splendidly, but how far forward are we foreseeing exactly? Certainly there is a reluctance by major emitting nations to drastically alter their drive for growth, their modus operandi or their striving for dominance (particularly US, China, Europe and India) - so they deny the 'science' or the urgency - and developing nations are busy trying to catch up.

'Greenhouse', increasing emissions and climate cycles are realities, as are modestly rising temperatures, ice-melts and sea-rise, and only the interplay of factors contributing to climate change are in question, and hence the likelihood of severe or even catastrophic climate change. Given the track record of economists and bankers, I'll put my money on the science, and on the best reasoned hypothesis.

>"Persisting with our carbon tax ... makes no sense"< Agreed.