No, Bazz, you are wrong on several counts. We had this discussion already, I'm not sure why you're falling back on claims you already accepted (or seemed to accept) as unfounded.

The most recent IPCC report was doctored under political pressure to remove mention of potential catastrophic positive feedbacks from anthropogenic warming. The report's "projections" represent the probable warmings due *directly* to hypothetical fossil fuel emissions scenarios, but fail to account for greenhouse gas sources that are not directly anthropogenic.

Two degrees of global warming is enough to thaw the Siberian permafrost and trigger the release of huge quantities of methane from decaying peat.

*Some* recent analyses indicate that fossil fuels are likely to become uneconomical to extract in the volumes once presumed possible. This is not a foregone conclusion -- it isn't the case that the fossil fuels will *run out*, just that it is expected that economics (including competition from nuclear and renewable energy sources) will prevent the higher-extraction scenarios from playing out.

But not even the lowest of the IPCC scenarios was low enough to avoid that crucial two degrees of warming.

The European carbon credit trading system has not "collapsed". The market, being immature, has been quite unstable and the *price* of carbon collapsed at one point -- indicating that too many emissions permits had been handed out to "grandfathered" polluters at no charge. The system is still up and running, and capable of doing the job correctly if not continually undermined by lenient public policy.

And the accounting difficulties are significantly less than those for eg. a GST -- an emissions cost is an *extra* input, but no harder to incorporate into production costs and pricing than material inputs or business overheads.

You do not seem to understand Xoddam, that the predictions upon which you rely are discredited.

The arch alarmist James Hansen of NASA, probably your favourite scientist, has a credibility problem.

In 1988 he produced some graphs. One was to show what would result from global warming, if no measures were taken to reduce emissions.

During 1998 Patrick Michaels, a respected scientist, gave evidence to the US Senate using Hansen's graph to show that his alarmist predictions were wrong. The global warming predicted, had not happened.

Hansen had produced 3 graphs. The first 2 were wrong. The third depicted minimal warming which would occur provided that emissions were lowered, by drastic restrictions to be imposed by government. No such restrictions were imposed, and the minimal warming in the graph resulted anyway.

Undeterred at being shown to be wrong, Hansen complained of the unauthorised use of his graph by Michaels.

Of course, now that Stephen McIntyre has gained acknowledgement from Hansen that his figures on warming are wrong, the graph is now wrong, so Hansen cannot get anything right. This is OK because no reputable scientist will represent that it is possible to predict climate. Hansen could admit this, were he so inclined, and seek credibility.

Contrary to your assertion, there has always been great doubt about the effect of human activity on global warming. The theory is likely to be abandoned soon, as it becomes more and more tenuous.

The greenhouse theory itself is problematic, but even as it stands, it is obvious that human emissions are insignificant.

You appear to believe, Xoddam, that bluster will somehow compensate for abysmal ignorance, and abuse will elevate your standing in the debate. It simply emphasises your lack of clear thought. Take this extract from your post above:

"EVEN IF the science were completely wrong, the urgent call to reduce greenhouse emissions amounts to little more than a call for investment in technologies and practices which are inherently more sustainable"

When you realise how stupid that is, you might do some research.

You might even discover the unsustainability of the IPCC Summary assertions.

Nick,
Hansen's figures were wrong, but by only a small amount I believe.
Xoddam;
Well maybe, but the trend seems to be that there will be less
available than expected fuel rather than more than expected.

I notice also that the local carbon credit scheme price has fallen so
that one company changing bulbs for free has shut up shop.
There is another still going I believe, but on what financial basis
I am unaware.

As you say the accreditation of the cost of the amount of emmission is
straightforward, but that was what they did in Europe and no one checked
if the companies statements were true so the valuation was up the spout from the start.
That is why the price collapsed.

The solution to that is more checking and accounting and bureaucrats.
The whole global warming thing has become a religious mess when it
becomes sacrilege to question anything to do with it.

Dear Nick,

I do not for one moment believe that bluster will compensate for ignorance. You've started naming names and mocking me with fandom, as though climate science was somehow not the body of work of thousands of well-informed people over many decades. I don't have a favourite scientist, I do not bluster and I am not ignorant.

I have followed McIntyre's climate audit project closely for years. He has been on the lookout for errors in official climate statistics for a long time, and is entirely in the right to point them out. McIntyre is a good mathematician and his criticisms are mostly valid, but he does not claim to have discredited or falsified the basics of climate science or the bulk of the evidence for global warming, nor does he refer to the people whose work he studies -- and *improves* -- as "arch alarmists".

McIntyre's corrections do not for a moment falsify the basic physics of greenhouse gases. Nor do any other debates on statistics, predictions or past temperature time series. You ought to be well aware that the chaotic behaviour of the Earth's climate system makes any "predictive" extrapolations tentative at best.

What can't be disputed is that if you trap more radiative energy within the atmosphere by adding greenhouse gases to it, surface temperatures will rise.

You say "Contrary to your assertion, there has always been great doubt about the effect of human activity on global warming." My actual assertion was that there has never been serious doubt "that adding greenhouse gases to the atmosphere would cause temperatures to rise". If you think I'm wrong, please demonstrate why.

I also repeat my challenge that you explain how action to reduce greenhouse emissions is in any way "harmful".

Could I inject some practical comments into this thread before it deteriorates into a slanging match? Despite my four year science degree and fifteen years work experience in natural resource management, I have no hope of following the scientific debate about climate change. Instead I use my understanding of scientific uncertainties and some basic ethical principles to decide my response to this challenging issue.

To the average Australian it doesn’t matter which scientist can prove or disprove the current global warming theories. What matters is that we may be looking down the barrel of a very big gun – and we simply can’t be sure if or when the trigger will go off. Scientific evidence appears to be mounting by the day to demonstrate our natural ecosystems are deteriorating at an alarming rate. Natural or human-induced climate change will accelerate that process.

There will never be total certainty or agreement about global warming, so I try to respond logically and ethically to this potential threat. Using the same reasoning behind buying insurance, I do everything I can to reduce my own ecological footprint in whatever ways are within my meagre financial means (and because of my ethical principles, even some that are beyond it). Of course others may have a different response to risk. But then, they’re the ones standing in front of their burnt house wondering how they’re going to put their lives back together and/or seeking a taxpayer-funded handout.

Back to the equity issue raised by Seibert, the onus is on every individual and organisation to share the burden of reducing this global risk, according to both their financial means and their practical ability to contribute to solutions. Governments seem to be too willing to subsidise those who have both the means and the ability, i.e. large corporations, while placing an unfair burden on those who can least afford it. Those consumers who are already reducing their environmental impact should be rewarded for their efforts, not penalised with indiscriminate economic measures that provide little incentive for profligate consumers to reduce the impacts of their current lifestyle.

wollsue,

I expect you're selling yourself short with the expectation that you can't follow the debate of climate science. Getting numbers right on such a large scale is obviously a challenge, and most of the work people have put in is developing data-collection methods which are halfway reliable, and developing computer models which halfway mimic the chaotic behaviour of the real globe.

But the basics are actually surprisingly straightforward. An excellent historical overview of discoveries and developments is here:

http://www.aip.org/history/climate/index.html

When it comes to debating it, in addition to the staid to and fro of "experts" in the relevant journals adjusting the consensus, there is of course a lot of politically motivated guff going about on both sides in "the blogosphere". Some of this -- on either side -- is surprisingly serious and scholarly, but all of it is couched in lay language and fairly comprehensible for someone who knows what isotopes, photons, wavelengths and proxy series are. A chief clearinghouse for online dissemination of climate science orthodxy (including unconfirmed results and speculation) is

http://www.realclimate.org/

and some of the more credible locations for critics to hang out are Steve McIntyre's site

http://www.climateaudit.org/

which is devoted to poking small holes in data recording, statistical methods, computer modelling and the presentation of paleoclimatic data, with a sideline in accusing people of academic fraud, of which some of them may indeed be a little bit guilty.

and, of course

http://www.junkscience.com/

which has devoted more considerable efforts to denying the whole basis of climate science by calling into question the physics of greenhouse gas radiation absorbtion and by saying outright that the earth has been much hotter in human history than it can possibly get in coming decades. Much of the data it presents is sound; some isn't. It's run by one Steven Milloy; to save myself from arguing ad hominem and sounding like a conspiracy theorist I'll simply recommend you google him by name.