Graham

We'll just have to agree to differ. The existence or non-existence of the "hotspot" is in any case not the be all and end all of global warming.

You cited two papers, one that claimed the hotspot existed but was not as "hot" as some models predicted and one that claimed global warming was occurring but not as rapidly as earlier models predicted. I have no quarrel with either of these. The scientific consensus does not embrace any particular climate model.

Leo Lane

And others

In my post of Tuesday, 15 November 2011 6:46:36 PM above I defined a "Science Group" (SG) and, somewhat facetiously, a Peter Hume Group (PHG).

I pointed out that SG has usually turned out to be more nearly right than PHG in its various manifestations.

Not always, but usually

Not necessarily precisely right but more nearly right.

Since I freely admit that I, as an amateur, am not in a position to decide between SG and PHG on this topic, which should I bet on? A rational man would bet on the group with the best track record of being correct and that is SG by a long margin. Nobody here has given me a rational reason for changing my mind.

This is not an appeal to authority; it is a decision on which of the conflicting "authorities" – to the extent that PHG can be called an authority – I should trust. If you like, I am in the position of a juror having to decide which witness is the more credible. Both are to some extent tarnished. But SG has the advantage of being approximately right most of the time; PHG, in many ways even more tarnished, has usually turned out to be wrong.

It helps that SG's position is in line with the laws of physics and what we do know about the current weather system. Many protagonists within PHG seem to ignore what we know about physics or weather.

I note that nobody has given me even a half way reasonable explanation of the dog that fails to bark.

Leo Lane,

In quoting Plimer you are yourself APPEALING TO AUTHORITY. Why you choose to believe Plimer against the stated positions of the National Academy of Sciences, the Royal Society and many other elite scientific bodies is itself interesting.

Well let's get on with examining the statement you attribute to Plimer. I am doing this merely for the record. I do not have any hope that anything I say could induce you to change your mind about Plimer's deceitful book.

I no longer have my copy of his book – my wife sold in on eBay – but his book was peppered with statements such as the one you quote so I'll assume it's accurate.

It was in fact statements such as the one you quoted that led me to conclude early on that Plimer had written a polemic rather than a serious book of popular science. Like most polemics it is economical with the truth.

>>To argue that human emissions of CO2 are forcing global warming requires all the known, … mechanisms of natural global warming to be critically analysed and dismissed. This has not even been attempted.”>>

This is a mixture of half truth and outright lie. Do we claim to understand fully "all the known, … mechanisms of natural global warming". Obviously not. In fact that is probably impossible.

But is it true that "This has not even been attempted."

NO!

THIS IS ONE OF PLIMER'S (MANY) OUTRIGHT PORKIES. Scientists are doing their best to track the history of the Earth's climate and relate it to atmospheric CO2 levels. There is abundant lierature on this. It is a difficult task. What scant evidence is available suggests that elevated CO2 levels have led to higher temperatures in the past. However deducing what past temperatures were is fraught. It may not be possible to examine in detail all the vicissitudes of the Earth's climate and their causes.

Let's examine Plimer's use of the word chaotic. Weather systems are chaotic. Chaotic systems have "attractors." What this means is that they cycle irregularly. Extremes occur but there are periodic reversions in the direction of the mean.

However chaotic systems are not immune to the laws of physics. The "attractors" may be moved in a particular direction. To put it in another way, the means may move.

What is more, chaotic systems can be tipped over into a whole different state. In the case of climate this could be a state that is less benign to human civilisation that the one we currently enjoy.

Now the NAS and the Royal Society number among their fellows scientists who are adept at the mathematics of chaotic systems. Do you think they don't know all this?

You may stick with Plimer who continues to disseminate falsehoods and half-truths even when they have been pointed out to him.

I prefer to deal with scientific bodies that, whatever their faults, do respond to critique and do issue corrections when their errors are pointed out to them.

rpg

You need to get your facts right.

Two points about Galileo.

--He was far from an amateur. He practised what we today would call science full time.

--But, most importantly, he did NOT challenge the SCIENTIFIC orthodoxy of the day. He did not even challeng religious dogma. HE DISSED THE POPE

Those scientists who were free to express their opinion without fear of retribution were already largely convinced of the reality of the heliocentric model when Galileo published his classic "Discourse on the two World Systems" that got him placed under house arrest.

Note, it was the Church, not scientists, who confined Galileo to his house. They didn't do it because of his science. In his book he ridiculed a character called Simplicimus which everyone recognised as Pope Urban VIII.

The Catholic Church's anti-science attitude has been exaggerated but you dissed the Pope at your peril.

What had previously convinced scientists of the truth of the heliocentric model was Johannes Kepler's three laws of planetary motion which put the heliocentric theory on a sound mathematical footing. Kepler published his three laws to wide acclaim before Galileo was placed under house arrest.

Galileo's achievement was to explain how the Earth could be moving without anyone noticing. His explanation is still worth reading.

http://www.philosophical-investigations.org/Galileo's_Thought_Experiments

(scroll down "Salvatius Ship". It makes fascinating reading.)

Whatever else you may say about Galileo he was not an AMATEUR challenging the SCIENTIFIC consensus.

And it is not actually true that he was challenging the scientific consensus to the extent that one existed in early seventeenth century Italy.

WHY DOES CLIMATE TRIGGER SUCH STRONG EMOTIONS?

I can understand certain proposed policy responses eliciting a strong, even emotional, response; but not the science itself.

Steven,

"I note that nobody has given me even a half way reasonable explanation of the dog that fails to bark."

It's probably a Basenji.

Steven, I quoted Plimer to show that Michael Ashley, to whom you referred in relation to Plimer, is either incompetent or lying. I compared what Ashley alleged Plimer said, to Plimer’s actual words.

This is another diversion from the fact that you are wrong again, and from the fact that you have produced no science to justify your support for the AGW myth.

You refer to statements by the scientific bodies, which are unsupported by science, as your basis. The fact that the members of these bodies are competent in science does not give authority to the statements, which are unsupported by science. Many members of these previously reputable bodies have spoken out in disagreement with the unjustified statements supporting the AGW scam. Harold Lewis made an apt statement about the global warming fraud in his resignation from the American Physical Society.

What Plimer says is correct. Instead of looking at the natural factors producing global warming, the AGW supporters look for global warming, and attempt to attribute it to human emissions. If the non existent “hot spot” upon which the IPCC relied in making its baseless assertion that AGW is “very likely” were found to exist, it would soon be shown that it did not comprise the “signature” for AGW.

The alarmist trick of pretending that some warming can be somehow separated out as identifiable as AGW has been tried before and found wanting. No wonder you rid yourself of Plimer’s book on e bay. It is outside of your comprehension abilities.

There is plenty of evidence that global warming leads to release of CO2. As you say, there is scant evidence that CO2 leads to warming. Properly examined, I would say none. I have read some of the tortuous efforts to say otherwise, and I would not give them so high a status as “scant” as you attempt to do.

Plimer is right, and the more you attempt to attack his erudite work, the more foolish you look.