Q&A says; "What if the sceptic side is right? Then we'll have devoted considerable resources to a cleaner environment and a sane, sustainable energy policy".

Now I know you're not serious. Let me get this right. You are saying that if the IPPC have grossly overestimated their estimates of the effect of increasing CO2 & other GHG's then by imposing costs on a phantom problem, penalising our export & import competing industries, increasing the costs of every household for no resulting benefit in terms of mitigation, this is sane. What it is my friend is the insane misapplication of vast financial resources to a problem which has been grossly exaggerated.

Why do I think this problem has been grossly overstated; why do I think the climate sensitivity as communicated by the IPPC, 3C +/- 1.5C, is actually much less. One reason is the work of Roy Spencer.

Bio: From his site linked below. "Roy W. Spencer received his Ph.D. in meteorology at the University of Wisconsin-Madison in 1981. Before becoming a Principal Research Scientist at the University of Alabama in Huntsville in 2001, he was a Senior Scientist for Climate Studies at NASA's Marshall Space Flight Center, where he and Dr. John Christy received NASA's Exceptional Scientific Achievement Medal for their global temperature monitoring work with satellites. Dr. Spencer is the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA's Aqua satellite. His research has been entirely supported by U.S. government agencies: NASA, NOAA, and DOE".

http://www.weatherquestions.com/Roy-Spencer-on-global-warming.htm

Anyone interested in this issue which affects us all should read the above link. In a nutshell Roy's thesis is that the warming radiative forcing effect of CO2 (& other GHG's), approx. 1C for a doubling of CO2 (2 X CO2), is moderated by negative feedback effects, or cooling effects, of precipitation systems. This is in contrast to the IPPC's position of positive feedback, or an increase from 1.5C to 3C for the median level of warming for a doubling of CO2. That's right, 2/3 of their warming comes from feedback; there lies the Achilles heel of their hypothesis.

to rstuart: I have no 'political' or 'party political' interest in this issue. My attention to it started intellectually, and remains that of someone trying to come to terms with an absorbing puzzle. In retrospect, I think you have made a fair point, at least in part. Yes, once Garnaut started on the job he had to accept the IPCC position, or tell his masters that they were barking up the wrong tree; but they hadn't asked him to do that. I think I am right in arguing that he nonetheless should have struggled with finding out how serious the extent of human-induced climate change was, because he was so gung-ho about urgency. That suggests to me he thinks all the warming is AGW. There was certain irony in my comments about his thought processes.

To Q&A: I have yet to read the Green Paper, and will decide whether or not to make a submission when I have done that. As to the stats, I think Lucia Liljegren is more convincing than Tamino, and suggest you go to the site referred to by G Larsen if you do not already know it.

to Sams: You misquote me. I said that the rise had faltered. I didn't say there had been cooling. They are not the same thing. The GISS data do not show a continued rise after 1998 — that is, the previous rise had faltered. And then you insult me for good measure. Sorry, Sams, you're off the list of people I'll respond to in future

Sams, you can go to your GISS site and believe what you find there to match your belief in belief AL-AGW*. The point is that anthropogenic sources of CO2 are insignificant.... and certainly it's effects have not been observable in the climate system. This has only been imagined but of course can only be found in the minds of infected ant-life opportunists.

The fact is that water vapor is literally everything to our lovely planet earth .... it is our sun's energy and water vapor when it comes to climate and CO2 when it comes to all life here.

The role of carbon dioxide in the atmosphere is minimal at only 38 out of every 100,000 molecules of air. It takes a full five years of human greenhouse gas emissions to add 1 molecule of CO2 to every 100,000 molecules of air. i.e. Human CO2 emissions represent a tiny proportion of a tiny proportion of a natural atmospheric gas that is absolutely essential to life itself.

I suggest you take a look at Southern Hemisphere temperatures where we live and if you are so seriously alarmed with carbon emissions you will see that our vast landscape and surrounding oceans easily make Australia carbon neutral.

* AL-AGW = alarmist AGW which is based on Algorian science.

Don Aitkin: "You misquote me. I said that the rise had faltered. I didn't say there had been cooling."

Nor did I ever present such a quote, so you in turn misrepresent me.

This is not faltering:
http://data.giss.nasa.gov/gistemp/2007/Fig1_2007annual.gif
If you think it is, may you never be a stock broker.

As NASA says: "It is apparent that there is no letup in the steep global warming trend of the past 30 years."
Everyone should read http://data.giss.nasa.gov/gistemp/2007/

Thus Don Aitkin are as wrong as ever and the entire premise of his article is false.

DA: "Sorry, Sams, you're off the list of people I'll respond to in future."

No need to apologise. Your responses so far, in the light of strong scientific evidence against your position have been "no, I'm right", so I'm not sure anyone will miss your input. I know I wont.

Keiran: "The role of carbon dioxide in the atmosphere is minimal at only 38 out of every 100,000 molecules of air."

This is about as valid as saying "your Honour, I only had a fraction of a percentage of alcohol in my blood, and besides its good for staving off Alzheimer's". Clearly you can't grasp simple physical concepts.

Keiran: ""Human CO2 emissions represent a tiny proportion of a tiny proportion of a natural atmospheric gas that is absolutely essential to life itself."

A 35% increase in CO2 over the industrial era is not a tiny proportion.

Keiran: "Sams, you can go to your GISS site and believe what you find there."

I much more likely to believe a NASA research site than a bunch of armchair pseudo-science mumbo jumbo that fails at the first hurdle.

G Larsen: "In a nutshell Roy's thesis ..."

I am sure its a very good thesis. But in order to evaluate it, I'd have to look at a fair sample of the competing theses. But isn't possible for me as there are 1000's of different influences on the climate, each with many competing theories about how relevant they are. It would take me months to get a feel for it all.

So, how do I evaluate Roy's thesis? Do I take your word over say Tim Lambert's or the IPCC's, or do I take their word over yours? Neither option is very appealing. The only sane alternative I can see is to rely on those that do have the undeniable expertise in this area. Fortunately, our society has developed a pretty good way of telling who they are and what they think - they publish in peer reviewed journals.

If Roy Spencer has published his thoughts in those journals, and if his peers show their agreement with them by citing them in their own works then Roy thesis will become the dominant meme in climate science. Until that happens I am more than content to go with the current dominant meme. Right now I am fairly certain it strongly favours AGW.

Now it just maybe, G Larsen, you have spent the months of full time work required to review the literature, and maybe you have gone to the relevant conferences and inhaled the vibe. But nothing you have posted so far gives me any confidence that is the case, and if you haven't done that any comment you make on the science itself isn't worth much to me.

My apologies if I am wrong about your credentials. If I am right, then please still make the comment, but have the good grace and do what Don Aitkin does and acknowledge its made from the armchair, not the coal face. That way I can put it into its proper context.

Sams, you are a laugh a minute.
e.g.
I think very soon it will be "your Honour, I only had a fraction of a percentage of " CO2 in my system that is part of being alive. Spare me the rod please.

With the pre-industrial atmospheric C02 at 335ppm and todays’ level at 390ppm we get an increase of about 55ppm, or a 16.4% increase in C02, about 1/2 what the alarmists claim plus our contribution is but 3%. I wish there was more CO2 to green the planet but those plants will just need to be patient i'm afraid.

You mean you much prefer the gospel according to diminished integrity Hansen with all that Algorian science. No worries ... each to his own.

I suggested you should take a look at Southern Hemisphere temperatures that easily make Australia carbon neutral. Is this just a bit beyond your comprehension to make a comment? Think so.