Graham,
the thing I'm really questioning is the notion that the temperature increase from CO2 is already mostly over. The fact that the world has been hotter with a weaker sun in the deep past speaks against that. Now, in your last post, you have clarified that it won't be above 3 degrees by 2100... there are a variety of predictions, I've seen 3 degrees before, but most predictions discount possible feedback mechanisms such as the release of carbon gasses (including methane) from ice cores -- something that is already happening -- due to their unpredictability. Similarly, the IPCC projections for sea level rise include only thermal expansion of the water, without taking into account glacial action or meltwater, as those factors are unpredictable.

I wouldn't, however, call such predictions 'guesses' -- while technically accurate, it's a misleading term. 'Estimates' would be the word I'd use, as they are working off models that have so far proven more or less accurate against real data. Personally, I don't know of any scientist who is putting a definite figure on temperature rise, not without significant caveats. In any case, 3 degrees doesn't sound like much, but it's actually rather dramatic.

On water vapor, I'm trying to find the Royal Society statement that addresses modelling of water. I am aware that water vapor is still a live issue, though as I undestand it, it's pretty clear that it's a feedback effect. The question is whether it's a positive feedback or merely a symptom. The jury's still out on this one (last I checked), as its temperature effect kind of cuts both ways -- it traps heat trying to leave, but it also reflects heat entering.

"Skeptics doubt that increasing CO2 leads to increasing temperature, there is no proof that it does, but the "consensus" comes out of the modeling (which cannot be easily disproved as most scientists, can hide the decline! Or tweak temperature measurements, till they fit .. now that's real science son. It's a trick evidently). Al Gore misused graphs to show CO2 led temp, but it turns out temp leads CO2 by hundreds of years .. anyway enough .. you need to go do some reading haha!"

No, Amicus, 'skeptics' don't dispute that. Skeptical scientists don't dispute the link between CO2 and warming, because that link has been solid science for over 100 years now. Most skeptical scientists don't dispute the warming trend; they just disagree about the cause. And I've never heard a scientist talk out against the East Anglia CRU; the out-of-context reading of the comments is quite striking in its dishonesty. The only people who dispute the basic facts are the non-scientific denialists such as Monckton and Durkin, two utterly disreputable and scandalous sources of information.

Al Gore did indeed misuse the information, but what he presented is still largely accurate... just usually pretty simplified, and he had a habit of presenting worst-case scenarios without stating probability or timeline. Durkin, on the other hand, fabricated graphs wholesale, to the point that the skeptical scientists who appeared in his film complained to the producers that their work had been misrepresented.

One of these is a more reliable source. But neither is a source that I'm using.

James, I see the issue you have now .. selective reading .

"I've never heard a scientist talk out against the East Anglia CRU; the out-of-context reading of the comments is quite striking in its dishonesty. The only people who dispute the basic facts are the non-scientific denialists such as Monckton and Durkin, etc etc ad hominims etc."

Here is just one example, it's all I need, go google this man, this is part of his resignation letter to the APS.

"In the interim the ClimateGate scandal broke into the news, and the machinations of the principal alarmists were revealed to the world. It was a fraud on a scale I have never seen, and I lack the words to describe its enormity. Effect on the APS position: none. None at all. This is not science; other forces are at work".- Hal Lewis

indeed ..

Your posts are the usual AGW believer site stuff, get off those sites and go do some reading. You haven't read the CRU emails - if you had, you could not make the statements that you do - they deliberately colluded to avoid an FOI request, the only reason they were not charged is the statute of limitations on the act.

Al Gore "he had a habit of presenting worst-case scenarios without stating probability or timeline", yet a UK court found 9 instances of dishonesty .. so, you say "what he presented is still largely accurate", no it's not.

Did you even know about the UK court ruling?

You are beyond any conversation we could have here, you need to go look at the data, and maybe a trip to the "denialist" sites might do you some good. You obvously have no idea what is actually on denialist sites, it's not the propaganda you think it is, though if you only go to believer sites, fair enough, you've been inducted into groupthink.

I look at all the data and all the sites, not just the data that suits what I want to hear.

You clearly only look for data that agrees with your views.

Amicus:

Heh. Well, there are always exceptions. I overstated the case -- let me rephrase. There are VIRTUALLY NO scientists who take 'climategate' seriously. Given the broad range of people who become scientists, it's not surprising that some are. If you can find biologists who dismiss evolution, you can find anything. The mistake is to see debate and assume that that means that there's no agreement.

The CRU emails themselves are a non-starter. Yes, I have read many of them. Not all of them; there are what, over 10 years' worth? I have read all the ones that were brought up by deniers. Quite striking that there were may a half-dozen examples in so much data, and each of those examples is taken out of context: such as 'hiding the decline' being presented as if it's in reference to a decline in temperatures. (Hint: it isn't.) 'Deliberate collusion' is not something found in the official findings of the inquests. They found they were lax and didn't keep proper records, but not that they were deliberately dishonest. Positing deliberate collusion is reading in something that there just isn't evidence for.

If they were guilty of collusion, they wouldn't have been charged because as far as I know, there isn't any legal duty on them to keep records. There's also no 'statute of limitations' on professional misconduct, because that isn't a legal finding.

On Al Gore: Yes, I did know about that case. It found nine instances of misrepresentation, many of which were merely 'made it look more solid or more likely than it should have'. Yes, I'll stand by my statement that the film is 'largely accurate'. Nine instances in a full-length documentary? That's pretty mild. Note that I don't give him a pass, and I don't use him as a source.

Finally, I hear what you say; but your denial of the basic science says otherwise. Have fun, anyway, I've said my piece here and am done for this particular conversation. =)

james, on the science, the CO2 is now in the logarithmic region as GrahamY says, so no further temperature effects .. so why do you question my understanding of science, when you clearly did not know that.

I'm not denying the science, see above, I'm questioning the government and average AGW believer's addiction to taxes to "change the climate", as if.. what a folly.

I do not believe though that CO2 is the culprit to rising temperatures, land clearing and lot of other things obviously change things, but the focus of our government is purely on CO2 .. absurd. Climate is too complex yet for us to understand and it is an arrogance beyond belief for climate scientists to declare "they know it all".

My point is, we should invest in adapting, not in the exaggeration and hysteria business of trying to change the climate - while we are occupied in this, so many other things are not being done or studied.

We spend time and effort on something we cannot affect at any rate.

Have fun, those deniers do have somewhat of a clue, as annoying as that is.

Graham, as I have said; there is much more data now than in AR4 and the computational power that is being accessed for AR5 is much greater. The resolution will be much starker and regional projections will be achievable. Whether you accept this or not is of no consequence.

Thank you for your advice Graham, however, I very much understand the mathematics, logarithmic functions and asymptotic analysis. What you (and Amicus - as he seems to think you are some kind of 'climate change guru') obviously don’t appreciate, let alone understand, is that the concentration of CO2 in the Earth’s atmosphere is NOT saturated, nowhere near it.

Ergo, at relatively low [CO2] the gradient of the logarithmic function that you think is minor is in fact major, and near linear.

Absolutely you are right IF the concentration of CO2 in the Earth’s atmosphere was very high (like Venus). Absolutely the temperature differential would not increase that much and indeed, “it reaches a point where it re-radiates nothing”, as you say. BUT, the Earth does NOT have CO2 concentrations anywhere near that of Venus (neither does Earth have temperatures like that of Venus).

“The probabilities that scientists assign to some of these things are just guesses (unlike probabilities that can be assigned to statistical measurements).” Very obtuse, but there you go.