For an imaginary problem, imaginary data will do just fine. In fact, since the main aim of the AGW movement is to give politicians and their environmentalist allies control over the rest of us, imaginary data is far more satisfactory, because it can be used to give any results that are required. Do you really think the Greens will smile and pat us on the head if we get our 'carbon emissions' down to, say, half their current level? Or will they merely urge us to greater efforts -- longer blackouts, colder houses, more expensive petrol and increasing misery? If you think the former, then I have a bridge I would like to sell you.

good point jon, will the activists stop their behaviour if they get what they want? Will the Greens disband?

No, they will go on to bothering us about going further, and even adding something else to the mix.

it's like watching the terrorists with AK-47s happily firing into the sky as a celebration, if they are given what they want, will they go back to normal occupations, clerks, shop assistants etc? No, they like being " a tough guy", a "doer" and it's the same with all the "look at me" activists.

Activists never keep it to themselves, they always have to bother everyone else with their new found or well worn religious fervor.

Much like the rabid AGW believers, the ones who call doubters "deniers", so they can be easily identified as people who need to be dealt with, when the revolution comes, will these people back off when there is a HUGE price on carbon and they shut down power stations?

Activism in AGW and as an eco/green type is a lifestyle choice for you, not for me - the moment you want to change what I do, in a land supposedly of free choice, then you have crossed the line and I will oppose it.

I do see though a lot of people who want to tell other people what to do, here's a hint to you all, when it gets too much, there will be a backlash, it's bound to happen sooner or later.

We will not just be pushed under like we are sheep, like you are sheep to your eco/green/AGW lifestyle choice. You are creating a class system, the people who want to get on with their lives do not necessarily want to continually lectured and bothered by the religious nutters of the eco type.

JonJ,

I think you've already bought the bridge, if you think that climate change is 'imaginary'.

John Le Mesurier, you should not be led astray by politicians who claim CO2 to be a pollutant, nor by TV news pictures which mischievously portray as CO2 the water vapour clouds shown rising from power stations. CO2 is a colourless, odourless gas which is necessary for life.
James Carman, climate change is indeed real. It is a natural process that has been going on since the beginning of time. It is AGW that is a figment of the imagination. No scientist or Academy of Science for that matter has been able to table scientific evidence that proves that anthropogenic greenhouse gas emissions have caused global warming.
Consequently, the Climate Committee is wrong in accepting climate science as being settled, and thus it will not have the necessary scientific justification for recommending the imposition of any carbon tax.
It is in the national interest that climate science be made the subject of a Royal Commission.

Raycom,

You need to read outside the denialist literature and their favorite strawmen. I can state confidently that you haven't, because you wouldn't have said something like that if you had. Recognise that people like Durkin and Monckton are professional liars (Monckton wasn't Thatcher's scientific advisor; Thatcher in fact recognised and accepted Global Warming as a real danger). I refuse to call people like that 'skeptics' -- skeptics make up their mind on evidence. Denialists ignore the evidence, stick their fingers in their ears and whine about how The Man is keeping them down.

The fact is that we know what has changed the environment in the past; sometimes it's CO2, sometimes it's the sun, usually it's a combination. Volcanoes also matter. However, we know what the value of the variables are. We're left with CO2, and it so happens that the atmospheric concentrations we're seeing are those that would be expected from industry. (And yes, of course CO2 is natural. And if we had no CO2 we'd freeze. But just like a heater in winter, if it's turned up too high, we roast. Natural things can kill, too; ebola is 100% produced by nature. The answer, as in all things, is a proper balance.)

Just do me a favour and google some of this stuff. skepticalscience.com is a great place to start. I can give you a few more places to look. Hell, you can even give NASA a try. Just try to broaden your reading, because what you're saying there is 100% wrong and is making you look foolish. You owe better to yourself.

James, your side is losing the debate. The expected Republican landslide will kill the AGW movement in the US, its most frenzied proponents are facing legal investigations, and former allies like the BBC, the Royal Society and Scientific American are cautiously backing towards the exits. The 10:10 video campaign, showing climate activists literally blowing up sceptic children, indicates the level of debate to which most of you have dropped. Compare the popularity rankings for skepticalscience.com (ranked about 128,000th from the top) with those for wattsupwiththat.com (about 16,000th) if you want to see what most people find credible.

And if you want further evidence, here is today's dose:

http://wattsupwiththat.com/2010/10/29/spencer-bottom-falling-out-of-global-ocean-surface-temperatures/

John Le Mesurier seems to have got some of his measures wrong. In the paragraph beginning…“We are being asked to believe…” The tonnages he cites as millions should be billions and the tonnages cited as thousands should be millions. But otherwise the article is reasonable and sound, though weather it offers practical solution is another matter.

While I agree that measuring emissions in a uniform, verifiable and fair manner is fundamental and needed, that does not necessarily mean it is going to be accepted by every country. China has already made it emphatically clear that it will not tolerate independent verification of what it claims its emissions to be.

Jon J would no doubt agree that the very idea is nothing more than a wicked conspiracy to undermine the sovereignty of nations and totally unnecessary because CO2 is so good for us.

The reality of course is that if we don’t measure it, we will never manage to effectively control it or its seriously deleterious effects. And those are likely to be experienced by Australia sooner than by other continents. So the sooner we think up effective measures to enforce the independent measuring of emissions, the better.

Interesting graphs JonJ, but eyeballing the data I suspect the trend has been flat over the time. If my memory is correct of earlier cooling periods, like the one in the 60s and 70s, there were actually temperature declines not a plateau. I don't see the temperature increase halt as being fatal to the IPCC case, at least at the lower end of projections.

So are we still on track for 2010 being the hottest year ever?

Will 2011 be even hotter?

Talking about being 'measured' ? "mene mene tekel uparshin"

James Carman

You are right in stating that skeptics make up their mind on evidence.

Conversely, in the absence of evidence to support their cause, warmists make up their mind on emotive claims, assertion, and environmentalist ideology.

Just do us all a favour and table the scientific evidence that proves that anthropogenic greenhouse gas emissions have caused global warming.

Deniers of global warming and climate change may be sufficiently gullible – or desperate – to believe that global temperatures are in decline because select measurements covering a few days or months show a fall. Anyone can draw a graph to show what they want but not one that is based on accurate, comprehensive data.

Others may feel that a greater range of temperatures over a longer term provide a much more accurate measure of trend. Statistically valid measurements of global temperature regrettably show that it is rising and that the first decade of this century is the warmest on record. The second decade of the century is not going to be cooler.

For inconvenient data try http://www.ncdc.noaa.gov/sotc/?report=globa

Link isn't complete Agnostic, but while you're looking for appropriate time scales worth reflecting that where in one of the cooler periods of the last 10,000 years. So the bit of temperature increase we will probably get from CO2 is not something to worry about.

http://www.wwfblogs.org/climate/content/peter-sinclairs-crock-week-video-heatwave-edition-and-denialist-smackdown

AGW is such a complex paradigm that all sorts of imaginary data can be superimposed. What can't be (but is) denied is that Humans are trashing the biosphere; somehow the thin atmosphere is exempt?
The minimifidianists, for mine, are a load of (rich) ignorant, fascist losers, who will probably win before they lose, ultimately, because the other side are pussies.
But AGIR, it's all part of God's divine plan, eh?
Pathetic.

"So are we still on track for 2010 being the hottest year ever? Will 2011 be even hotter?"

Some people still think that global warming means hotter years each and every year.

GrahamY raises an interesting point though, but doesn't expand on the "bit of temperature increase".

What does a global average of 3 degrees centigrade (say) by 2100 imply? And the time-line doesn't stop at 2100, by the way.

It is well known that regional temperature anomalies have tracked well above that already e.g. the higher latitudes of Antarctica and the Arctic (less so for the tropics).

It's good to see the "debate" focus more on impacts and mitigation measures though.

"So are we still on track for 2010 being the hottest year ever? Will 2011 be even hotter?"

Some people still think that global warming means hotter years each and every year."

Ah .. so this is like Climate Astrology then, so the UK Met forecast that snow would become a novelty and that it would eventually never be seen again, but when the UK had a huge winter, they said, well of course it also means more snow.

Just as AGW can mean higher and lower temperatures.

So when will we be able to have events not due to AGW?

Sounds like all the bases are covered now, anything that happens, AGW, doesn't happen, AGW .. so all you silly deniers, don't you realize it's over, the religion has won? That is the basis of a religion isn't it, that everything is explained by referring to the higher authority of priests (conforming scientists and media personalities) and the technical basis is protected by hiding evidence, making sure there is no dissent, and tweaking (or adjusting) data.

It's like your astrology forecast now isn't it, so vague as to fit anything that happens into it .. earth, forecast for the next six months, weather .. yep, that'll cover it. (let's see the deniers wriggle out of that one eh!)

bonmot, just keep sneering at people who you think are gullible, and to be honest you like the fool when you make statements as above. A big deal is constantly made in the MSM about 2010 being the hottest year ever, now a known "denier", Amicus asks it, and is scorned .. why is that? Does it worry you?

Personally, I know AGW believers have won the "debate" in Australia, it's a bit like the dingo and the baby .. it took a long time for good sense to prevail there, I expect the same here. There really has been no debate, any skepticism is suppressed constantly.

Ultimately it's overall emissions and the resultant concentrations of GHG's that matter. Still, I can understand why developing nations are not happy with big per capita emitters like Australia who, despite the relative financial and technological advantages aim for doing the least they can get away with rather than the most they are capable of. As the world's highest per capita emitters and the biggest exporter of coal, we are not winning the long term goodwill of the rest of the world with our preference for delay and continuing profit taking from selling the raw materials of climate change. Our unwillingness to act will have economic and security repercussions that will be in addition to the economic harm that will result directly from climate change.

James, I agree with what you've said but convincing members of the cult of climate science disbelief that frequent this forum is next to impossible.

<<<What does a global average of 3 degrees centigrade (say) by 2100 imply?>>>
Well, reading some of the recent media reports, one could get the impression that it will mean Greenland and the Antarctic are gonna feverishly f-f-f-f-f-f-fade away, and speedily flood all lands below 100 metres, and hordes of faminished Bangladeshi climate refugees are going to fan out across the subcontinent (desperately seeking the most despicable people smugglers to despatch them to OZ).

However, some like William Ruddiman* --whom even the most finicky of the faithful should hold kosker enough--has a different view(If I remember rightly):
--A 5 °C increase will likely cause Greenland to melt away –in about one thousand years! But temperatures below 5 °C (ironically) are likely to cause more inland snow over Greenland and cause it’s ice sheet to grow.
--He also believes that by 2100, oil whose derivates are one of the major inputs into GHGs is likely to have been all but consumed
(though coal-- which incidently is found in many countries other than OZ--most of whom have been exempted from the provisions of Kyoto--will continue for hundreds of years thereafter)
* Plows, Plagues and Petroleum: How Humans Took Control of Climate is a 2005 book published by Princeton University Press and written by William Ruddiman, a paleoclimatologist and Professor Emeritus at the University of Virginia.

<<<“ Still, I can understand why developing nations are not happy with big per capita emitters like Australia who, despite the relative financial and technological advantages aim for doing the least they can get away with rather than the most they are capable of. As the world's highest per capita emitters and the biggest exporter >>>

Per capita measures are only a dishonest way of framing the West for the upkeep of the rest of the world –and worse, it sends a message to the developing world : if you want to escape culpability –and get a whole bundle of freebies ---keep breeding beyond your means.

Bonmot, I think the temperature increase is likely to be less than 3%. Most of the warming we are going to see from CO2 has already occurred because of its logarithmic reaction to infra-red radiation. The only way models get it as high as they do is by postulating positive feedbacks from water vapour, but the experimental evidence says that this is overstated - this is the importance of the failure to find the tropospheric hotspot.

So, another 1 to 2 degrees is not only tolerable but probably beneficial, which is why I am quite relaxed about CO2 emissions.

I think Amicus' reference to whether 2010 would be the hottest ever was probably a reference to the predictions by BOMA and I think NASA before 2010 was even half over that it would be the hottest ever. This was off the back of the El Nino at the time, but now we are in La Nina territory I suspect the annual temperature will not be as high as 1998. Makes you wonder what sort of a person makes predictions when less than half the data is in, and why.

Raycom,
I provided a link to a round-up site and suggested you google a bit to read outside the denialist literature. For me, the main thing is, frankly, the consensus.No matter what Michael Chrichton said, is precisely how science works. Scientific consensus is good enough for me on atomic theory, gravity, relativity, particle/wave duality, evolution and heliocentrism. Why would it suddenly not be good enough on this one area?

Debate and eventual consensus is the heart of science. Even after consensus is reached, there will naturally be debate continuing. This is used by the Young Earth Creationists to try to rubbish evolution, and it's used by people like Chrichton or Monckton to rubbish climate science. Eventually, unless you have the appropriate degrees and experience, it comes down to trusting one pack of experts or another. I've put my lot in with the scientists -- the group for whom debunking majority views is a fast-track to fame. These aren't people who form consensus easily.

GrahamY,
That's the first time I've seen information about the temperature limits from CO2 being limited. I did a quick google and found a couple of things, but couldn't follow what they were saying. That goes against my knowledge of the field, though; in the deep past, despite having a sun much weaker than today's, massive CO2 concentrations managed to lead to temperatures far higher than we have now. I'm really not sure that the logarithmic limit on CO2 absorbtion is something to rely on.

Graham, on a “global” scale you may be right (for the wrong reason) that the “global” temperature increase by 2100 will be less than 3 degrees C. However, my point was that some regions will experience (much) higher increases, some less. The IPCC’s AR5 should make it clearer as to what different regions should expect – increased data and computing technology will enable this.

Think of the troposphere as the planet’s lungs, it can expand and it can contract – what you say about the “logarithmic reaction to infra-red radiation” would be true if the tropopause was ‘fixed’ and/or the concentration of CO2 beneath it were at saturation levels – it’s not and it isn’t, far from it. Therefore, 3 degrees C (+/-) per doubling of [CO2] is established in the literature (Lord Christopher Monckton would disagree :) This century or next is neither here nor there.

As to water vapour, positive and negative feedbacks – it all depends (though “overstated” does seem somewhat harsh insofar that real scientific studies cater for uncertainties). Roy Spencer is doing some good work on the “negative” side of things, but that is largely unproven and less robust that the “positive” side of things.

Raising the tropospheric hot-spot in the same sentence (as you do) does conflate and confuse the issue for many who might be reading this. Perhaps readers with a bent for techno-stuff should have a peak at this:

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-2-2.html

then this: http://www.skepticalscience.com/tropospheric-hot-spot.htm

As to CO2 emissions, I would be more relaxed if we focussed on the way we use and utilise our energy resources, there are better ways than just burning fossil fuels. Having said that, coal will be around for sometime yet.

BOM (and NASA) report their “predictions” with caveats and/or in probabilistic terms. People really should understand the significance of "uncertainty", most don't. To see a climate ‘trend’, you have to be able to filter out the ‘noise’ (natural variability) e.g. ENSO, Sun cycles, etc.

James, I suspect most people who get involved in this debate don't understand that the relationship between CO2 and heat is logarithmic, not a straight line. But it is, and you need to get your head around that, because that is where the whole genuine debate is.

Interesting that you obviously read blog sites by proponents of the catastrophic theory and haven't picked that fact up, because it's part of the consensus. It's just easier for them not to talk about it, because then the focus gets thrown onto the high uncertainties in modelling water vapour.

Bonmot, one of the things everyone agrees on is that the models aren't very good at regional forecasts. We do know that the heating tends to be more at the poles, which is one reason that we are likely to have less severe storms with global warming because it decreases the energy differential in the system and therefore decreasing the strength of energy flows.

Your comment about the logarithmic effect of CO2 depending on whether it is saturated or not says you need to do more research in this area. As it reaches saturation it reaches a point where it reradiates nothing, but that doesn't mean that the effect doesn't occur at all levels.

The Skeptical Science blog post is a bit of disinformation. The issue isn't whether CO2 causes the hot spot, but whether the modelling of water in the models is accurate. The recent Royal Society statement concedes that there are issues here.

The probabilities that scientists assign to some of these things are just guesses (unlike probabilities that can be assigned to statistical measurements).

Dear Graham,
I've been looking over old threads looking for inconsistencies in your stand on this issue. But though they're bound to be there, in some degree, you do seem by and large to be consistent; that a little more Co2 is not a bad thing and may even be salubrious. you base this stand on your faith (presumably you're not a scientist) that warming wont exceed three degrees "because of its logarithmic reaction to infra-red radiation".
I'd remind you that Co2 is not the only greenhouse gas and water vapour not the only possible positive-feedback--we are in unprecedented territory after all. Indeed, as I'm sure you'll acknowledge, the science is very complex indeed, ergo I side with raycom in deferring to the experts; surely scientific consensus (overwhelming) should decide how we deal with the issue. Which brings us to the conspiracy hypothesis. It seems to me then that the most pressing considerations for this or another thread are a) is Co2 in the atmosphere self-inhibiting? and b) is there a world-wide conspiracy abroad, and if so what is its aim?

haha Looks like James Carman bought the bridge.

So after all the sanctimonious little lectures and finger wagging about "denialist" sites, you don't even understand what this is all about? Talk about a true believer indulging in blind faith.

So, hey James, hey .. here you go

"You need to read outside the BELIEVER literature and their favorite strawmen. I can state confidently that you haven't, because you wouldn't have said something like that if you had."

There you go, fixed ..

You've swallowed the whole consensus thing without having realized what the whole skeptical side of the "debate" is about - which is, now I'm sure this will be new to you ..

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!

Oh that's made my day.. thanks.

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.

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

To be clear, it does NOT approach the asymptote that you think or infer.

Bonmot, you're trying to fit me up. I didn't say that CO2 was saturated, just that most of the warming that could be due to CO2 has already occurred. Not sure what your point about linear is because we are not at "relatively low" levels of CO2. But if you look only at a segment of the curve it will probably look linear, if you only look at a smal enough segment.

Using Venus as a comparison is ridiculous. It has an atmospheric pressure about 90 times earth's which changes the absorption behaviour somewhat.

James, "hide the decline" did in fact mean to hide the temperature decline. They were using proxies to gauge temperature and the proxies, after showing temperature the way they wanted it pre the 1960s started declining at a time thermometers said it should be increasing. So they just spliced the thermometer temperatures onto the proxy temperatrues and voila.

Of course what this says is that the proxy was entirely unsuitable because it didn't agree with reality.

The inquiries into the climate gate emails were whitewashes. They didn't look at the science, and mostly just interviewed the perpetrators.

Amongst their non-scientific crimes were trying to get people sacked who published scientific papers disagreeing with them.

It is quite a disgraceful event, and attitudes to it are a good touchstone of whether people actually care about the issues or are just barracking for global warming.

Oh, and I forgot Bonmot. You're the only one who thinks that regional forecasts are any good. The IPCC warns against them, and their unreliability is also noted in the latest Royal Society statement on climate change.

There are so many unknowns that increased computer power won't sort the problem out.

GrahamY "It is quite a disgraceful event, and attitudes to it are a good touchstone of whether people actually care about the issues or are just barracking for global warming."

Well said, my sentiments exactly - and anyone who claims the "reviews" were a model of probity is kidding themselves. Much the same as the reviews of the hockey-stick guy, who is extremely litigious is protecting his fiefdom.

When you have universities or old boys reviewing their mates, you know how it will come out, so very Yes, Prime Minister.

I agree with Amicus on this as well, that a lot of scientists are horrified by what came out of CRU in the climategate emails - however they got out, it was a good thing to show the peer review process is corrupt and cannot be relied upon, this had been used for years against skeptics and is now shown in climate science to be a tool for suppressing information.

Everyone,

This thread is getting somewhat heated. While there are still points to address, do we all want to calm down and walk away before it gets too far?

james .. clearly you are new to OLO Climate discussions, this is still very mild, no one has been scolded yet or sent to purgatory.

but to head back to the article in question, the whole per capita debate is a furphy, when Australia has 20 million (or thereabouts) people and we thrash ourselves with the bushes while China has 1.2+ Billion and finger wags at us.

Our emissions for the next 100 years, would probably not equal their emissions for the next week.(they already have how many coal powered power stations?)

We are but an ant, trying to dance with elephants, with the obvious consequences - no one notices us, we will self inflict damage, no one will care.

That's us Australia, big hat, no horse.

Graham Y makes some interesting points. He states that: “… temperature increase is likely to be less than 3°. Most of the warming we are going to see from CO2 has already occurred because of its logarithmic reaction to infra-red radiation”.

These are novel claims – that the correlation between increasing temperature and increasing atmospheric CO2 being logarithmic rather than linear limits the ability of CO2 to increase global temperature by more than 3°. Could you cite a peer-reviewed reputable source that provides evidence to support this, and explain what is meant by “its logarithmic reaction to infra-red radiation” and show how this limits the effect of further CO2 emissions.

Bonmot says that “at relatively low (CO2) the gradient of the logarithmic function that you think is minor is in fact major, and near linear”. The repost that anything can be made to appear linear if a short enough time span is quite valid. However, over the 100 years of the 20th century, the correlation between the rate of increase in atmospheric CO2 and temperature, particularly over the latter half of the century, appears quite good and near linear as shown at

http://zfacts.com/p/226.html
http://www.skepticalscience.com/news.php?n=61 and
http://wattsupwiththat.com/2008/01/25/warming-trend-pdo-and-solar-correlate-better-than-co2/

Asserting an international conspiracy to falsify temperature records so as to show decadal increases in global temperature over the last 50 years, when global temperature actually fell is all very well. But simply saying that is the case does not make it fact and unless supported by credible evidence, preferably science-based evidence, it certainly does not make it a proven fact. Where is the evidence?

The warming or ‘greenhouse gas’ effect of CO2, when compared to temperature, is logarithmic such that there is rapid but decreasing warming between 0ppm and approximately 50ppm of atmospheric CO2 – increasing the ‘greenhouse’ temperature effect by about 15º to 35ºK (Kelvin), with a marked decline in its warming effect between 50ppm and around 200ppm – representing about a 4ºK increase; beyond around 200ppm to well over 800ppm the warming effect declines to about 1ºK or less. Therefore, the capacity of increased atmospheric CO2 to increase temperatures, from whatever the source, is very limited above 300ppm or so.

Engineers who deal in greenhouse systems point to the classic text book “Heat Transmission” by William H. McAdams (McGraw-Hill, 1954), still used in the design of industrial furnaces, which discusses this limiting effect, which has to do with the radiation bands on which the gas absorbs heat. There is good agreement on this science, and it is well understood.

It is important to remember that it is the total amount of atmospheric CO2, derived both naturally and by the addition of anthropogenic sources that has the potential to warm the Earth’s atmosphere, with the logarithmic decay of temperature versus CO2 limiting this possible warming. Because of this logarithmic decay a doubling of CO2 to 760ppm from the current 380ppm is likely to be approximately 0.12°C.

A compilation by Sundquist [(1985) Geological perspectives on carbon dioxide and the carbon cycle, in Sundquist, E.T. & Broecker, W.S. (Eds.): The carbon cycle and atmospheric CO2: natural variations Archaean to present, American Geophysical Union, Geophysical Monograph 32, 5-59] lists the results of 36 separate studies, based on a number of different measurement methods that give for both naturally and anthropogenically-derived an atmospheric CO2 residence or turnover time (not to be confused with e-folding time) ranging between two and 25 years. (Continued)

(Continued from above) In summary, these studies show that CO2 has an average atmospheric lifetime of about five years and that approximately 135 giga-tonnes (about 18%) of the atmospheric CO2 pool is exchanged each year. This large and fast natural CO2 cycling flux is far more than the approximately 6 giga-tonnes of carbon in the anthropogenic fossil fuel CO2 now contributed annually to the atmosphere. On these figures anthropogenic CO2 accounts for just 4.45% of the annual atmospheric turnover – it therefore has only a corresponding 4.45% influence on the 0.12°C mentioned above, at any one time - in other words the effect is negligible.

Nonetheless, many climate models project a global temperature increase of several degrees; obviously then, if the models are correct, another mechanism must be involved. The assumption is that atmospheric water vapour, a known powerful greenhouse gas, acts as a positive feedback amplifer mechanism. This notion assumes that initial warming leads to increases in water vapour concentration that in turns enhances the original warming (amplifers it) which further increases water vapour concentration resulting in additional warming and so on, implying that the feedback mechanism is the dominant factor driving anthropogenic climate change.

By giving dominance to the water vapour feedback mechanism this signifies an amplifer input signal that is much greater than the initial anthropogenic CO2 forcing. Is this really the case? If it were true then at the end of the last glaciation, when atmospheric CO2 was increasing, we would expect to see runaway climate change – this clearly did not occur. Rather the climate has ranged or oscillated between interglacial warmth heat and glacial cold as the world has swung in and out glacial periods – this would suggest (in part) a negative feedback mechanism.

There are many other problems associated with the positive feedback amplifier mechanism, not least of all it is impossible to obtain empirical confirmation of the value of any feedback by direct measurement. On this, and it would take a few pages worth of explanations to discuss, the science on the positive feedback amplifier mechanism is definitely not settled.

Very well articulated Raredog.

Raredog

In response to my call for credible evidence of the claims made by Graham Y, you assert that anthropogenic emissions are 4.45% of natural emissions. It follows that anthropogenic emissions are only responsible for 4.45% of the increase in CO2 since pre-industrial times. Ergo, anthropogenic emissions can only have a 4.45% effect on temperature.

This is wrong because natural CO2 sources are balanced by natural sinks and have no long term effects on concentration. ALL of the increase of CO2 concentration in the atmosphere is anthropogenic.

I am indebted to Dr Lambert (UNSW) for his advice on the behaviour of Logarithms in which he notes that: A logarithmic response means that the warming for increase in CO2 from 50 to 200 (a quadrupling) will be the same as from 200 to 800 (also a quadrupling). It does not mean that the first will be four times the second. Logarithms do not behave like that.

That invalidates the material you put forward arguing the effects of increasing CO2 concentration on temperature. It certainly does not mean, as claimed by Graham Y, that increasing CO2 concentration will not result in temperatures exceeding 3°C. They most certainly can and unless anthropogenic emissions are curbed, they will.

The penultimate paragraph of your comment in effect argues that climate sensitivity can not be as high as the IPCC range because otherwise we would have had runaway climate change at the end of the last ice age. This is exactly backwards. It was 5K colder at the last Glacial Maximum with CO2 concentrations half what they are to-day.

If sensitivity was as low as you suggest, there is no way that there could have been an ice age. The fact that we have ice ages is one of the strongest pieces of evidence that climate sensitivity is around the IPCC value.

Agnostic of Mittagong - sorry, about the late reply. I have abbreviated your quotes to fit in with the word limit.

"You assert that anthropogenic emissions are 4.45% of natural emissions."

No, anthropogenic CO2 accounts for just 4.45% of the ANNUAL atmospheric CO2 turnover.

"It follows that anthropogenic emissions are only responsible for 4.45% of the increase in CO2 since pre-industrial times."

No, most of the increase is possibly anthropogenic with a contribution from the natural warming post the Little Ice Age, for instance.

“Ergo, anthropogenic emissions can only have a 4.45% effect on temperature.”

Most likely, in terms of the warming effect of atmospheric CO2, at any one point in time.

“This is wrong because natural CO2 sources are balanced by natural sinks and have no long term effects on concentration.”

There is a range in concentration as exemplified by changes in atmospheric CO2 levels between the glacial/interglacials periods as well as in response to natural warming/cooling periods (eg Little Ice Age, etc) - as such atmospheric CO2 concentrations oscillate over the longer term. The assumed STATIC balance of natural sources and sinks is another argument based on a number of assumptions.

“ALL of the increase of CO2 concentration in the atmosphere is anthropogenic.”

Mostly but with the addition of possible natural sources.

“A logarithmic response means that the warming for increase in CO2 from 50 to 200 (a quadrupling) will be the same as from 200 to 800 (also a quadrupling).”

I do not understand this example in terms of CO2 concentration verus temperature.

“That invalidates the material you put forward arguing the effects of increasing CO2 concentration on temperature. It certainly does not mean that increasing CO2 concentration will not result in temperatures exceeding 3°C.”

Not so. The effect of increasing atmospheric CO2 concentration on temperature increase, due to its inverse logarithmic relationship, declines as the concentration increases – in other words, there is a diminishing return of temperature increase for each additional increase in CO2 concentration. (Continued)

(Continued) The “3°C” you mention depends not only on CO2 concentration but also on atmospheric water vapour acting as a POSITIVE feedback amplifier mechanism. Without an assumed POSITIVE feedback amplifier mechanism atmospheric CO2, on its own, cannot produce the 3°C you quote at current concentration levels or with future projected increases in atmospheric CO2.

“Climate sensitivity can not be as high as the IPCC range because otherwise we would have had runaway climate change at the end of the last ice age. This is exactly backwards.”

No, I said “by giving dominance to the water vapour feedback mechanism” (upon which climate sensitivity related to CO2 forcing is based) then “at the end of the last glaciation, when atmospheric CO2 was increasing, we would expect to see runaway climate change – this clearly did not occur.”

“It was 5K colder at the last Glacial Maximum with CO2 concentrations half what they are to-day.”

At that time atmospheric CO2 concentrations were around 180-200ppm so the CO2 warming component contributed something around the 5K figure you quote.

“If sensitivity was as low as you suggest, there is no way that there could have been an ice age. The fact that we have ice ages is one of the strongest pieces of evidence that climate sensitivity is around the IPCC value.”

I do not suggest sensitivity per se, only the increasingly diminishing contribution of atmospheric CO2 relative to concentration, which around 200ppm is a few degrees while a doubling from the current approximate 380ppm to 760ppm is around 0.12°C. Climate sensitivity due to CO2 forcing of the order you quote (3°C) is based on the atmospheric CO2 concentration’s relationship to temperature in ADDITION to there being a POSITIVE feedback amplifier mechanism – it is not just atmospheric CO2 concentration on its own.

I should have added the “but” Raredog.

The concentration of CO2 in the atmosphere is not saturated and will continue to absorb (and irradiate) energy as its concentration increases, albeit at a diminishing rate - as both you and Graham state.

It is the change (and rate of change) and the relationship between "temperature change" and "radiative forcing" that most people don’t seem to fully grasp.

http://folk.uio.no/gunnarmy/paper/myhre_grl98.pdf

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html

As you say; water vapour is "assumed" to be a positive feedback mechanism - I would add for very good reasons.

Can you provide a robust reason why it should not, or why water vapour should be considered a forcing, rather than a feedback?

You may also find these helpful:

http://www.giss.nasa.gov/research/news/20101014/

http://pubs.giss.nasa.gov/docs/2010/2010_Schmidt_etal_1.pdf

Cheers

The link was just emailed to me. Some people with an aversion to the site won't even go there:

http://tinyurl.com/more-on-feedbacks

They should if they are a real "sceptic", agnostic even.

Thanks Bonmot and Raredog for these edifying exchanges. But Bonmot, your last link doesn't appear to work.

I would just add that whatever the outcome of the atmospheric Co2 debate, the acidification of the world's oceans, and their saturation point as carbon sinks, is surely every bit as catastrophic as warming, even if it does stay below three degrees.

Squeers, tinyurl site was down, now up - try again.

"Catastrophic" warming won't happen anytime soon, this is taken way out of context by "alarmists" and by those most to gain from the FUD, the "sceptics".

The oceans are becoming more acidic, they are not acidic per se and are extremely unlikely to become acidic, ever. Nevertheless, the "acidification" is having serious repercussions at the bottom of the ocean's food chain - that in itself is cause for concern.

3 degrees C per doubling [CO2] is worrisome, it will take a while (time doesn't stop at 2100). It is going to be hard enough to limit it to 2 degrees this century - we should try. In any case, it won't happen overnight, CO2 is a long lived greenhouse gas..

Bonmot, there is not much point posting links if they have little to do with your argument. The first couple provide a definition of radiative forcing. I don't think that was at issue.

The second two hilariously try to work out the radiative forcing of gases other than CO2 by using models. But the models paramaterise the forcings in the first place, which means they pick a figure they think is probably right and use it to amplify the CO2 (warming which we can calculate because the physics is well understood). Which means they are basically assuming the thing that they try to prove.

Agnostic, it is well accepted that CO2's reaction to heat is logarithmic. If we need a scientific citation before that is accepted, we are going to need citations to prove that the sun rises in the east, that massive objects exert a force on other massive objects inversely proportional to the distance between them (actually there is a paper for that, but I'm not sure that it is peer reviewed) etc. It's not a novel claim that I've made, it's well-accepted scientific fact.

It says something about the misdirection in the whole debate that so few people seem to be awarea of what the real argument is about.

Raredog

You claim that there is ... “a marked decline in its (CO2’s) warming effect between 50ppm and around 200ppm – representing about 4°K increase; beyond around 200ppm to well over 800ppm the warming effect declines to about 1°K or less”.

In other words the logarithmic effect of CO2 concentration on temperature is such that the first (50-200ppm) is four times greater than the second (200->800ppm).

Wrong. A logarithmic response means that the warming for increase in CO2 from 50 to 200 (a quadrupling) will be the same as from 200 to 800 (also a quadrupling). It does not mean that the first will be four times the second. I repeat, Logarithms do not behave the way you describe.

No Graham. It is patently obvious that some people don’t understand the relationship between radiative forcing, temperature change and GHG concentrations. And some, Graham, appear to be deliberately obtuse in their comments or 'opinion'. Whether they do this in ignorance or by deliberate/malicious spread of FUD does not really matter, the damage is done.

For example, you said to me;

“You're the only one who thinks that regional forecasts are any good. The IPCC warns against them, and their unreliability is also noted in the latest Royal Society statement on climate change.”

Graham, you are deliberately distorting and misrepresenting what I said – which was;

“The IPCC’s AR5 should make it clearer as to what different regions should expect – increased data and computing technology will enable this,” and

“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.”

Most people would see the difference. However, I will try and make it clearer for you.

Regional climate projections since AR4 will improve because of more data and more advanced computing power. Here in Australia the CSIRO, BOM and the Departments of Climate Change; Sustainability, Environment, Water, Population and Communities; Agriculture, Fisheries and Forestry, and so on (federal, state, local) including major industry and private stakeholders are encouraged by these recent developments. I should not have to explain why.

AoM

I am sure Raredog understands and if I may (he will correct me if I’m wrong, I hope) will re-phrase what he has said (in part).

i.e. To achieve the same temperature “change” at higher CO2 concentrations requires more CO2 than previous.

For example, given IPCC 'climate sensitivity' (lambda) = 3 degrees:

A “3 degrees temperature change” requires a doubling from 280 ppmv to 560 ppmv.

A *same* “3 degrees temperature change” requires also a doubling from 560 ppmv to 1120 ppmv.

In other words, only 280 ppmv is required for the initial 3 degrees “change,” while 560 ppmv is required for the next 3 degrees “change”.

The “change in temperature” is proportional to the “change in radiative forcing” (1st order approximation) and GHG’s are a significant radiative forcing. The fact that Graham thinks this does not contribute to some or other “argument,” or the models are “hilarious,” is simply astounding – expected on an open forum I suppose, but from the site owner?

Anyway, look at the graph top of page 2717 in Myhre et al http://folk.uio.no/gunnarmy/paper/myhre_grl98.pdf

The slope (gradient) of the log function at current atmospheric [CO2] levels is quite steep ... and it is still quite steep at 600 ppmv. Indeed, the concentration of CO2 will have to be very much higher before the slope approaches the horizontal asymptote – extrapolated in the order of 5,000 ppmv. This is extremely high and life as we know it would not exist. But you are right, it will be bad enough at 720 ppmv.

"For example, given IPCC 'climate sensitivity' (lambda) = 3 degrees"

should read;

For example, given IPCC 'climate sensitivity' (lambda) = 5.35

Please disregard my last 2 comments (now had a strong coffee).

Best see http://en.wikipedia.org/wiki/Radiative_forcing

You can see the values for 'climate sensitivity' and the log function there.

Bonmot

Thank you. I know how logs work and I share your belief that Raredog knows exactly what he is doing.

Take for example his claim that anthropogenic CO2 has only a 4.45% effect on global warming. How does he come to this conclusion?

First he asserts that …. “anthropogenic CO2 accounts for just 4.45% of the annual atmospheric turnover – it therefore only has a corresponding 4.45% influence on the 0.12°C mentioned above, at any one time – in other words the effect is negligible.”

He then claims that annual anthropomorphic carbon emissions are 6 giga-tonnes. The last time I looked those emissions were 31 giga-tonnes and rising. He then divides 6 giga-tonnes of carbon by 135 giga-tonnes of CO2 supposedly recycled each year (assuming the atmospheric CO2 pool is 750 gig-tonnes and stable. It isn’t) and hey presto! 4.45%.

Carbon and CO2 are of course not the same thing. It’s rather like dividing apples by oranges and getting lemons. A scientific approach would you say Grahame?

AoM: My last couple of posts went awry, the problem with trying to do too many things at once. Anyway, the gist was there for anyone with patience to follow.

I think Raredog’s reliance on a 1985 publication (Sundquist) is misleading, particularly the calculations based on it. I think you are right and I too am baffled by Raredog's;

“these studies show that CO2 has an average atmospheric lifetime of about five years and that approximately 135 giga-tonnes (about 18%) of the atmospheric CO2 pool is exchanged each year. This large and fast natural CO2 cycling flux is far more than the approximately 6 giga-tonnes of carbon in the anthropogenic fossil fuel CO2 now contributed annually to the atmosphere. On these figures anthropogenic CO2 accounts for just 4.45% of the annual atmospheric turnover – it therefore has only a corresponding 4.45% influence on the 0.12°C mentioned above, at any one time - in other words the effect is negligible.”

One has to wonder why he couldn’t source the data from CDIAC’s ‘Global Carbon Project’.

http://www.globalcarbonproject.org/carbonbudget/08/hl-full.htm

Interestingly, they conclude “The human perturbation of the carbon cycle continues to grow strongly and track near the most carbon intensive scenarios of the UN-Intergovernmental Panel on Climate Change.”

I don’t see this changing – world population is growing strongly, developing countries are developing (sic) and western economies are abandoning responsible growth for unfettered consumerism.

The ‘Carbon Budget’ for 2009 is going to be released in the next week or so. It will be interesting to compare it with this last one.

Well Squeers, as for the edifying exchanges - they've evaporated.
Thank you anyway :)