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« DownWard | Main | The third-world ambition of the UK »
Thursday
Mar032011

Crisis over?

Anthony Watts is reporting a new paper that puts the climate's no-feedback sensitivity to CO2 at 0.45°C per doubling, less than half that of previous estimates. Interesting stuff.

 

 

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Reader Comments (59)

Less than half!? It's a fifth of the lower and a seventh of the average IPCC estimate.

Mar 3, 2011 at 8:18 AM | Unregistered CommenterPhillip Bratby

"...new paper that puts the climate's no-feedback sensitivity to CO2 at 0.45°C per doubling".

What you mean by "no-feedback sensitivity"? Normally sensitivity does include feedback (certainly the various alarmist GCMs include feedback in their sensitivity estimates. It would not make sense to compare a sensitivity with feedbacks to a sensitivity without feedbacks, would it?

Mar 3, 2011 at 8:40 AM | Unregistered CommenterSteve Koch

The weighted average over all regions as the global climate sensitivity is found to be CS = 0.45 ̊C with an estimated uncertainty of 30%.

The reality of such a figure means the Global Warming Scare is well and truly over.

The only thing humanity need worry about now is the onset of the next Ice Age.

Mar 3, 2011 at 9:14 AM | Unregistered CommenterMac

I still say that 0.45C is too high; the planet has only warmed by about 0.7C degrees in the last 100 years, or rather the northern hemisphere has - the south seems to have warmed less if at all. I then put half the 0.7C warming down to UHI, dodgy station selection and homogenisation and bald adjustments. That only leaves a rise of 0.4C to account for and the natural warming from the end of the little ice age can account for that. Then we have the uncertainties from long term oceanic cycles, solar magnetic and cloud cover changes. CO2 concentration is pretty much irrelevant - it is the H2O cycle which dominates and regulates the planet's temperature.

Mar 3, 2011 at 9:39 AM | Unregistered Commenterlapogus

'The only thing humanity need worry about now is the onset of the next Ice Age.' Mac


Well, no - we still (and always) have politicians toi worry about!

Mar 3, 2011 at 9:54 AM | Unregistered CommenterIan E

I find it amazing that people and those responsible for these blogs place faith in an abstract submitted for a meeting that is not even held yet. a)It has not been presented to the meeting in Vienna. b)It has not been checked through any peer review. c) It is not even a paper submitted to a reputable journal. d)It remains unclear wether the analysis include the feedbacks that normal assessments in other papers and summarized by the IPCC includes. If you wish to pinch a hole in the consensus view of climate sensitivity, please apply some elements of scientific thinking, rigour and analysis.

Mar 3, 2011 at 9:56 AM | Unregistered CommenterSvein S

Svein S. So you think peer review does checking?. Think again before telling us how to think.

Mar 3, 2011 at 10:00 AM | Unregistered CommenterPhillip Bratby

Svein S

All empirical studies for calculating Climate Sensitivity produces a figure much lower than IPCC estimates.

This study is certainly on the low side in this regard, but it adds to the picture being built up that Climate Sensitivity is greatly over-estimated.

The data is saying one thing, the models are saying the other.

Who do you believe in?

1. The actual data, or the

2. Modelled assumptions.

If we build robust datasets there can be no arguements. The data wins everytime.

Mar 3, 2011 at 10:17 AM | Unregistered CommenterMac

lapogus

"it is the H2O cycle which dominates and regulates the planet's temperature."

That can't possibly be right can it? - the IPCC doesn't recognise water vapour as a greenhouse gas!!!!!!

I thought this was a relevant presentation from a highly respected source -

http://joannenova.com.au/2011/02/the-oceans-clouds-and-cosmic-rays-drive-the-climate-not-co2/

Note that there is a link near the top to the complete presentation in pdf format. His conclusions say it all.

I struggled to keep up in a couple of places (and it is stuff I should know), and if you read the comments on the JoNova thread, he did start a lively discussion on energy balance.

Mar 3, 2011 at 10:26 AM | Unregistered CommenterRetired Dave

Svein S. Your points b) and c) are pretty much irrelevant given the quality of some climate science that has passed pal.. I mean peer review in your 'reputable' journals. Given it's a pretty contentious claim, you can be sure it's going to be subject to a pretty thorough extended peer review by sceptics and believers.

Mar 3, 2011 at 10:32 AM | Unregistered CommenterAtomic Hairdryer

Ian E

"we still (and always) have politicians to worry about!"

I always like Mark Twain's take on these matters

"No man's life, liberty or property is safe while the legislature is in session."

Or Thomas Jefferson

"A government bid enough to give you everything you want, is strong enough to take everything you have"

Two very relevant quotes from the colonies of 150 to 200 years ago.

Mar 3, 2011 at 10:34 AM | Unregistered CommenterRetired Dave

Svein S: "I find it amazing that people and those responsible for these blogs place faith in an abstract submitted for a meeting that is not even held yet."

Svein this is a sceptical site, I doubt anyone here is taking the abstract at face value, it's interesting for sure in that it uses real world data and conflicts with the generally accepted estimate from the Stefan-Boltzmann equation of around 1C. Moreover it does make sense the heat accumulated in CO2 does so logarithmically so we would expect the forcing to be higher in the earlier stages of CO2 increases in the atmosphere. As it stands, the infinitely flexible IPCC AR4 is postulating that around half of the increase in temperature in the last 150 years is caused by human emissions, that would be about 0.4C for an increase of around 37% of CO2 in the atmosphere, we can expect the increase to slow down as the logarithmic effect of heat retention kicks in, so these numbers are interesting. But only that, because they haven't been checked by anyone else yet a you point out. I doubt anyone will get excited until they are, and even then, the excitement won't be ecstatic because as with the hundreds of other peer-reviewed scientific papers that have challenged the orthodoxy it will be suppressed or subject to a sustained attack from the climate science establishment, with the author's reputations dragged through the mud.

We've a long way to go before the science is king in this debate.

Mar 3, 2011 at 10:35 AM | Unregistered Commentergeronimo

geronimo

Pretty much sums it up.

Mar 3, 2011 at 10:52 AM | Unregistered CommenterBBD

Svein

If you follow the link to WUWT you will see that Anthony Watts has also put in this caveat:

"The paper is being presented at the EGU General Assembly 2011 in Vienna.
Perhaps our WUWT readers can dissect this and see how well it holds up. It is important to verify if the paper’s methodology is sound."

I also thank Bishop Hill for bringing what maybe an interesting paper to our attention.

Mar 3, 2011 at 11:10 AM | Unregistered CommenterJack Cowper

Svein S: "I find it amazing that people and those responsible for these blogs place faith in an abstract submitted for a meeting that is not even held yet."

In addition Sven, the post is a link to WUWT! If you find it amazing try popping over to RC. There you will find plenty of stuff to amaze and astonish you! To paraphrase Geronimo..Beware! Here be sceptics!

Mar 3, 2011 at 11:12 AM | Unregistered CommenterPete H

Hate to be a Parade Rainer, but the journal is 'An Open Access Publication'

I take this to mean they take any paper without peer review. Basically they publish abstracts prior to acceptance to mainstream journals.

I could be wrong and would welcome being disabused.

Mar 3, 2011 at 11:16 AM | Unregistered CommenterJerry

Svien

I read your post after I posted mine. You are spot-on. This is not ground-breaking till it's been torn to pieces by 'the enemy' and found not wanting.

Mar 3, 2011 at 11:19 AM | Unregistered CommenterJerry

Svien S - we sceptics don't need to pinch a hole in the consensus view of climate sensitivity - it was already done for us in WG1. I re-post a recent comment from Dave Salt which is relevant here:

================================================
http://www.bishop-hill.net/blog/2011/2/17/spectator-debate.html
Phillip Bratby (Feb 17, 2011 at 7:00 PM) asked about evidence for CAWG in the IPCC AR4 WG1 papers and the lack of references to them in support of this ‘meme’. Well, here are a few ‘clippings’ from WG1, plus some other peer-reviewed references, that may be of interest to show just how candid the WG1 people were about their uncertainties… though they seem to have been ignored by the subsequent groups that built upon their findings.

Note that in reviewing these reports, I couldn’t find one examples where CAGW had been verified by the Scientific Method (i.e. predictions tested against real-world data). There is widespread use of model ensembles to ‘bound’ the uncertainties, though I suspect this approach may be fundamentally flawed if these models do not include all physical processes and their interactions with sufficient fidelity.

——————————————————-
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch08.pdf
8.6.2.3 What Explains the Current Spread in Models’ Climate Sensitivity Estimates?
Using feedback parameters from Figure 8.14, it can be estimated that in the presence of water vapour, lapse rate and surface albedo feedbacks, but in the absence of cloud feedbacks, current GCMs would predict a climate sensitivity (±1 standard deviation) of roughly 1.9°C ± 0.15°C (ignoring spread from radiative forcing differences). The mean and standard deviation of climate sensitivity estimates derived from current GCMs are larger (3.2°C ± 0.7°C) essentially because the GCMs all predict a positive cloud feedback (Figure 8.14) but strongly disagree on its magnitude.
8.6.3.2 Clouds
In the current climate, clouds exert a cooling effect on climate (the global mean CRF is negative). In response to global warming, the cooling effect of clouds on climate might be enhanced or weakened, thereby producing a radiative feedback to climate warming.

Therefore, cloud feedbacks remain the largest source of uncertainty in climate sensitivity estimates.
8.6.3.2.1 Understanding of the physical processes involved in cloud feedbacks
The sign of the climate change radiative feedback associated with the combined effects of dynamical and temperature changes on extratropical clouds is still unknown.

The role of polar cloud feedbacks in climate sensitivity has been emphasized by Holland and Bitz (2003) and Vavrus (2004). However, these feedbacks remain poorly understood.
8.6.3.2.4 Conclusion on cloud feedbacks
Despite some advances in the understanding of the physical processes that control the cloud response to climate change and in the evaluation of some components of cloud feedbacks in current models, it is not yet possible to assess which of the model estimates of cloud feedback is the most reliable.
8.6.4 How to Assess Our Relative Confidence in Feedbacks Simulated by Different Models?
A number of diagnostic tests have been proposed since the TAR (see Section 8.6.3), but few of them have been applied to a majority of the models currently in use. Moreover, it is not yet clear which tests are critical for constraining future projections. Consequently, a set of model metrics that might be used to narrow the range of plausible climate change feedbacks and climate sensitivity has yet to be developed.
——————————————————-
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf
9.6.4 Summary of Observational Constraints for Climate Sensitivity
Structural uncertainties in the models, for example, in the representation of cloud feedback processes (Chapter 8) or the physics of ocean mixing, will affect results for climate sensitivity and are very difficult to quantify.
——————————————————-
http://www.climatescience.gov/Library/sap/sap3-1/final-report/sap3-1-final-all.pdf
4.1.1 Equilibrium Sensitivity and Transient Climate Response
We understand in much more detail why models differ in their equilibrium climate sensitivities: the source of much of this spread lies in differences in how clouds are modeled in AOGCMs.
4.2.1 Cloud Feedbacks
Differences in cloud feedbacks in climate models have been identified repeatedly as the leading source of spread in model-derived estimates of climate sensitivity (beginning with Cess et al. 1990). The fidelity of cloud feedbacks in climate models therefore is important to the reliability of their prediction of future climate change.
——————————————————-
http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf
Structural problems in the models, for example in the representation of cloud feedback processes or the physics of ocean mixing, in particular in cases in which all models make similar simplifications, will also affect results for climate sensitivity and are very difficult to quantify.
——————————————————-
http://chriscolose.wordpress.com/2009/10/08/re-visiting-cff/
Clouds are the largest source of uncertainty in quantifying the extent of climate feedbacks.

clouds have competing effects between reflecting sunlight (low clouds mostly) and influencing the outgoing infrared radiation (high clouds mostly). It is still not clear how these two effects will balance out, and thus the magnitude and even the sign of the feedback is not well constrained.
——————————————————-
Feb 17, 2011 at 8:52 PM | Unregistered Commenter Dave Salt
=================================================

Is that enough scientific thinking, rigour and analysis for you?

Mar 3, 2011 at 11:22 AM | Unregistered Commenterlapogus

Oops sorry Svein. I misspelled your name.

And having read the rest of the comments, I'm a bit uncomfortable about the BH site right now. In this post the comments are starting to look like some of the more rabid comments from the warmists and/or the anti-warmists. When people start quoting Jo Nova I realise there's a significant problem arising.

Mar 3, 2011 at 11:26 AM | Unregistered CommenterJerry

Jerry

And having read the rest of the comments, I'm a bit uncomfortable about the BH site right now. In this post the comments are starting to look like some of the more rabid comments from the warmists and/or the anti-warmists. When people start quoting Jo Nova I realise there's a significant problem arising.

This is a singularly unhelpful remark. Stick around and enforce some common sense rather than moaning to BH about what 'people are saying'.

Mar 3, 2011 at 11:53 AM | Unregistered CommenterBBD

Svein
"Sceptic" means just that. And this paper (welcome though it may be on the face of it as another potential nail in the coffin of the "catastrophic" and "anthropogenic" aspects of global warming) will be well scrutinised by the sceptics before we all come to a conclusion on whether its conclusions are reasonable (I should perhaps say 'they' rather than 'we' since I am not qualified to judge the science).
The idea that sceptics are as committed to a belief system as some of the cAGW proponents is simply not the case, much as those proponents would like to believe we are. Most of us are supporters of the Royal Society motto loosely translated as "don't take anyone's word for it" even though it appears that the RS has been having second thoughts about that in the last few years.
The assumption that people who do not instantly roll over every time Hansen or Mann or Steig or Jones or Schmidt make a pronouncement on climate are either ignorant or evil is not only incorrect it's stupid. If this paper is supported by other findings or because its conclusions are sound it will be welcomed by the sceptics (and almost certainly vilified by the doom-mongers regardless). If it is not then it will be consigned to the dustbin and anyone who quotes from it here and on any other sceptic web site will be treated appropriately.

Mar 3, 2011 at 12:14 PM | Unregistered CommenterSam the Skeptic

Svein S
You are absolutely right.
All scientific paper should be queer reviewed before being cited with credibility.
Lets start by reviewing the self proclaimed programmers and statiscians first.

Mar 3, 2011 at 12:16 PM | Unregistered CommenterEdwin

"All empirical studies for calculating Climate Sensitivity produces a figure much lower than IPCC estimates.
This study is certainly on the low side in this regard, but it adds to the picture being built up that Climate Sensitivity is greatly over-estimated.
The data is saying one thing, the models are saying the other.
Who do you believe in?
1. The actual data, or the
2. Modelled assumptions.
If we build robust datasets there can be no arguements. The data wins everytime."
Mar 3, 2011 at 10:17 AM | Mac

errr, Mac.

You do know that this (un-reviewed) paper uses modelling don't you? Did you actually take the time to look at the abstract before posting?

Also, what's all this about emprical studies of climate sensitivity? It's impossible to examine clmate sensitivity without using modelling.

Mar 3, 2011 at 12:21 PM | Unregistered CommenterZedsDeadBed

It looks like real science, though, which makes a change from models.

Mar 3, 2011 at 12:22 PM | Unregistered CommenterJames P

Zed

There are models and models. At least this study is using empirical data.

BTW, Charlie has found you something to wear...

Mar 3, 2011 at 12:31 PM | Unregistered CommenterJames P

"It looks like real science, though, which makes a change from models."
Mar 3, 2011 at 12:22 PM | James P

You guys make is so easy to demonstrate that you're not actually sceptics at all. Here's yet another poster, who clearly hasn't looked at the paper, but is prepared to support it, based solely on its findings.

It's actually hard to be less sceptical than that.

Mar 3, 2011 at 12:33 PM | Unregistered CommenterZedsDeadBed

Roy Spencer has created models from observational data:

http://www.drroyspencer.com/2010/08/our-jgr-paper-on-feedbacks-is-published/

Peer reviewed as well - and delayed due to one hostile reviewer. Wonder if that was one of the team.

Mar 3, 2011 at 12:51 PM | Unregistered CommenterJack Cowper

Have to agree with you, ZDB. Yes, it does rely on a model, albeit a very simple one, and as I posted at WUWT, we will have to see whether this stands up to scrutiny. However in general, as someone who has seen the catastrophic failure of models in banking and insurance close up, I am more comfortable with simple, testable models than with over-parameterised ones that seek to explain everything but miss out the biggest variable of all, and are permanently being tweaked to try to keep them in line with actual outcomes.
How about you?

Mar 3, 2011 at 12:59 PM | Unregistered CommenterDavid S

Certain types of systems can be simulated to an acceptable level of accuracy by computer models. Climate is by its very nature a system of interacting non-linear complex systems which means it cannot ever be modelled to any useful degree of accuracy.

http://thepointman.wordpress.com/2011/01/21/the-seductiveness-of-models/

The models, like the science in this area are toast.

Pointman

Mar 3, 2011 at 1:11 PM | Unregistered Commenterpointman

Pointman

Certain types of systems can be simulated to an acceptable level of accuracy by computer models.

I agree. We used very complex thermal-hydraulics models at work. We spent a fortune in time and money verifying and validating them against tons of exprimental data before we could ascertain the uncertainty and were able to use them in anger.

Can't do it with modelling the climate.

Mar 3, 2011 at 1:27 PM | Unregistered CommenterPhillip Bratby

I've read the abstract, and it appears that the calculation includes feedback, as it mentions the effects of clouds among others. Perhaps the authors didn't try to calculate a no-feedback value to compare with the accepted value (from Myhre et al., mostly) of about 1 C / CO2 doubling.

What I like about the approach is that the standard approach takes the average atmospheric composition, assumed constant geographically as I recall, and then varies CO2. It sounds as though this paper considers a more accurate breakdown by geography, before varying CO2. The inclusion of varying atmospheric composition by altitude (and latitude) would seem to be an improvement.

However, I'd have preferred to see a no-feedback calculation first, though, as that is much more easily compared with the existing approach. Once you get into including the feedback effects, the assumptions made become more debatable. Indeed, even accepting the standard no-feedback sensitivity of 1 C/doubling, there are claims that including feedbacks, sensitivity is from 0.5 C to (I think!) over 10 C, although the IPCC consider the likely range 2 to 4.5, if I remember correctly. So the discussion about the paper may devolve into debate over their assumptions about feedback effects, which is not an improvement over the current situation.

Mar 3, 2011 at 1:32 PM | Unregistered CommenterHaroldW

Zed, did you read my post above about scepticism? It's equally important to be sceptical about what you would "like" to be right as about what you would "like" to be wrong -- more so in fact.
Mac was perfectly entitled to use the word "empirical" to describe something that is calculated from and based on real-world data as opposed to the purely theoretical output of models programmed according to the level of objectivity and honesty of the programmer.
Likewise there was nothing wrong with James P's statement that it "looks like" real science.
Neither, nor the rest of us, is making any assumption at this stage about the reliability or accuracy of the paper referred to, peer-reviewed or otherwise. But likewise none of us is trying to undermine it before we have had the chance to look at it or its authors have had a chance to explain or defend it.
Which, I would suggest, puts most of the contributors to this site on the side of honest scientific endeavour and you on the side of trollery.

Mar 3, 2011 at 2:05 PM | Unregistered CommenterSam the Skeptic

Zed

Also, what's all this about emprical studies of climate sensitivity? It's impossible to examine clmate sensitivity without using modelling.

Yup, that and paleo studies. All neatly set out in Knutti & Hegerl (2008). And that's precisely the problem with the consensus median estimate of +3C per doubling. It relies on necessarily assumptive and incomplete modelling and necessarily incomplete and assumptive paleoclimate work.

This approach - the only approach, as you rightly point out - is fraught with danger from converging confirmation bias and circular logic.

That's why many people who understand the way in which the IPCC consensus formed around +3C are uncomfortable with the figure and the false certainty with which it (or higher values) are presented to politicians and the public.

Mar 3, 2011 at 2:06 PM | Unregistered CommenterBBD

Bishop Hill

OT I'm afraid, but FYI:

I have had repeated problems posting comments, with the usual 'page reset' error from Firefox.

It can be resolved, at least temporarily, by re-booting the router or the whole system.

I mention this as Firefox auto-updated to v3.6.14 yesterday, which is when the problem started.

OS is Vista, fully patched.

Mar 3, 2011 at 2:11 PM | Unregistered CommenterBBD

Zed

Inputting REAL and ROBUST data into computers?!?!

WOW that's radical!

Do they know what real data is the virtual world of climate science?

Mar 3, 2011 at 2:38 PM | Unregistered CommenterMac

"Inputting REAL and ROBUST data into computers?!?!
WOW that's radical!"
Mar 3, 2011 at 2:38 PM | Mac

You still haven't even got as far as reading the abstract, have you. Different parts of the world have been given different weightings before they even go into the model.

Comments on highly-biased blogs seem to be all the evidence you require to form an opinion on something. Again, this is a very, very long way from being sceptical behaviour. It seems far more like you justify your bias-confirmation by telling yourself it's scepticism.

Mar 3, 2011 at 2:56 PM | Unregistered CommenterZedsDeadBed

Thank you, Sam - that's exactly why I said "looks like"!

It's also why Anthony Watts used the phrase "at first blush", but Zed would have missed that as well. Plus ça change.

Mar 3, 2011 at 3:03 PM | Unregistered CommenterJames P

What is your complaint Zed?

1. The data
2. The methods
3. The model
4. The conclusion
5. The lack of peer review.

In expressing such SCEPTICISM over the study it would appear to be all five.

Mar 3, 2011 at 3:06 PM | Unregistered CommenterMac

BBD - same problem at home with Opera and FF. No problem at work with FF...

Mar 3, 2011 at 3:06 PM | Unregistered CommenterJames P

This result agrees with interseasonal climate sensitivity (feedbacks all-in) based on observations. Anyone can perform this calculation using the datasets at the following site-

http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/mon2/state.html

1. Select a city.

2. Look at the measured solar insolation by month and pick out the max and min solar insolation in kWhr/m^2/day. Take the difference and multiply by 1000/24 to get the change in forcing in W/m^2 between the winter and summer seasons.

3. Look up the monthly temperature data at the bottom of the same data page for the selected city and take the difference between the max and min temperatures that correspond (roughly) in time with the months selected in step 2.

4. Take the difference between the two temperatures, and divide by the change in forcing found in step 2.

The result is the climate sensitivity in degrees C per W/m^2 of forcing at the surface. Since the data is based on 30 year averages of observations, all feedback effects are included.

The result will range from 0.03 - 0.2 C per W/m^2, depending on distance from the coast. For a doubling of CO2, or 3.7 W/m^2, this gives an average of about 0.4 C increase.

The database link is only for the U.S. It would be interesting to find similar databases for other regions of the globe.

Mar 3, 2011 at 3:10 PM | Unregistered Commenterchris y

Zed
I've actually tried very hard to avoid this but I'm rapidly coming to the conclusion that you are either dim or dishonest. Since your writing does not suggest the former, I'm not left with much in the way of choice.
Almost every posting here and at WUWT (even more so) accepts this paper as a contribution to the debate on CO2 but is to a greater or less extent sceptical.
If anybody round here is suffering from "bias-confirmation" (by which I presume you mean conformation bias) then it's you. None of us is about to accept uncritically a paper on such a tendentiousness subject without good reason, the more so because it would bolster the argument against the doom-mongers which is an outcome that many would like to see.
Which bit if this are you having trouble with?

Mar 3, 2011 at 3:17 PM | Unregistered CommenterSam the Skeptic

The paper can be summarised as:

1. Actual spectral absorbance of GH gases from HITRAN'2008 database
2. Line-by-line calculations for sunlight 0.1 - 8.0 um (short wavelength) and emitted earth radiation from 3.0 - 60.0 um (long wavelength)
3. Water vapour parameters use measured data from GPS-delay
4. Vertical variation in humidity/temperature is considered for 228 layers up to 86km - so fine layered and well beyond tropopause to the edge of the atmosphere
5. Geographic latitude and climate zones are simplified to considering the earth as a truncated icosahedron
6. The resulting forward modelled climate sensitivity for doubling of CO2 is 0.41 degC in the tropics, 0.40 degC in moderate zones and 0.92 degC for polar regions, with a global weighted average of 0.45 degC

This is a forward model calculation based on the known physics of the parts, together with actual measured data for the atmosphere. In terms of comparable "models", this is real world physics modelling like Svensmark, rather than statistical curve fitting models like GCM's and Steig09.

Someone at WUWT estimated this would give human-warming of about 0.15 degC for 20th Century. I tend to agree with lapogus above that the temperature warming is probably only half what is stated (the adjustments/corrections alone in GHCN contribute around 50% of the temperature change observed in the 20thC) so this climate sensitivity seems to fit reasonably with the idea that (a) some of the warming is manmade and (b) much of the warming is natural. The latter might explain (by natural causes) why temperature has plateaued for a decade or so.

Note also the abstract very clearly states assumptions, methods, data and results. This appears to conform with science as I remember it and was taught it. Looks like an interesting paper and very relevent. I look forward to reading it in full when it is published and to see what counter-arguments are offered or what other supporting papers appear as a consequence.

Mar 3, 2011 at 3:39 PM | Unregistered CommenterThinkingScientist

Jerry at 11:16 AM today: This is just an abstract, so it is a publication in the loosest sense of the term so far. However, what is meant in this context by 'Open Access' is that anyone can read it on the web - it is not behind a paywall, with the expenses associated with publishing it having been covered in some other way. The website says: "All summaries must undergo an access review by the session conveners, editors or organizers" - which is a way of saying that this abstract will have been refereed, albeit in a very light-touch way (if you submit an abstract claiming that the moon is made out of blue cheese you may find it gets spiked - some way North of that in scientific credibility, and you should be OK - this by the way is broadly what peer-review does all the time).

About scepticism and your 11:26 AM post: The Bishop doesn't get 5 Fellows of the Royal Society to peer-review every post here - its a blog, right? And you will find confirmation bias here, sure. Readers of Bishop Hill are more receptive to things which feed the sceptic view of CAGW than readers of RealClimate are. But things that are wrong tend, eventually, to get criticised here. True of RealClimate?

About the Abstract: to be honest, from a quick look, the work behind this looks unlikely to be correct to me. The author appears to have built a rather crude 1-dimensional GCM model using the same sort of radiative transfer model as used in conventional GCMs, but appears to be claiming that pressure-dependent line-broadening effects on water infrared absorption (a) have been neglected in conventional GCMs and (b) tend to swamp the absorption due to CO2 at higher water partial pressure. Well, not having written a GCM myself, I can't be sure of this, but my guess is that both (a) and (b) are wrong. So I would provisionally classify this paper as an eccentric attempt to disprove all of global warming theory, based on some flawed analysis. There are lots of those around. But I may be wrong - and even if I'm right about this abstract, it doesn't change the fact that I'm an AGW-sceptic (or perhaps a lukewarmer) - there are far too many other reasons for being sceptical of AGW.

Mar 3, 2011 at 3:53 PM | Unregistered Commenterj

James P

BBD - same problem at home with Opera and FF. No problem at work with FF...

Sorry – missed this. But it’s important in that it strongly suggests machine-specific cause.

There are two that I can think of, both of which might be avoided by using an office network.

The first is Squarespace tracking cookies going wrong somehow.

The second is malware designed to sod up the ‘BH experience’ and injected via the Squarespace servers to all commenters.

It needs sorting out, right now. Enough is enough.

Mar 3, 2011 at 4:09 PM | Unregistered CommenterBBD

errr, Mac.
"Also, what's all this about emprical studies of climate sensitivity? It's impossible to examine clmate (sic) sensitivity without using modelling."
Mar 3, 2011 at 12:21 PM | Unregistered CommenterZedsDeadBed

Typical ZDB from the Daily Mail comments! Watch the pea under the shell! You know she is upset when the spelling mistakes crawl in!

ZDB, have you even read any of the posts very early on...?

Svein S. So you think peer review does checking?. Think again before telling us how to think.
Mar 3, 2011 at 10:00 AM | Unregistered CommenterPhillip Bratby

But as usual you bring your religion here and continue to, as Phillip put it, to "Tell us how to think"!

I will forever trust Phillip! He has brought more to this blog and to the UK paper blogs in the way of empirical scientific comment that your eco rantings. Once your glorious "Climate Scientists" (I am still waiting for someone with a basic degree on the subject to show up!) please feel free to show ONE model that can in anyway show a chaotic system with all the known parameters being proved by empirical, falsifiable science!

You will never understand that no matter what you type, you are well know for your pure non scientific bias. Back to the D.M. with you and leave this place to people that have the balls to doubt either way and once again...This was a link to WUWT! Your objectivity is to distract... It will never happen!

Rant < ! Sorry Bish ;-(

Mar 3, 2011 at 4:40 PM | Unregistered CommenterPete H

BBD, James P, you may recall I was meeting this problem yesterday.

What appears to be causing it is a wrongly set "session cookie".

These session cookies are supposed to be just that, and are deleted when you close your browser. In FF, they appear to occasionally have a greater residual life than they're supposed to have, which I'm unreliably told is probably caused by FF "experiencing a problem" on exit - i.e. crashing on unload. The session cookies are not deleted in case the user wishes to restore the previously viewed pages when FF restarts next time.

These problems are, first and foremost, caused at the Squarespace end with errantly set session cookies. In Firefox I'm doomed. In Chrome, all is well unless I choose to preview my post before submitting it to the site. I can't do that, and if I try I get the "EMPTY_RESPONSE" error. Once I've got that, if I don't delete (or can't find) the session cookies I have to wait for 30-50 minutes before I can submit anything to BH.

In short, it's a mess. I don't think there's anything suspicious or untoward going on, just some genuinely suspect coding at Squarespace.

Mar 3, 2011 at 5:08 PM | Unregistered CommenterSimon Hopkinson

An interesting paper, put out in the open, for all to see, comment upon, shred, improve & refine.
Now, what's not to like about that?
It will attract a lot of attention, indeed it should attract a lot of attention.
The "Warmists" will be trying to sink it, the "Denialists" will be merrily bailing it out.
We'll see if it sinks or swims.

Mar 3, 2011 at 5:24 PM | Unregistered CommenterAdam Gallon

Quick follow up to my 3:53pm post:

Open-access journals are free to the reader, not open-access to the people wishing to publish.

Line-broadening and its role in models of atmospheric absorption: see this page and related ones at Science of Doom. These do not discuss the exact line broadening effect mentioned in the abstract by Harde, but they do suggest that this effect is well known to GCM-programmers. As they should be: line broadening is such a basic effect in molecular interaction with radiation that it would be amazing if it was not treated in GCMs.

Mar 3, 2011 at 5:37 PM | Unregistered Commenterj

I see the Guardian have given blustering Bob Ward another page to rant on - ironically at that famous home of climate sceptics the BBC...

Mar 3, 2011 at 5:54 PM | Unregistered CommenterAnyColourYouLike

ZDB, as you seem to be concerned at the way we sceptics are so easily mislead by headlines and our inability to read the contents of reports, I’d like to ask you the same question I posed you a few weeks back, as you seemed to have missed it: where is the real-world (i.e. scientific) evidence to support CAGW theory? More specifically, where within the IPCC’s AR4 WG1 reports (i.e. the ones that discuss the actual science) is real-world evidence presented that would enable anyone to verify/falsify CAGW theory via the Scientific Method?

I note that ‘lapogus’ re-posted within this thread (Mar 3, 2011 at 11:22 AM) a post of mine from a few weeks back that listed some of the statements I came across while trying to research this question myself, more than a year ago. I even went so far as to ask the same question (and presented the same set of clippings) in a thread on RC but was essentially told to… well, I can give you the links if you’re really interested.

So, assuming that you have respect for science and are knowledgeable about the way it works, I assume that you must know where I can find the evidence that validates the CAGW hypothesis. I would, therefore, be very grateful if you could point me to it.

Thanks in advance… again.

P.S. Maybe ‘j’ could also help answer this very basic question?

Mar 3, 2011 at 6:19 PM | Unregistered CommenterDave Salt

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