Well I don’t quite accept your high opinion of his record as chancellor, given that we ended up in what was then the worst recession since the war, but that’s an argument for a different forum.
Still, he was, as you say, holder of one the great offices of state so that does give him a certain amount of prestige. But that’s no reason to treat him as any kind of authority on climate science.

The problem is that the alarmist members of the so-called Consensus insist that “uncertainty” requires us to act.

Unfortunately what is needed in order to evaluate the merits of any action is understanding of “risk” – that measure (both measurable and measured) of likelihood of identifiable scenarios. Why do we need that? In order to weigh the expected costs and benefits in a world where we have limited resources and must make trade-offs (e.g. lots of intermittent wind power at the cost of less health care, transport or communications infrastructure, or even simple holidays and bottle sof beer on a hot day).

And there lies the point of criticism of most so-called Skeptics. The available literature is teeming with unknowns (quite possibly unknowables), to the extent that even after spending tens of billions of dollars on formalised modelling of this Consesnsu hypothesis (dangerous climate change) we cannot even demonstrate the ability to produce a robust zero dimension climatic forecast. In fact, quite the opposite – the efficacy of the modelling as proven in forecasting is inconceivably and irredeemably trashed.

Ironically, what this excercise of the Military beaurocracy demostrates is indeed risk mitigation on the parts of the generals concerned who commissioned this work, except it isn’t the climate related risk.

It is known to you and me as covering your a**e and it costs them nothing.

Agreed.

But neither can he be dismissed as a non-serious Cabinet Minister as the previous correspondent attempted to do.

And in so doing he merely emphasises his inability to discuss any sensible argument. ‘Play the man, not the ball’….the alarmist’s #1 tactic.

Nick Stokes:

Let me suggest that you read what I wrote a little while ago, in ‘An essay on the current state of the climate change debate’
posted above on March 29, 2011. In that essay I set out what I saw as the central AGW propositions, drawn from the Summary for Policy Makers in AR4, with the last proposition drawn from repeated statements from ‘concerned scientists’. They go like this:

1. The earth is warming.
2. This warming is unprecedented.
3. The warming is caused by the human burning of fossil fuels.
4. The warming is dangerous to humanity, perhaps catastrophic.
5. The only way to prevent dangerous outcomes is to curtail greenhouse gas emissions, everywhere.
6. Things are getting worse, not better.

You seem to me to be talking about something else altogether. Don’t you think that these statements are the core of the IPCC position? If you don’t, what do you think they core IPCC propositions are?

My argument is that the first three and the last all depend on good data. Propositions #4 and #5 depend on models. You seem to agree to that. I don’t think the data are at all good, not nearly good enough to justify the scary statements that one hears (most recently, in Australia, that there is likely to be a one-metre increase in sea levels by the end of the century. You seem to be saying that lousy data don’tt matter, because the science is sound. But, as others have said to you, and I join them, the science ultimately depends on observations, and the ‘data’ are those observations. But, as Brown (top of this thread) has argued, the data are awful, and full of error. I agree with him, because I am looking at the source data myself. It simply doesn’t allow three-decimal-places for the GTA. So we are not able to say, with confidence, that the planet is warming in any other than a vague way.It might be dangerous, it might be beneficial, it might be inconsequential. We simply don’t know.

I would like us to work on getting much better data before we engage in carbon taxes. Are you opposed to that?

or humour s we say in English!

Nick Stokes

The “argument” for AGW, per se, is correct as you stated, with my addition to part 3. (IOW “temperature rise” is already a deduced “consequence”, which may occur unless another compensating “consequence” occurs, for some as yet unknown reason or “natural thermostat” mechanism). As a result, I would also specify that part 3 is a deduced “consequence” of parts 1 and 2.

I would also eliminate the subjective phrase at the end of paragraph 2: “in a big way”.

We then have:

1. GHG’s absorb outgoing IR
2. We are adding GHG’s to the air
3. As a consequence, the increased absorption of outgoing IR means that temperatures will have to rise to restore radiation balance unless other changes, such as increased reflection of incoming SW radiation, compensate correspondingly.

This formulation leaves open whether “temperature rise” could be imperceptible (and hence, insignificant) or perceptible (and hence significant).

The problem is, Nick, that IPCC is selling us a “package”, which speculates that “temperature change” caused by AGW is highly “significant” (compared to that caused by natural forcing) and includes part 4 and 5 as I stated as integral parts.

4. AGW, caused principally by human CO2 emissions, has been the primary cause of observed 20th century warming

5. AGW represents a serious potential threat to humanity and our environment, unless human CO2 emissions can be reduced drastically.

I do not think that you will have many rational skeptics arguing against your 1-3 (with the additions I recommended), however many will object to the IPCC (or “mainstream”) “package”.

Incidentally, that is what is being debated here, Nick, not your parts 1 and 2 plus the modified 3.

Max

I take the UAH data to be good enough to make a determination. It shows (1) no warming from 1978 to 1997, (2) no warming from 2001 to today and (3) that the later flat line is warmer than the former, so a step up in temp during the 1998-2001 ENSO cycle. While there is some warming it is inconsistent with GHG warming

Muller: “A few years later, McIntyre came out and, indeed, showed that the hockey-stick chart was in fact incorrect. It had been affected by a very serious bug in the way scientists calculated their principal components.”
Is this the statement that Mann believes is “false” and “libelous”? It is interesting to me that just today Steven McIntrye posts his frustration with Mann, noting that “Rather than conceding even seemingly indisputable points, Mann and his associates contested every single issue – even the seemingly indisputable and elementary observation that Mannian principal components mined datasets for hockey stick shaped data” http://climateaudit.org/2011/05/23/climategate-documents-confirm-wegmans-hypothesis/
So Mann views a statement as libelous (i.e. false) that McIntrye views as “indisputable and elementary”. As a layman who follows this debate, I think that this accurately reflects the state of the debate, but if I am missing something, I would be happy to be corrected.
To better understand the source of this dispute, I would like to review several propositions to see exactly where the dispute lies.
1) McKitrick asserts that Mann did not apply standard Principle Component Analysis to derive the hockey stick. Specifically, they assert:

“In a conventional PC analysis, if the data are in differing units it is common to “standardize” them by subtracting the mean of each column and dividing by the standard error. This re-centers and re-scales all the data to a mean of zero and a variance of 1. With tree ring data no such re-scaling is needed since the data are pre-scaled before archiving. In Mann’s program, he applied a scaling, but with a difference. Rather than subtract the mean of the entire series length, he subtracted the mean of the 20th century portion, then divided by the standard error of the 20th century portion. ” http://www.uoguelph.ca/~rmckitri/research/McKitrick-hockeystick.pdf at page 8

For those who support Mann’s methods, do you agree that Mann applied a non-standard form of principle component analysis? If you believe that Mann’s method can be defended, do you at least agree that he should have disclosed his method and defended it in his paper?

2) McKitrick further asserts that Mann’s methodology has a significant effect on the results. He observes,

“Since the mean of the 20th century portion is higher than the mean of the whole series, subtracting the 20th century mean ‘de-centers’ the series, shifting it off a zero mean. This, in turn, inflates the variance of these series. PC algorithms choose weights to maximize the explained variance of a group of data series. If one series in the group has a relatively high variance, its weight in the PC1 gets inflated. The Mann algorithm did just this. It would, in effect, look through a data set and identify series with a 20th century trend, then load all the weight on them. In effect it ‘data-mines’ for hockey sticks.” http://www.uoguelph.ca/~rmckitri/research/McKitrick-hockeystick.pdf

This allegation makes sense to me intuitively. Is this disputed by someone?

3) To test whether this assertion is correct, M&M tested it by running Monte Carlo simulations. McKitrick explains:

“To test the power of Mann’s data-mining algorithm we ran an experiment in which we developed sequences of random numbers tuned to have the same autocorrelation pattern as the NOAMER tree ring data. In an autocorrelated process a random shock takes a few periods to drift back to the mean. Initially we used a simple first-order autocorrelation model, but later we implemented a more sophisticated ARFIMA1 routine that more accurately represents the entire autocorrelation function associated with tree ring data. In statistics these kinds of models are called “red noise.” The key point was that the ARFIMA data is trendless random noise, simulating the data you’d get from trees in a climate that is only subject to random fluctuations with no warming trend.
In 10,000 repetitions on groups of red noise, we found that a conventional PC algorithm almost never yielded a hockey stick shaped PC1, but the Mann algorithm yielded a pronounced hockey stick-shaped PC1 over 99% of the time.” http://www.uoguelph.ca/~rmckitri/research/McKitrick-hockeystick.pdf

4) The Wegman report claims that it was able to duplicate M&M monte carlo simiulations. Are M&M’s and Wegman’s Monte Carlo simulation results disputed by anyone?

M&M’s conclusion was that the PC methodology used by Mann created hockey stick graphs out of random red noise data. If this is true, it would seem to support Mueller’s assertion that Mann’s methods contained a “serious bug”. Although there have been many other hockey stick graphs that used different methods and/or different proxies, I am not aware of any peer-reviewed articles or even blog posts that dispute this basic point. Are there any?

Don Aitkin

Our two posts to Nick Stokes crossed, but I see we are saying essentially the same thing.

Max

What I set out is just the content of the first section of the SPM – the section “HUMAN AND NATURAL DRIVERS OF CLIMATE CHANGE”, from p 1 to about 5.5. You will find nothing there about the temp record. That is the AGW case.

The next section is “DIRECT OBSERVATIONS OF RECENT CLIMATE CHANGE”. These are the observations which help to affirm the theory, and of course, make more real the consequences to us. I think they do that. But if you don’t believe it, then AGW lacks that affirmation (at present). Doesn’t mean it’s wrong – just that we don’t have the data.

Then there is the section “UNDERSTANDING AND ATTRIBUTING CLIMATE CHANGE”. This makes the connection of the observations to the theory. Of course, if you deny the observations, then this means nothing. It affirms nothing and refutes nothing.

Then there are the PROJECTIONS. They are deductions from the AGW theory which can’t yet be tested against the record.

That’s the SPM.

I think carbon taxes are justified on present knowledge. Just as I think taxes to support the military are justified even though there are no currently proven threats. Just because a risk is uncertain doesn’t mean it should be ignored.

kunhkat, Pekka et al.
For a quantitative rigorous thermodynamic development of the lapse rate, see:

Robert H. Essenhigh
Prediction of the Standard Atmosphere Profiles of Temperature, Pressure, and Density with Height for the Lower Atmosphere by Solution of the (S−S) Integral Equations of Transfer and Evaluation of the Potential for Profile Perturbation by Combustion Emissions
Energy Fuels, 2006, 20 (3), 1057-1067 • DOI: 10.1021/ef050276y

This analytical solution, believed to be original here, to the 1D formulation of the (1905−1906) integral (S−S) Equations of Transfer, governing radiation through the atmosphere, is developed for future evaluation of the potential impact of combustion emissions on climate change. The solution predicts, in agreement with the Standard Atmosphere experimental data, a linear decline of the fourth power of the temperature, T4, with pressure, P, and, at a first approximation, a linear decline of T with altitude, h, up to the tropopause at about 10 km (the lower atmosphere). From these two results, with transformation using the Equation of State, the variations of pressure, P, and density, ρ, with altitude, h, are also then obtained, with the predictions again, separately, in substantial agreement with the Standard Atmosphere data up to 30 km altitude (1% density). . . . Numerical closure is not yet complete, with only one parameter at this time not independently calculated but not required numerically for validation of analytical closure.

Enjoy

“This conference seems like a really good idea, and it is good sign to see the climate establishment engaging with some serious skeptics. ”

I’m sorry, which skeptics were the serious ones??

Bishop Hill has a very interesting post re the Cambridge workshop, on what we can agree on.
http://bishophill.squarespace.com/blog/2011/5/24/what-we-agree-on.html

I had a thread sort of like this previously what we know with confidence,
http://judithcurry.com/2010/11/14/what-we-know-with-confidence/

we should discuss Montford’s list, i’ll get a thread up on this in a few hours.

The abstract contains a reference to “a gray-body equivalent average for the effective radiation absorption coefficient, k, for the mixed thermal radiation-active gases at an effective (joint-mixture) concentration, p”. That makes me wonder, what is the value of the solution as it’s not possible to describe the real atmosphere by a grey-body equivalent average.

In any case this calculation has no bearing on the issue discussed above as we have been discussing the case of totally transparent atmosphere, not a grey atmosphere, and as all the issues are specific to the totally transparent case.

“Is this the statement that Mann believes is “false” and “libelous”?”
How about some facts? Citations? When and where did Mann say such a thing?

“For those who support Mann’s methods, do you agree that Mann applied a non-standard form of principle component analysis? If you believe that Mann’s method can be defended, do you at least agree that he should have disclosed his method and defended it in his paper?”
It seems to me that Mann made a simple programming error. He subtracted the calibration mean instead of the total mean. This had minor practical effect.

“McKitrick further asserts…”
“The Wegman report claims…”
What none of these people did is what anyone really interested to find out would do – redo the calculations using correctly centred PCA. Show what the difference is. Why didn’t they do it?

Well, Wahl and Ammann did. And they found the hockey stick was still there.

As did all these people. And they weren’t using decentred PCA.

2007? Possibly more now. In 2007 there were predictions multi-year ice would be recovered by 2011. Where are they now?

The left leaning scientific community has used its keen intellect to conclude that we are all doomed from climate warming because that rascal mankind is filling the air with CO2. Meanwhile, hundreds of millions on the planet suffer and die for want of a basic commodity. The lethal problem lies with energy, not global warming.

Rather than spend billions of dollars on the intellectual pursuit of what amounts to determining the number of angels-dancing-on-the-head-of-a-pin, we should be concentrating on the wise use of energy, with the operative drivers being efficiency and cost effectiveness.

Consider this simple exercise. If energy is wisely used, greenhouse gas emissions will always be reduced. The reverse, however, is not true.

tonto52

You’re starting to get tedious with your statements such as:

If Judith Curry has changed her mind she needs to clear things up.

I have followed Judith’s blog site here for several months, and she has been pretty clear on her views.

(These may not agree completely with yours or with mine, but she has certainly expressed them quite clearly.)

She has also recently given testimony to US congressional committees which are quite clear.

Of course, we all reserve the right to change our opinions on some facets as we gain new knowledge; anyone who does not do this no longer has a rational open mind, but instead is stuck with a dogmatic belief.

I’d suggest you get caught up on all this rather than hauling out old “but you said back in…” remarks .

Just my advice.

Max

“I later extended this to the carbon-based economy of the whole world. The result: no significant change in global temperature by 2100. The conclusion: We are unable to change our climate, no matter how much money we throw at it… No one has at yet shown me where these estimates are incorrect.”

That’s quite incorrect, Max. On more than one occasion, I’ve shown the calculations indicating a substantial temperature effect. On one of those occasions, I believe it was in response to a previous comment you made along the same lines, or that it was immediately followed by a comment from you (I don’t remember which), and I expect you saw it. If you search back through these threads, I expect you’ll find it. The fact that you disregarded it once disinclines me to take the trouble to search myself or do a recalculation, particularly since the evidence is already well known.

Brandon, you said
“The censored directory shows Mann knew his work was unsupportable”
and your latest comment does nothing to support that extravagant charge.

All you have now is the observation that it is possible to select a subset of the data from which PCs can be computed which don’t have a marked HS shape. That is a very different proposition, and actually not surprising. Mann used the whole set.

But there’s a fundamental misunderstanding of the importance of Mann’s work here, which Steve M has promoted. The proxy study is not about the blade of the HS, but the shaft. It’s the contrast between the fairly constant temperatures of the past (proxy) and the known rise of the last century that is significant. The fact that some proxies may not show a recent rise does not create doubt that such a rise occurred. The instrumental record is more convincing when it’s available.