Bishop Hill Where there is harmony, let us create discord
Jul 3, 2014 Climate: Statistics Climate: Surface My recent posts touching on statistical significance in the surface temperature records have prompted some interesting responses from upholders of the climate consensus, with the general theme being that Doug Keenan and I don't know what we are talking about.
This is odd, because as far as I can tell, everyone is in complete agreement.
To recap, Doug has put forward the position that claims that surface temperatures are doing something out of the ordinary are not supportable because the temperature records are too short to define what "the ordinary" is. In more technical language, he suggests that a statistically significant rise in temperatures cannot be demonstrated because we can't define a suitable statistical model at the present time. He points out that the statistical model that is sometimes used to make such claims (let's call it the standard model) is not supportable, showing that an alternative model can provide a much, much better approximation of the real world data. This is not to say that he thinks that his alternative model is the right one - merely that because it is so much better than the standard one, it is safe to conclude that the latter is failing to capture a great deal of the variation in the data. He thinks that defining a suitable model is tough, if not impossible, and the only alternative is therefore to use a physical model.
As I have also pointed out, the Met Office does not dispute any of this.
So, what has the reaction been? Well, avid twitterer "There's Physics", who I believe is called Anders and is associated with Skeptical Science, tweeted this:
Can @MetOffice clarify their position wrt statistical models - in a way that @aDissentient might understand?
A response from John Kennedy appeared shortly afterwards, which pointed to this statement, which addresses Doug Keenan's claims, noting that there are other models that give better results and suggesting that the analysis is therefore inconclusive. Kennedy drew particular attention to the following paragraph:
These results have no bearing on our understanding of the climate system or of its response to human influences such as greenhouse gas emissions and so the Met Office does not base its assessment of climate change over the instrumental record on the use of these statistical models.
I think I'm right in saying that Doug Keenan would agree with all of this.
Anders has followed this up with a blog post, in which he says I don't understand the Met Office's position. It's a somewhat snide piece, but I think it does illuminate some of the issues. Take this for example:
Essentially – as I understand it – the Met Office’s statistical models is indeed, in some sense, inadequate.
Right. So we agree on that.
This, however, does not mean that there is a statistical model that is adequate.
We seem to agree on that too.
It means that there are no statistical models that are adequate.
Possibly. Certainly I think it's true to say that we haven't got one at the moment, which amounts to the same thing.
Then there's this:
[Statistical models] cannot – by themselves – tell you why a dataset has [certain] properties. For that you need to use the appropriate physics or chemistry. So, for the surface temperature dataset, we can ask the question are the temperatures higher today then they were in 1880? The answer, using a statistical model, is yes. However, if we want an answer to the question why are the temperatures higher today than they were in 1880, then there is no statistical model that – alone – can answer this question. You need to consider the physical processes that could drive this warming. The answer is that a dominant factor is anthropogenic forcings that are due to increased atmospheric greenhouse gas concentrations; a direct consequence of our own emissions.
Again, there is much to agree with here. If you want to understand why temperature has changed, you will indeed need a physical model, although whether current GCMs are up to the job is a moot point to say the least. (I'm not sure about Anders' idea of needing a statistical model to tell whether temperatures are higher today than in 1880 - as Matt Briggs is fond of pointing out, the way forward here is to subtract the measurement for 1880 from that for today - but that's beside the point).
All this harmony aside, I hope you will be able to see what is at the root of Anders's seeming need to disagree: he is asking different questions to the one posed at the top of this post. He wants to know why temperatures are changing, while I want to know if they are doing something out of the ordinary. I would posit that defining "the ordinary" for temperature records is not something that can be done using a GCM.
I think Anders' mistake is to assume that Doug is going down a "global warming isn't happening" path. In fact the thrust of his work has been to determine what the empirical evidence for global warming is - when people like Mark Walport say that it is clear that climate change is happening and that its impacts are evident, what scientific evidence is backing those statements up? I would suggest that anyone hearing Walport's words would assume that we had detected something out of "the ordinary" going on. But as we have seen, this is a question that we cannot answer at the present time. And if such statements are supported only by comparisons of observations to GCMs then I think words like "clear" and "evident" should not be used.
Bishop Hill
In my post above I said:
If you want to understand why temperature has changed, you will indeed need a physical model.
As I put it in a tweet to Anders, he and I are in glorious harmony.
He has just replied:
No, I really don't think we are. If you want to understand GW you need a physical model.
I laughed so much I got cramp in an intercostal.
Reader Comments (307)
Oh bring me my bow of gratitude for that typo. Can I call you WSC?
Anders, you need to realize that arguing through perambulating casuistry - you can get hurt when hurtling along you crash, when meeting yourself coming back.
Andrew, I hope your fits of laughter caused you no serious discomfort.
John Shade, you draw a powerful and cogent analogy and de facto, on this chaotic conjecture, there can be no argument.
It's just another slam dunk for the realists or, Brazil v Margate Town FC.
And Then There's Physics @ Jul 3, 2014 at 1:45 PM
"However, you still seem to be arguing that deficiencies in statistical models mean that we can't be certain that global warming is happening. That doesn't appear logically consistent."
How do you define "certain"?
"On the other hand, if you mean empirical evidence for anthropogenic global warming then we seem to be back where we started. We can't determine that with a statistical model alone."
Yes, we can, old friend. Or I should say we could.
If temperatures can be shown to go over above the range of variability exhibited in the instrumental record that was seen before CO2 went above its range of variability due to anthropogenic sources, you have your determination.
@ Ron C
From his blog it seems to me that he assumes that aCO2 must have a warming effect. That temperatures now are higher than they were in 1880, and that aCO2 must have had an effect - he says a "dominant factor" - on the cause of this warming ... see ...
"However, if we want an answer to the question why are the temperatures higher today than they were in 1880, then there is no statistical model that – alone – can answer this question. You need to consider the physical processes that could drive this warming. The answer is that a dominant factor is anthropogenic forcings that are due to increased atmospheric greenhouse gas concentrations; a direct consequence of our own emissions"
Now suppose we could go back to 1880 and have a discussion about why the temperatures "today" (ie, in 1880) were higher than they were in 1780 (assuming, for the purposes of my point, they were).
What anthropogenic forcings would we be considering "now"?
Surely you cannot even begin to consider what effect anthropogenic forcings might or might not be having on the climate (let alone the question of whether or not those anthropogenic forcings are "dominant") unless and until you have a proper idea of what the climate does without those forcings?
Further to the Bishop's point about statistical models.
A linear trend implies a constant forcing (to be explained by physics).
As Bob Tisdale has often pointed out, a linear trend is not the only (and not the best) model for Sea Surface Temperature patterns since 1980s. His graph of step changes in the anomalies is here:
http://bobtisdale.files.wordpress.com/2014/05/05-s-atl-ind-w-pac.png
Of course, step changes imply a pulsing, intermittent forcing, not a constant one. Bob therefore concludes that the warming is due to El Nino events releasing energy into the climate system from the oceans.
@WFC
I also replied to your original questions (at 12:39pm).
The earth is (roughly) a closed thermodynamic system, but it is not in equilibrium and constantly emits entropy. Consequently evolutionists should feel fine.
"The earth is (roughly) a closed thermodynamic system,"
Closed? Are you sure. The word I would have used is open.
Shub,
"Old friend" - I'm not convinced you really mean that :-)
I don't think what you've suggested invalidates what I was saying. Statistical models can tell you, for example, whether the data during some recent period has the same properties as (or is different to) the data for some earlier period. That, however, still doesn't tell you why. Even if the data does turn out to have similar properties, that doesn't mean the processes were the same. There are many processes that can influence our climate and - in fact - the response of our climate to a change in external forcing does not really depend on what produces that change in forcing. All I'm pointing out is that if you want to understand the underlying processes, you cannot do so with a statistical model alone.
God exists and creates miracles
You can see his traces everywhere, he permiates the world with is influence
He works in mysterious ways so we cannot fully understand him
If you do not believe in God and follow the righteous path, you will suffer eternal purgatory
It is obvious that God exists, I challenge you prove he doesn't exist!. Since you can't he must exist.
@ Philip Richens - so you did. Thanks for both answers.
@ Richard Drake - damn my dark satanic keyboard!
WFC,
The law of conservation of energy really just means that energy can't simply disappear. The Earth gets most of its energy from the Sun (there's a small amount of geothermal energy being released). The reason people mention conservation of energy is because if you consider our entire climate system (oceans, ice, land, atmosphere) all components are gaining energy. The only way that this can be happening is if we are getting more energy (from the Sun) than we are losing (back into space). That - at a fairly fundamental level - is what anthropogenic global warming is about.
There is no use in conflating the statistical argument with anything to do with physics or climate. Stats knows nothing about climate. All they are doing is looking at a signal of 'some metric' vs time and deciding whether there is a statistically significant trend. To know whether it is significant, you need a model to compare it to. What we have here is a dodgy metric (in terms of consistency) and a pretty short timescale. It really doesn't show much. We don't have a comparable data set from 'normal times' to see any distinction. This is not going to get better, these facts are not about to change unless the signal becomes visibly different from what we have seen up to now. THEN, when there is something to explain, we can try to explain it via physics.
The statistical approach here only supports a conclusion along the lines of 'nothing much is happening as far as we can see.' No more. Not much material for a mass debate.
@rhoda
"Closed" means only that matter is not exchanged. "Isolated" is possibly the term you have in mind - earth is not isolated.
Whilst we speak, the new metric for 'climate change' (TM) is being discussed in detail elsewhere. 'Emergence' is now the in thing, i.e. "climate departure" at some specified future date when the climate of any given region becomes 'unprecedented' in the context of the 'historical record' (defined, somewhat conveniently one might suspect, as 1860 to 2005).
http://www.nature.com/nature/journal/v502/n7470/full/nature12540.html
http://www.climate-lab-book.ac.uk/2014/uncertain-emergence/
There's Physics: "All I'm pointing out is that if you want to understand the underlying processes,..."
But why are you pointing this out? The understanding of 'underlying processes' is irrelevant to what conclusions are allowed to be drawn from the instrumental record. The conclusions that can be drawn from the instrumental record must be independent of the the forces we presume or hypothesize to influence it.
If 'underlying processes' produce a change large enough to be different, an appreciable change may be evident. If changes are not appreciable, that does not mean there are no underlying forces.
No change is appreciable in the instrumental record.
The climate is a complex system. 'Simple physics' BBD style - cannot help determine its emergent behaviour. That does not mean its behaviours and processes are not underpinned by physics.
@ And Then There's Physics
Thank you for that. Would it be safe to assume that the geothermal energy is a "constant", in that it remains at the same level throughout?
This may be a daft question, but can the increased energy in each of the components be directly (empirically) measured? (Otherwise than through temperature readings, I mean.)
Seems to me that this is just another way of saying climate science does not understand natural variability. Until it does it will continue to have no credibility. Science by assertion may impress the likes of Anders but not those that can think for themselves (even if they don't got no head).
PS H2O is the miracle molecule - not CO2.
Shub,
Sorry, but that doesn't even really seem to make sense. If you mean our statistical analysis should take place without being influenced by some kind of prior hypothesis, then sure. The intrinsic properties of the data should not change because we change our hypothesis. However, what we can conclude based on the instrumental record has to be influenced by the physical processes that could drive the observed warming. I don't really see how you can be suggesting otherwise. You can't really be suggesting that we can draw conclusions without considering the underlying physical processes in any way whatsoever, can you? Are you sure you really meant to say this?
WFC,
Yes, you can safely assume that the rate at which geothermal energy is released is roughly constant. It reduces over geological timescales, but over the timescale of interest here, it's constant.
I'm not quite sure what you mean (and I'm slightly reluctant to get into a big debate about data quality). As long as you know the equation of state of a medium, them a measurement of temperature is equivalent to a measurement of energy. So, the instrumental surface temperature record tells us that the amount of energy in the land and sea surface and in the near-earth atmosphere has increased since 1880. We have measurements of the ocean heat content which also shows an increase over the past 50 years or so (there are also two ways of doing this, sea level rise and direct measurements). We have measurements of the reduction in land ice mass which can only occur if energy is melting the ice, and the mass of sea ice is also reducing. Overall, the entire climate system is gaining energy, hence we are warming.
WFC
when Anders says 'all components are gaining energy' he is practicing the art of science by assertion. Quantifying the energy of the system with any degree of accuracy is not currently possible. And then to say it is anomalously greater than it should be is a giant leap of faith normally only practiced by a high priest of the church of the absurd.
Headless chicken,
Interesting, until you asserted this, I did not know it to be true.
Of course, it's not actually about quantifying the energy of the system, it's about determining whether it is increasing or not. Whether you like it or not, there is data that suggests that it is indeed increasing. Asserting otherwise, while accusing others of science by assertion, would seem remarkably ironic.
> Except I don't seen Montford or Keenan making points (2) or (3).
Well, for the (3):
http://www.bishop-hill.net/blog/2014/7/2/the-debate-at-the-fst.html
Must be a vocabulary thing.
A little twist on John Slade's manufacturing story may contain a useful analogy:
In the well known process of injection molding a manufacturer attempts to produce parts within a certain tolerance. The factors within his control include pressures, temperatures, cycle times and his plant environment. If the part is 'goes out of tolerance,' he usually tweaks these parameters - this is where he expends his energy and effort.
However, he has very little information about the raw material he is supplied - the tolerance limits and batch to batch material variations are a 'black box.' Raw material suppliers are very much like Mother Nature. What they supply is an unknowable 'trade secret' beyond the ability of the molder to understand or control.
As a result, despite his very best efforts the molder has less influence on his process than he thinks and often wastes a tremendous amount of energy trying to compensate for conditions he can't possibly predict or understand. Because you are so damn smart and skilled at controlling the stuff you know it is very difficult to accept that an 'unknowable unknown' can wreck your sophisticated process!
And yes, Slade said it better!
There's Physics: You've gotten into the habit of fighting your strawmen of the arguments proposed to you, instead of the real thing. The post, and your response to my comment above show this. Stop disagreeing when there is no disagreement. ;)
Further to the Bishop's point about statistical models.
A linear trend implies a constant forcing (to be explained by physics).
As Bob Tisdale has often pointed out, a linear trend is not the only (and not the best) model for Sea Surface Temperature patterns since 1980s. His graph of step changes in the anomalies is here:
http://bobtisdale.files.wordpress.com/2014/05/05-s-atl-ind-w-pac.png
Of course, step changes imply a pulsing, intermittent forcing, not a constant one. Bob therefore concludes that the warming is due to El Nino events releasing energy into the climate system from the oceans.
People like Anders are the ones in denial.
They NEVER admit or acknowledge anything that may compromise their AGW belief-theory. No matter how valid the question, no matter how obvious the flaw in data, observations or anything else. THEY are the ones deliberately enacting a policy of 'never apologise, never admit you're wrong'.
You're embarrassing them, Bish'. Keep at it.
Seems to me that the sole evidence Anders relies on to prove Mann Made Global Warming (tm) is happening is that the temperature has gotten a fraction of a degree warmer than 1880. Therefore Mann Made Global Warning (tm) is true.
He comes to this conclusion inspite of the fact there is no evidence currently detectable that supports his conclusion and completely ignores any role natural variability may have.
Is that a fair comment?
so, no need to go searching for missing heat in the deep oceans or in the arctic
got it!
Ron C.
What Bob Tisdale has failed to do is show how El Nino events produce any kind of change in forcing. Simply moving energy from the oceans to the land/atmosphere is not - in itself - a forcing. Without a change in forcing, the system will simply radiate this energy back into space in a time of only a few months, as the heat content of the land and atmosphere is low.
Chesirered,
Good to see you haven't changed since I last encountered you. If you have a message to spread, consistency is important.
Well, Shub, if you can't recognize that our beloved Bishop claims that "manmade climate change is not "clear"" and then cites Douglas to back up that claim, you might need to do a bit of reading to make sure that the agreement is mutual.
If that does not suffice, there's this gem in the editorial above:
I'm not sure how the MET office would react to this claim, but it seems to me that Douglas is playing the "yes, but random walk" gambit all over again.
If I am correct, I don't think the agreement is as general or mutual than our beloved Bishop would like it to be.
For more on the "yes, but random walk", cf. Bart V's death thread:
http://ourchangingclimate.wordpress.com/2010/03/01/global-average-temperature-increase-giss-hadcru-and-ncdc-compared/
***
Claiming that temperatures follow a random walk may be more than inadequate. Our beloved Bishop's trick hides much of the disagreement under "inadequate" as an euphemism for "not even wrong."
With a nuclear explosion (expansion in all directions) all first arrivals will be moving away from the source. The signature is quite distinct, and no statistics needed here.
Jul 3, 2014 at 1:22 PM | Registered CommenterHector Pascal
Well bviously, if you are sitting on top of the ground where an underground detonation occurs, you don't need statistical analysis to figure out what has happened.
But if you are hundreds or thousands of kilometres away, and the explosion has been decoupled from the ground by being conducted in a large underground cavity, you need sophisticated systems involving spatial arrays of sensors and multidimensional filtering to discriminate between the signature of a nuclear detonation and the background of seismic activity. By the time its signal gets to your sensor array, it has been scrambled by underground reverberation and it is not longer a simple case of pointing to where the bang took place and its yield.
In the 1950s and 1960's a whole load of work was done on detection of nuclear detonations far from the site where a test would potentially have taken place. The objective was to find to what extent underground explosions could have conducted without being detectable outside the borders of the country concerned. It lead to the development of techniques for multi-dimensional Weiner filters which eventually found use in other fields.
Because of the political issues involved (revealing non-confirmance to test ban treaties), detection had to have high confidence levels. It always was a complicated problem - but was addressed by people on a different intellectual plane from that occupied by 'climate scientists'.
Mailman,
Is that a fair representation of what I'm saying? No.
All I'm really saying is that statistical models - alone - cannot tell us what physical processes are causing the warming. Therefore you can't use the inability of statistical models to do this, to then argue that we don't know what's causing the warming. Of course, Bishop seems to be suggesting that all that's really being suggested is that statistical models cannot provide empirical evidence for warming. Well, since the surface temperatures today are higher than they were in 1880, we have warmed, so this would seem to be wrong..
@willard
Which statistical model do you think is the best match for temperature reconstructions?
Doesn't the law of conservation of energy require a closed thermodynamic system to apply? Is the Earth a closed thermodynamic system?
And, if it is held to be so, how do the evolutionists feel about that?
(Note - I do not subscribe to creationism in any way. It just appears to me to be ironic that the one theory (AGW) appears to require a closed system, whilst the other (evolution) requires an open one.)
Jul 3, 2014 at 1:44 PM | Unregistered CommenterWFC
So far as we know, the law of conservation of energy is universally true. It applies everywhere and has nothing to do with whether some system or other is closed or not.
If, by a closed thermodynamic system, you mean one that from which matter can neither leave nor enter, then the Earth approximates a closed system. Some matter (meterorites, nuclear particles) arrives and some (spacecraft and hydrogen molecules) leaves it.
"How do evolutionists feel about that?" What has whether the Earth is a closed thermodynamic system have to do with evolution? Can you explain why there should be some connection? Why should evolution require an open system (open in some sense)?
Bill said: <I>The answer is that a dominant factor is anthropogenic forcings that are due to increased atmospheric greenhouse gas concentrations; a direct consequence of our own emissions." Well yes, one does need to consider the physical processes that COULD drive this warming. <B>One COULD also consider that natural processes dwarf man's activity. Warmists need to argue their case, not just proceed by assertion.
Since you're talking specifically about GG concentrations, one would be wrong:
Annual CO2 emissions from volcanic sources are 130–230 million tonnes annually, while human emissions are roughly 35 gigatonnes (2010) (http://volcanoes.usgs.gov/hazards/gas/climate.php)
Why worry about assertions when facts are so easy to find?
"are the temperatures higher today then they were in 1880"
Well ... HADCRUT4 said Feb 2014 was colder than Feb 1878.
So .... the answer is ... not always. Ad not by much.
I went looking on John Kennedy's and the metoffice twitter feed to see if they mentioned that interesting fact.
They didn't.
@ willard, 3:43 PM
The Met Office seems to be in broad agreement with His Eminence and myself in believing that we currently do not know how to choose a statistical model—ergo, we cannot do statistical analysis. That point is made in the blog post. For reference, see the briefing paper written by the Met Office Chief Scientist, Julia Slingo: “Statistical models and the global temperature record”.
More generally, if you dig underneath all the hype, ignorance, and corruption (a difficult task), you will find that there is broad agreement among those (few) who have both integrity and knowledge. There are three main points.
1. There is no observational evidence for significant global warming, due to any cause—natural or anthropogenic. (Claims to the contrary are based on insupportable statistical analyses.)
2. There is evidence for significant global warming, from computer simulations of the climate system; additionally, that evidence supports the cause being anthropogenic. The strength of this evidence is disputed, but what is certain is that this evidence is not conclusive.
3. Based on what we currently know, it is plausible that Earth will enter a cooling phase during the next several decades.
The computer simulations are impressive, but they are being held back by inadequate hardware. Given the enormous cost of the policies that have been adopted pursuant to global-warming alarmism, I would like to see much more money spent on computer hardware. That need not be done by one country; their might be a consortium (as with the LHC).
@ATTP
Semantics. You use "forcing" to mean something unnatural to the climate system, to exclude factors like ocean oscillations. Yet temperatures are affected by these, and sorting natural and unnatural factors is precisely the issue.
Bob's graph shows anomalies, so the higher SSTs persist and continue to add warmth over several years. Whether you want to call that a forcing or not, it is a causative factor in the time frame being examined.
> Which statistical model do you think is the best match for temperature reconstructions?
Thank you for the tu quoque, Philip Ritchens. It means a lot to me. Here's what the Auditor says on such occasion:
http://neverendingaudit.tumblr.com/post/34253462351
So I'd say that it might be time to sell the "yes, but random walk" stock. I'd even go so far as to suggest selling short the "inadequate" equivocation, and put that ClimateBall (tm) episode to rest.
Hope this helps,
w
PS: If Douglas would so kind to declare once and for all that he released his correspondence without Richard Muller's consent, that would be nice.
> Which statistical model do you think is the best match for temperature reconstructions?
Thank you for the tu quoque, Philip Ritchens. It means a lot to me. Here's what the Auditor says on such occasion:
http://neverendingaudit.tumblr.com/post/34253462351
So I'd say that it might be time to sell the "yes, but random walk" stock. I'd even go so far as to suggest selling short the "inadequate" equivocation, and put that ClimateBall (tm) episode to rest.
Hope this helps,
w
PS: If Douglas would so kind to declare once and for all that he released his correspondence without Richard Muller's consent, that would be nice.
Douglas,
Would you be willing to actually find a citation for this claim because, as I understand it, what you've said is wrong.
This too,
indicates a significant misunderstanding of radiative physics. If we continue to increase our emissions, the only physically plausible way in which we could enter a long-term cooling phase is if there were a major asteroid strike, or significant volcanic activity. I'm assuming that you're not suggesting that we're likely to have anything quite that catastrophic occurring in the next few decades.
"The computer simulations are impressive, but they are being held back by inadequate hardware."
Held back by inadequate hardware or held back by an inadequate understanding of how the earth's climate actually works?
Perhaps the two are not mutually exclusive. But I think the latter is a much bigger issue than the former.
Sorry to nitpick, but...
"And Then There's Physics" as a climate blog moniker?
This technique to try and enhance your own credibility has been tried, and let's just say the results have been well mixed, like a trace gas in the atmosphere.
Andrew
I believe the original debate sprang from this - “I was, however, interested to learn from Walport that it is "clear" that climate change * is happening and that its impacts are already evident.”
The definition of clear is “easy to perceive, understand, or interpret”. Climate models are not easy to understand, they are if anything convoluted. It is impossible to perceive from the climate data any man made element of climate other than things like UHI. I suppose it is easy for warmists interpret a dangerous man made effect (they do it all the time) but I’m not sure that’s what the dictionary meant.
* Climate change being code for dangerous, man made, CO induced climate change or why else would people like Walport bang on about it?
Ron C.,
No, it's not semantics. I'm using forcing as it's defined - a change in radiative forcing. If there is an increase in radiative forcing, we have more energy coming into the climate system than leaving, the energy will rise, and the temperatures will rise until the outgoing flux increases to balance this radiative forcing. Oceans oscillations are not - by themselves - a forcing. They are simply a variation in some climate quantity. Therefore, an ENSO event cannot - by itself - produce a long-term increase in surface temperatures. A long-term increase has to be associated with a change in forcing. If ENSO events cannot produce a change in forcing (which there is no real evidence to suggest that they can), then they can only really be associated with variations about a mean temperature. Does the blog owner not pop in now and again and correct these misconceptions?
Doug Keenan:
According to folks like Christopher Essex and Robert G. Brown they're also being held back by inadequate software. Increasing the size of the hardware won't help with this. How does one achieve practical openness with the GCMs? I like Brown's proposal here as a step on the way:
But just adding bigger hardware, no.
ATTP
Regarding the pause:
http://www.metoffice.gov.uk/research/news/recent-pause-in-warming
http://judithcurry.com/?s=the+pause
Global Cooling over the next few decades:
http://wattsupwiththat.com/2008/07/20/shifting-of-the-pacific-decadal-oscillation-from-its-warm-mode-to-cool-mode-assures-global-cooling-for-the-next-three-decades/
http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/
The Real Climate article suggests that Natural Variability will hide the AGW signal over a multi-decadel time scale. Time will tell if this is just a weasel worded essay or not.
There's Physics says (emphasis mine):
Not a supportable assumption. The climate system exhibits noise-like variability at all timescales, and especially at long timescales. One look at the GISP2 record will tell you.
Moreover such statements speak to a loose use of terms like 'long-term', the very concept of which is under question here.
Doug states:
"The Met Office seems to be in broad agreement with His Eminence and myself in believing that we currently do not know how to choose a statistical model—ergo, we cannot do statistical analysis."
I don't know how much clearer it can get.
@ Bloke in Central Illinois, 4:49 PM
Certainly there needs to be more than just faster hardware, and the two are not mutually exclusive, as you say. Hardware inadequacy, though, is something that can be addressed in a straightforward way. Moreover, several climate subsystems seem to be fairly well understood.
As an illustration of the last point, simulations of the circulation of the Mediterranean Sea seem to be really good. The circulation of the world ocean is on the same principles as that of the sea, but the ocean cannot be well simulated because of inadequate hardware.
I am not saying that more powerful hardware will solve everything; of course that would not be true. I am saying that a cost–benefit analysis makes an extremely strong case for increasing the hardware budget tenfold or more.