Global Warming Concensus Broken

[MSimon]

icarus,

I did a blog post on your link.

http://powerandcontrol.blogspot.com/200 ... ctors.html

I need to give you a H/T. Thanks!

[IntLibber]

The validation of the turbulent modelling of Navier-Stokes part of GCM's is the best kept dirty secret of the GW cartel. The man who wrote the book on turbulence modelling has said so from the beginning and they refuse to address the problem or admit the models' limitations. Good luck "tomclarke" on your quest up that particular rat-hole.

The Kolmogorov length scale of the atmospheric turbulence is less than 1 km. When they can solve at better than the Kolmogorov spatial and temporal scales the horrible non-linearity of turbulence will manifest itself. The GCM's are so far off they are not even close to being wrong and in the game, yet. They are a huge fudge of global proportions.

Read Tennekes and get some humility for the complexity of nature.

http://www.sepp.org/Archive/NewSEPP/Cli ... nnekes.htm

"Popper would have been sympathetic. He repeatedly warns about the dangers of "infinite regress." As a staunch defender of the Lorenz paradigm, I add that the task of finding all nonlinear feedback mechanisms in the microstructure of the radiation balance probably is at least as daunting as the task of finding the proverbial needle in the haystack. The blind adherence to the harebrained idea that climate models can generate "realistic" simulations of climate is the principal reason why I remain a climate skeptic. From my background in turbulence I look forward with grim anticipation to the day that climate models will run with a horizontal resolution of less than a kilometer. The horrible predictability problems of turbulent flows then will descend on climate science with a vengeance."

Then again, you can't go far wrong with Armstrongs condemnation, which was based on comparing the hockey team's models against 'naive models'. Firstly, he shows how the naive models show historically 5% or less variance from true results.

Conversely the Hockey Team types try to claim a 1% max error, yet their models keep getting corrected every few years by margins significantly greater than 1%, when their models aren't getting totally blown out of the water. But, most importantly, the Hockey Team's models have failed to actually model the historical record..... not surprising given they are committed to overemphasizing peaks while ignoring centering and ditching all troughs in the data.

The result is you could hand the hockey team a set of data with a true cooling trend coupled with a trend of increasing volatility, and the hockey team would only pick out the peaks and claim there was actually warming going on...... hence why cherry picking is synonymous with junk science.

[IntLibber]

http://wattsupwiththat.com/2009/02/17/t ... #more-5702

Simon,
You were interested in the impact of PDO and ENSO on global climate, the guys at wattsupwiththat.com seem to have verified the ENSO link and backtracked it to the strength of pacific trade winds, particularly western pacific trade winds.
There are also some linkages between particulate pollution in asia to the strength of these winds, so it may be possible to blame whatever AGW signal there may be on Chinese and southeast asian air pollution, two regions which are exempted from Kyoto CO2 mitigation protocols.

It may also explain why volcanos in the southwest pacific seem to have a much stronger impact on global climate than those in other regions of the world.

However the kicker is in comment number 17 on this piece:

" RH (22:56:01) :

Compare your graphs of trade wind velocity above with the upper troposphere temperature graphs at http://discover.itsc.uah.edu/amsutemps/ ... ?amsutemps. I checked quite a few years and it looks like there is a correlation between high velocity trade winds and colder upper air temperatures, and lower velocity trades with higher upper air temperatures. It once again looks like the sun is in control of these wind speeds and El Nino and La Nina. The colder air should result in higher pressures around 30 degrees latitude which should increase the strength of the trade winds."

With the solar wind at its lowest level in a long time, the atmosphere of Earth has shrunk and cooled significantly at high altitudes. This means we should see significantly higher pressures and very strong trade winds. This should cause a Historically strong La Nina unlike that seen in the 20th century, and significant global cooling.

[MSimon]

Wasn't tomclark going to look into the PDO etc and report back? No report for a while. I wonder if he found something that didn't agree with him?

[tomclarke]

The trouble is that to do justice to this I will need to spend very long time. Establishing (from first principles - assuming the peer reviewed literature is distorted) whether given models are overfitted or not will take a long time.

Even doing a throrough review of the literature will take a long time. And I bet none of the armchair AGW skeptics have done this. By proper review I do not mean cherry picking some ideas that sound problematic, but looking at everything, and all the challenges and rebuttals.

From what I have read there are a whole load of potential problems none of which hold water (so to say).

Here is a simple (rather crude but accurate) summary of most of the arguments used on this thread and elsewhere by AGW skeptics:
http://news.bbc.co.uk/1/hi/in_depth/629/629/7074601.stm

Here is a well-written and throught provoking peice about climate skepticism, media bias, etc:
http://news.bbc.co.uk/1/hi/sci/tech/7095968.stm

Here is a journalist's summary of the case for and against sun-driven climate change:
http://news.bbc.co.uk/1/hi/sci/tech/7092655.stm

The concern that AGW models are bad and have little predictive power is one which can not simply be answered. It needs a lot of detailed investigation of the source scientific literature (not just quoting blogs whether pro or anti AGW). But it requires a masive conspiracy theory - since you need to suppose that thousands of scientists working in this field are not capable of reading the literature and drawing fair conclusions.

The simplest solution is just to wait. Another 15 years and whatever the short-term fluctuations it should be clear whether the clear trend of the last 30 years is continuing or not. And if continuing the only credible forcing factor over this timesclae is CO2 & other GW gasses.

But of course if the scientific community is correct waiting will lead to much greater adaptation in the future, or temperature and sea-level rises that will be very disruptive (to put it mildly).

Best wishes, Tom

[tomclarke]

Furthermore, I don't really need to do this comprehnsive review - it has already been done...
http://news.bbc.co.uk/1/hi/sci/tech/7082088.stm

[Billy Catringer]

I have yet to hear or read an explanation to one simple question. How is it that refrigerant gases in tiny concentrations act as potent insulators?

[TallDave]

The concern that AGW models are bad and have little predictive power is one which can not simply be answered.

Yes, it can. There is a whole scientific field devoted to forecasting.

Their conclusion? There is no scientific basis for global warming predictions.

But it requires a masive conspiracy theory - since you need to suppose that thousands of scientists working in this field are not capable of reading the literature and drawing fair conclusions.

A whole bunch of experts being wrong is not a "conspiracy," especially when what they're wrong about generally isn't even in their field of expertise. Was Steady State theory a conspiracy? No, it was just the scientific consensus of the time, a prediction about what the future looked like that turned out to be wrong (fortunately, they weren't making recommendations that cost trillions of dollars based on their conclusions).

This is actually something the forecasting scientists directly addressed:

Expert opinions are an inappropriate forecasting method in situations that involve high complexity and high uncertainty. This conclusion is based on over eight decades of research. Armstrong (1978) provided a review of the evidence and this was supported by Tetlock’s (2005) study that involved 82,361 forecasts by 284 experts over two decades.

In fact, they go further and say the climate is so stable that predicting models are probably useless anyway:

7. The climate system is stable.

To assess stability, we examined the errors from naïve forecasts for up to 100 years into the future. Using the U.K. Met Office Hadley Centre’s data, we started with 1850 and used that year’s average temperature as our forecast for the next 100 years. We then calculated the errors for each forecast horizon from 1 to 100. We repeated the process using the average temperature in 1851 as our naïve forecast for the next 100 years, and so on. This “successive updating” continued until year 2006, when we forecasted a single year ahead. This provided 157 one-year-ahead forecasts, 156 two-year-ahead and so on to 58 100-year-ahead forecasts.

We then examined how many forecasts were further than 0.5°C from the observed value. Fewer than 13% of forecasts of up to 65-years-ahead had absolute errors larger than 0.5°C. For longer horizons, fewer than 33% had absolute errors larger than 0.5°C. Given the remarkable stability of global mean temperature, it is unlikely that there would be any practical benefits from a forecasting method that provided more accurate forecasts

[MSimon]

http://wattsupwiththat.com/2009/02/19/s ... ive-years/

TomVonk (04:45:46) :

AnnaV

You are right and I am surprised that Tsonis is not more frequently analysed on blogs dedicated to the climate because I am convinced that he is on the right track .
D.Koutsoyiannis who also has a similar statistical approach (power laws and scaling) comes independently to similar insights .
This :
This is the first time that this
mechanism, which appears consistent with the theory of
synchronized chaos, is discovered in a physical system of
the size and complexity of the climate system.
says it all .

However I think that you have not the right idea about what the GCM do .
They do NOT solve any coupled non linear PEDs (Navier Stokes) .
With the too coarse gridding they are obviously unable to do that .
What they do instead is merely conserve energy , mass and momentum IN AVERAGE what is much easier .
As the system is cut up in cells , f.ex 100kmx100kmx1km , the bulk of the cell is actually represented by only 1 point with 1 velocity , 1 pressure , 1 density and 1 temperature .
So the only thing you need is to write the boundary conditions with the 6 cells surrounding the one you look at (6 other points with different parameters) and then go one temporal step farther by conserving energy , mass and momentum .
All the complexity is concentrated in the equations describing the boundary conditions and the way how the characteristic parameters (subgrid parametrization) change .
And then , of course , as it is a numerical exercice , you get rounding errors and such that make you violate conservation laws so you must make sure that those deviations are “absorbed”/”redistributed” numerically over the whole system before going a step farther .

So the right picture of a GCM is more a simulation of a discrete system with N points (like N molecules) that obeys conservation laws and some boundary conditions rather than solving fluid dynamic and thermodynamic equations for a continuum .

[tomclarke]

Well -

Talldave - your argument (well - Armstrong's argument) is easily demolished.
Armstrong (who wrote the source paper from which you and Wattupwiththat are quoting) is an economist, with track record in econimic forecasting. This is stochastic - and has no physical laws that determine result. Human hopes & fears are difficult to forecast - and it is well known that experts tend to get them wrong.

Replace "scientific" by "economic" and I would agree.

Armstrong - in applying his economic principles to climate change modelling - therefore not surprisingly misunderstands climate models and thinks that they are wholly stochastic. Ecomomic models are a matter of getting best fit to data, physical laws don't exist. Also he clearly can't distinguish between climate and weather and sees future climate as being a chaotic process like future weather (whereas when spatially & temporally averaged of course deterministic trends emerge from chaotic noise). And he has neither the expertise nor the inclination to read the literature that he dismisses.

It is as though a fisherman with 30 years experince catching fish wrote a paper attempting to dismiss evolutionary theories about how mammals developed from fish without bothering to read the extant literature.

Climate models do have parameters which must be determined from fit to data - but these are at many different levels and the data that fit them are not the global temperature that is the forecast/hindcast. That global match provides some extra validation (in case of hindcast). Other data: mesoscale, micogrid modelling, is used to determine the vertical mixing parameters which are impossible to model directly over long time periods and the whole globe.

This whole structure of physical equations, modelling, validation is foreign to economic forecasting. indeed only somone who had no understanding of physics would confuse the two.

For a vicious (not really to my taste - but "tit-for-tat" application of "scientific principles" to Armstrong's own work on IPCC see realclimate). I can see why the pro-AGW web advocates like Gavin reply to character slur and partial reporting with their own material of the same kind, and to be fair, they do not do this stuff often.
http://www.realclimate.org/index.php/ar ... -forecast/

Simon has a more subtle line of argument. It has two prongs:
(a) GCMs do not (cannot) model NS equations well enough to have any predictive power.
(b) Past 30 years apparent global warming is explained by some combination of (select your anti-AGW argument of choice - many of been advocated - none have withstod scrutiny. Nowadays few get into the serious scientific literature and when they do they are rebutted).

(a) Is subtle and difficult to challenge. Neither Simon (unless he has written papers of a standard that would pass peer-review) nor I have looked at the field enough to be authoritative. I take the view that 1000s of peer-reviewed papers of 10s of years will expose obvious holes. especially because there are many academics who are emotionally wedded to the "AGW is rubbish" viewpoint. Anyone can publish papers and they will be taken up by others if ideas are good. You might imagine that climate modelling is a closed coterie of like-minded advocates. Read the IPCC AR4 report - there are a large number of models with warming predicted between catastrphic and very mild. As time has progressed the models have reached greater agreement, though there is still a wide variation. And the average has been moving towards greater warming.

So the evidence we have on this (most subtle and difficult to debunk) argument is really meta-evidence.
Do you trust the scientific peer-review process? (Not do you trust the scientific community!).
Do you find it strange that if the holes in AGW are as large as your favourite AGW blog claims, there are NO serious papers knocking down AGW which have been published and not comprehensively rebutted? There is diversity of opinion among both academics and editors of journals.

Note BTW that the answer to a) shifts with time. A few years back GCMs could be criticised for not modelling ocean currents - now they do. The computing power available P, and therefore just on the basis of brute-force computation the spatial resolution D (D ~ 1/P^(1/3)) gets better.

(b) is frankly feeble. The anti-AGW arguments (bad data - heat effect - variable solar forcing - ocean current dependence - etc, etc) all fall down when examined. They all HAVE been examined. And anti-AGW advocates have shifted ground from "GW is not happenning" to GW is not anthropogenic" or "GW is a multi-decadal effect".

Unfortunately - as proved in this forum - these anti-AGW myths, rather like the fertility ritual mythologies of ancient societies, have great staying power in the uncritical blogosphere.

Best wishes, Tom

[MSimon]

none have withstod scrutiny.

The PDO papers are due out later this year or some time next. Be patient.

And what about the GCM I referred to above where the PDO was included and cooling predicted for a while? The head of the IPCC agreed with their assessment. I wonder if they have written up their work?

Actually I'd like to make four points.

1. How is the "average" weather defined in a grid square. Suppose you have mountains and ocean mixed.

2. The NS equations if they could be solved for a planetary type problem are inherently noisy and very much influenced by initial conditions and rounding errors. So you run them and say: this is the sort of thing that can happen. Then you have to add: there is no way to predict what will happen.

3. So the only way to make predictions is to take a lot of complexity out of the system. But the essence of the system is its complexity.

4. So far there has been no correction of the warming "signal" for the known effects of past PDOs and other ocean currents. If we have attributed to CO2 something that is actually PDO then the effects of CO2 have been exaggerated.

[tomclarke]

none have withstod scrutiny.

The PDO papers are due out later this year or some time next. Be patient.

Yes. let us not put too much weight on cutting-edge work which has not yet been cross-checked and validated. usually it changes.

And what about the GCM I referred to above where the PDO was included and cooling predicted for a while? The head of the IPCC agreed with their assessment. I wonder if they have written up their work?

The IPCC AR4 is distilled from very comprehensive 2 year literature survey conducted by (for each chapter) 20 or so scientists of varying views but with a solid record of research relevant to the area. These scientists are not propounding their own views - they are stating what is the current state of the published literature. We can always wait for the next IPCC report.
Otherwise here is a PDO paper by Latif, a prominent PDO author:
http://ams.allenpress.com/archive/1520- ... 0-2407.pdf
look at the last paragraph "PDO predictivity is max 1/2 a cycle"
Also note that this paper is making pedictions based on CGCMs. Either you don't believe in GCM predictions, in which case you can't know the PDO predictions either, or you do.

Actually I'd like to make two points.

1. How is the "average" weather defined in a grid square. Suppose you have mountains and ocean mixed.

As an engineer I am sure you have used discrete models - and know the answer. There is another answer - wait a year of two and there will be computer power enough to resolve your squares better.

2. The NS equations if they could be solved for a planetary type problem are inherently noisy and very much influenced by initial conditions and rounding errors. So you run them and say: this is the sort of thing that can happen. Then you have to add: there is no way to predict what will happen.

That is true except when you average enough to suppress noise. The IPCC are warning about a signal which is spatially averaged over whole globe and temporally averaged over 20 years or more. Enough to average out the chaos - incluing decadal ocean oscillations - and look at the long-term trends.

If people, pro or anti AGW, are expecting GCMs to predict well on shorter timescales they are stupid. IPCC has a wide range of GCMs all predicting different things on these shorter timesclaes but nevertheles the whole makes a convincing case for global warming.

3. So the only way to make predictions is to take a lot of complexity out of the system. But the essence of the system is its complexity.

Well this is very debatable. The issue is how much does microscale complexity lost effect not just mesoscale features (where clearly chaos predominates and any loss of precision will be amplified) but macroscale features which are dominated by physics not chaos. This BTW is the no 1 big misconception that semi-educated people have about GCMs. They don't see that while medium term chaos predominates, long term it averages out. That is because we do not naturally think interms of global & decadal averages - we think in terms of forecasts that we can personally use. So for example we overestimate the importance of recent NH climate temperature increases.

4. So far there has been no correction of the warming "signal" for the known effects of past PDOs and other ocean currents. If we have attributed to CO2 something that is actually PDO then the effects of CO2 have been exaggerated.

Agreed - in part. The GCMs are not just tuned basd on last 30 years data so the innacuracy is less large than you think. Also whatever the effect of PDO its effect GLOBALLY on temperature will be much less than its effect on headline grabbing US & European temperatures. However I would expect other things being equal forecasts to go down (a bit) in response to PDO modelling.

Unfortunately other things are not equal. IPCC AR4 assumptions on "typical" CO2 emmissions are already out of date since India & China have been increasing emmisions more rapidly than expected.

Best wishes, Tom

[tomclarke]

IPCC Uncertainty

The IPCC AR4 is a sophisticated and well-balanced process (whatever its defects) look here at the open published note (see IPCC AR4 link from eg wikipedia) on how chapter authors whould deal with uncertainty:
Plan to treat issues of uncertainty and confidence
1. Consider approaches to uncertainty in your chapter at an early stage. Prioritize issues for analysis. Identify
key policy relevant findings as they emerge and give greater attention to assessing uncertainties and
confidence in those. Avoid trivializing statements just to increase their confidence.
2. Determine the areas in your chapter where a range of views may need to be described, and those where LAs
may need to form a collective view on uncertainty or confidence. Agree on a carefully moderated (chaired)
and balanced process for doing this.
Review the information available
3. Consider all plausible sources of uncertainty using a systematic typology of uncertainty such as the simple
one shown in Table 1. Many studies have shown that structural uncertainty, as defined in Table 1, tends to
be underestimated by experts [3]. Consider previous estimates of ranges, distributions, or other measures of
uncertainty and the extent to which they cover all plausible sources of uncertainty.

[TallDave]

Armstrong (who wrote the source paper from which you and Wattupwiththat are quoting) is an economist, with track record in econimic forecasting...applying his economic principles to climate change modelling

What? No, economics is just one popular use for forecasting; others include engineering, social sciences, and --- surprise! -- climate (it's right on the IIF homepage). There is a science to forecasting in general, which the IPCC violates in sundry ways.

If you're going to say

The concern that AGW models are bad and have little predictive power is one which can not simply be answered

you can't then blow off a study that does just that.

And he has neither the expertise nor the inclination to read the literature that he dismisses.

It's not a question of literature or expertise, it's a question of whether they are following the rules one should use in any kind of forecast. He's an expert forecaster, evaluating a forecast. A better question would be: why didn't the IPCC forecasters follow forecasting guidelines? Apparently they didn't read the literature before venturing into a field in which they are not experts.

This constant reduction of pro-AGW arguments to the same ad hominem -- "well, you're not a climate scientist and don't know the field" -- shows how incredibly weak they are, especially given that most people on the IPCC are from fields like biology or physics.

Now we're supposed to believe that IPCC climate forecasts are so special they don't have to follow any of the rules established for forecasting. Sigh. If the AGW crowd are going to argue from nonfalsifiability, why not just establish a church and get it over with? Then they can be tax-exempt too.

It is as though a fisherman with 30 years experince catching fish wrote a paper attempting to dismiss evolutionary theories about how mammals developed from fish without bothering to read the extant literature.

No, it's like a an expert on fishing is objecting to evolutionary biologists who claim to have a wonderful new way to fish, which actually violates most scientifically established principles of good fishing.

The RealClimate piece is a hoot. Gavin asks, without a hint of irony:

This seems surprising - why wouldn't people want better forecasts?

Gee, it's almost like some people prefer an outcome that meets their ideological needs.

Do you find it strange that if the holes in AGW are as large as your favourite AGW blog claims, there are NO serious papers knocking down AGW which have been published and not comprehensively rebutted

There have been all kinds of such papers (I just cited one), because we're constantly finding new factors that need inclusion like PDO. The AGW folks just shrug and make another model that's slightly less wrong, or they ignore it. It doesn't matter, as long as they can still forecast a long-term outcome that justifies an environmental crusade.

[IntLibber]

Well -

Talldave - your argument (well - Armstrong's argument) is easily demolished.
Armstrong (who wrote the source paper from which you and Wattupwiththat are quoting) is an economist, with track record in econimic forecasting. This is stochastic - and has no physical laws that determine result. Human hopes & fears are difficult to forecast - and it is well known that experts tend to get them wrong.

Replace "scientific" by "economic" and I would agree.

More uninformed excuses. A climate IS an economy, where the currency is heat and the flows are as chaotic as a free market economy. In any economy there are sources and sinks.

In fact, to show how similar they are, there is a movement about to create a global currency based on the calorie.

Armstrong - in applying his economic principles to climate change modelling - therefore not surprisingly misunderstands climate models and thinks that they are wholly stochastic. Ecomomic models are a matter of getting best fit to data, physical laws don't exist. Also he clearly can't distinguish between climate and weather and sees future climate as being a chaotic process like future weather (whereas when spatially & temporally averaged of course deterministic trends emerge from chaotic noise). And he has neither the expertise nor the inclination to read the literature that he dismisses.

Typical left wing economic ignorance. Economies follow laws that are the equivalent of physical laws.

Now, to further compound this, were we to take you seriously, you would yourself be impugning the IPCC itself, which is largely made up of economists and other non-climatologists. As one of the Hockey Team recently admitted, only about 20% of IPCC scientists actually have even a passing experience with climatology.

Climate models do have parameters which must be determined from fit to data - but these are at many different levels and the data that fit them are not the global temperature that is the forecast/hindcast. That global match provides some extra validation (in case of hindcast). Other data: mesoscale, micogrid modelling, is used to determine the vertical mixing parameters which are impossible to model directly over long time periods and the whole globe.

Except that we are learning more and more about how these 'models' are rigged to produce the intended result. These are not scientific models, they are rigged prophesies no better than the claims of some evangelist touch healer.

This whole structure of physical equations, modelling, validation is foreign to economic forecasting. indeed only somone who had no understanding of physics would confuse the two.

For a vicious (not really to my taste - but "tit-for-tat" application of "scientific principles" to Armstrong's own work on IPCC see realclimate).

RC is about the most unscientific POS around. All they do is ad hom those who criticise their shoddy work. Even Schmidt was recently outed as trying to steal credit for a correction posted by CA about the fraudulent "Harry" station records, where the papers author blatantly copied data from an entirely different station and grafted it onto the Harry record, then said 'oops, how did that happen?' when he was caught red handed.

I can see why the pro-AGW web advocates like Gavin reply to character slur and partial reporting with their own material of the same kind, and to be fair, they do not do this stuff often.
http://www.realclimate.org/index.php/ar ... -forecast/

Simon has a more subtle line of argument. It has two prongs:
(a) GCMs do not (cannot) model NS equations well enough to have any predictive power.
(b) Past 30 years apparent global warming is explained by some combination of (select your anti-AGW argument of choice - many of been advocated - none have withstod scrutiny. Nowadays few get into the serious scientific literature and when they do they are rebutted).

(a) Is subtle and difficult to challenge. Neither Simon (unless he has written papers of a standard that would pass peer-review) nor I have looked at the field enough to be authoritative. I take the view that 1000s of peer-reviewed papers of 10s of years will expose obvious holes. especially because there are many academics who are emotionally wedded to the "AGW is rubbish" viewpoint. Anyone can publish papers and they will be taken up by others if ideas are good. You might imagine that climate modelling is a closed coterie of like-minded advocates. Read the IPCC AR4 report - there are a large number of models with warming predicted between catastrphic and very mild. As time has progressed the models have reached greater agreement, though there is still a wide variation. And the average has been moving towards greater warming.

So the evidence we have on this (most subtle and difficult to debunk) argument is really meta-evidence.
Do you trust the scientific peer-review process? (Not do you trust the scientific community!).

Actually, this is a good question. As more and more of the Hockey Team's data and methods are being audited, we are finding so many flaws that are NEVER EVEN BEING CHECKED IN PEER REVIEW. The climate journals are claiming that such deep due diligence is not the job of peer review and none of the peer reviewers are being paid sufficiently to do such a stringent audit of Hockey Team papers. They are passing it off saying that peer review is not intended to do that, it is only to check plausibility.

Do you find it strange that if the holes in AGW are as large as your favourite AGW blog claims, there are NO serious papers knocking down AGW which have been published and not comprehensively rebutted? There is diversity of opinion among both academics and editors of journals.

The Hockey Team's idea of rebutting papers critical of them (and there have been many, some even published in climate journals, others in related journals) is to ad hominem the authors and refer to their own previously published papers as "independent verification"

Note BTW that the answer to a) shifts with time. A few years back GCMs could be criticised for not modelling ocean currents - now they do. The computing power available P, and therefore just on the basis of brute-force computation the spatial resolution D (D ~ 1/P^(1/3)) gets better.

(b) is frankly feeble. The anti-AGW arguments (bad data - heat effect - variable solar forcing - ocean current dependence - etc, etc) all fall down when examined. They all HAVE been examined. And anti-AGW advocates have shifted ground from "GW is not happenning" to GW is not anthropogenic" or "GW is a multi-decadal effect".

Unfortunately - as proved in this forum - these anti-AGW myths, rather like the fertility ritual mythologies of ancient societies, have great staying power in the uncritical blogosphere.

Best wishes, Tom

On the contrary, they do a very good job decimating the fraud being perpetrated by some pseudoscientists operating on a political agenda. The problem is tha they, and their political masters, have no intention of being confused by the facts, their minds are made up and they intend on continuing to perpetrate their fraud to achieve their political goals.