This site is interesting:
http://climatechangepredictions.org/

revised link https://nsidc.org/data/seaice_index/

it must have been corrupted by EM. But I would say that the error bars suggest that we don't know very much

TBYJ your idea is very interesting. However I would suggest that one of the major things is about data. Science is about data. In climate science there is very little data.

When the BBC talks about the warmest thing on record, it actually means the warmest x since 1910, or thereabouts.

When the BBC talks about rainfall, it means since 1939, or thereabouts.

In other words the data sets are very very short.

In global terms it gets even worse,

The GCMs rely on inputs that are not captured by anyone. The modellers would like to include figures for particulates and sulphates etc but the data simply does not exist. How nmuch reliance should you place on outputs from models that do not have reliable inputs?

This is key to my scepticism. We do not have the data. When it comes to polar ice, the GRACE data reported in the last IPCC report showed a small chance of ice loss. The measurements are almost always outweighed by the uncertainties.

Where is the data for the things that the IPCC tells us will happen in increasing frequency? If only the IPCC had set up as a repository of data. We can only regret that it decided not to be scientific.

https://nsidc.org/data/seaice_index/

if the NSIDC graphic does not display, the message is the slope is 4.6 +-4.1 % per decade. In other words, not very much is happening.

diogenes, if the IPCC had been scientific, a lot of time, money and lives could have been saved.

The UN may have to charge it's own IPCC with Climate War Crimes against Humanity.

Entropic

I see this as a serious problem.
For example, GISS quote their global annual average to +/-0.09C, based on their analysis of the NOAA data. CRU give confidence limits of +/-0.1C.

You're getting confused between claimed confidence and actual error bars. GISS I have less problems with (but there are problems) but let's take CRU, with their reported confidence limits of +/-0.1°C. Have a look at this graph

This is a plot of CRUTEM3 and CRUTEM4 over the years 2005-2007, so well into the modern era with accurate reporting. Before there was a CRUTEM4, we were told that CRUTEM3 was +/-0.1°C. That means that they were claiming that, for instance, the reported anomaly value of 2005.8 was 0.85°C +/-0.1°C. So in effect within the range 0.75°C - 0.95°C.

So when CRUTEM4 came along, the anomaly value of 2005.8 is now 1.2°C +/-0.1°C. These ranges don't even overlap. So which one is right? If you're claiming with confidence pre-2012 that the real absolute anomaly value is in the range 0.75°C - 0.95°C and then you do some fiddling in 2012, and suddenly that modern era, high-precision anomaly is now 1.10°C - 1.30°C. What does that tell us about how the confidence limit given on the previous product actually relates to the real world? And what does that imply about the confidence limits given in CRUTEM4?

Remember out there in the real world there is an ACTUAL value for this anomaly. It's clear when we were told that CRUTEM had nailed it to within .2°C that they were incorrect. And if they were incorrect then, then I don't believe them now either. They have a track record for claiming an accuracy that they don't even stay consistent with between model runs.

In your repository would you express whatever you thought as an opinion or would you be able to present independent calculations?

The wiki would contain no original work, it would merely demonstrate (as I have done above) that there is serious doubt about the claimed accuracy of the various temperature trend products.

Remember that BEST, the last sceptic attempt to falsify the climate data, ended up validating it.

Oh please, you don't seriously believe that BEST was a sceptic attempt to falsify climate data? That was the most blatant stupid farce to have come along in the climate story since Michael Mann claimed he was a Nobel laureate. Mueller was never a sceptic, he was always part of the climate orthodoxy, but by claiming he was a sceptic it produced irresistible story for the touchy-feely brigade which comprise climate alarmism, bad man made good.

Ultimately, if your repository isgoing to be taken seriously beyond the scepticosphere you will need to be able to present evidence credible to a wider audience . Where are you going to get it?

It's all over the place, EM, but the wiki won't be trying to prove any competing theses, just show that there is a level of error/doubt in the original theories. That all the scepticosphere does. That's its job. The repository won't be trying to "take down" the climate orthodoxy, just be a place where all the niggles, doubts and errors are documented. A person reading it may just shrug at the end and say, yeah I can see what you're saying but the evidence is still good enough for me. That's fine. At the moment, it's not even out there in the public domain, it's lost in the archives of blog postings and the odd paper that's missed by the climate police on editorial boards.

1. No original work (except demonstrative examples)
2. All statements to be referenced (to original papers or blogs)
3. No polemics
4. Right to reply.

TheBigYinJames

I did an approximate calculation.

The average difference between corresponding CRUTEM3 and CRUTEM4 values was 0.16C.

The 95% confidence limits they quote are +/-0.1C. The difference at which the probability that both samples are from the same population drops below 5% is 0.2C. I found three pairs which exceeded this value. The differences were 0.21,0.37 and 0.45.

Statistically that's marginal. The overall average difference is within limits, but the number of significant differences looks a bit high.

I plotted the two algorithms from 1970

They look identical from 1970 to 2000. Post 2000 CRUTEM4 looks slightly higher.

I have to go to work More later

EM, you have spectacularly missed the point again.

When someone says to a layman: The temperature in 2008 was 18°C plus or minus 1°C, that means that you have calculated (by statistical means) that given the errors in the individual measurements, once you have applied some sort of averaging algorithm to it, you have calculated that the range of possible values is plus of minus 1°C.

This means you are saying that given the errors in the original measurements, this is the error in the mean.
What you are also saying to the layman is that the ACTUAL value out in the universe is within this range.

When you later recalculate that mean (on the same, overlapping or completely distinct population of measurements) and come up with a range which does not overlap the original one in any way, it can only mean one of two things.

1. The error of the measurements is larger than reported.
2. The populations in one or both products are unrepresentative.

What it also means to the layman, is that when you reported the range of values within which the ACTUAL real world value lay, then you later contradict that with a range which does not overlap with the previous one, then at least one of them is wrong. They can't both be correct.

So you are left with three options:

1. The earlier one was correct and the ACTUAL value was within the original bounds
2. The earlier one was wrong and the ACTUAL value is within the new bounds
3. Both of them are wrong and the ACTUAL value cannot be determined from either population

Since the earlier calculation was vociferously sold to us as THE ABSOLUTE SETTLED TRUTH, then the layman is perfectly within his rights to discard both sets as fiction and go with 3.

I suspect that these are correct.

2. The populations in one or both products are unrepresentative.

2. The earlier one was wrong and the ACTUAL value is within the new bounds.,

As you say, the purpose of a temperature record such as CRUTEMP is to approximate reality. This is no easy task.

When one finds a way of making that approximation a closer match to reality, one does so; hence the change from CRUTEMP3 to CRUTEMP4.

I put up a graph showing that the two records agree until 2000 and CRUTEMP4 then runs higher. From your graph I estimated the average difference as 0.16C, not statistically significant but large enough to be apparent.

Richard Betts might be able to clarify the reason for the change. IIRC the electronic thermometers and buoys which came into use in the 21st century tend to give averages about 0.2C cooler than mercury thermometers. An adjustment to compensate would produce the data we have seen.

Since the earlier calculation was vociferously sold to us as THE ABSOLUTE SETTLED TRUTH, then the layman is perfectly within his rights to discard both sets as fiction and go with 3

You were doing fine up to this point. Then you went all polemic on me again.

I very much doubt that any scientist worth his salt believes that the evidence isTHE ABSOLUTE SETTLED TRUTH, though a politician might claim it.

To a layman, this is a statistical argument, and might or might not be understood. I hope you would not take advantage of his ignorance to present a slanted version of the statistics. You do not have THE ABSOLUTE SETTLED TRUTH either.

We look at BEST very differently.

Do you have good evidence? Hunter and various others claim that the burden of proof is on the warmists and that they do not have to provide evidence. Cynical old me has long since concluded that if they had evidence, then they would be trumpeting it from the rooftops. A conclusive falsification of AGW would be worth a Nobel Prize, at the very least.

Last Fall, during the media blitz ahead of Paris COP, I was asked by some persons for references to read on the issues. One of the most appreciated sites was the Paris Climate Challenge website which is organized around 10 questions ( a manageable number for newbies). Some of the content is dated, but people found it useful.

http://pcc15.org/the-ten-questions/

"polemic", EM did you find that word in your Christmas cracker? Don't overuse it, you might give the game away.

Nothing wrong with passion.

Do not let EM dictate how this approached, and I am not even talking about the science. He wants the rules stacked in his favour. CAGW advocates do not expect anything else. Turn him off.He defines the system to have everything stacked in his favour. Do not take his definition.

I would just ignore them for this exercise and think about it from how things should be done. But I am not sure you can provide one set of info that will work. You could have one viewpoint about the global temp and the issues with it. But you can also have an article asking does having a global temp have any validity at all? I am not answering that question, but it is a valid question to have.

The alien engineer meets his buddies in the bar back home after a inspection trip of Earth.

He opens the bottle of absinthe for his mates.

"They really drink this shit?"

"Strongest I could find, not very good drinkers."

Well the drinks are flowing the war stories start to flow...

Our visitor starts to get into full flow about the peccadilloes of the third most intelligent species on the planet earth....

"...not only that, but they base this reducing the gross domestic product of the planet on about 40 years of climate related data. And some of it based on tree rings. "

They all fall about laughing and respond in union.."No?! How old is their planet? Are you sure they are the third most intelligent?"

"I kid you not."

"have they discovered quantum fusion power yet?"

"Quantum fusion? They think think putting up windmills is a solution".

"Planet apes!", and with that they open another bottle.

-----

I think you should imagine you are a visiting alien to define the framework for this.

EM 6:42, "cynical old me" suspects that if global warmists had evidence and proof of CO2's impact, they might have published it by now. Mann must be keen to win a Nobel Prize after all of his deceit.

We already discussed the Essex paper on two threads. He uses Celsius where he should use Kelvin to calcultae his curves in figure 1. This is obvious from the fact that R4 curve starts at just under 28C, as discussed elsewhere. And whether Earth as a whole has an average temperature when viewed from afar (because its spectrum doesn't match that of black body etc) has no bearing on surface temperatures.

...and Raff keeps repeating the same objections which were rejected on the other threads as being wrong or irrelevant.

I do try to give different views on things. Here is another go...

http://www.theguardian.com/artanddesign/2016/feb/18/500m-private-sale-believed-to-be-new-record-for-contemporary-artwork

USD 500 million for a few (and I mean a few) contemporary art works.

De Kooning - Interchange

Note: this is not a comment on the artworks themselves (I do believe skill is a nice thing to have as well as expression, but art is art).

There is a contemporary art System created that creates values in these paintings that are weighted not just as expensive art but astronomically expensive art. I remember visiting the top floor of the Centre Pompidou and seeing a triangle painted on a canvas.

Valid art, but there is a self contained System of experts and consensus that decide one piece of art is for promotion and one for the fridge door from your son.

The members of that System try to spread the consensus. So they want you to argue about the art on their terms. And of course they control the system. And supply to people, ready on a plate, "taste". And at the top there is always expensive taste because people with money like to show their taste.

They will use a language that is deliberately made to sound like it has some substance and value. "The firmness of the brushstrokes, counterpoised with the delicacy of the colours, all within a framework that contains contrasts of subtlety and even humour" (I just made that crap up.)

And Climate Science is a similar system.

I am outside of the Art System, refuse to be swayed by its tentacles and reach. by its consensus. I will walk up to a piece of modern art from outside the system. I do not see all the layers of the art world built on top of an artist. I do not see a USD80 million painting.

And I do believe that scepticism has to stop trying to follow and even beat the rules of Climate Science. it is just an invented system, where the value is only within the system.

Hence, my thoughts of always looking at Climate Science from the eyes of an alien.

The gruff Miner taken to a London museum by his university daughter and presented with an artwork that elicits the response "It's bollocks", is a very direct and powerful critique. And not one that should dismissed because he not a member of the system.

I am not with the clearest of heads this afternoon, that was my best, do not let Climate Science bring you into their system, their rules, their dictates.

Martin A

Just read your Essex link.

Buried in the obfuscation is an argument for a thermodynamic measure of planetary energy content . On that basis you must support the energy content approach the heat content approach to measuring global warming.

Ocean heat content is therefore your proper measure of climate change.

PS Before you go off half cocked about the non-existance of average ocean temperatures, remember that you can measure changes in ocean heat content by deriving volume change from sea level rise.