Bishop Hill Walport's reverse thinking
Jan 27, 2014 Bureaucrats Climate: Sceptics Walport Hidden behind the Times paywall, I gather that Sir Mark Walport is being rude:
Climate sceptics should stop attacking the science of global warming and have a “grown-up” debate, the Government’s most senior scientist has said.
Sir Mark Walport accused climate sceptics of questioning the scientific evidence in order to dodge the more challenging question of what to do about it.
OK, so let me get this right. The world hasn't warmed for 17 years or so. Climate scientists can only hypothesise as to the reasons why. We can't detect any significant changes in the surface temperature record. The evidence about climate sensitivity is that it's much lower than we had been led to believe (but the IPCC obfuscated the issue).
And Sir Mark thinks we are wrong to discuss the science?!
What does this tell you about our chief scientific adviser?
Reader Comments (159)
Martin A
Mere denial, or do you have evidence to support it? Most of what I get from you is stale propaganda memes, without evidence.
Bishop Hill complains about the lack of scientific debate. I'm debating. Your turn to show some data.How about specific confidence limits for the large uncertainty in the energy imbalance you claim, and data in support.
You might also explain why you suddenly have so much confidence in HadCRUt.
Phillip Bratby at 7:21 PM
Thank you for the reference, from the DECC on 19/09/13. It does give a bewildering array of choices. I thought I was in the right ballpark with the outdated 430kg/MWh, when I found something from the Carbon Trust on energy conversion factors for businesses trying to calculate their CO2 savings. This gives 445.48kg CO2 per MWh of grid electricity. This in turn refers to a DEFRA sponsored consultants paper "2013 Government GHG Conversion Factors for Company Reporting" from July 2013.
But the conversion factors are largely irrelevant. Using Stern's figures the renewables obligations credits for offshore wind turbines, worth £84 per megawatt hour, are only of net benefit if this saves at least 1650 kg of CO2. The IPCC AR4 SPM stated the median social cost of per tonne of CO2 from various studies was $12, or £7.50. On that basis, the offshore wind turbine is only of net benefit if it saves well over 6667kg per megawatt hour.
So whilst there might be a wide range of figures for converting CO2 to megawatt hours, none come close to making current policy as net beneficial. This is before one starts questioning the broad range scientific evidence that Sir Mark Walport believes we sceptics should accept as a singular and fundamental truth.
I have been working on the issue of the benefit-cost ratio of the Climate Change Act 2008 for a while now. Whatever figures are used, the Act causes net harm. If >1 is net benefit, the question is whether the actual ratio is closer to 0.5 or zero.
EM - I was simply repeating in condensed form what the heroes of climate science themselves say. You could have looked it up for yourself if you had been interested in getting to the truth.
For example, from Trenberth, K. E., J. T. Fasullo, and J. Kiehl, 2009: Earth's global energy budget. Bull. Amer. Meteor. Soc., 90, No. 3, 311-324:
Martin's translation:
[A] = "the imbalance from satellite measurements is too large to be plausible so it's got to be measurement error."
[B] = "so we use climate models (unvalidated, uncalibrated) to give us what we pretend are actual values for radiation imbalance - confirming what Martin A said"
To Entropic Man,
Re your comment to Martin A, according to Stephens et al 2012 the energy flux imbalance at the surface of the earth is 0.6 W/m2 ± 17. The surface of the earth is where the sea meets the sky, and it is where the missing heat is supposed to be diving into the oceans.
When the error margin is 28 x the size of the quantity we are trying to estimate it means we don't have a *!?** clue what the real value is. Bearing in mind that the zero value is very close to the centre of this range, we can have absolutely no confidence that there is any missing heat. Of course, the fact that global temperatures have flatlined for so many years is entirely consistent with there being no missing heat.
I hope this meets your request for evidence with specific confidence limits.
Perhaps we can now get back to the topic of this post which is Sir Mark Walport demonstrating his lack of knowledge on the scientific case against CAGW and thence his unsuitability to be the government's chief scientific adviser.
Alternative translation. The imbalance is even larger than we expected. This favours large secondary forcing and therefore higher climate aensitivity. Another opportunity to improve the skill of our models and provide even more reliable long term forecasts.
David Lilley
Stephens et al 2012 gave a top of atmosphere (TOA) imbalance of 0.6W/m^2 +/- 0.4. That is an imbalance between 0.2 and 1.0. His surface figure was 0.6 +/-17.The two mean values agree exactly. The higher uncertainty for the surface measurement is due to the greater difficulty of ganing worldwide data coverage on the surface compared to satellite sensing.
In practice, the surface value isconstrained within the TOA limits unless you are willing to accept much larger rates of energy flow between the ocean and atmosphere than even the most pessimistic scientific estimates.
Time's up! The answer is: in the "Science Journalists in the Raw" video, from Mark Henderson from about 20:10.
Bold emphasis added. The way in which Henderson seems to allude to uncertainty about feedbacks, then apparently elides that question, the question of environmental impacts, and the question of economic impacts all together looks a bit like a three-card trick, but we have to give the benefit of the doubt to someone who was speaking off the cuff. Of course this new line raises some other obvious questions too. (I bet that Richard Tol and Bjorn Lomborg are pleased to learn that strictly-economics-based questions about the current decarbonisation strategy are actually a thing and totes legitimate and important after all.) But regardless, as TinyCO2 said it does seem to be a new party line.
(Full disclosure: I haven't seen the paywalled Times article.)
While I appreciate Sir Mark-keep-the-lights-on-Walport's efforts to persuade the government to keep the lights on, I think he has a lot of reading to do, hopefully before they go out. [In fact, a lot of street lights have already been turned off permanently in the town where I live. What is Sir Mark doing to make it affordable for the local council to switch them on again in my life time?]
While he is catching up on his literature reading about atmosphere, weather & climate, he may also wish to learn how to speak Chinese. If he thinks his exhortations in English are going to carry any more weight than a traditional running-dog-western-imperialist-lackey in the far East, then he has got another think coming. It's 2014, for crying out loud.
Yes, Mark, I am laughing at you if you think you could have any effect human CO2 emissions, let alone the concentration of carbon dioxide in the atmosphere. You can't, and you know you can't. You are doing your country, your people, and science, a great disservice. Shame on you.
I think the reason young people are so idealistic (relative to me now, but not to when I was young) is that they have not seen what goes on behind the curtain. They are still in the stage where they believe much of what they read (certainly about climate change).
If we could get them to be more widely read...even if it were limited to Bish and Matt Ridley and Steve McIntyre...people like Walport would be chewing their cuds in oblivion somewhere.
Sir Mark Walport a medical scientist with no known training or experience relevant to the debate asks me a physicist with experience in temperature control, weather measurement and renewables whose studied climate science for well over 6 years with a business degree to "grow up" and deny the principles of science, engineering and economics which were all thoroughly drilled into me in several relevant university courses and a career in engineering.
Well all I can say is this:
Thank you Sir Mark for not calling us 'deniers' :)
Dr John Galan : "Walport’s suggestion that sceptics should have a grown-up debate with those supporting the “science” of global warming is an opportunity similar to that offered by Paul Nurse to Nigel Lawson."
Unfortunately, I doubt it is that simple. From Walport's point of view, he has been advised by all those he believes are credible that there's a massive problem etc. etc., however he sees that not only have sceptics largely been proven right (when you actually look at what we say and not what others say we say) but that the public trust us more than his side.
This is no doubt hugely confusing. How can a band of disorganised people be so effective? - Indeed this is why it is often assumed we must be hugely organised.
So, I suspect partly he is trying to "reach out and persuade", party he is trying "understand where we are coming from".
Unfortunately, he is still in the baby-grow section of understanding sceptics. He is used to dealing with heavily financed Universities and technology institutes who have massive budgets to force their views at him. He probably expects us to behave the same way ... to hire a $100,000 lobby company and $1milllion PR firm to "sex up" their results and push it at him at some all-expenses paid business do where he gets treated like a lord to butter him up.
He doesn't realise, that if he wants to meet sceptics, then - horror of horrors - he will have to do the work and either read blogs like this - or he will have to pay for us to meet him.
Indeed, as "scepticism" is in large part, the bypassing of the traditional hierarchy in science, I doubt whether any of those at the "top" of science really have a chance of being able to comprehend us.
I have said several times that EM is a naive man who has swallowed the CAGW story whole. He'll believe anything that seems to back it up and if he can't find it, he'll make it up. From that point on, his own BS becomes his reality.
For example:
In a 10 minute break, I plotted the GISS global temperature data (annual jan-dec averages) from 1997 - 2013. Even a casual glance shows the absence of warming in the GISS record - in contrast to EM's confidently expressed BS.
My letter to the a Times wasn't printed this morning but this is what Inwrote:
Sir
Sir Mark Walport is absolutely right that we need a grown up and honest debate concerning what we should do about climate change. However, that can only take place if some light is shone on the scientific uncertainties surrounding the matter. Whilst it is true that the vast majority of scientists agree with the simple statement that man is affecting the global climate, this agreement is insufficient to inform policy as there is no scientific consensus about the degree of man's contribution to rising temperatures as opposed to other natural factors which are beyond our control. A key concern must be that the computer models which are used to make future temperature projections are increasingly at odds with actual observations, and this coupled with the lack of recent warming calls into question the predicted scale of the problem. Given the expense of many of the proposed climate mitigations, it is right that these uncertainties are discussed openly as part of Sir Mark's grown up debate. It may well be that we are best to do nothing for the moment.
RobB -
Good letter! Concise, measured, accurate.
Testing
Martin A
Look a little closer at your graph.
The 5-year average anomaly for the first five years was 0.49C.
The 5-year average anomaly for the latest five years was 0.06C.
Your casual glance missed an increase of 0.11C over 11 years.
Indeed, as "scepticism" is in large part, the bypassing of the traditional hierarchy in science, I doubt whether any of those at the "top" of science really have a chance of being able to comprehend us.
Jan 28, 2014 at 9:52 AM | Registered CommenterMikeHaseler
Who would you suggest as suitable representatives for scepticism?
A representative group would include a lukewarmer, a political lobbyist, a conspiracy theorist and a sky dragon slayer.
It is indeed difficult for a non-sceptic to comprehend scepticism when the movement includes such a range of positions.?
It may well be that we are best to do nothing for the moment.
Jan 28, 2014 at 9:34 PM | Unregistered CommenterRobB
Talk to a pilot, diver, or other high risk professional and they would regard this strategy as a good way of getting killed.
Google "incident pit"
from the fount of stupidity EM:
"Alternative translation. The imbalance is even larger than we expected. This favours large secondary forcing and therefore higher climate aensitivity. Another opportunity to improve the skill of our models and provide even more reliable long term forecasts."
In other words, we have no clue what is going on and are busy inventing epicycles and secondary/tertiary forcings that we do not measure to try to explain our lack of rigour. Whenb he looks in the mirror to shave, does he see a tiger?
Diogenes
I know what is probably going on. Some combination of decreased insolation, ENSO and aerosol negative forcing has slowed the rate of atmospheric and sea surface warming. This is countering part of the increased energy input due to cAGW. Details to follow when all the data becomes available.
If you have a better idea, and the data to support it, the world will beat a path to your door. If all you have is a belief that nothing is happening, without the data, best say nothing.
We may be coming into more active warming. The ENSO forecasts are showing increasing probability of El Nino conditions in the second half of this year and into 2015.
http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html
EM, you should know by now that, like clouds, the effects of aerosols come with the largest of uncertainties. Pretending otherwise is disingenuous.
Do many people, apart from those that reply to him, read the comments by Entropic Man?
Entropic Man = Ectopic Man?
Anyone else hear Sir Walport on Radio 2 this morning talking about consensus etc? As usual with the BBC he was totally unopposed, the standard hatchet job tactic as used all too frequently by the BBC unfortunately.
Further to my last post, it seems the Times liked my letter after all as it was published behind the paywall this morning minus some remarks concerning models and recent data. The gist of it was still there though.
MIke Haseler
Perhaps we could try inviting him to the next pub-meet?Jan 28, 2014 at 11:24 PM
EM - it's a natural human trait to see patterns in random data. And it seems you are blessed in abundance with that talent.
If you believe there is a significant difference between the GISS points I plotted and a curve consisting of a constant value with the addition of a zero-mean random quantity to each point (representing year-year random natural variation with zero year-year trend), then you are free to do so. I ran off a few such curves and anyone asked to identify "the odd one out" would have had no reason to identify visually the GISS curve from the synthetic curves.
Likewise, if you believe that the GISS curve shows that it is false that "The world hasn't warmed for 17 years or so" you are free to do so, but I think you are seeing what you want to see in essentially random data.
I suppose that what we are really discussing is whether it is realistic to say "the world is still warming" when the trend in the data can be perfectly well accounted for by entirely random year-to-year variation but, by chance, the random variation has resulted in a positive trend.
To me, it's like my looking at my car's fuel consumption records, seeing that there is a slight trend in the plot over the past month and saying 'Ah good, my car has become more economical'. I think that you would say 'that's what the data says, so that's how it is'. Right?
If one or other of us wished, we could compute likelihood ratio for the following two models.
[A] A constant value (0.57) + a random value of zero mean and std dev 0.076 (model for no warming/cooling)
[B] A constant value (0.57) + a trend of 0.0064/yr + a random value of zero mean and std dev 0.07 (model for continued warming)
The numbers are what my spreadsheet computes from the GISS 1998-2013 data. 0.070 is the std deviation it computes for the residual.
But, without bothering about likelihood ratios, doesn't the 0.076 / 0.070 ratio tell you enough?
*GISS annual data
1998 0.62
1999 0.41
2000 0.41
2001 0.53
2002 0.62
2003 0.61
2004 0.52
2005 0.66
2006 0.60
2007 0.63
2008 0.50
2009 0.60
2010 0.67
2011 0.55
2012 0.58
2013 0.61
EM @ Jan 28 9:34
"Talk to a pilot, diver, or other high risk professional and they would regard this strategy as a good way of getting killed."
As an admittedly low risk pilot who survived a long career, I should like to inform Entropic that he is totally wrong. One of the first things that a young pilot learns is that in an emergency it is better to "sit on your hands" and work out what is wrong before rushing into the wrong action!
One of the first things that a young pilot learns is that in an emergency it is better to "sit on your hands" and work out what is wrong before rushing into the wrong action!
Jan 29, 2014 at 1:26 PM Mike Post
That's also the fundamental principle of quality improvement - don't take action until you understand the process and have diagnosed what the problem is. If you change something because intuition (ie a guess) tells you that's what's wrong, there is every chance you will make things worse, the problem will have been complicated and made more difficult to analyse. Meanwhile more unsatisfactory product will have been produced.
RobB -
A shame they cut "A key concern must be that the computer models which are used to make future temperature projections are increasingly at odds with actual observations, and this coupled with the lack of recent warming calls into question the predicted scale of the problem." It seems rather a key point, that not only should one be concerned with the high cost of proposed policy vs. its effectiveness, but if the problem is not as serious as some believe, that the "avoided cost" does not justify the policy in the first place.
A day or two back there was a comment on the radio (R5, I think) to the effect that Sir Mark will be giving a series of presentations around the country to push the CAGW message.
I have not been able to find any programme for this "roadshow" but I did pick up one event on the Climate South West website http://climatesouthwest.org/events:
"4th Feb 2014, Sir Mark Walport: The Planet in Our Hands - Responding to Climate Change Talk, Bristol
Sir Mark Walport is the new Chief Science Adviser to the UK Government. From a background in immunology, he now turns his attentions to the most pressing issue we face as a global society: our climate. In this talk he explores what the science tells us, and asks what should we, as a developed nation, do in response?
Join the event from 6.30pm for a chance to mingle with people involved in climate and sustainability from across Bristol. To be held at Rosalind Franklin Room, At-Bristol (main talk 7-8pm). For further information and to book your space click here."
Without knowing the format, it would be very good if a few sceptics could get to these events and, hopefully, ask some pertinent questions.
Knowing how such folk can dissemble and digress, any questions would have to include a strong point for him to try and refute. For example:
" Meeting climate targets will cost this country many billions of pounds but it will have no discernible effect on global temperatures because our emissions are trivial compared to China and others so why should we impoverish ourselves and cripple our industry?"
HaroldW, RobB
The sentence cut from the letter disagrees with the position of most climate scientists. Perhaps the letters editor asked the science editor and decided to excise a possibly erroneous statement.
Mike Post, splitpin
I do not advocate precipitate action. My own flying instructor would have been as rude as yours.
However, we have 130 years of science and data telling us that there is a problem. What sort of pilot would listen to a rough running engine, start to divert and then return to his original course when the rough running improved slightly?
EM
I don't want to push the aviation metaphor too far, but I would argue that the climate is behaving as it always has and wasting a huge amount of money on unnecessary diversions would soon bankrupt your airline. Can you explain why you believe that there are 130 years of data indicating that the climate is running rough?
EM - I suggest dropping the silly analogies. You're not teaching a class of 13 year olds now.
Occasionally you'll come up with a valid or thought-provoking point. Diluting those occasional insights with a stream of BS and tritenesses is not doing anyone - least yourself - a favour.
Entropic Man: "The sentence cut from the letter disagrees with the position of most climate scientists. Perhaps the letters editor asked the science editor and decided to excise a possibly erroneous statement."
The sentence was "A key concern must be that the computer models which are used to make future temperature projections are increasingly at odds with actual observations, and this coupled with the lack of recent warming calls into question the predicted scale of the problem." This does not seem to me to disagree with the position of most climate scientists. Perhaps you should read this post by Jules Annan, who is not a person one would characterise as a "skeptic". If the observations call into question the climate sensitivity -- and I think this is acknowledged in AR5 WG1 -- then they equally call into question the scale of the global warming problem.
Mike Post
All the paleo data defines a gradual temperature decline from the peak of the current interglacial until the industrial revolution hit its stride.
Thereafter the trend reversed into rapid warming, along with other potentially dangerous trends such as sea level rise.
I mentioned the incident pit metaphor and would regard it as the most apposite.
Through IPCC the scientists describe the shape of the incident pit, our position on the slope and the probable outcome of different mitigation options.
The politicians produce a policy response little better than BAU, which let's us slip further into the pit.
The lukewarmers tell its all right, its only a small pit.
You tell me that we should continue to slide inwards, ie do nothing about it, until we can see the pit more clearly.
The deniers say"What incident pit."
Harold W
The uncertainty cuts both ways. IPCC discuss a likely 2100 temperature range between 1.5Cand 4.5C based mainly on different mitigation and climate sensitivity options. Your concern that uncertainty has been underestimated means that there is a possibility that little change may occur. There is also the possibility that the change may be much bigger than the IPCC worst case forecast.
I see nothing in Jules Annan's blog to change the prevailing view that ECS is probably between 3and 4C, and that the observation based studies such as Nic Lewis' are underestimations due to measuring an intermediate between TCR and ECS
Given our increasing population and propensity for living on coastal plains, betting that IPCC are pessimistic is reckless.
I was reluctant to bet my little pink body on optimistic weather forecasts when flying. I am equally reluctant to bet my civilisation on optimistic climate forecasts now.
Martin A
Why do you expect poor manners to change my mind, when poor evidence has not?
EM - My intention was to be direct but not to be rude. I think you let yourself down by coming up with feeble or invalid analogies, presented as if they were pearls of wisdom.
Entropic Man (12:09 AM):
"The uncertainty cuts both ways. IPCC discuss a likely 2100 temperature range between 1.5C and 4.5C based mainly on different mitigation and climate sensitivity options. Your concern that uncertainty has been underestimated means that there is a possibility that little change may occur. There is also the possibility that the change may be much bigger than the IPCC worst case forecast."
First (nitpick), we should be more precise when giving ranges. I believe the 1.5 - 4.5 range is relative to pre-industrial; AR5 WG1 rather confusingly alternates between expressing global mean temperatures relative to pre-industrial and reIative to a 1986-2005 baseline.
Second, to reach a 4.5C rise would seem to require both the largest emissions scenario (RCP8.5: 2.2 doublings by 2100) and a TCR of about 2.0 K, which is the top of the Otto et al. range of estimates (that is, the 95th percentile), about 50% higher than the Otto et al. best estimate, and even 10% above the CMIP5 multi-model median (& mean). So I find the uncertainty really only works one way, only because the AR5 figures for 2100 are based on GCM results and were not adjusted downward by the observation-based figures of sensitivity, as were the medium-term expectations.
Entropic Man - as far as I am concerned, your 'incident pit' is just another unsubstantiated model. A pretty construction - but does it represent the real situation we are in? I see no reason to believe this. But I appreciate your willingness to debate seriously. Those who respond by explaining your motives do not, to my mind, show the same willingness.
Harold W
IPCC can be confusing. They expect an increase of 1.5 C to 4.5C from a 1880 start line of 13.8C or an anomaly of -0.2 from the 1961-1990 baseline temperature of 14.0C.
Expressed as temperatures the increase is from 13.8C to somewhere between 15.1C and and 18.1C.
The mean estimate is an anomaly of 2.8C, an increase of 3C to 16.8C.
I confess to being a little bit more lukewarm than IPCC. If there was a sweep I'd bet on anomaly 2.5C. This puts me in the gap between the paleo and model estimates, which put sensitivity around 3C and the obs estimates which centre around 2C.
We could play reference hockey on this. For example, Murphy et al 2004 estimated sensitivity based on a model ensemble between 2.4C and 5.4C.
http://www.nature.com/nature/journal/v430/n7001/abs/nature02771.html
In practice, the difference between us is mostly about our choice of valid information. Your emphasis on the OBS models makes your expectations cooler. My willingness to accept paleo and model estimates makes me warmer. Once again we will have to agree to differ, and wait for reality to catch up with forecasting.
From my viewpoint, I still don't like the idea of waiting till we've fallen in the hole and then trying to climb out.
Osseo
The purpose of the incident pit is as a visualisation of risk management practice. Awareness of the tendency for minor difficulties to escalate into lethal problems can help guide one's response to a crisis.
From the viewpoint of this warmist the crisis is under way and the response is inadequate. Is your view that the incident pit is not a useful concept, that it does not apply to the climate change problem, or that there is no problem?
Osseo
My motive? I like discussion with dissimilar minds.
Martin A
Tamino has been considering our problem.
http://tamino.wordpress.com/2014/01/30/global-temperature-the-post-1998-surprise/
EM - I looked very quickly but could not really take in what he is saying. (have things to do before going to bed tonight).
I think he is saying "If the pause had really started in 1998, we would not have seen as many annual temps above the blue horizontal line as we actually saw"
I think he says he fits a straight line from 1979 - 1997 and then extends it to 2013. I think he then says that the temperature predicted by this line is roughly what it is now. So (if I understood him right) there has actually been no 'pause' in the increase of global annual temperature.
*If* I understood right, it seems to be seems an argument with a lot of assumptions buried in it, including the dynamic behaviour characteristics of the climate system. Understanding what the assumptions all are - including the effect of the starting date he chose - would need thinking about a bit.
EM - if you look at the data you can see what he's on about.
Martin A
You have the right idea..
Tamino took Dr Curry's statement to Congress that no warming had taken place for 16 years. This put the beginning of the slowdown as 1998.
He then calculated the linear regression line for 1980 to 1997, included the upper and lower 95% confidence limits and used it to construct two alternative possibilities.
1) Warming continued at that same rate. This used the three lines continued from 1997 along the same slope.
2) Warming stopped. The three lines were drawn horizontally from 1997.
Finally he plotted the yearly averages from 1998 onto the two graphs and discussed which line they fitted better.
Choosing 1980 looks fairly neutral. He could have choaen any year from that period and got a similar slope.
EM - a small point to start with. He says "we’ll add extra lines, two standard deviations above and below, to mark out the expected range." (not upper and lower 95% confidence limits, which would assume distributions are known). Also, I think he says he took from 1979, not 1980.
A basic problem in any such discussion is that there is no model for the stochastic process that generates the time series. As Doug Keenan has pointed out several times on BH, if you don't have a statistical model, you can't draw meaningful conclusions from analysis of the time series, so 'yes it is' 'no it isn't ' discussions will never get anywhere.
However, if you maintain that the line fitted from 1979 - 1997 shows that warming continued until very recently (rather than ending at the point where the temperature became constant) , should you not equally insist that warming started around 1968 ? (as shown by the line ).
That is to say, shouldn't you also maintain that the 1978 - 1998 warming began *before* the temperature actually started to rise? (To be consistent with maintaining that Tamino's line says that warming continued *after* the temperature became constant.)
Martin A
Two standard deviations and 95% confidence are synonymous.
When you calculate the mean for a sample from a larger population, you should also calculate the standard deviation, a measure of the spread of individual measurements either side of the mean. The result can be expressed three ways:-
95% of the measurements will be closer than two standard deviations from the mean.
If you take hundreds of other samples this size from the same population, 95% of them will have a sample mean within two standard deviations of this one.
There is a 95% probability that the mean for the whole population is within two standard deviations of this sample mean.
In this context the means are the average figures for each year, the regression line is the trend derived from them and the two standard deviation lines define the uncertainty of the trend.
The statistical model for the 1979-1997 period assumes a constant rate of increase during that period. Thereafter two models are compared.
One assumes that the rate of warming remained the same after 1998, so the regression line and its 95% confidence limits continue along the same slope (tamino's red line)
The second model assumes that warming stopped after 1998 and temperatures remained constant ( tamino's blue line ).
Tamino plotted graphs for these two models using each of the six datasets available and compared their post-1998 values with the two statistical models
Tamino has not considered pre-1978 behaviour of the system, nor has he attempted to account for any of the other variables in the system. He has asked a specific question.
Has the linear regression trend derived from the 1979-1998 data continued to the present or has the trend flattened since 1998?
If the annual values are a better fit to the blue line and its confidence limits, warming has paused and the sceptic meme "no warming since 1998" is correct.
If the fit is better to the red line and limits, this sceptic meme is wrong.