Take a look at Figure 1.4 from the AR5 draft (shown below). The gray bars in Fig 1.4 are irrelevant (because they flubbed the definition of them), the colored bands are the ones that matter because they provide bounds for all current and previous IPCC model forecasts, FAR, SAR, TAR, AR4.
Look for the surprise in the graph.
Here is the caption for this figure from the AR5 draft:
Estimated changes in the observed globally and annually averaged surface temperature (in °C) since 1990 compared with the range of projections from the previous IPCC assessments. Values are aligned to match the average observed value at 1990. Observed global annual temperature change, relative to 1961–1990, is shown as black squares (NASA (updated from Hansen et al., 2010; data available at http://data.giss.nasa.gov/gistemp/); NOAA (updated from Smith et al., 2008; data available at http://www.ncdc.noaa.gov/cmb-faq/anomalies.html#grid); and the UK Hadley Centre (Morice et al., 2012; data available at http://www.metoffice.gov.uk/hadobs/hadcrut4/) reanalyses). Whiskers indicate the 90% uncertainty range of the Morice et al. (2012) dataset from measurement and sampling, bias and coverage (see Appendix for methods). The coloured shading shows the projected range of global annual mean near surface temperature change from 1990 to 2015 for models used in FAR (Scenario D and business-as-usual), SAR (IS92c/1.5 and IS92e/4.5), TAR (full range of TAR Figure 9.13(b) based on the GFDL_R15_a and DOE PCM parameter settings), and AR4 (A1B and A1T). The 90% uncertainty estimate due to observational uncertainty and internal variability based on the HadCRUT4 temperature data for 1951-1980 is depicted by the grey shading. Moreover, the publication years of the assessment reports and the scenario design are shown.
So let’s see how readers see this figure – remember ignore the gray bands as they aren’t part of the model scenarios.
I’ll have a follow up with the results later, plus an essay on what else was found in the IPCC AR5 draft report related to this.
I used to look forward to finding a Mosher comment with eager anticipation of learning something. Since he became equipment manager-mascot for Muller’s BEST team, it seems he just wants to kick sand in the faces of his old homies. What has happened to that boy? On one thread he is bashing Willis and on another Anthony. Will he turn on Lucia and Steve Mc. next? Stay tuned.
I think a more important question, is how do they find these so called scientists that,ignore all other scientific disciplines, only to take an obvious complex system like the earths climate, and narrow it down to the least likely smallest least influential component (co2), take a few decades of temperature readings and claim the sky is falling. The geologic record is clear,its readable, and precise. It show no influence by co2 on temperature increases, quite the contrary 286 – 360 million years ago Average global temperatures in the Early Carboniferous Period were hot- approximately 20° C (68° F). However, cooling during the Middle Carboniferous reduced average global temperatures to about 12° C (54° F),.this is comparable to the average global temperature on Earth today! Similarly, atmospheric concentrations of carbon dioxide (CO2) in the Early Carboniferous Period were approximately 1500 ppm (parts per million), but by the Middle Carboniferous had declined to about 350 ppm — comparable to average CO2 concentrations today! Earth’s atmosphere today contains about 380 ppm CO2 (0.038%). Compared to former geologic times, our present atmosphere, like the Late Carboniferous atmosphere, is CO2- impoverished! In the last 600 million years of Earth’s history only the Carboniferous Period and our present age, the Quaternary Period, have witnessed CO2 levels less than 400 ppm, To the consternation of global warming proponents, the Late Ordovician Period was also an Ice Age while at the same time CO2 concentrations then were nearly 12 times higher than today– 4400 ppm, This is a completely opposite effect and shows co2 decreasing as the period warmed. Ice core samples, also indicate co2 follows heat increase not precedes it. Every physical science professional knows the difference in trying to cherry pick minimal time frames to geologic time, and how important it is to truly see cause and effect,. Although cycles of glaciation are believed to occur in response to solar input variations like the Milankovich Cycle and Precession of the Equinoxes (changes in the earths orbit due to preccession , another important factor is the rearrangement of continental landmasses over geologic time by the processes of continental drift. So when you look at all the data, chart the ice ages and warming trends, it shows an obvious uniform pattern every 100,000 years we have an ice age, followed by 10 to 20 thousand year warming trends, every single record shows the same thing, interestingly enough Milakovitch, and his then theory mathematically proved this only later to find the ice core samples conferred. Earth’s climate is complicated and influenced by long term and shorter term events. some are major influences and some are minor. and there are so many that have a much greater impact than GHG (green house gases) Water vapor is by far the most abundant greenhouse gas, accounting for about 95 percent of Earth’s greenhouse effect, and man’s contribution to it is insignificant. Anthropogenic (man-made) CO2 contributions are responsible for only about 0.117 percent. Now if what geologists say is true, that we are always coming in and out of an ice age with only short warming intervals of 20,000 years, and its been 18,000 since the last ice age, if co2 were shown to cause heat and temperature increases we should be pumping as much as we should into the atmosphere, we will not survive another ice age.
It seems that the IPCC is becoming more and more moderate, while the alarmist blogosphere is becoming ever more radical. Look for the alarmists to dump the IPCC in the near future.
I have a couple of points that haven’t been made:
9 of the 10 warmest years on record have occurred since 2000. There may not have been a warming trend over the last 10 years but the decade is consistently warmer than those before it.
Everyone is quick to point out 2012 and 2009 is particularly cool but 1998 was particularly warm. If 1998 wasn’t there then your arguments would have less weight. Of course, 1998 is there but it was also a record El Nino year and El Nino has a warming effect on global temperature.
Chris Shuker:
Your post at December 17, 2012 at 12:20 am says in total
“Haven’t been made”? Warmunists make those silly – and meaningless – talking points at every opportunity. It is their attempt ‘to clutch at straws’ now global warming has stopped for 16 years.
Firstly, look at the above graph. Delete 1998 data and it makes no difference to the fact that there has been 16-years (and counting) of no discernible change in global temperature (at 95% confidence)
Secondly, the most recent temperatures being among the highest is meaningless. The Earth has been warming from the Little Ice Age (LIA) for centuries and since long before the industrial revolution.
A person walking up a hill is at his highest when walking across its top. Similarly, the global temperature is not rising as it was, but it is still higher than it was.
The natural rise from the LIA was not continuous: it included periods of no discernible rise. The present period of no discernible change in global temperature (at 95% confidence) will end. Then, either the global temperature will continue to rise towards the temperature of the Medieval Warm Period (MWP) or fall towards the temperature of the LIA.
But the present period of no global temperature change is important in terms of assessing the climate models. The US National Oceanic and Atmospheric Atmospheric Administration (NOAA) reported in 2008
The present 16-year (and counting) period of no discernible change in global temperature (at 95% confidence) shows the climate models are wrong.
Richard
[snip – Geoff, I’ve banned you before for your over the top remarks, and let you back in against my better judgment – this time, with this ugly comment it is permanent, beat it, zealot. – Anthony]
Richar S Courtnay wrote: “there has been 16-years (and counting) of no discernible change in global temperature (at 95% confidence)”
However, there is no discernable change in the rate of warming (at “95% confidence”) either, as the confidence interval on the observed trend includes both zero AND the long term trend. Thus on the basis of the observations alone, there is little *statistical* reason to conclude that there has been a change in the rate of warming.
Statistical hypothesis tests are not summetrical; the lack of a statistcally significant OLS trend does not mean that it is safe to conclude that the underlying trend actually is flat. The assymetry in the test is to introduce an element of self-skepticism, so if your hypothesis is that there has been warming, you start off will a null hypothesis that the trend is flat (i.e. the thing you don’t want to be true), and only procede to make a claim ON THE BASIS OF THOSE OBSERVATIONS ALONE iff the null hypothesis can be rejected. If you want to claim that there has been a pause in the warming (and that the apparent hiatus is not just an artefact of the noise), then you need to start with a null hypothesis that you don’t want to be true (e.g. that the trend is actually the same as the long term trend) and see if that null hypothesis can be rejected.
“The present 16-year (and counting) period of no discernible change in global temperature (at 95% confidence) shows the climate models are wrong”
This is not correct, because (a) the statistical test has too little statistical power for the lack of a rejection of the null hypothesis to be surprising and (b) because the climate models predict that such occasional periods of little or no warming will occurr every now and again and (c) the observations lie within the spread of the model predictions for SRES A1B and hence there is no statistically significant discrepancy between the models and the observations.
dikranmarsupial:
Your post at December 17, 2012 at 5:12 am is such a mish-mash of logical errors that it would require a book to correct it all. I will address its main errors.
You say,
I will ignore your multiple mis-spellings of my name and address the fallacious guff which I assume you are copying from some propaganda blog such as RC or SkS.
A difference to the discernible rate of change has occurred and the “long term trend” is not relevant to consideration of it. I spell this out for you as follows.
Take 16-year periods and consider the confidence with which one can assess their rate of change. The three most recent 16-year periods show no trend discernibly different from zero at 95% confidence. And the recent 16-year period shows no discernible change at 90% confidence, but the previous two 16-year periods do show a positive trend at 90% confidence.
Clearly, the global warming discernible at 90% confidence stopped 16-years ago.
Which, of course is not evidence that there has been no global warming over the last 16 years, but it IS evidence that the warming has changed in such a manner that the ability to discern it has reduced. This could be because the variabilty of the data has increased (it has not) or the rate of warming has reduced.
So, the rate of warming has reduced and there is no discernible warming at 95% confidence over the last 16 years.
And your guff about lack of statistical certainty concerning the models is plain wrong.
As the quotation I provided states, in 2008 NOAA said the models RULE OUT a period of 15 years with no discernible warming at 95% confidence. The most recent 16 years provides a period longer than 15 years with no discernible warming at 95% confidence.
That shows the models are wrong according to the modellers own criteria. Live with it.
You clearly do not understand the Null Hypothesis and you attempt Trenberth’s trick of reversing it. To avoid others being misled by your misrepresentation, I again explain the matter.
The Null Hypothesis says it must be assumed a system has not experienced a change unless there is evidence of a change.
The Null Hypothesis is a fundamental scientific principle and forms the basis of all scientific understanding, investigation and interpretation. Indeed, it is the basic principle of experimental procedure where an input to a system is altered to discern a change: if the system is not observed to respond to the alteration then it has to be assumed the system did not respond to the alteration.
In the case of climate science there is a hypothesis that increased greenhouse gases (GHGs, notably CO2) in the air will increase global temperature. There are good reasons to suppose this hypothesis may be true, but the Null Hypothesis says it must be assumed the GHG changes have no effect unless and until increased GHGs are observed to increase global temperature. That is what the scientific method decrees. It does not matter how certain some people may be that the hypothesis is right because observation of reality (i.e. empiricism) trumps all opinions.
Please note that the Null Hypothesis is a hypothesis which exists to be refuted by empirical observation. It is a rejection of the scientific method to assert that one can “choose” any subjective Null Hypothesis one likes. There is only one Null Hypothesis: i.e. it has to be assumed a system has not changed unless it is observed that the system has changed.
In the case of global climate no unprecedented climate behaviours are observed so the Null Hypothesis decrees that the climate system has not changed.
Importantly, an effect may be real but not overcome the Null Hypothesis because it is too trivial for the effect to be observable. Human activities have some effect on global temperature for several reasons. An example of an anthropogenic effect on global temperature is the urban heat island (UHI). Cities are warmer than the land around them, so cities cause some warming. But the temperature rise from cities is too small to be detected when averaged over the entire surface of the planet, although this global warming from cities can be estimated by measuring the warming of all cities and their areas.
Clearly, the Null Hypothesis decrees that UHI is not affecting global temperature although there are good reasons to think UHI has some effect. Similarly, it is very probable that AGW from GHG emissions are too trivial to have observable effects.
The feedbacks in the climate system are negative and, therefore, any effect of increased CO2 will be probably too small to discern because natural climate sensitivity is much, much larger. This concurs with the empirically determined values of low climate sensitivity.
Empirical – n.b. not model-derived – determinations indicate climate sensitivity is less than 1.0deg.C for a doubling of atmospheric CO2 equivalent. This is indicated by the studies of Idso from surface measurements
http://www.warwickhughes.com/papers/Idso_CR_1998.pdf
and Lindzen & Choi from ERBE satelite data
http://www.drroyspencer.com/Lindzen-and-Choi-GRL-2009.pdf
and Gregory from balloon radiosonde data
http://www.friendsofscience.org/assets/documents/OLR&NGF_June2011.pdf
Indeed, because climate sensitivity is less than 1 .0deg.C for a doubling of CO2 equivalent, it is physically impossible for the man-made global warming to be large enough to be detected (just as the global warming from UHI is too small to be detected). If something exists but is too small to be detected then it only has an abstract existence; it does not have a discernible existence that has effects (observation of the effects would be its detection).
To date there are no discernible effects of AGW. Hence, the Null Hypothesis decrees that AGW does not affect global climate to a discernible degree. That is the ONLY scientific conclusion possible at present.
Richard
Richard writes:
“It is a rejection of the scientific method to assert that one can “choose” any subjective Null Hypothesis one likes. There is only one Null Hypothesis: i.e. it has to be assumed a system has not changed unless it is observed that the system has changed.”
I’m afraid you have not got the story right here Richard. There is no statistical reason why a null hypothesis has to be restricted to a no-change baseline. The null hypothesis tells you the base case that you consider random samples as being drawn from. In this case we are interested in the slope coefficient of a regression of temperature anomaly on year number. Repeated drawing random samples of size 16 from an uncorrelated (zero slope) population generates a sampling distribution of slope coefficients and the position of the sample data within that distribution gives you the probability of a value exceeding the observed slope (assuming a one-tailed test). The test proceeds from there. Of course for a standard case like this the results are tabulated so no need to conduct the random number experiment yourself.
However there is no reason why a non-zero correlation (remembering the almost equivalence between the correlation and the slope coefficients) should not be postulated and set up as a null hypothesis – Fisher’s z-transformation serves for the simple case. So if one had a strong expectation based on external evidence that the slope coefficient ought to be .01K/yr, then it is possible to set this up as the null hypothesis and construct a test accordingly. A study of UHI might be a climatological contextfor performing such a test, another might be if you had a prior expectation based on solar radiation. No statistician would rule the test invalid if that’s what you did, nor any peer reviewer tell you you were breaking the rules of the scientific method. A no-change baseline is already implicitly rejected in a way if you choose to perform a one-tail test implying you have already ruled out the possibility of one of the signs of the change.
Of course there is a confusing factor here, that the “y” variable has its own correlation structure but this can in most cases and to adequate accuracy be accommodated by adjusting downward the value of n used in the test.
dikranmarsupial
scientific gobbledegook will get you nowhere on this blog. You are speaking nonsense and you are about to discover why marsupials are extinct on every continent except Australia. It has to do with their intelligence.
Sorry mpainter, I am happy to engage in a rational discussion of science (something that I find very interesting), but I am not in the least interested in an exchange of rhetoric or insults; there is too much of that sort of behaviour on climate blogs and it gets nobody anywhere.
REPLY: Oh please. Dude, we can read what you write at other blogs, so kindly, stop making a hypocritical fool of your with such faux moralistic protestations – Anthony
henry@dikranmarsupial
(earlier on in the thread)
Amazing. I wonder how long you all and the ipcc will finally pick up on the fact that they have always been looking at the wrong parameter…..
dikranmarsupial says
“because the climate models predict that such occasional periods of little or no warming will occurr every now and again (sic)”:
henry said
(earlier on the thread)
http://wattsupwiththat.com/2012/12/14/the-real-ipcc-ar5-draft-bombshell-plus-a-poll/#comment-1174204
your name must be
dik..ranmarsupial
not being able to read graphs
Henry says
please do continue to ignore the obvious
we will be cooling,
and all the old arctic ice will be back in 2 decades
mark my words.
\
http://wattsupwiththat.com/2012/12/14/the-real-ipcc-ar5-draft-bombshell-plus-a-poll/#comment-1174568
[snip – Geoff, I’ve banned you before for your over the top remarks, and let you back in against my better judgment – this time, with this ugly comment it is permanent, beat it, zealot. – Anthony]
A bridge too far Anthony….expect a backlash.
REPLY: Oh, nice….threats. How mature. All because you and your friends insist on calling a long term solar minimum that hasn’t been called yet and name that hasn’t been approved by the solar science community. I don’t call it “the Eddy Minimum” in day to day comments because it is premature. You however call it the “Landschiedt minimum” at every opportunity you get to the the point of being annoying. I point out when you and your friends call it the “Landscheidt minimum” is wrong when:
A. It hasn’t happened for certain yet, (one solar cycle does not a grand minimum make).
B. It hasn’t been officially named yet.
C. The solar science community has taken up the idea to name it for Jack Eddy, discoverer of the Maunder Minimum.
Do you listen to yourselves? This is zealotry. – Anthony
dikranmarsupial
Come, come, you are too obvious. You will find no marsupials on this blog to swallow the obsfuscations which you try to pass off as science. You do not seem as a sincere type who wishes to engage the issues, and your pretenses fool no one here. Go back to Skeptical Science. That’s where you feel comfortable and it’s where you belong.
This scientist who is used to interpreting such graphs sees 19 data points and experimental error bars within the model bands and three outside the bands. There are no error bars given for 2012 but unless they are unusually small 2012 will fall inside the bands. Climate models do not forecast unpredictable (and short term) effects such as volcanic eruptions and el nino /la nina events. Points below the band are 1996, and 2000, each corresponding to la nina years, as are 1999 and 2008 which are just inside the band. The point above the band is the 1998 el nino year.
Chris Shuker says:
December 17, 2012 at 12:20 am
I have a couple of points that haven’t been made:
9 of the 10 warmest years on record have occurred since 2000. There may not have been a warming trend over the last 10 years but the decade is consistently warmer than those before it….
________________________________
Only if you use ‘Adjusted’ data.
The length of the arctic Melt season link
The fall (October) Northern Hemisphere snow cover link
For the USA
The 1990 -2000 decade is close to the average for the 20th C but the 1970’s are way colder link 1 and link 2
The number of daily US temperature readings over 40C, recorded at all 595 HCN stations continuously active since 1900 shows the above climate boundry graph is not ‘off’ link
So does the US Heat Wave Index link
All the ‘corrections’ to the actual temperature data are UP for recent data and DOWN for past data. link 1 and link 2 and link 3
Philip Shehan says
Climate models do not forecast unpredictable (and short term) effects such as volcanic eruptions and el nino /la nina events. Points below the band are 1996, and 2000, each corresponding to la nina years, as are 1999 and 2008 which are just inside the band. The point above the band is the 1998 el nino
Henry @Philip
Philip, if you look carefully at that graph you will be able to see a parabolic curve developing from 1992 up until 1998. After reaching the top in 1998 it has started to curve down.
All major data sets see a cooling trend developing from 2002.
see here:
http://www.woodfortrees.org/plot/hadcrut4gl/from:2002/to:2012/plot/hadcrut4gl/from:2002/to:2012/trend/plot/hadcrut3vgl/from:2002/to:2012/plot/hadcrut3vgl/from:2002/to:2012/trend/plot/rss/from:2002/to:2012/plot/rss/from:2002/to:2012/trend/plot/gistemp/from:2002/to:2012/plot/gistemp/from:2002/to:2012/trend/plot/hadsst2gl/from:2002/to:2012/plot/hadsst2gl/from:2002/to:2012/trend
My own data set also showed these parabolic curves, all three, for maxima, means and minima,
with very high correlation coefficients, (but also very high current cooling rates)
therefore, in the end I settled for an a-c curve
http://blogs.24.com/henryp/2012/10/02/best-sine-wave-fit-for-the-drop-in-global-maximum-temperatures/
So everything that you see happening is natural and predictable. We will continue to cool at the highest rate for the next 8 years and temperatures will continue to fall until ca. 2038.
Sorry pal.
Shame they didn’t show the whole period back to WWII, because then it would be clear that for the last 25% of the time when CO2 has been pumped into the atmosphere in significant quantities the tempereature has not been rising, despite the fact that this last 25% of the period is when 30% of all the CO2 increase occurred.
With a failure to correlate of that magnitude most scientists would have the good grace to admit that their theory was fatally flawed.
Since when has the Null Hypothesis had anything to do with the IPCC?
That humans are mucking up the climate is taken as the given and the IPCC goes on from that ‘Law” There is no room for any testing of a Null Hypothesis because human induced climate change is reality to them and therefore there is no reason for a Null Hypothesis. This has been the ongoing fight from day one.
This is why the citing of the IPCC as an ‘Authority’ would be a ROTFLMAO laugh if they did not have so much power and the consequences were not so devastating for mankind. The Sheeple believe we have spent billions studying the climate and investigating the various factors that could drive the climate when no such action has occurred.
Only the money and the number of people in positions of power that are involved has kept CAGW from becoming a bigger scandal than Bernie Maddoff or Enron.
richardscourtney, firstly I apologise for having mispelled your name.
Your write “The three most recent 16-year periods show no trend discernibly different from zero at 95% confidence.” I agree, however, my point is that those same trends are not discernablly different from the long term trend either at the 95% level of significance. Thus the statistical analysis is equivocal, it doesn’t rule out the possibility that the trend is really flat, but it doesn’t rule out the possibility that there has been no change in the underlying rate of warming either. Thus, if the only evidence for a hiatus were the observed trend, it would go against normal scientific practice to claim the existence of a hiatus without statistically significant evidence.
“The Null Hypothesis says it must be assumed a system has not experienced a change unless there is evidence of a change. ”
Well quite, if we apply that to the *rate* at which the system has been warming, then the null hypothesis should be that the *rate* has not changed. The choice of null hypothesis depends on the claim you wish to test in performing a significance test. It should essentially be the opposite of what you wish to claim.
The null hypothesis should be the hypothesis that goes against our experimental hypothesis; if you want to assert that there has been a hiatus (i.e. the rate of warming has declined) then the null hypothesis should be that the rate of warming is unchanged. That is how statistical tests are used in science, to enforce self-skepticism, only allowing a claim to be made if you can demonstrate that the alternative is not supportable (i.e. the null hypothesis can be rejected).
Essentially, the observations are quite noisy, and a 16 year window is not long enough to be able to distinguish with any great confidence whether there has been no warming (or even some cooling), or whether the warming has contunued at the same rate, or (less likely) even above the long term rate. This is clearly demonstrated by the confidence interval on the estimated trend.
maxberan:
Thankyou for your post at December 17, 2012 at 8:30 am. It begins
Sorry, but I have “got the story right”.
The misunderstanding is explicit in your statement that says
Indeed, there is such a “reason”: otherwise, there could not be a Null Hypothesis.
The “no change” applies to the system behaviour.
And all of your examples agree with my expression of the Null Hypothesis.
Some systems behave randomly. The appearance of, for example, a cyclical behaviour within the randomness would be a change.
Other systems exhibit cyclical behaviour, and loss of that cyclicity would be a change.
Gain or loss of correlation between parameters of a system is a change.
Indeed, you describe such a case when you say
Etc.
All your examples demonstrate the difficulty of statistical determination of a change in some systems. They do not dispute my statement of the Null Hypothesis in any way.
Richard
Say you wanted to see if your town followed some rule that you had read based on a large scale study of the link between UHI-induced slope (of temperature v time) and population. Based on the study you had a baseline expectation for what the slope ought to be if it followed the rule – say it was .001K/yr – and you had a 50 year time-series temperature data for your town from which you could calculate its slope, say it was .002K/yr.
The null hypothesis in that case would be the .001K/yr prior expectation and this would form the basis for the test. You would construct the sampling distribution of slopes obtained by random drawings of size 50 from a population whose slope was 0.001 and from the probability beyond the .002 point judge whether it was in accord with the rule or not. No statistical regulation disobeyed, no scientific method principle breached, a fully kosher procedure.
And the null hypothesis was not a no-change case, it postulated a change or a non-zero slope (or equivalently, correlation coefficient). This was precisely what you said was disallowed with your point about “no subjectivity” and “no change” and, because it is allowed, why I said you had got it wrong.
Did you look up Fisher’s z- transformation – it is about testing whether an observed correlation coefficient could derive from a population of arbitrary (not necessarily zero) correlation so bang on what you said couldn’t be done? It’s especially relevant as the slope coefficient of a regression is a simple linear multiple of the correlation coefficient so what goes for the one goes for the other.
The above example is a lot simpler than the current case where we are testing whether the models could derive from a population based on the observations. Also we have additional information about the uncertainty in the observations which we would also wish to build in. We also have a distribution of models so the test would be looking at the overlap between the distribution of the models and the null-hypothesis distribution based on the observations. But the basic principle remains and the simple truth applies – a null hypothesis is not limited to a null change case.
Philip Shehan
Let me put it to you like this: Do you agree that there the record shows no warming these past sixteen years?
Perhaps you would explain for us why the data points require experimental error bars. What experiment? These appear as a device to fuzz over the fact that the models are refuted by observations, and thus give an opening for someone to say:
“This scientist who is used to interpreting such graphs sees 19 data points and experimental error bars within the model bands and three outside the bands. There are no error bars given for 2012 but unless they are unusually small 2012 will fall inside the bands. Climate models do not forecast unpredictable (and short term) effects such as volcanic eruptions and el nino /la nina events. Points below the band are 1996, and 2000, each corresponding to la nina years, as are 1999 and 2008 which are just inside the band. The point above the band is the 1998 el nino year.”
Now, please point out the model that has forecast sixteen years without warming. Also, please tell us what you think of all the panic talk about future climate disaster, “tipping points”, and suchlike propaganda which is based on the extreme warming forecast by these models, and whether such models show any reliability.
Also, please tell us what CO2 mitigation steps should now be undertaken, and whether the vast expenses involved in these models were justified, and whether a carbon tax is justified.
Thanking you in advance for your contribution here.
dikranmarsupial:
I am replying to your post addressed to me at December 17, 2012 at 9:16 am.
I will restrict my discussion of the Null Hypothesis to interaction with Max Beran. He has often disagreed with me over many years and I respect him, his arguments and his opinions whether or not I agree with them. Also, his great mathematical knowledge and ability are known to me.
Your post ignores the importance of the 16-year period of no global warming discernible at 95% confidence. I again repeat that the climate modellers said their emulations “rule out” periods of 15 or more years of no global warming discernible at 95% confidence. This is a falsification of the models according to the criterion specified by the modelers.
The models are wrong. Live with it.
Richard
dikranmarsupial,
I agree with most of your comment. However, the climate Null Hypothesis is not as you have explained it. The Null Hypothesis states that nothing unusual or unprecedented is now occurring. All current climate parameters have been exceeded during the Holocene, when CO2 levels were much lower.
The Alternative Hypothesis — that rising CO2 is causing an unprecedented acceleration in global warming — is wrong. Not only is there no acceleration in global warming, but as you acknowledge, the warming has stopped for the past sixteen years.
The Null Hypothesis has never been falsified. Nothing unusual or unprecedented is occurring. The planet is recovering from the LIA along the same long term rising trend line, and within the same long term parameters, with no acceleration in global warming. Conclusion: rising CO2 has no measurable effect.
richardscourtney, it is unfortunate that you are unwilling to participate with me in a discussion of this issue as it could have been very productive. I would be interested to read the NOAA report you mention, can you give me a full reference so I can look it up?
However, the point I was making has nothing to do with whether the models are correct or not, but on whether there is statistically significant evidence for a change in the rate of warming. It is easy to demonstrate that there isn’t becuase the confidence interval for the trend includes both zero and long term rate. Thus it is an error to claim that there has been a reduction in the rate of warming, just as it was an error to claim that there had been an increase in the rate of warming in say 1998. Those that want to claim there is statistically significant evidence of a reduction in the rate of warming need to wait until the confidence interval on the trend no longer includes the long term rate.
D Böehm The hypotheses discussed in my post have nothing to do with AGW, just about what we can infer about the rate of warming from the observations we have for the last 16 years, and this is entirely independent of what is causing any warming that may or may not be happening.