A Message from CSICOP: Global Warming is REAL!

[Stumpy]

The temperature will be that at the location of the Vostock core in Antartica, so this is local. Carbon dioxide, on the other hand, is well-mixed in the atmosphere so it will be pratically the same independently of location.

In that case the temperature should closely correlate to the atmospheric CO2 content if the global warming hypothosis is correct. Your graph suggests otherwise. For instance the temperature increases 7000 years ago whilst CO2 content decreases. Relatively sharp increases in atmospheric CO2 content at approximately 1300 and 1100 appear to occur AFTER the increase in temperature. Yet the depicted massive rise in CO2 content most recently is not matched by a corresponding sharp rise in temperature, we are lead to believe that the increase in CO2 is BEFORE an increase in temperature.

If you're thinking of the two spikes at the right hand edge of the graph, note that the high spike occurs 400 years ago, during the Little Ice Age, rather than the 1000 years you would expect if it marked the Medieval warm period.

There are no such corresponding spikes in the data supplied by Mann et al for use by the IPCC. Which of the conflicting bits of data are the Global Warming lobby basing their claims on?

Why is it junk science? Using two methods to make a measurement is perfectly acceptable, so long as the two sets of data are consistent with each other.

How do you know they are consistent in entirity? It is pure speculation.

In this case, there's an overlap between the Law Dome ice core data and Mauna Loa station data between 1958 and 1978. If you compare the two by following the links under the graph in the link I provided, you'll find that the two sets are in close agreement with each other.

So, because 0.0001% of the data correlates closely, we can extrapolate from that that the remainder of it will. I don't think so!

Your argument that carbon dioxide concentration follows temperature rise relies on the data from the ice core. If you thought that the data was dodgy, why did you use the data to make your point?

I don't know which comes first! I am merely pointing out the contradictory nature of both the evidence for and against man-made global warming. There are certainly viable alternative views, views which aren't based on apparent fraud. The 1995 IPCC report is not the only example

 

[RichardR]

Two points:

a) In the article you linked to it lists the objections to the ice core data, but then goes on to say that "Most of these objections have now been overcome, with a recent study on the Law Dome ice cores by Etheridge et al."

b) Your argument that carbon dioxide concentration follows temperature rise relies on the data from the ice core. If you thought that the data was dodgy, why did you use the data to make your point?

You noticed that too.

 

[Brian the Snail]

In that case the temperature should closely correlate to the atmospheric CO2 content if the global warming hypothosis is correct. Your graph suggests otherwise. For instance the temperature increases 7000 years ago whilst CO2 content decreases. Relatively sharp increases in atmospheric CO2 content at approximately 1300 and 1100 appear to occur AFTER the increase in temperature.

I'm not sure what you mean by sharp increases "at approximately 1300 and 1100"- there's no CO<SUB>2</SUB> data for those years. The correlation overall between CO<SUB>2</SUB> and temperature looks pretty good to me. You wouldn't expect the correlation to be perfect since there's other factors that play a role, like volcanism, changes in solar activity, and ocean currents.

Yet the depicted massive rise in CO2 content most recently is not matched by a corresponding sharp rise in temperature, we are lead to believe that the increase in CO2 is BEFORE an increase in temperature.

It might be because it's difficult to see due to the scale of the graph. There's another graph on the same site that shows this a bit more clearly.

Brian the Snail: If you're thinking of the two spikes at the right hand edge of the graph, note that the high spike occurs 400 years ago, during the Little Ice Age, rather than the 1000 years you would expect if it marked the Medieval warm period.

Stumpy: There are no such corresponding spikes in the data supplied by Mann et al for use by the IPCC. Which of the conflicting bits of data are the Global Warming lobby basing their claims on?

I don't understand the question. The ice core data shows the local temperature for the site at Antartica. The Mann data is supposed to represent the temperature averaged over the whole globe (or at least the northern hemisphere). You wouldn't expect the two to be the same. Especially if the LIA and MWP weren't global events, which was the point I was trying to make all along.

Brian the Snail: In this case, there's an overlap between the Law Dome ice core data and Mauna Loa station data between 1958 and 1978. If you compare the two by following the links under the graph in the link I provided, you'll find that the two sets are in close agreement with each other.

Stumpy: So, because 0.0001% of the data correlates closely, we can extrapolate from that that the remainder of it will. I don't think so!

It shows that the different methods, measuring the same things, give the same results. This is an important cross check that the ice core data is correct. Just like you could check that your clock is correct by comparing it to some accurate, standard clock, such as an atomic clock. If the two agree, then you can be pretty sure that your clock keeps the correct time.

Stumpy:I don't know which comes first! I am merely pointing out the contradictory nature of both the evidence for and against man-made global warming. There are certainly viable alternative views, views which aren't based on apparent fraud. The 1995 IPCC report is not the only example

Doesn't surprise me. The popular media in general is pretty bad at science reporting, on this topic in particular. That's why I generally don't get my science from the newspapers.

 

[CapelDodger]

From the Daly link that impresses Stumpy:

The resulting `Leaf emergence' graphic, which was published by the Sunday Times, is attempting to create the false impression that leaves in England are emerging earlier each year in response to global warming.

(My emphasis)
You can always depend on a little paranoia and conspiracy theory in a piece from Daly. Now the media are in on the scam, along with scientists and historians. And, of course, phenologists (possibly the earliest recruits to the conspiracy). The clear trend towards earlier leaf emergence in the IPCC graph - based on data collected by a Mrs Combes (a phenologist, I assume) in one location - is given rather less attention than the Sunday Times graph. The inaccuracy of that graph becomes the story for the Daly bunch. By drawing attention to that, with a lot of scientific-sounding obfuscation, they avoid the real subject - the clear downeard trend. One has to wonder just what axe Murdoch has to grind.

They do draw attention to the earliest emergence date being in 1989 (15 years ago), when there was a particularly warm spring, ignoring the second earliest in 1998 and the obvious trend. But then, these people aren't trying to inform, but to provide justification for other denialists and comfort for those who simply don't want greenhouse warming to be happening.

Skiing resorts that have been complaining about short (or non-existent) skiing seasons are in it too, of apparently. Trying to reduce their local taxes, I'll be bound. I've spent too much time kicking Daly's crap around; it was fun at first, but I prefer a challenge. Does anybody have the latest arguments on the MWP? And is there even a tentative explanation for the permafrost not melting then, as it is now?

I really should start keeping a record of when my first strawberries ripen, and my last. One thing's for sure: the season has lengthened over the last 15 years.

 

[Stumpy]

From the Daly link that impresses Stumpy:
(My emphasis)
You can always depend on a little paranoia and conspiracy theory in a piece from Daly. Now the media are in on the scam, along with scientists and historians.

Of course, the popular media has an excellent reputation for accurately reporting science.

And, of course, phenologists (possibly the earliest recruits to the conspiracy). The clear trend towards earlier leaf emergence in the IPCC graph - based on data collected by a Mrs Combes (a phenologist, I assume) in one location - is given rather less attention than the Sunday Times graph

Probably because even they recognized it as a shining example of the extreme value fallacy

The inaccuracy of that graph becomes the story for the Daly bunch. By drawing attention to that, with a lot of scientific-sounding obfuscation, they avoid the real subject - the clear downeard trend.

Clear, only if you don't appreciate extreme value theory.

these people aren't trying to inform, but to provide justification for other denialists and comfort for those who simply don't want greenhouse warming to be happening.

Ummmm....greenhouse warming IS occuring, thank goodness, this natural process is essential to life on the planet.

I've spent too much time kicking Daly's crap around; it was fun at first, but I prefer a challenge.

Unable to offer a rebuttal to his 12 proofs of MWP being a global event you are reduced to merely kicking his crap around? IF you want a challenge, try explaining why the IPCC feel the need to resort to fraud.

Does anybody have the latest arguments on the MWP? And is there even a tentative explanation for the permafrost not melting then, as it is now?

Are you absolutely certain that it is melting or is this another speculative prediction from the IPCCs "fat chance" canon? How have they established that it is melting? Were the same techniques used during the MWP to show that the permafrost wasn't melting? Did the permafrost melt during the MWP then re-freeze during LIA?

really should start keeping a record of when my first strawberries ripen, and my last. One thing's for sure: the season has lengthened over the last 15 years.

Data based on the extreme value fallacy will fit snugly in to the dodgy evidence provided by the IPCC to date, so fill yer boots.

Typically all contrary evidence is ignored. Your case that Global Warming is occurring is based, presumably, on land based weather stations. You know full well that they are subject to the Urban Warming bias, particularly those many ones situated near urban areas or airports. Furthermore non-western stations are poorly maintained and cannot be relied on. There is simply insufficient numbers of land based stations to effectively measure GLOBAL temperature. The only effective way to measure a non-linear global thermal system with a land based system is to place vast numbers of properly calibrated and maintained sensors globally and at regular spacing. There is an alternative to this, that is to use a satellite system that continuously monitors the planet. This has already been done, the results , which closely match readings from ballons, do not show a warming trend, if anything they show slight cooling.

 

[CapelDodger]

from Stumpy:

Of course, the popular media has an excellent reputation for accurately reporting science.

The "paranoia and conspiracy" I refer to is exemplified by "attempting to create the false impression". Not an accusation of bad journalism but of an intent to deceive. To what end? The promotion of the greenhouse warming "scam", I'm guessing. Journalism was, of course, the source of the "scientists predicted ice-age" so often cited by denialists. I agree that it's not a trustworthy source.

Probably because even they recognized it as a shining example of the extreme value fallacy

Cute. Because that is exactly what the Daly bunch are doing with their "1989 was the earliest date" argument. Didn't you notice that? And you keep on about it throughout your post. What I referred to is the clear trend, not any extreme value. That is the subject which the Daly bunch ignore while pushing their "look at 1989" extreme value fallacy.

Clear, only if you don't appreciate extreme value theory.

Look at the graph and tell me it isn't trending downwards. I notice the "fallacy" has become a "theory"; is there an "extreme value theory"? Is it succinct enough to post?

Ummmm....greenhouse warming IS occuring, thank goodness, this natural process is essential to life on the planet.

A pointless piece of sophistry, since we all know what the subject is.

Unable to offer a rebuttal to his 12 proofs of MWP being a global event you are reduced to merely kicking his crap around? IF you want a challenge, try explaining why the IPCC feel the need to resort to fraud.

I did that with a fart called Diamond/Titanpoint and I'm not doing it again for you. Perhaps I'll give you a flavour of it at some point.

Are you absolutely certain that it is melting or is this another speculative prediction from the IPCCs "fat chance" canon? How have they established that it is melting? Were the same techniques used during the MWP to show that the permafrost wasn't melting? Did the permafrost melt during the MWP then re-freeze during LIA?

Alaskan towns are sinking into it. There's a report in Science 11th June (vol 304 no 5677, focus on Soils, very interesting issue) on the rate of permafrost melting and effects it's having on vegetation, the tree-line (latitudinal and vertical) and soil emissions. Data is collected by satellite and on-the-ground observation, and the two have been found to match very well. The fact that the permafrost has been frozen for 11,000 years was established decades ago by carbon-dating. Had there been a period of melting it would have shown up as a gap in the time-sequence; there is none. The techniques that scientists used to establish this are exactly the kinds of techniques that Daly extols when he selects them to present as evidence.

You know full well that they are subject to the Urban Warming bias

You know about the Urban Warming bias, so why do you think the people involved in collecting the data don't? After all, they spend more time on this kind of subject than you do. They establish protocols and attempt to eliminate biases. You're not cleverer than them. The Urban Warming bias is a smokescreen. Global Warming is occurring. Just how old is your data? You're not actually relying on the Daly bunch, are you?

Most clued-up denialists have given up on the "it's not happening" line because it's untenable. People will insist on looking out of their windows and noticing that something's happening, however hard they're told that it's not. Perhaps not so much in the US, where so much time is spent in controlled environments, but even there eventually. The favoured lines now are "It's not anthropogenic" and "It's a good thing really". Occassionally "It's too late now anyway".

 

[CapelDodger]

Musings on Greenhouse Denialists:

Those who don't want to change their lifestyles, and want to be told they don't have to so they don't feel guilty about it.

Those who have a vested interest in the status quo. They provide a lot of popcorn for the first type, finance and promotion for the next type.

Scientists who have taken a contrary position and refuse to change it despite the evidence. Many of these are simply obdurate - it has been said that new theories don't make converts, it's just that the old school dies out. Others, consciously or not, crave the limelight. and they get it courtesy of the other types.

Disciples of the above. Often indistinguishable from the next type.

The cultists. These are true believers. Usually coming to the subject with little or no knowledge and even less critical thinking, they absorb the word. Now they are holders of special knowledge and special intellect, for they can see the truth. All around are dupes, fools, blind to the word of, say, the Daly bunch. These don't just believe (like the first type), they are driven to spread the word, to demonstrate their superior knowledge and access to the true secrets. To proselytise. As the counter-arguments and evidence come in they are often driven to conspiracy theories as a way of fending them off - basically, climatologists are doing it for the money and environmentalists are doing it because they're anti-capitalist. Hating the US often comes into it as well. At least Stumpy hasn't gone that far. Accusing the IPCC of deliberate fraud isn't necessarily an accusation of conspiracy, is it? There are multiple members, I suppose, and statisticians and document shredders and general apparatchiks, but does that make it a conspiracy? I'm no lawyer, so I'll give him the benefit of the doubt. I'll call it a gross calumny and slander.

 

[CapelDodger]

I forgot the idealogues. Their realities preclude externalities such as greenhouse warming, so they cannot be real.

 

[Cain]

Musings on Greenhouse Denialists:

Those who don't want to change their lifestyles, and want to be told they don't have to so they don't feel guilty about it.

"The American lifestyle is not up for negotiation." -- Bush Sr., 1992 Earth Summit in Rio de Janeiro

The first section of Peter Singer's book _One World_ deals with global warming (source of the above quotation). It's quite good.

 

[Mr Manifesto]

"The American lifestyle is not up for negotiation." -- Bush Sr., 1992 Earth Summit in Rio de Janeiro

The first section of Peter Singer's book _One World_ deals with global warming (source of the above quotation). It's quite good.

I don't know if he mentioned it in that book, but in "President of Good and Evil" he makes a good point that if global warming does exist (and there's fairly compelling evidence that it does), we need to act now to combat the adverse effects of it. If it doesn't exist, we really aren't that worse off by reducing our carbon emissions, and we can always put them back up later.

The way I see it, it's like buying a door for your house, but you forgot to measure the doorway before buying it. If you buy a door that's too large, you can always trim a bit off it to fit. If you buy one that's too small because it's more economical (I know, I know, but this is an analogy), you can't make it fit.

 

[Brian the Snail]

Originally posted by Stumpy

Typically all contrary evidence is ignored. Your case that Global Warming is occurring is based, presumably, on land based weather stations. You know full well that they are subject to the Urban Warming bias, particularly those many ones situated near urban areas or airports.

The surface temperature record is adjusted for urban heat island, among other things. See this paper for an overview.

Furthermore non-western stations are poorly maintained and cannot be relied on. There is simply insufficient numbers of land based stations to effectively measure GLOBAL temperature. The only effective way to measure a non-linear global thermal system with a land based system is to place vast numbers of properly calibrated and maintained sensors globally and at regular spacing.

Do you have references to the peer-reviewed literature to support these assertions?

There is an alternative to this, that is to use a satellite system that continuously monitors the planet. This has already been done, the results , which closely match readings from ballons, do not show a warming trend, if anything they show slight cooling.

Yes it does show warming. The data in the second graph is the same as in the link you presented earlier, which shows a warming trend of 0.083 degrees/decade. This can be seen by clicking on the graph.

As for the first graph, that does show strong cooling, but in the stratosphere. This is what you would expect for an enhanced greenhouse effect, since the increased concentrations of CO<SUB>2</SUB> near to the surface absorb the IR radiation before it can reach high altitudes. Part of the decrease is also due to ozone depletion. See this page. And by the way, this stratospheric cooling is evidence that the present warming isn't due to increased solar radiation, since if this was the case then one would expect both the stratosphere and troposphere to be warming.

 

[Stumpy]

Cute. Because that is exactly what the Daly bunch are doing with their "1989 was the earliest date" argument. Didn't you notice that? And you keep on about it throughout your post. What I referred to is the clear trend, not any extreme value. That is the subject which the Daly bunch ignore while pushing their "look at 1989" extreme value fallacy.

No, it's not what Daly is saying. It's what I'm saying, the leaf study is based on the extreme value fallacy.

Look at the graph and tell me it isn't trending downwards. I notice the "fallacy" has become a "theory"; is there an "extreme value theory"? Is it succinct enough to post?

In essence, where you have random variables then rank them, those at the extreme ends (top and bottom or first and last) have their own rules for distribution. That is the theory, the fallacy comes when you take those extreme values and treat them the same as the other variables. EVT is used widely in the Insurance industry in assessing risk, also financial institutions use it in predicting equity risks.

A pointless piece of sophistry, since we all know what the subject is.

Not so, it's axiomatic that the popular media confuses and interchanges "Greenhouse gasses" and "CO2 emissions". Greenhouse Gasses are still portrayed as an evil effect caused entirely by human activity.

I did that with a fart called Diamond/Titanpoint and I'm not doing it again for you. Perhaps I'll give you a flavour of it at some point.

That's why I'm posting here! To try and get more info. Go Ahead.

Alaskan towns are sinking into it.

So, from a small sample you are extrapolating a GLOBAL effect? Hang on! When we had the MWP, the GW lobby tell us that it was just local and cannot be extrpolated to a global event (despite the other proofs that Daly puts forward). Now we have some local effect and the GW lobby tell us that we can extrapolate that to a global event. Confused.

You know about the Urban Warming bias, so why do you think the people involved in collecting the data don't? After all, they spend more time on this kind of subject than you do. They establish protocols and attempt to eliminate biases. You're not cleverer than them.

.

Maybe they do know about Urban Warming bias, if so it raises interesting questions about why they continue to use flawed data. What attempts to eliminate this bias is being made, surely the best one is to use Satellite data?

The Urban Warming bias is a smokescreen.

No, Urban Warming is a reality, well documented and well proven, apart from being obvious.

Global Warming is occurring.

IF if is, the GW warming lobby are light years away from proving that it is due to human activity.

Just how old is your data? You're not actually relying on the Daly bunch, are you?

Nope, the satellite data is from a crackpot organisation of psuedo-scientists called NASA, and is bang up to date. Must be faulty data though, it doens't support the man-made GW hypothosis so must be discounted.

Most clued-up denialists have given up on the "it's not happening" line because it's untenable.

Only those that ignore the most relaible data i.e. the satellite data.

People will insist on looking out of their windows and noticing that something's happening, however hard they're told that it's not.

So, observing changes in the weather is an activity that never occurred prior to the GW hypothosis? When people observed changes in weather patterns, which they undoubtedly did, I seem to recall that they often resorted to magical thinking, normally some sort of deity or suchlike being responsible. The more things change, the more they stay the same eh?

 

[Stumpy]

Yes it does show warming. The data in the second graph is the same as in the link you presented earlier, which shows a warming trend of 0.083 degrees/decade. This can be seen by clicking on the graph.

From the page containing both graphs:

Surface thermometer measurements indicate that the temperature of the Earth is warming, while the satellite data show long-term cooling trends.

 

[Brian the Snail]

Brian the Snail: Yes it does show warming. The data in the second graph is the same as in the link you presented earlier, which shows a warming trend of 0.083 degrees/decade. This can be seen by clicking on the graph.

Stumpy: From the page containing both graphs:

"Surface thermometer measurements indicate that the temperature of the Earth is warming, while the satellite data show long-term cooling trends."

Yes, but when was that written? The satellite data for the troposphere used to show a cooling trend, but with some corrections and more data it now shows a warming trend. As I said, if you click on the graph you'll see the data set, and at the bottom of the page there's this line:

DECADAL TREND= 0.083 0.154 0.013

The first number is the global trend, which is a warming of 0.083 degrees per decade.

And also as I said, the stratospheric temperature (as opposed to the tropospheric temperature, which shows warming) does show a cooling trend, but this is consistent with GHG forcing.

Edited to add: And actually, in a previous post you cited this figure, saying:

Having now seen Mann's graph comprehensively rebutted, we can find some accurate figures for warming over the past two decades here.

This is far more reliable satellite data, as it covers the oceans and therefore eliminates bias due to the urban warming effect of land based temperature stations. We can see that the temperature increase over two decades is 12 times more in the Northern Hemisphere than the northern one (so much for it being a GLOBAL effect). Nevertheless the global change is a truly terrifying 0.083 degrees C.

 

[a_unique_person]

Musings on Greenhouse Denialists:

Those who don't want to change their lifestyles, and want to be told they don't have to so they don't feel guilty about it.

Those who have a vested interest in the status quo. They provide a lot of popcorn for the first type, finance and promotion for the next type.

Scientists who have taken a contrary position and refuse to change it despite the evidence. Many of these are simply obdurate - it has been said that new theories don't make converts, it's just that the old school dies out. Others, consciously or not, crave the limelight. and they get it courtesy of the other types.

Disciples of the above. Often indistinguishable from the next type.

The cultists. These are true believers. Usually coming to the subject with little or no knowledge and even less critical thinking, they absorb the word. Now they are holders of special knowledge and special intellect, for they can see the truth. All around are dupes, fools, blind to the word of, say, the Daly bunch. These don't just believe (like the first type), they are driven to spread the word, to demonstrate their superior knowledge and access to the true secrets. To proselytise. As the counter-arguments and evidence come in they are often driven to conspiracy theories as a way of fending them off - basically, climatologists are doing it for the money and environmentalists are doing it because they're anti-capitalist. Hating the US often comes into it as well. At least Stumpy hasn't gone that far. Accusing the IPCC of deliberate fraud isn't necessarily an accusation of conspiracy, is it? There are multiple members, I suppose, and statisticians and document shredders and general apparatchiks, but does that make it a conspiracy? I'm no lawyer, so I'll give him the benefit of the doubt. I'll call it a gross calumny and slander.

Just about sums it up.

 

[CapelDodger]

from Stumpy:

Not so, it's axiomatic that the popular media confuses and interchanges "Greenhouse gasses" and "CO2 emissions". Greenhouse Gasses are still portrayed as an evil effect caused entirely by human activity.

We are not the popular media, our audience is not uninformed and nobody could have failed to understand what this thread is about. More pointless sophistry, or the product of an untidy mind.

So, from a small sample you are extrapolating a GLOBAL effect?

I was merely pointing out one example that is not in a remote region. The same thing is happening in Canada, Sweden and Russia. As I pointed out, satellites have been used to track the effect, which is clearly visible due the changes in vegetation. On-the-ground surveys have confirmed the accuracy of the satellite data. All around the Arctic Ocean permafrost is melting, having been frozen for 11,000 years. It's not an esoteric subject

Maybe they do know about Urban Warming bias, if so it raises interesting questions about why they continue to use flawed data. What attempts to eliminate this bias is being made, surely the best one is to use Satellite data?

The reason satellite data is touted as the superior method by denialists is that it is a relatively new science where the correct interpretation of data is subject to debate. This means that the denialists can pick and choose from the interpretations, and of course ignore any progress that is made. Brian the Snail has pointed you at the most recent findings. The Urban Heat Island effect has been studied for decades and adjustments can be made for it. This is why you can depend on the temperatures for the whole of the 20thCE. See Box 2.1

No, Urban Warming is a reality, well documented and well proven, apart from being obvious.

And is adjusted for. Using Urban Warming to rubbish the data - which is unwelcome to denialists - is a smokescreen, convincing to some but not to those who know the subject

IF if is, the GW warming lobby are light years away from proving that it is due to human activity.

You will never regard anything as proving anthropogenic warming (I hope that term is specific enough for you). I don't normally make such unequivocal statements, but in this case I'm going to stick my neck out. You are, let's face it, a Cultist. It is, of course, axiomatic in science that nothing is ever proved except in logic and mathematics. However, when a theory makes predictions and the observed data support the predictions a theory is regarded as "sound". Not speaking as a scientist, I'm assured that greenhouse warming is occurring. Nor has anybody come up with a theory that predicts no warming when the CO2 component of the atmosphere is increased by 30%.

When people observed changes in weather patterns, which they undoubtedly did, I seem to recall that they often resorted to magical thinking, normally some sort of deity or suchlike being responsible.

Now we have people who think the climate "just" cooled down and now is "just" warming up again and it "just" changes. They don't even look to magic as a cause, things just, like, you know, happen? What is the species coming to?

 

[CapelDodger]

from Stumpy:

No, it's not what Daly is saying. It's what I'm saying, the leaf study is based on the extreme value fallacy.

Please elucidate. How does the "extreme value fallacy" apply to the clear downward trend in the graph? From your link defining the fallacy:

If you take a number of samples of a random variable and put them in order of magnitude, the extreme values are the largest and smallest. These extreme values exhibit special distributions of their own, which depend on the distribution of the original variate and the number of ranked samples from which they were drawn. The fallacy occurs when the extremes are treated as though they were single samples from the original distribution.

The graph is a graph of single samples. Each year, one date.

The expectation (or mean) for the largest value actually increases (logarithmically) with the number of samples from which it was drawn.

The number of samples being 1 in all cases on this graph. Which has a clear downward trend.

 

[Stumpy]

from Stumpy:

Please elucidate. How does the "extreme value fallacy" apply to the clear downward trend in the graph? From your link defining the fallacy:

The downward trend is a result of an error in the statistical analysis. The "trend" is based on taking variables at the extreme end of the sample, in this case the first leaves to appear. By treating them as if they are representative of the entire leafing process you are committing an error.

The graph is a graph of single samples. Each year, one date.

The variables chosen are not representative of the leafing process. They are extremes that must be treated differently. Even choosing a much more representative process I'm not sure what it achieves. You could annually observe the entire leafing process and identify the day for the optimum leafing, i.e the day that proDuces the most leaves and compare them annually. However, there are still too many variables to draw any firm conclusions, does tree growth naturally mean that leafing occurs earlier as it becomes stronger and hardier? What effect do weather patterns (as opposed to climate) have on leafing? Does a period of relatively cool but wet weather lead to early leafing? Does a period of relatively warm but dry weather lead to early leafing? Does sun-spot activity lead to early leafing? Who knows???? The only definitive thing you can say about the process that you have highlighted is that that partiular process is deeply flawed.

The number of samples being 1 in all cases on this graph. Which has a clear downward trend.

A downward trend from a flawed process looking at an unrepresentative sample!

 

[Stumpy]

Yes, but when was that written? The satellite data for the troposphere used to show a cooling trend, but with some corrections and more data it now shows a warming trend. As I said, if you click on the graph you'll see the data set, and at the bottom of the page there's this line:

DECADAL TREND= 0.083 0.154 0.013

The first number is the global trend, which is a warming of 0.083 degrees per decade.

The spikes of increased temperature correlate with El Nino activity, as the page explains. If human CO2 emissions are increasing and increased CO2 emissions lead to warming then those satellite readings should show an increase of global temperature consistant with the increase in CO2 content. They don't.

 

[Brian the Snail]

Brian the Snail: Yes, but when was that written? The satellite data for the troposphere used to show a cooling trend, but with some corrections and more data it now shows a warming trend. As I said, if you click on the graph you'll see the data set, and at the bottom of the page there's this line:

DECADAL TREND= 0.083 0.154 0.013

The first number is the global trend, which is a warming of 0.083 degrees per decade.

Stumpy: The spikes of increased temperature correlate with El Nino activity, as the page explains.

So? We're talking about the trend, not about the spikes.

Stumpy: If human CO2 emissions are increasing and increased CO2 emissions lead to warming then those satellite readings should show an increase of global temperature consistant with the increase in CO2 content. They don't.

How do you know? All we've looked at so far is the corrections to the data by Spencer and Christy. As I mentioned before, other groups find a larger trend closer to that of the surface data. For example, Mears et al find a trend of +0.131 degrees/decade. The main difference arises because the temperatures weren't measured by a single satellite, but by a number of satellites, all calibrated differently. To combine the temperature measurements into one series requires some corrections to be applied, and different methods of doing this give different results. There's still a debate about which one gives the correct answer (if any).

Plus, as I mentioned earlier, you're looking at a relatively short series of about 25 years. If you look at the actual data, there's a lot of peaks and troughs (larger than for the surface data) so if you fit a straight line to get a trend, you'll get different results depending on where you start and end your fit.

This graph from the Hadley Centre is interesting I think. It shows the surface temperature (black), balloon radiosonde (red) and Spencer and Christy's version of the satellite data (blue) on top of each other:

Looking at the top graph, notice how all three track each other quite well, with the main difference that the satellite and balloon data (which look at the troposphere rather than the surface) have larger fluctuations around the trend. This is even true for the surface and balloon data before 1979. Now look at where the satellite data starts. See anything interesting? Now do you see why calculating a trend over such short times might not give the same answer as the surface data?