Does a global temperature exist? This is the question asked in a recently published article in Journal of Non-Equilibrium Thermodynamics by Christopher Essex, Ross McKitrick, and Bjarne Andresen. The paper argues that the global mean temperature is not physical, and that there may be many other ways of computing a mean which will give different trends.
The common arithmetic mean is just an estimate that provides a measure of the centre value of a batch of measurements (centre of a cloud of data points, and can be written more formally as the integral of x f(x) dx. The whole paper is irrelevant in the context of a climate change because it missed a very central point. CO2 affects all surface temperatures on Earth, and in order to improve the signal-to-noise ratio, an ordinary arithmetic mean will enhance the common signal in all the measurements and suppress the internal variations which are spatially incoherent (e.g. not caused by CO2 or other external forcings). Thus the choice may not need a physical justification, but is part of a scientific test which enables us to get a clearer ‘yes’ or ‘no’. One could choose to look at the global mean sea level instead, which does have a physical meaning because it represents an estimate for the volume of the water in the oceans, but the choice is not crucial as long as the indicator used really responds to the conditions under investigation. And the global mean temperature is indeed a function of the temperature over the whole planetary surface.
Is this paper a joke then? It is old and traditional knowledge that the temperature measurements made in meteorological and climatological studies are supposed to be representative of a certain volume of air, i.e. the arithmetic mean. Essex et al. argue that it is not really physical, but surely the temperature measurements do have clear practical implications? Temperature itself can be inferred directly from several physical laws, such as the ideal gas law, first law of thermodynamics and the Stefan-Boltzmann law, so it’s not the temperature itself which is ‘unphysical’. Even though the final temperature of two bodies in contact may not be the arithmetic mean, it will still be a weighted arithmetic mean of the temperatures of the two initial temperatures if no heat is lost to the surroundings. Besides, grid-box sizes for numerical weather models often have a minimum spatial scale of 10-20km, and the temperature may be regarded as a mean for this scale. Numerical weather models usually provide useful forecasts.
And what distinguishes the mean temperature representing a small volume to a larger one? Or do Essex et al. think the limit is at greater scales. For instance at the synoptic spatial scale (~1000 km)? The funny thing then is that the concept of regional mean temperature would also not be meaningful according to Essex et al. And one may also wonder if the problem of computing a mean temperature is meaningful in time, such as the summer-mean temperature or winter-mean temperature?
Essex et al. suggest that there are many different ways of computing the mean, and it is difficult to know which make more sense. But when they compute the geometric mean, they should not forget that the temperature should be in degrees Kelvin (the absolute temperature) as opposed to Celsius. One argument used by Essex et al. is that the temperatures are not in equilibrium. Strictly speaking, this applies to most cases. But in general, these laws still give a reasonable results because the temperatures are close to being in equilibrium in meteorology and climatology. The paper doesn’t bring any new revelations – I thought that these aspects were already well-known.
Update: Rabett Run has a very detailed set of posts pulling apart this paper more thoroughly.
Re 66: Krog, I’m not sure about the at-rest definition. As to the cold ocean question, the amount of thermal energy absorbed from the mantle (the ocean is thousands of miles way from the the core) is small compared to the mass of water. The vents, volcanoes, etc. only affect things locally. The upper ocean absorbs solar radiation, and so is warmer, while the lower ocean never sees the light of day, and so is cold. Since cold water is denser than warm water (unless the warm water is much saltier), the stratified situation is stable.
RE #91, & “It occurs to me to wonder if this “no average” nonsense is a preemptive strike against pulling Triana /DSCOVR out of the warehouse and getting it launched.”
You’d think if the denialists were so certain they’re right, they’d be pushing for its launch….so as to definitively prove that the sun is emitting more radiation, or whatever.
Ergo, the denialists are NOT at all certain they’re right. In fact, methinks, they realize they’re wrong. They sort of remind me of lawyers who staunchly argue a person is innocent when they know he’s guilty as sin.– which is the beauty of our justice system, but is totally inappropriate for science. In my eigth grade science class we learned: “A scientist is honest.”
I say, gather the evidence, and let the chips fall where they may. I’d be quite delighted if GW were proven false.
One point: the celsius/geometric-average team is not presenting any new evidence or theory of some bizarre forcing, but, it seems, simply investigating how they can manipulate the existing data to get the results they want. I wonder how many different avenues and techniques they followed until they came up with the one they used in their report. And then how long it took to come up with a justification for using it.
[[I doubt there is any easy answer or methodology to answering “Does a global temperature exist?” ]]
“Well, you’re wrong.”
No its your opinion that I am wrong and its your opinion that the methodology you stated is the right one, only one, and the correct.
I failed to see a scientific or mathematical citation stating your invoked methodology, as it relates to a global temperature and or global warming as the paper being discussed here indicates, was somehow the right one.
There is no such thing as right or wrong. Who are you, or anyone else to judge what is right or wrong?
Right or wrong is human created concept.
Computations are just methodologies, often different, employed and invoked by a person.
Not right or wrong.
And thank you for your rudeness, lack of citations of your rightness and or my wrongness, that was offered with your god like assurances of what you hold in esteem to be right.
Along with your intrusion to impinge upon my personal right to think and express what I choose.
It was well received, not unsurprising, as the behavior seems
to be rather common, as of late, upon realclimate by posters.
Good day.
Enjoy being right.
#89
Richard, I looked into it. Very educational. I learn something new from all sides every day. Thanks.
By the way, there is a little known, yet huge side to the warming equations scientific studies: What the military knows of climate change that they are not divulging, and they know plenty.
They have been studying atmosphere, oceans and icepacks globally, minute by minute with unlimited resources, since the 50’s for strategic reasons. They only let out normal information that never raises red flags or interests anyone. Be interesting to get into the real classified info that their scientists can’t talk about.
This is only vaguely related to the current topic, but I have a question. The temperature decrease from the 40s to the 70s I have heard is explained by the use of certain aerosols (don’t know details).
If this is the case, then clearly aerosols can mitigate global warming since it already has. Couldn’t we, then, just take up aerosols like we did in that period to stabilize temperatures? We’d create our own pseudo-“temperature sink” through anthropogenic global cooling. :)
I’m sure I’m not the first to have this idea by a long shot, so someone please explain to me why I’m wrong or this is a bad idea. Thanks.
[Response:They are sulphate aerosols, mostly from coal burning. They are also acid rain, so aren’t a great idea. They also don’t stay up for long, so (unlike CO2) would need to be constantly replenished -William]
Rasmus points out:
“The funny thing then is that the concept of regional mean temperature would also not be meaningful according to Essex et al.”
Exactly the same applies to macroscopic temperature of any piece of material. e.g. any volume of gas contains a set of molecules each of which has its own independent translational kinetic energy and hence molecular temperature. Hence the “temperature” of a volume of gas is an “average” of the temperatures of all its molecules. Essex et al tell us that we could arbitrarily choose an “average” that would give us the temperature of the hottest or coldest molecule in the volume of gas and because of this inconsistency there is no such thing as “temperature” of a multi-molecule volume of gas.
So folks, throw away all your thermometers, meaningless devices that they are. They are all just meaningless arbitrary averaging devices.
In section 4.1 “Contradictory Trends in Global Temperature Averages”, the authors demonstrate with a particular set of data, you can get either a warming or cooling trend depending on what value of “r” or “s” you use for your r-means or s-means averaging.
While that’s somewhat curious mathematically, the fact that they’re using data from just twelve (yes 12!) locations makes the whole example rather suspect.
The authors in fact essentially acknowledge that: “Stations were selected to give reasonable geographic variation, but whether it is a ‘global’ sample or not is secondary for the purpose of the example.”
That’s a bit disingenuous. Seems to me that if they really want to convince anyone that the global average temperature is meaningless, the authors should at least use a reasonably large number of points. I don’t know offhand what a reasonable number of points is, but offhand, 12 sample points to cover 500 million sq km of surface area seems a tad on the low side :-)
If you use temperature data from a much larger set of locations, and then used different methods to compute the mean (r-means and s-means, with different values for “r” and “s”), would you still get such a large variation in the size (and even the sign) of the global warming trend? I rather doubt it.
Does a global Ocean PH exist? I am pretty sure that nobody is getting spot measurements and averaging them, or similar analogy to what we are measuring with global temperature. How can we be sure that PH has decreased (by 0.1 or whatever since industrialisation) and is this averaged out over the whole ocean? Just the measurable bits?
Hi, first time I’ve commented here, although I’ve been reading with
interest for some time. I’m a (pure) mathematician.
As well as the question of the small number of locations they used, they
would only get results of the sort they did if (roughly speaking) their
hottest and coldest sites both had a trend of cooling over the period
they looked at. I looked at the data on the GISS website, and yes: they
included two very hot sites (Cartagena, Colombia and Chiang Mai, Thailand)
of which one had been cooling and one staying roughly the same over the
period — this is just from looking at the graphs, I haven’t done any
rigorous analysis — and one very cold site (Halley, Antarctica), that
had been cooling, as well as nine intermediate sites that had mostly
been warming or staying roughly the same.
Is there a general trend of the very hottest and coldest places on Earth
cooling rather than warming since 1980? Otherwise, it looks as though
they’ve been very selective with their choice of locations.
#107 Gerry Beauregard
If I understand the discussion above correctly then the very high values of r which they use mean that at the limits of the graph in r you select increasingly strongly the trend in the maximum and minimum temperature series.
This would seem to imply that of the twelve stations they selected the hottest and the coldest stations both exhibited cooling.
[[ I’m sure out of 17,000 scientists, there must be at least a couple of hundred that may actually know what they are talking about, but if it falls on deaf ears, then none of it really matters. ]]
Why don’t you do a google search on “Oregon Petition.” This thing has been completely discredited. Of the alleged “scientists” signing it, the vast majority are engineers, doctors, or people with science degrees in fields other than climatology. The fact that you don’t realize this thing was discredited a long time ago indicates that you’re only reading information from your own side.
[[the key point I pick up from this is that a global mean temperature, although we can define a way to calculate it, does not really provide anything useful. ]]
Well the key point you pick up from this is wrong. Mean global annual surface temperature is used all the time in climatology and planetary astronomy. Essex and McKitrick, as usual, don’t know what they’re talking about. They won’t convince any scientists, but they’ll convince enough of the public to slow down efforts to mitigate the problem.
[[There is no such thing as right or wrong. Who are you, or anyone else to judge what is right or wrong?
Right or wrong is human created concept. ]]
Then why are you arguing with me? If there’s no right or wrong, why are you saying I’m wrong to judge? You have to think these things through.
Aside — John D. commented on not knowing “what the military knows” — and isn’t the first.
Example from almost a decade ago —- opening up military archives of climate change info:
ScienceDaily: Newly Declassified Submarine Data Will Help Study Of …
The area is known as the “Gore Box” for Vice President Al Gore’s initiative to declassify Arctic …
Arctic Sea Ice Shows “Striking” Decline Since 1960s …
http://www.sciencedaily.com/releases/1998/01/980129074316.htm
re: 104 – John D.
Regarding what the military “knows”…
You might want to read “An Abrupt Climate Change Scenario and Its Implications for United States National Security”. Fortune ran a piece on it, as I recall, as did other sources.
The site where it was located has gone dead, apparently:
http://www.ems.org/climate/pentagon_climate_change.pdf
But Grist archived it:
http://www.grist.org/pdf/AbruptClimateChange2003.pdf
Seems the Pentagon was pretty clear about what it knew.
[Response:Fair enough, as long as you read the caveats, which basically say its not going to happen. Still I guess the military got a fair few nice lunches out of it -William]
Apologies in advance for a not completely on-topic post, but in this morning’s LA Times, there’s an interesting column entitled, “Why the right goes nuclear over global warming”. It’s available at http://tinyurl.com/2abdbl (free registration may be required).
Here are some excerpts:
—————————————————-
So, the magazine asked the question again last month. The results? Only 13% of Republicans agreed that global warming has been proved. As the evidence for global warming gets stronger, Republicans are actually getting more skeptical.
…..
But the financial relationship doesn’t quite explain the entirety of GOP skepticism on global warming. For one thing, the energy industry has dramatically softened its opposition to global warming over the last year, even as Republicans have stiffened theirs…
…..
A small number of hard-core ideologues (some, but not all, industry shills) have led the thinking for the whole conservative movement.
……
Meanwhile, Republicans who do believe in global warming get shunted aside. Nicole Gaudiano of Gannett News Service recently reported that Rep. Wayne Gilchrest asked to be on the Select Committee on Energy Independence and Global Warming. House Republican leader John Boehner of Ohio refused to allow it unless Gilchrest would say that humans have not contributed to global warming. The Maryland Republican refused and was denied a seat.
Reps. Roscoe Bartlett (R-Md.) and Vernon Ehlers (R-Mich.), both research scientists, also were denied seats on the committee. Normally, relevant expertise would be considered an advantage. In this case, it was a disqualification….
re 102: Yes, Lynn, but 8th grade science teachers are not immune from little white lies.
And to say scientists are ignores history and reality.
#109 Jeremy wrote: [[Otherwise, it looks as though they’ve been very selective with their choice of locations.]]
This is one thing that the juried peer-review process is pretty good at: Weeding out problems such as selective cherry picking….purposeful or otherwise.
It is one problem that gets the climate-change deniers in a lot of trouble. An example is many of their claims that the Earth is cooling because a few places on Earth have been cooling while tbe global average has been rising…”A few trees do not make the forest”…and to claim so is slimply deceitful.
This is a real quote currently from one of their largely fossil-fuel funded websites…and I kid you not:
[[Pensacola’s mean annual temperature has cooled by 0.06 degrees Fahrenheit. Not much global warming here!]]
http://www.co2science.org/scripts/CO2ScienceB2C/Index.jsp
Seeing what difficulty even solid state physicists have in agreeing beyond the first two decimal places on the characteristic temperatures of real crystals of real solids involving the lattice dynamics of more than one isotope , all I can say after viewing this dialog is that I feel your interdisciplinary pain – defining room temperature is no cakewalk either,because rooms don’t have temperatures.
Things in rooms have temperatures. Unfortunately, those things tend to be made of stuff , and even specimens of the same stuff vary in their thermal characterization , because perfect solids don’t exist unless you build them one atom at a time.
Forgive the reductionism, but that’s the way things are at 4 Kelvins , and while taking them up one crise de regime at a time to beyond the boiling point to mix into an atmosphere may provide gainful employment for practitioners of statistical thermo , it does not make matters easier for anybody else. Some problems are too large to frame perfectly in finite time.
Re #103: [There is no such thing as right or wrong. Who are you, or anyone else to judge what is right or wrong? Right or wrong is human created concept.]
(Sigh) Semantic quibbling. You’re confusing the moral/ethical meaning of the words with the technical. Replace them with correct and incorrect, if you like.
[Computations are just methodologies, often different, employed and invoked by a person. Not right or wrong.]
OK, how about letting me take over your bookkeeping? I assure you I can come up with some really creative computational methodologies to conceal the amount of money I’ll be embezzling :-) There’s no such thing as an average account balance, is there? And as you say, who are you to judge what’s right or wrong, in either sense of the words?
re 115 – William’s comment
As a follow-up to my previous post, I should likely add that I do not necessarily subscribe one way or the other to the analysis linked, and I apologize if I was taken to say the Pentagon is somehow transparent in the manner in which it plans, or that the report I provided represents a revelation of what the Pentagon “knows”. I am not a scientist nor a Pentagon analyst, just an everyday citizen. My only intent in providing the link was to answer in somewhat tongue-in-cheek fashion a remark that I found rather interesting as it was a bit of a non-sequitur. How does one claim of knowledge of unrevealed knowledge when one freely acknowledges he or she has no knowledge to support the claim? Curious.
Regardless, the Pentagon has these assessments, and we can only guess at how seriously they might take them, particularly when we reflect on the relationship of the current Administration and climate science. Beyond that, what I do think is that the extreme climate change cited in the “analysis” is not needed for many of the scenarios discussed – and likely many yet to be imagined – to occur. The combination of even mild climate change with swelling populations, dwindling resources, political and religious differences and the ongoing use of our planet as humanity’s personal toilet bowl will likely have the potential of triggering a variety of incidents and blow-ups akin to the scenarios discussed in the report. The part of the report that discusses carrying capacity is rather illuminating in this regard.
This is all my opinion, of course, somewhat informed in the layman’s sense, but an opinion nonetheless:
It strikes me how the issue of global warming invariably parallel issues such as pollution, habitat loss, resource depletion and overpopulation. Even more interesting is how addressing the likely causes, such as carbon emissions, would likely have long-term positive effects economically and in terms of quality of life for people in general. We see the trends. We see the solutions. The question seems to be what we will do about them. Make plans for war we may fight over a problem we seem incapable of agreeing upon? That seems rather self-defeating, and I’m not even touching on the rather insane reasoning this kind of planning infers. Similarly, optimistic predictions of what will occur fifty years down the line rarely see fruition. If you doubt that, review the predictions made during the 1938 World’s Fair. (Or, even better, check out David Brin’s 1989 novel “Earth” and see how his predictions of the next fifty years are turning out.)
The problem isn’t global warming, not really. In the sense it’s a done deal. We know it is happening; even the majority of denialists probably agree. The problem is taking the bull by the horns, if you’ll excuse the metaphor, and grappling with it in earnest. Yet here we are, better than a quarter-century into understanding we have a problem, with the reports we’re seeing becoming steadily more compelling regarding the need to act, and we’re caught up in arguments with people who do all they can to muddy the waters in an effort to delay addressing the problem. What has been done to address global warming is so miniscule in comparison with what needs to be done it is as if we have done nothing at all. The progress in addressing the problem can be measured in inches when it needs to be measured in miles. If this were a race, we wouldn’t even be in it.
This is the real problem, the insurmountable problem: Invariably, as a species, as a civilization, our practice is to react to problems, whether man-made or those posed by nature. We wait for disaster before we move. The kicker here is the time-debt associated with global warming, something that natural tendency to delay doesn’t account for. Effects we experience today were caused 20-30 years ago, if I read the science correctly. When we finally reach a point where the effect is undeniable to the masses and decide to move, we’ll be much like the famous little Dutch Boy with his finger in the dike – only there will be millions of holes and he’s only got ten fingers.
So given the nature of the real problem, the likelihood of how we’ll respond, you’ll excuse me if I remain a bit pessimistic about civilization’s chances. I hope, and try to do what I can – I have to, as I have a child and this future we’re shaping is going to belong to her and her generation, and to their children. But it is a sad hope, filled with necessary dread. I think they will learn to hate us.
*sigh* Sorry. Didn’t mean to run on like that, but there it is.
That said, have a bright day.
Regards,
re 116, “…Only 13% of Republicans agreed that global warming has been proved….”
I read and have to believe the stats. But as I’ve stated before, I’m at odds to figure out why AGW pro and con would naturally split between Rep/Dem or conservative and liberal. Can anyone explain it?
Some banks base fees on the average account balance.
http://hypertextbook.com/facts/2001/AlbertEydelman.shtml
Temperature on the Surface of Mars
(A collection of different estimates, each interesting as an example of how such numbers are arrived at.)
Re #96 (Eric): I have reproduced the results of the Figure 2 of the Essex paper using their data but writing a program to do it in MATLAB (see my comments about the results in comment #32 above).
You are right that they eliminate all months where any station has missing data and that they calculate the r at those values spaced by 1.2. However, neither of these are fundamental problems: The first may change somewhat exactly what the results are for this particular example but don’t fundamentally alter their basic point. The second is of no consequence. (For example, I computed for r spaced by 0.1.)
I don’t think the problem with their paper is little choices they made like this. The issue is that there is no justification for going to such large positive and negative r’s that your averaging method basically becomes a method for picking either the lowest or highest temperature reading for each of the months.
Yes, if I define my average in a completely silly way, I will get completely silly results. The solution is to not define my average in a completely silly way and not to be so rigid as to believe that if I can’t justify thermodynamically an absolutely best choice for an average, then any one is as good as any other. That’s just absurd logic…although the kind of logic that I think might be appealing to those non-scientists who think that science is always based on absolute rigor and certainty.
Re #107, 109, 110: I tend to agree with you that they have likely cherry-picked their stations to give a particularly dramatic result. I.e., with a different choice of stations they would not have necessarily had the r-means and s-means converging to a significantly negative trend for large positive and negative values. However, for most sets of data of this size, they still probably would have tended to see a strong dependence of the trend on the r-means and s-means on the values for r and s if one allows r and s to range over ridiculously large domains as they do.
[By the way, a very technical point: The large positive and negative values of r and s don’t exactly pick out the trend for the one station that is hottest and coldest on average. Rather, it picks out the trend you get if you use either the hottest or coldest station data point for each and every month over that period. So, for example, while the Antarctic station may tend to have the lowest temperature for some months of the year, it doesn’t for all months of the year. So, the trend you get as r or s become large and negative is not simply the trend for that one station.]
I tend to think there is some truth to the statement that a data set with a much larger number of stations would tend to be better behaved. I haven’t tried to check this and my guess is that there could still be some significant variation with r if you look over a broad enough range but there may also tend to be a larger plateau region.
However, it is important to recognize that even in their 12-station example, the temperature trend is pretty well-behaved as long as you choose a “reasonable” value for r or s. E.g., as I noted in comment #32, even changing r from 1 to 4 (which is about the largest change I can see coming up with any physical justification for) results in only a small change in the computed temperature trend.
The “evil brilliance” of Essex et al. was in making a plot where r goes from -125 to +125 so that the region over which the temperature trend computed from the r-means is well-behaved gets very compressed on the plot!
After reading the comments here I am now certain that I must convince Bill Gates to move to Elk River. That simple act on his part will make my humble town of Elk River among the more wealthy communities in the USA.
The proposition might be true, but it has no context. Our leftist state legislature would likely “fix” our excessive Elk River wealth “problem” by raising my taxes.
So I ask the global warming groupies here, are all averages indeed roughly “equal” in context? When someone says the Earth’s “average” temperature rises (or declines) by 0.0x degress, shouldn’t we really ask what they mean by that? Remember here in Minnesota we’re all above average as Garrison Keilor would put it.
And for our erudite climate experts, just what type of averaging DO you use, (Arithmetic mean, modal average, median, RMS etc. etc. etc….ad infinitum) and more importantly why do you chose one method over another when calculating the current Earth “fever”, to recall how your most well known spokesman puts it.
Is it possible that one method might produce an opposite trend to another? If so the issue is not quite so readily dismissed as your fans suggest it should be.
Re #70 and other comments. What counts is the ratio of the trend in the average to the year-to-year variability. The larger that ratio, the more significant the trend. The statistical theory for arithmetic averges (r = 1) is long-established, making such calculations easy to make and interpret. Using larger and larger values of r puts increasing emphasis on “outliers”, i.e., “oddballs”, making it increasingly difficult to detect the trend. An analogy: Suppose a drug company was testing a new blood-pressure drug and found that the AVERAGE blood-pressure reduction was 30% greater than that in a group using a placebo. They reject the drug, however, because in ONE case the reduction was only 1%. Thus, a potentially valuable drug is kept off the market because it didn’t work on one person. In the same way, using averages with high values of r would delay action to reduce greenhouse-gas emissions. (One would would have to wait longer before significance could be established.) But, perhaps that’s the point?
It the verdict then that 20% of the earth gets 5-7 degrees hotter,the average goes up, and somehow this represents a real picture of earths temperature?
Re. 122, it’s all about policy, not science. Those with a very strong vested interested (whether emotional, political or financial) in there being no government action to reduce greenhouse gas emissions will try their hardest to convince themselves that the science is flawed. Hance the reason that anti-regulation lobby groups run almost all of the disinformation sites on the web.
RE: 120 Re #103:
I would suggest reading my original posting #49 “I doubt there is any easy answer or methodology to answering “Does a global temperature exist?” along with the citations.
A comment was posted in relation to my #49 that was of a personal nature rather than a comment that discussed my provided citations as it related to the topic contained therewithin Essex et al, along with the topic/commentary provided and being discussed here at RC.
The comment posted did not correspond or make sense in relation to what I originally posted, along with my citations, as an easy answer to a posited question.
Especially as I posted it in relation to the theme being discussed, the original paper (Christopher Essex, Ross McKitrick, and Bjarne Andresen) which put forward the dimensions of global temperature as it related to the topic global warming.
Does a Global Temperature Exist?
http://www.uoguelph.ca/~rmckitri/research/globaltemp/globaltemp.html
“Physical, mathematical and observational grounds are employed to show that there is no physically meaningful global temperature for the Earth in the context of the issue of global warming. ”
All that said, you are welcome to your thoughts and opinion as they related to my original posting and citations as they applied to the topic at hand; however, these comments, like the other, escape me as to how either would have been applicable to what I originally posted.
And it’s certainly been noted about addressing the need for climate
science metrics, hence my use of the word methodologies.
Reconciling Observations of Global Temperature Change
http://books.nap.edu/catalog/9755.html
Review of the U.S. Climate Change Science Programâ??s Synthesis and Assessment Product on Temperature Trends in the Lower Atmosphere (2005)
http://books.nap.edu/catalog/11285.html
Thinking Strategically: The Appropriate Use of Metrics for the Climate Change Science Program (2005)
http://books.nap.edu/catalog/11292.html
Thank you for your comments.
,” an infinite range of such statistics is mathematically permissible
if physical principles provide no explicit basis for choosing among them.”
That argument my be true. One can drive meny nambers from the met data.
But for global warming the only important questions are is “global temperature” defined and is it useful concept.
1st. I understand that we mean “global surface temperature” surface mean the temp at standart met box
and global mean (â�«Tds)/(surface fo earth) dim=[T] and “global teemperature” is well defined.
2nd. Is “global temperature” is useful? In Venus global temperature is higher then in Earth I gess it is useful exemple.
[[I read and have to believe the stats. But as I’ve stated before, I’m at odds to figure out why AGW pro and con would naturally split between Rep/Dem or conservative and liberal. Can anyone explain it? ]]
Because commentators like Rush Limbaugh who have huge audiences, and scientists funded by the big oil companies, who desperately want to be able to go on selling people fossil fuels, have turned it into yet another endless shouting match between conservatives and liberals. In a rational world this wouldn’t have happened, but we live in a US with a strong anti-intellectual current and a number of people ready to jump on any bandwagon that supports their party.
[[http://hypertextbook.com/facts/2001/AlbertEydelman.shtml
Temperature on the Surface of Mars
(A collection of different estimates, each interesting as an example of how such numbers are arrived at.) ]]
Collections and reviews will list anything, even if it comes from some 50-year-old textbook. The American Heritage Dictionary still lists the mass of Mars as 0.15 that of Earth, which is actually the volume of Mars — the mass has been known to be about 0.11 that of Earth for more than a century.
There haven’t really been any good studies of the thermal balance of Mars. A radio emission study from 1962 came up with the 218 K figure. Barth et al.’s 1985 standard atmosphere for Mars lists surface temperature as 214 K, which is what I usually use. But we really need a Mars climate orbiter…
Simply picking the complete set of stations would not help. First of all, they are not uniformly distributed in area or time. Read the description of how the station data is put onto a grid at the GISS site for example. Second, changes will be dominated by changes in the annual cycle. You need a procedure to “deseasonalize” (help! I don’t remember the right word)which turns out to be taking the monthly averages at each data point for thirty years and subtracting that from each monthly average at that point. It is only after that step that you can sensibly compare the trend in Patagonia with that in New York (or at least the trends at the location of the nearest grid points to be more exact). Because only anolmalies make sense for looking at global trends, you get into the problem of finding averages with zero and negative and positive values, which quickly drivew you to linear averages. See the GISS web site.
Do Sato and Hansen plan to send a reply?
Re: #125 Joel Shore
Thanks. It’s obvious that their technique can’t handle missing data. They exclude 33 of 264 months. I’ve looked at the data a bit and what they actually did is even more interesting.
The Halley station is the source of most of the missing months in their data file with 20 missing. But, the NASA GISS data does not show any missing months “after homoteneity adjustment”. Are these guys using the raw data? They don’t actually say so.
It gets better. The Chiang Mai station had 15 months missing in the GISS data set, but they only show 6 missing. And the Cartagena data is missing 9 months in GISS, but they show only 4 missing months. Why is this? They used interpolation to fill in where single months are missing. What’s this again? Is it that they don’t like the corrected GISS data, but they do think it’s OK to use THEIR corrections? They offered numerous objections to simple averaging and grid box binning, yet they apply a simple average to fill in the missing data? They don’t like the use of anomalies, where the long term average seasonal cycle could be used to fill in missing months, which is likely to be more accurate than interpolation.
Just one more nail in the coffin. I think that the paper should be withdrawn.
What I find odd in all this, is that it is undeniable that we are seeing profound changes in climate–especially in polar latitudes. If anything, “global temperature” understates the magnitude of these changes–as indicated by all the nonscientists that claim to be unimpressed by a <1 degree change in global temperature. To my knowledge, not even Essex et al. would deny that climate is changing. If global mean is a useful metric for reflecting these changes, and if it can be calculated in a self-consistent manner, then it has validity. There may be other metrics that are better, but global mean temperature has the virtue of familiarity and history. It seems to me that the denialists are re-arranging the deck chairs on their sinking ship. I’d be happy to throw them a line if they’d just start swimming.
Re #137 Eric Swanson
Frankly, I don’t much care what they do with missing data. I doubt it
makes much difference.
But in another part of the article they state (correctly) that the limit
as r goes to infinity of the “r-mean” is the maximum. So they clearly
know that if they are looking at large values of r then the r-mean is
going to be roughly the highest temperature. So their statement that
“Stations were selected to give a reasonable geographic variation, but
whether it is a ‘global’ sample or not is secondary for the purpose of
this example” is frankly dishonest. They know perfectly well that it’s
irrelevant whether it’s a ‘global’ sample, and all that matters for them
to get the results they want is that they pick “hot” sites (for large r)
and “cold” sites (for large negative r) that have a cooling trend. And of
course, that’s what they’ve done.
They may well be right that there is no particular reason to choose the
arithmetic mean rather than other reasonable “averages”, but their
assertion that taking an arithmetic mean of temperatures is no more
sensible than taking arithmetic means of telephone numbers is frankly
preposterous.
RE#118, Richard noticed that CO2science is running a weekly ‘temperature record’ that shows cooling. What those people must do is sift through records looking for cooling trends, and then they claim that their selective reporting of data means that no global trend exists! This is just scientific fraud, and it’s the same behavior that Richard Lindzen railed against some years when he complained that record temperatures can’t be used as evidence of global warming. (Though I don’t hear Lindzen or Pielke condemning CO2science for using that approach!) However, I wouldn’t link directly to CO2science.org – that only encourages them. They’re run by Sherwood Idso, the same one who was attacking radiative calculations and modelling efforts back in 1980:
“In 1980 a scientist at the U.S. Water Conservation Laboratory in Arizona, Sherwood Idso, joined the attack on the models. In articles and letters to several journals, he asserted that he could determine how sensitive the climate was to additional gases by applying elementary radiation equations to some basic natural “experiments.” One could look at the difference in temperature between an airless Earth and a planet with an atmosphere, or the difference between Arctic and tropical regions. Since these differences were only a few tens of degrees, he computed that the smaller perturbation that came from doubling CO2 must cause only a negligible change, a tenth of a degree or so.
Stephen Schneider and other modelers counterattacked. They showed that Idso, Newell, and Dopplick were misusing the equations â�� indeed their conclusions were “simply based upon various violations of the first law of thermodynamics.” Refusing to admit error, Idso got into a long technical controversy with modelers, which on occasion descended into personal attacks..”
If anything, this does show that efforts to discredit global climate science do indeed reach back almost 30 years. CO2science is the best example of how this process works (they also offer to help companies with ‘greenhouse gas reporting requirements’, which makes one highly skeptical about any the effectiveness of any ‘carbon trading’ schemes).
As stated by several others here different values of ‘r’ yield averages with different physical meanings. I worked for many years in the field of particle sizing in that case there are many different ‘mean diameters’ resulting from different values of ‘r’ and the choice for a paticular application depended of the phenomenon being studied, for example r=2 gives a mean with the same surface area (useful in absorption), r=3 gives the same mass etc.. In the case of the earth it seems to me that r=4 has some merit as it’s significant with regard to radiation exchange and is presumably what one would determine at a distance from space?
Re #133 and upthread to #116: without going into the politics as such, but just to offer a clarification from the standpoint of survey research — the “13% of Republicans” figure refers to members of Congress. There is considerable, but less, partisan polarization among ordinary citizens. See, for instance, the Pew Center report here.)
Attentive partisans tend to follow their political leaders. It’s striking, in the Pew report, that the gap between college-educated Republicans and Democrats is wider than the gap between their non-college-educated counterparts. (Of course education doesn’t equal attentiveness — it is only a crude proxy.)
Re #122:
Actually it stands to reason that there would be a split in tendency to believe the science based on political persuasion; those more inclined to favor collective action will be more willing to take seriously a phenomenon which seems to indicate a need for collective action than those who are disinclined.
The huge opinion spread on climate change is disconcerting though, and the trend toward increasing disbelief among the right while the substantive evidence against them becomes ever more compelling is downright alarming.
To some extent even this is actually not hard to understand. The commercial interests that are threatened by the actual facts of the matter have an enormous motivation to confuse the public discourse, and they play on natural inclinations. What is hard to understand is how spectacularly successful they have become in moving their audience ever further away from the center of gravity that the facts portend.
I do note an increasing testiness and terseness from the leading posters on this site, and even occasionally from the editors in response to such provocations. I would like to caution that this behavior plays very much into the hands of the malefactors and their innocent sympathizers. They are trying, all too successfully, to convince their audience of several things including
It all ties together into a pretty clever strategy:
That’s not the whole strategy (for instance there’s the “house of cards” strategy that tries to make out that the whole “global warming theory” is abstruse and delicate, and that any single error is enough to “disprove” the “theory”) but it’s emerging as a central feature.
The best counter is to avoid the appearance of arrogance in public forums. Accordingly, if I could venture my advice to serious informed posters:
are not open to new evidence. Be very careful in explaining, repeatedly and calmly, that some of the counter-arguments we hear are totally at odds with the facts, and that put together they don’t constitute a coherent hypothesis. Don’t snip or huff no matter how many times you see the same nonsense repeated; the writer knows this history very well but the target reader does not.
The fact that regular posters and even occasionally editors here are being baited into intemperate statements plays into the hands of the malefactors. Justifiable anger and frustration plays out as arrogance.
Preaching to the choir is beside the point. That there is an influential segment of the society which is becoming more rather than less skeptical is a hugely serious problem. It would be best if realclimate were part of the solution, but we are up against very clever opponents who don’t want it to turn out that way.
Please remember (though they may, by personalizing matters, try to make you forget) that your effect on the third party reader is vastly more important than your effect on the person who is writing. Your correspondent may well be deliberately trying to make you look nasty or arrogant under the pretense of some weakly substantive argument. Nothing you can say will cause that person to change their opinion, because what they are voicing is not actually an opinion about a matter of fact but rather a tactic in a battle for influence over the casually interested.
If you find yourself angry the best way to fight back is to say nothing and let someone else do the talking. If you win the game of substance and your opponent wins the game of polemics, in the end your purpose in participating in the discussion is not achieved.
This helps with the Monckton part of the below:
http://n3xus6.blogspot.com/2006/11/debate-over-good-guys-win.html
I think the objection to spectroscopic determination is that Earth is not a black body (despite what Monckton would have us believe).
However, I’m surprised the real problem isn’t imprecision.
OIM is not, I thought, proven to be a fossil fuel funded enterprise. It did do the petition in conjunction with one. Let’s be precise.
Robinson is a good example of a fringe scientist, not meaning an idiot or lunatic, but someone who simply is likelier than not to not be in the mainstream (because he’s long past his prime, because his increasingly ideological concerns make it hard for him to embrace anything he sees as anti-Jesus or anti-business, because he honestly believes some studies and some formulations trump all the others, because he’s been mostly stumping for contrarianism vs. boning up on the latest consensus). In any population you have honest people who disagree as well as paid hacks (albeit, I suspect what Robinson REALLY thinks he’s disagreeing with is not a scientific consensus but those damned lying atheist socialists).
It cuts both ways: If a preponderance of climate scientists went the other way, you could easily, quickly come up with reasons to believe the minority who accepted anthropogenic GGs increasing warming. Indeed, I’d lean that way myself since I believe there literally are NO forces pushing a socialist or anti-business bias on scientific research. All the noise, in fact, comes from either generally right-wing or specific nest-feathering business spending.
That the climate scientists are standing firm in an era where businesses will spend a fortune for defense but not one cent for tribute to reality, where the sole superpower FIRES PEOPLE for accurately reporting CARIBOU HERD OBSERVATIONS and CLIMATE DATA, indeed, puts young interns in charge of determining science policy on explicitly ideological grounds, should be all the human evidence we need. There’s always way more money on the business-flattering, elite-flattering, industry-appeasing side of the street.
Indeed, most of the richest nations have comparatively conservative governments completely beholden to rich special interests, so why they’d insist on funding science in an anti-business direction is left as an exercise for recreation hour at the Rand asylum.
Could someone please explain how measurements of the earths temperature which depend on the method used or the programs used or the technology used could ever come up with the same temperatures for a particular year, day, hour, or century. Considering the inconsistent methods of temperature evaluation being used today, how is it possible for everyone to be coming up with anything that is even close to each other never mind to an accuracy of tenths of a degree f. The results of these studies need to be extremly accurate for them to have any value. Inconsistencies and inacuracies do not cancel each other out, instead they tend to contribute to cumulative error. The only way we can have an agreement on the temperatures of the earth today or yesterday or tomorrow would be to design a program that will give you the results you want. If anyone believes that this is not what is being done they are not living in the real world.
I am particularly interested if anyone has an idea of what effects on the surface temperature does the core of the earth contribute to the earths overall temperature. It would seem to me that the core is what is actually keeping the earth warm, not the sun. I would like to know what temperature the earth would be without the heat being generated at the core. Considering that the core is not symetrical and not absolutly consistent, i imagine this would need to be a large part of any program that establishes the temerature of the earth in an accurate way. When we can all agree on the method and the result of todays temperature of the earth we can then go on to find a way to agree on yesterdays temperature and tomorrows temperature. I doubt that we agree on the method or the results for many years to come unfortunatly. My real problem is with those that say outside my window it was colder or hotter last year, I think.
I am truly concerned for the planet but if global warming is occuring due to some other reason or if warming is not even really occuring we are only chasing our tails and the money and energy being spent to prove man generated co2 is causing the warming of the planet is being ill spent and could be used for projects that would actually help mankind.
I ask these questions because i believe there are people who read this that will actually think carefully about these issues.
If you think I am all wet please say so.
Thanks
By mistake, I had posted this message to the wrong thread, here it goes again.
Is there anybody out there that could provide an approximation to the following quantity? (back of the envelope calculation)
Assuming a very simple system, where everything stays the same, except for the increased CO2, what is the extra amount of heat introduced into the climate system by the current CO2 level, relative to the total amount of heat that the Earth received from the Sun before the CO2 increase?
This number should be relatively easy to estimate from basic physical considerations.
It seems to me that this number is a crucial first step in demonstrating to doubters that the CO2 increase is indeed a potentially very serious problem, instead of getting tangled in knots talking about temperatures. After that comes the hard work of checking exactly how the climate system reacts to the increased heat input, and explaining to non-scientists all sorts of complicated things about feedbacks and such.
Going straight into discussions about exact temperatures, climate sensitivities, feedbacks, aerosols, etc. just muddies the argument and obscures the main point: We are introducing a significant perturbation into the climate system. In general, if the inputs of a dynamical system are perturbed in a significant way, there is a non-negligible probablity that the behavior of the system will change in a significant way. And, change will most likely be for the “worse” because of the basic fact that there are many more “undesirable” (“disordered”) than “desirable” (“ordered”) states in any system (basic entropy considerations).
Papos, OK, you asked for it: You’re all wet. ;-) Here’s why. Earth gets about 4×10^13 watts from its interior–due to both radioactive decays and latent heat of condensation of liquid outer core onto solid inner core. Average insolation is about 10x that amount. What is more, heat from the interior can only decrease as its sources are depleted. If for some unknown reason we were seeing a blip in energy from the interior, it would lead to increased volcanism–which we aren’t seeing.
[[ am particularly interested if anyone has an idea of what effects on the surface temperature does the core of the earth contribute to the earths overall temperature. It would seem to me that the core is what is actually keeping the earth warm, not the sun. I would like to know what temperature the earth would be without the heat being generated at the core.]]
The net average contribution of sunlight to the climate system is about 240 watts per square meter; the geothermal flux is about 0.090 watts per square meter. Thus the geothermal flux is usually ignored.
To convert a flux to a temperature we invert the Stefan-Boltzmann law (leaving out emissivity, which I’m not sure how to apply here):
T = (F / σ)0.25
where σ is the Stefan-Boltzmann constant (about 5.6704 x 10-8 in the S.I.). Thus if Earth depended on geothermal heating alone, its average surface temperature would be about 36 degrees K. For contrast, water freezes at 273 K and the Earth’s mean global annual surface temperature is about 288 K.
Ray Ladbury (#148): Earth gets about 4×10^13 watts from its interior–due to both radioactive decays and latent heat of condensation of liquid outer core onto solid inner core. Average insolation is about 10x that amount.
Barton Paul Levenson (# 149): The net average contribution of sunlight to the climate system is about 240 watts per square meter; the geothermal flux is about 0.090 watts per square meter. [240 / 0.090 = 2,667X]
Whoa! Someone’s calculations appear to be way off!