This is a guest post by Paul Murphy – and I’d like to thank Mr. Watts for giving me this opportunity to present it here.
This is a very long post by WUWT standards – nearly 3,000 words all driving toward the basic conclusion that what we know about global warming is pretty much nothing: we’ve no baseline, so don’t know if it’s happening; we’ve no cost/benefit evaluation so don’t know whether it would be net positive or net negative; if it is happening we don’t understand its causation and if it isn’t we don’t understand why not; and really the only thing we’re pretty sure of is that the people jumping up and down screaming that they have the answers are either deluded or charlatans.
I drafted this article on November 19th, 2010. At about ten that morning the weather channel, which gets its data for Lethbridge, Alberta from environment Canada and thus ultimately from sensors less than ten kilometers from my house, said the temperature was -17C. At that same time, however, the sensors about four feet above my roof reported a temperature of -19.2C.
By coincidence, and again according to the weather channel, the all time record low for November here, -35.6C, was set on that same day in 1921.
The source number for that claim, presumably 32.08F, is actually an interpolation from various agricultural research and military facilities across southern Alberta, because the airport weather station has been moved a few times and many of the source records lost – but it should be obvious in any case that neither the thermometers in use at airports in 1921 nor the processes in place to record temperature supported anything like that level of precision.
So how cold was it here before I left that morning? there’s really no way to know – and how did that compare to 1921? I don’t know that either.
What I do know is that the values shown were averages taken over time; that neither instrument is predictably accurate to even one decimal place; and that the air between the two is of variable depth, variable humidity, in constant motion, and had markedly less than one chance in twenty-two of being at a real average temperature of -18.1C at about 10 AM that day.
So how does this extrapolate to sticking a thermometer into the troposphere to estimate our planet’s near ground air temperature? Well, in total the world has less than one sensor for every sixty thousand square kilometers; about three quarters of them are closely grouped in the United States, western Europe, and the militarily significant part of southeastern Russia; almost none have trustworthy time-of-readings records for more than a few years; most of the records are both short and discontinuous; most of the readings are accurate only within loose bounds; and an unknown proportion of the time series supposedly formed from instrument readings contain unknown interpolations.
There are other sources of information. For example, weather satellites have produced records for perhaps half the earth’s surface since about the mid seventies – but those records too have unknown source errors; may now contain accumulated and largely undocumented differences from the source data; show significant coverage bias favoring areas important to civil aeronautics; and are generally accessible only in the form of time series whose values are derived from real measurements pertaining mainly to the upper troposphere through calculations calibrated against the same ground sensor readings they’re used to extend and correct.
In contrast many of the proxy records are both long and internally consistent – but they don’t help because these are very coarse grained: whether they’re based on isotope decay or tree rings, the best “rulers” these produce are location specific and marked in decadal or century intervals, not globally applicable and marked in seasons or years.
The bottom line on this is simple: I can’t pretend to know the temperature within a few kilometers of my house right now to within a couple of degrees C without making basic scientific errors in everything from measurement and imagined precision to application – and when people like Jones and Hansen announce in all apparent seriousness that the entire earth is now 0.5C degrees warmer than it was during the period from 1961 to 1990 they’re asking us to accept a very precise number on the basis of data that’s much worse than mine and in the face of applicability, measurement, and computational ambiguities that are orders of magnitude greater.
There seem to be two arguments for not dismissing their claims as nonsense. First, that we don’t need to know the atmosphere’s temperature now because climate science is about change and X + 0.7 degrees will have visible effects regardless of the value of X. The Polar bear, for example, will go extinct and Manhattan will flood – except that we’re pretty sure the medieval warming period was just one of many such in history and not only did the polar bear make it through those embarrassingly undead, but what’s known of civilizational history in estuaries and around tidal basins from the Thames to the Yellow does not suggest the existence of longer term human noticeable flooding during any of those extended warm periods.
Second there’s the Foundation myth: the belief that it’s possible to predict the direction and extent of motion of something like a collection’s center of mass (or the chartrist’s Dow Jones average) without knowing anything about the motion of the individual units involved – or, in other words, that we can predict where a herd of cattle will go when stampeded without needing to know where they started, how many there were, what frightened them, much about the land they’re on, the direction each animal starts in, or even whether they’re actually cattle.
The Frank Slide took place on April 29th of 1903, about an hour’s drive from here when an estimated 90 million tons of limestone tipped off Turtle Mountain to bury the people, their town, and the railway beneath an estimated two kilometer rubble run-out. This slide hasn’t moved much since, has been extensively studied, is comprised of materials for which the basic physics of motion and energy transfer are well understood – and yet the best we can do in terms of placing its center of mass is plus or minus about fifty meters – roughly on the same order of accuracy as predicting yesterday’s temperature in Lethbridge to within a few degrees.
Basically the Foundation idea is intuitively obvious and makes for great science fiction, but the reality of any analysis aimed at actually making it work is that you need a secure grip on starting conditions, an understanding of the physics of change, strong boundaries on the range of change, and a small enough data set to make the simulation computationally feasible – so if you’ve ever wondered why the best known climate models come down to thirty or forty years of encrusted tinkering you now know: these models are continually adjusted to predict their own inputs, but cannot reliably predict excessions because the underlying climate science does not meet any of the conditions required for this kind of modeling to work.
So what do we know? We know that many of the people warning us of the horrible consequences of human caused global warming haven’t been the disinterested scientists they’ve pretended to be – basically from Hansen and Jones to Gore and Waxman most of the more deeply committed have shown themselves deeply corrupted. That’s sad, but even sadder is the hidden reality: that knowing Mann and Bradley made up the hockey stick to defend a lie doesn’t tell us anything about global climate change – it just tells us things we didn’t want to know about them.
Most people, of course, know the numbers don’t work but rationalize accepting alarmist conclusions anyway because they think that “greenhouse science” – the belief that increasing greenhouse gases in the atmosphere will cause traumatic global warming – is settled; and so see the lack of response to increasing atmospheric CO2 in weather data as a reflection on the quality of the data, not the theory.
Basically these people assume the wolf to justify the alarm: picturing Gore et al as yelling “Wolf!” because “greenhouse science” proves the wolf – and then excusing the business of rather obviously drawing improbable conclusions from inadequate data as laudable and necessary moral sacrifice by experts committed to rousing the rest of us to action.
Unfortunately the science on greenhouse gas effects is not only not settled, the claims made for it seem rather more likely to be wrong than right.
Specifically, the usual assertion is that human actions distort natural processes to negative effect – with the supporting proposition being that the planetary atmosphere will trap more solar energy, thus causing atmospheric heating, when it contains relatively more greenhouse gases, particularly CO2, then when it contains relatively less.
The classic demonstration for this involves adding CO2 to the air in only one of a pair of similar, closed, containers; exposing both to a radiant heat source until the containers reach equilibrium with the surrounding atmosphere; and then comparing one or both of the internal temperature and/or duration of the cool down period for the two. Do it, and you’ll find that the one containing some additional CO2 retains more heat and the claim is that this demonstrates the greenhouse effect.
It doesn’t. The experiment actually demonstrates two things about heat energy capture and storage: first, that increasing density increases heat storage capacity; and, second, that increasing the volume being heated at some constant rate increases the rate of energy transfer. Imagine the same experiment with the addition of a piece of non reflective metal material of comparable weight to the CO2 placed in the jar previously containing only air. What you would find is that the jar containing the CO2 changes internal temperature more quickly than the one with the metal sliver does, but that the total energy transfers are about the same.
Basically doing only the first half of the experiment and not thinking about the result supports the case, but going beyond that does not – and neither does looking at what real world extrapolation from the jar experiment might mean.
Most importantly, the material in the CO2 enriched jar is of a fixed mass, in a fixed state, and there is no expectation that its energy absorption and retention rates will change over time. Imagine glimpsing the earth from some significant distance and it can look just like that: a gravitational container filled with air and a bit of heavier stuff in the center. But up close, time passes and things happen: water and greenhouse gases move into and out of the atmosphere, mixing occurs at different rates both vertically and horizontally, some surfaces are net radiators, others net absorbers – overall the longer term energy balance seems to work, but many of the specifics and nearly everything about the rates of change involved, are neither understood in the science nor modeled in the jar experiment.
For most purposes the biggest difference between the experiment and reality is that in the real world there’s only one jar: i.e. the CO2 introduced into the test jar comes from the test jar. Thus it’s true that the materials in the planetary jar change state over time – trees grow, coal burns – but because the total mass in the jar is very nearly constant, the assumption that the input energy is roughly constant means that the total amount of heat energy the entire system can hold in long term equilibrium against the space around it has to be close to a constant too – and thus that a glaciated world cannot become tropical without significant change in energy input.
Thus the bottom line on the argument that alarmists can justify patching over weaknesses and contradictions in the data they purport to base their conclusions on because the effect of increasing greenhouse gas concentrations in the atmosphere is certain, is perhaps best illustrated in a joke generations of mathematicians have told about an experimental physicist testing the proposition that all odd numbers are prime: “1”, he says, “is, so is 3, -and 5, 7, 9, umm, 9, umm, 11 is, 13 is, 17 is, 19” -ok, they’re all prime and nine? experimental error, it’ll come out right next time.
So if we can’t believe in the data, the people, or the “settled science”, what can we believe? Perhaps that a hypothetical Canadian Canute party offering a credible commitment to end winter would win in a landslide? Or, more seriously, that all the fuss about whether or not humans are influencing global climate change has allowed the alarmist lobby to insert an obvious falsehood into the public consciousness on this issue: the belief that even minor global warming will produce terrible harm when what we know of both history and biology says the contrary is far more likely to be true.
By 10 PM on the evening of November 19th, for example, it was about -27 here with the wind chill dropping that down to an effective -40 something: an environment just as much the opposite of the green and fecund jungle most of the earth’s life has evolved in as the driest deserts in north Africa, central Asia, and Australia.
Come spring the area around here will go green with rain and erupt with life: people in our parks, ducks on our lakes, fawns in our coulees – and the water cycle effects that might well go with even a few degrees increase in “average” atmospheric temperaure worldwide might do the same for the roughly one third of the earth’s potentially arable land that’s now too dry or too cold for agriculture.
So there’s something else we don’t know: why do “greens”, people who profess to favor life and bio diversity in all its forms, so strongly oppose change most likely to strongly favor life and bio-diversity?
The obvious answer, that many of the leaders involved are merely using environmentalism as a handy bludgeon for the achievement of unrelated political or monetary goals, may well be correct, but is merely an ad hominem argument allowing us to dismiss them while telling us nothing about either the desirability or reality of anthropomorphic global warming.
So when you get down to it, what we know about global warming is pretty much nothing: we’ve no baseline, so don’t know if it’s happening; we’ve no cost/benefit evaluation so don’t know whether it would be net positive or net negative; if it is happening we don’t understand its causation and if it isn’t we don’t understand why not; so really the only thing we’re pretty sure of is that the people jumping up and down screaming that they have the answers are either deluded or charlatans.
Wow – so because I haven’t a clue how to go about getting the information needed to address any of this, I’m going to do what I did at about this time back on November 19th: throw another log on the fire, and watch The Good Guys on TV.
To say that we cannot make any predictions from models is inaccurate. However, a combination of the scarcity / inaccuracy of data and the highly complex nature of climate systems severely limit what we can be extrapolated. We are restricted to the most basic of “pattern predictions”. With respect to future temperature changes this is most probably restricted to the range of longer-term (30 plus years) trends. Prof. Bob Carter’s analysis is probably as far as we can go on the available data. That is we have a uniform, increasing, average temperature trend over the last 150 years, with 60 year cycles providing deviations around this trend. This trend is unexceptional when viewed from temperature data from ice-cores going back hundreds of thousands of years.
The attempt to cast every unusual weather event in terms of anthropogenic warming, and only selecting the data that fits the theories, not only risks policies that are inappropriate. It may lead us in failing to pick up the signals of potential trends for which the signal is weak, or where detection is from trends or patterns that do not fit theory. For example my house, along with hundreds of others in the area, has been without water for over twelve hours now due to a burst water main, caused by the severe cold. A contributing factor to the delay in repair was the lack of resource available. Too much reliance on speculative forecasts of increasingly mild winters, and snow being a rare event has virtually eliminated contingency planning for extreme cold. Yet natural factors (e.g. La Nina, lack of sunspots) would have suggested otherwise.
The AGW science is not only costing us more for fuel. It is also putting us at greater risk of the consequences of extreme weather.
For Robert Carter’s views, see a video at http://video.google.com/videoplay?docid=-1326937617167558947#
David Kitchen:
As a student, if I were to cite an authority I would certainly want to know his/her credentuals, but such citation would come from published literature, not an online site. If I found something interesting online, I would seek out confirmation from the relevant experts in the field. I don’t think I would suggest any online discussion site – or (and especially) Wikipedia as a legitimate source of fact without extensive additional research.
At a certain point a person should be able to recognize a well-reasoned argument, supported by verifiable facts, without relying on the author’s credentials, and should be capable of further researching the topic him/herself. That’s the time to engage in these sites, IMHO.
‘Climate science’ is not a single subject, and requires input from most all fields of science. I don’t think a major university or college even had a degree program in climate science before the year 2000. It is surprising what the formal education of “climate scientists” include. As a result, people from far flung fields contribute to the overall understanding of climate. Additionally, there are many, many people who study different sciences as a hobby and have no formal education nor career related experience. Their contribution should not be dismissed for this lack.
A fresh voice from the outside is sometimes necessary to upset the cart and show growing biases in an area of study. This happened in the field of history a few years back, when a popular, award winning, historian named Michael Bellesiles was shown to be a fraud by a software engineer and amature historian (Clayton Cramer) and a law professor (James Lindgren). Historians resisted the idea of a fraud being perpetrated because of Bellesiles’ credentials, and his support of their strong anti-gun biases. Indeed, Bellesiles primary defense was that his detractors were rank amatures. To a great extent, the airing of the relevant facts via the Internet made the fraud impossible to contain and cover up. Credible historians had to address the issue. I have seen a lot of parallels between that episode and global warming.
It is far better to read the views and ideas of the contributors and accept or dismiss them based intrinsic value of the ideas rather than the reputation of the contributor. I don’t think we need to bias our opinions of the message based on the reputation of the messenger, unless the messenger has already been shown to be of disrepute.
As far as what one writes about himself or herself on a blog, I have to wonder what Einstein or Feynman would have written in their own bios. (I have read Feynman’s books – whatever he would have written would be funny, true, and not exactly inspiring as to his credibility as a scientist!).
As a final potshot, if you do tell your students to dismiss anything produced by an “uncredentialed” contributor, I would suggest that you must tell them to dismiss the IPCC report, since its content and conclusions were controlled by Pachauri, a railroad engineer.
David Kitchen says:
December 26, 2010 at 7:26 pm
A number who post here also post at Judith Curry’s blog:
http://judithcurry.com/
There’s a link on the main page, near top right, labelled “denizens”. Click that for bio information.
Mike says:
December 26, 2010 at 7:43 pm
What is so hard about the concept of a mathematical average? With more data random measurement errors tend to cancel out. Even the most extreme skeptics acknowledge the world is warming. What do you think is causing glaciers to melt all over the world?
What is so hard about the concept that the temperature record could be badly skewed in favor of warming, due to rural station drop-out, UHI, and poor station placement? Nothing random about it. “Extreme Skeptics”? LOL. Do tell us more, but in any case, it is incorrect to say “the world is warming”. We only know that it did warm up some amount from the LIA, but the evidence is that the warming has stopped, and we may in fact be cooling.
Regarding glaciers, again, many have receded from their growth during the LIA, and at this point one of the biggest causes for glacial melt, such as in the Himalayas appears to be soot deposition. Others are stable, and some are growing. The reasons for the disappearance of the Kilamanjaro glacier are well known, and have nothing to do with warming.
Excellent post, Paul.
I am still trying to figure out the rationale of the ‘average global temperature’ which, to me, seems based on so much uncertainty in both measurement and methodology that the concept itself has no meaning and is merely a convenient myth to frighten those who refuse to think for themselves. What matters is not a mythic ‘ideal temperature’, but the ‘livibility’ of the parts of the planet where Man chooses to live. Right now, my experience of cold in the UK tells me I would be sensible to opt to live in a temperate zone where I don’t have to worry about freezing to death because idiot politicians hell-bent on saving the planet from plant food are making domestic energy too expensive for the average wage-earner or retiree to stay warm and healthy.
Is this really the author of this entry? Must be some confusion… which is exactly why short bios and background would be a real help. It would stop this kind of confusion with students- or at least helps them reach an informed opinion on the credibility of divergent opinions.
You would only be teaching them subservience to apparent authority.
Crucial in this world of drive through academic qualification is the tool of critical thinking and research plus more research. Of course we need to access prior knowledge gained through years of learning and experimentation of those who have gone before. There are many text books that deal with the foundation stones of our classical sciences and it’s philosophies. Many these texts can found on the web at no cost.
Nullius in Verba
http://www.spiked-online.com/index.php?/site/article/3357/
Re Darren Parker:
December 26, 2010 at 4:41 pm
“The ocean can’t have a lower pH if it get’s warmer at the same time – you can’t have both Onion.”
Well it is Darren.
I would recommend everyone read DN’s reply to me marked “December 26, 2010 at 5:07 pm” and try to figure out just how DN managed to misread my clear points multiple times and instead address strawmen. What’s up with that?
Blackhole2001 says:
December 26, 2010 at 1:19 pm
Who cares about how many temp gauges there are and how accurate they are! Open your eyes and see the physical REAL world effects of global warming! And they are probably caused by man made burning of fossil fuels, which create heat and CO2 in the process. 75% of the scientists think that this is the case.
You are kidding, right?
Hear, hear. Thanks for that. You said it better than I could have late last night.
An argument should stand on its own merits. If we accept arguments only from the ‘credentialed’, ‘qualified’, ‘experts’ on politically-charged or contentious subjects, we’d be well and truly screwed. Being credentialed, qualified, and expert on a subject is no guarantee that political/personal/financial agendas have been scrubbed from the material being presented.
I have been waiting to hang these questions on to a post and it strikes me that Paul Murphey’s excellent article might just provide an opportunity.
On a recent visit to a marine lab, I noticed that modern equipment enabled atmospheric temperatures to be recorded continuously. Hence the mean temperature over a single day (or any other period) can be accurately (as far as the piece of equipment is accurate) assessed from the area under the curve.
Many years ago, at school, when we had a max/min thermometer and took daily readings the mean temperature was taken as the average of these two figures. It does not require a mathematician to prove that such an average, even if taken more frequently, does not provide the true mean temperature.
My question is when were the old-fashioned max/min thermometers replaced by continuous measuring instruments? And are mean temperatures now calculated on a continuous basis, even though they are recorded daily?
Onion says: December 27, 2010 at 8:50 am
I would recommend everyone read DN’s reply to me marked “December 26, 2010 at 5:07 pm” and try to figure out just how DN managed to misread my clear points multiple times and instead address strawmen. What’s up with that?
————————————————————————-
Onion. I know that this is a waste of time to even bother to comment but – a question – how can you be so obtuse?
Douglas
Onion says:
December 27, 2010 at 8:50 am
I would recommend everyone read DN’s reply to me marked “December 26, 2010 at 5:07 pm” and try to figure out just how DN managed to misread my clear points multiple times and instead address strawmen. What’s up with that?
I read it, and it looks like he refuted your pathetic claims pretty thoroughly. Would you like a new shovel? Yours must be pretty worn by now.
Thanks Paul, excellent article!
There are many things we don’t know about climate, a few we could be beginning to learn. One thing we should know is that when trickery is being used, it usually from the side that is wrong and knows it.
Happy New Year!
Henry@onion
Perhaps if you read my blog
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
you find a few more reasons other than those already pointed out to you as to why many here doubt that CO2 has got something to do with global warming and why some of us actually believe that more of it is beneficial rather than catastrophic….
It is written in clear language without difficult formulae so even a non scientific man like yourself should be able to understand it.
After you have read everything, do come back to me if you still have any questions or if you (still) disagree with (some of) my findings. Rather than calculated estimates, actual test results from actual measurements would always be welcome and much appreciated, if you have them.
Note that I did not get any of bigoil’s money to do my investigations. Like Newton, I was challenged to start playing with a few pebbles on the beach. An apple did fall on my head. I was a strong AGW man before I started my investigations….
Strange, how a man can turn in his steps once he is confronted with truth….
Miracles do happen, even with onions. (They multiply when they start growing up).
Many years ago, at school, when we had a max/min thermometer and took daily readings the mean temperature was taken as the average of these two figures. It does not require a mathematician to prove that such an average, even if taken more frequently, does not provide the true mean temperature.
My question is when were the old-fashioned max/min thermometers replaced by continuous measuring instruments? And are mean temperatures now calculated on a continuous basis, even though they are recorded daily?
#########################
a min/max sample is an unbiased ESTIMATOR of the mean. This has been established over and over again. Since historical measurements are min/max if you want to build a continuous record you have to use min/max.
You can if you like establish this for yourself. Merely ask And I will point you to data collected from about 190 stations over a decade. The measurements are taken ever hour. You can then do the following.
1. calculate the area under the curve (Tmean)
2. calculate (Tmin+Tmax)/2 (Tave)
3. Then calculate (Tmean-Tave) for every day.
4. then calculate the mean of (Tmean-Tave). This measure will be close to zero.
5. Then calculate the trend in Tmean for every station
6. Then calculate the trend in Tave for every station.
7. then subtract those trends. This measure will be zero.
(Tmax+Tmin) is an estimator for the mean. It’s unbiased and it preserves trends.
if you want to do it with 5 minute data I can arrange for that too. However, nobody to date has wanted to repeat the tedious work to reprove what has been shown many times.
Mr. Mosher,
Many thanks for taking the trouble to reply to my questions. I understand the need for consistency between modern measurement methods and those of the not so recent past.
In my varied experience as a statistician I have found that a min/max sample is very often not a good estimator of the mean. Admittedly this refers to samples other than temperature. But in many areas of work it is common place to disregard the outliers (sometimes wrongly).
But to revert to temperatures, I am still puzzled. Let me explain. Take a 24 hour period. Let Tmax and Tmin represent the max and min temperatures recorded that day, then using your notation Tave = (Tmax + Tmin)/2.
But Tave =/= Tmean. It is quite possible for T > Tave for 8 hours and for T < Tave for 16 hours.
Or, the sake of argument, let us assume that during the 8 hours,
T – Tave = 1 degree
and that during the 16 hours,
Tave –T = 1degree
then
Tmean = Tave – 0.3 degrees.
You say that, over a period, the mean of Tmean – Tave will be close to zero. While this not an unreasonable assumption has it ever been proved? For any station using continuous recording it should not require any elaborate calculations, since daily max and min will be available together with the running mean.
You also say that pooling the trends first for Tmean and then for Tave for every station and then subtracting these trends will result in a measure of zero. Again not an unreasonable assumption, provided that the trends in Tmean and Tmin are identical. But are they? Has anyone proved that they are?
You say that the work has been done many times. I have no desire to waste my time reworking what has already been proved. I should, however, be grateful if you could point me to a paper showing where this work has been carried out and reported.
I said: “that CO2 levels are already at 850,000 year highs, that they are probably at 15 million year highs. That the rate of CO2 rise may have no precedent for even longer”
DN replied: “wrong again. During the Late Carboniferous and Early Permian periods (ca. 270-300 MY ago), for example, both temperatures and CO2 concentrations were similar to today’s levels.”
Noone sees that DN hasn’t addressed what I said? Hint: Look at the dates I reference and then look at the date DN references. (hint 2: “MY ago” means million years ago)
Henry@onion
it does not matter when the CO2 was higher
what matters is that is was high before
and earth was luscious, probably close to paradise
for without carbon dioxide there would not be any onions (food)
Did you read my blog?
Acc. to my books the safe working limit of CO2 is 9000 mg/m3
that is 0.75% (9/1200 x 100%)
We are now at only 0.04%
Even at 0.75% you would not die.
Same book says you would need 20% to fall asleep and 30% to die.
So it is not that easy to kill yourself in a car. If caught in time,often people can still revive suicide victims who tried this method….
If you, as an onion want to grow, you need more carbon dioxide, not less.
Sorry, I posted before I completed reading the whole story in my book.
Rabbits have been shown to live for hours in 65% CO2 as long as there was a continuous supply of fresh oxygen….
The conclusion (of that study) was that CO2 cannot be regarded as a poison. People and animals dying of CO2 “poisening” were simply deprived of the required amount of oxygen.
(Remember Co2 is heavier than air)
An attempted omnibus answer..
1) thanks for all the nice comments! And, no, I have no “climate science” qualifications.
2) re: no point in questioning the greenhouse gas effect
Sorry, but there is. The jump from bench experiment to atmosphere isn’t supported in either the theory or the observations we have.
There are some difficult issues underlying this. Temperature is measured, for example, in terms of the energy of motion of molecules and we can model, but don’t really understand, the mechanism by which a single arriving photon interacts with a CO2 molecule in air to produce a change in that molecule’s kinetic energy. Similarly, heat is a measure of the transfer of energy not the thing itself, so we know CO2 enriched air will connect a heat source to a heat sink slightly more efficiently than non enriched air, but next to nothing about how this actually works out in the lower troposphere.
Notice that the people who talk about blankets or greenhouses gases as insulators or one-way heat gates have it completely backwards – in reality adding heavier molecules (e.g. water vapor or CO2) to dry air makes it a better heat conductor, not a better insulator.
3) re: “preaching to the choir” –
Not really the intent. The intent was to point out that we have no basis for any set of comprehensive conclusions about the earth’s climate, that debunking the other guy’s claims provides a valuable public service but tells us nothing about climate, and that we really have neither the data nor the definitions needed to even express reasonable hypotheses about global climate behavior.
4) re: satellite data offers near universal coverage, is generally trustworthy, and is compared to radiosonde data, not surface temperature data.
Yes, this is the best data we’ve got – however the record is very short, not universal, not easily available in raw form, of varying quality, and the underlying calculations are not the same for all instruments – even those measuring on the same wavelengths.
5) it’s ok to average sensor outputs showing similar trends.
Yes and no. Yes, if you have a bunch of temperature sensors in some region and most move in one direction during some interval, then you can reasonably describe the temperature in that region as changing in that direction over that period.
For most purposes that’s good enough – but, no: computing an average southern Alberta temperature change over fifty years of +0.65 degrees C on the basis of a handful of locally applicable observations that are only accurate to plus or minus one or two degrees is absurd.
6) averaging and over simplification via strawmen
6.1 You’re quite right that were the reading of -35.6C based on a single observation, that observation might have been -32F and therefore that no precision need have been magically added by the calculation. Unfortunately.. the number is an interpolation from several records originating at different times, in different places, and under different protocols (e.g. some from the military, some from the ag research station, and some from civil air ops).
6.2 Of course we can compute a diver’s center of mass: my point is that there are conditions under which this kind of model works, and conditions under which it doesn’t – with climate models in the latter group (and diver’s in the former).
6.3 I agree science should object to the word “traumatic” – but the sentence refers to popular belief – hence the quotation marks
6.4 Pointless to question the CO2 meme: – please see comment 2 above.
6.5 To profess does not mean to clearly state real beliefs. (grin). More to the point, species diversity is highly correlated with access to water and heat – so if the research were done, I’m guessing we’d find that a warmer earth would hold more life.
7 – daily min/max and averages
Trends computed on daily averages work if the underlying processes are closed, continuous, and not correlated with time of day. For example temperatures in a brewery vat, (proxy for chem/bio-activity), fit this model.
However, outside air temperatures do not meet the conditions – for example day/night lengths change, chinooks disrupt everything; and, in general, actual readings reflect multiple, non synchronous, input signals added together. A day whose minimum is reached at 11:59PM is very different from one with the same average temperature whose minimum is reached at 5:30AM.
Henry@Steven and Solomon
I have worked with continuous temp. recorders in ovens….
First of all, they need to be calibrated at regular intervals (1 year)
the error of the ones I worked with was at least 0.5 degree C
I would be interested to know what the error is of the temp. recorders you are talking about?
Satellites “calibrated against the same ground sensor readings they’re used to extend and correct. ”
I dunno. Dr. Spencer has, if I recall correctly, several times posted articles to the effect that certain satellite sensors are calibrated by regularly pointing them at outer space and setting the resulting reading to the kinown background (3 deg K, I think), and others are individually calibrated in the lab before launch. Look around drroyspencer.com .
Of course, the averaging and other statistical crunching of the satellite readings has the effect of oversimplifying the results, but the (incredibly huge) quantity of raw data is accurate — for what it is.
Aside from this quibble, a fine article; thanks.
Henry@onion
Just to be clear on this:
If someone claims that global warming is caused by an increase in carbon dioxide it is up to that person to provide me with the evidence. In this respect I would need to see clear results in the relevant concentration range and it must show how much cooling and how much warming is caused by the CO2. This would have to include the radiative cooling caused by CO2 and the cooling by CO2 caused by taking part in the process of photo synthesis.
Just because someone or some entity makes a claim it is not up to me to”prove” that it is not so. A good lesson from the bible it is that you should never follow the crowd if you are not sure they are doing the right thing(s).
So if you make the claim (to me) that carbon dioxide is the cause of global warming, it is up to you to provide me with that evidence. For that, I would expect you to show me exact test results and the method and instruments used to get those results.
People I corresponded with like Weart and Alley, all claim, like you, that those results
do actually exist. Well, I could not find them.
IPPC and them used a system whereby the increase of CO2 and other GHG’s were measured from 1750 to 2005 and then a value of forcing was attributed to each of them according to the warming observed. This would make sense if we knew for sure that GHG’s are the cause of modern warming.
But, surely, that is looking at a problem from the wrong end? That is assuming you know what is causing warming and then working your way back. It is the worst mistake any scientist can make.
To be completely truthful, I did make a similar mistake myself in the past. It happens when you get carried away too much with what you think is right or what you think ought to be.
So, I know what went wrong here.
Re: daily min/max and averages
As a grape-grower I realized that if I was to get the best result from Pinot Noir, which has a thin skin and very sensitive to heat I needed to choose a cool ripening environment. A regular heat spike for a couple of hours in an environment subject to regular cooling overnight is invisible when you look simply at the mean i.e. Max plus Min/2.
I started logging temperatures at 15 minute intervals, but today I would consider a hour sufficient. I discovered that the average of 24 hourly readings can lie up to 2°C either side of the mean.
I realized that what I needed to do was calculate the area above a critical point, in the case of Pinot Noir the critical point could be taken as the average maximum in Burgundy, a good practical bench mark. That is 22°C. The temperature in most parts of France has a narrow range of variation in autumn and that enables grapes to ripen at relatively high temperature without experiencing the damage that accrues when heat spikes occur.
So, practically speaking, if you want to characterize a thermal environment it pays to look at the thermal experience above or below some critical point or within the range that you consider desirable.
The mean is not a good statistic to rely on when money, time and trouble is involved.
As to whether it accurately reflects trends one would have to do some checking. And I have never seen that work in print.
Electronic temperature loggers are now cheap and they can be in the field for a year or more accumulating hourly temperature data. If remote, some communication device may be required and unfortunately in many official records that I have seen there are gaps where one must extrapolate. Hourly temperature data is available from airfields and the USA does a great job of archiving this information and making it freely available on the web. In Australia where people have kept good records for 100 years or more you will have difficulty accessing hourly data for many places earlier than the mid nineteen eighties.
My view: the temperature records are dodgy. Cities are grow ever warmer. The location where the temperature is observed is shifted about as a town grows. The instruments break and are replaced. The environment in the vicinity is constantly changing as houses and roads are built, lawns planted or replaced with concrete, trees grow etc. To estimate the temperature of the globe heroic assumptions and spectacular projections are required in order to get what one might call the the raw data. Its really raw but some might think it is actually ‘cooked’.
Where I live, in the south west corner of Western Australia we have an equable climate with average minima about 10°C in the coolest month. It never snows. People like to take off in the winter to warmer places. Holidays in Bali are very popular, even in summer. That tells you something. Its always best to try and keep a sense of perspective.
Photosynthesis is optimal at about 25°C. Average temperature of this planet is 14-16°C, and there is this awkward thing called ‘seasons’.
The notion that the current temperature is somehow just right is questionable.