A couple of days ago WUWT carried a story, talking about intense cold in Antarctica, carbon dioxide, and the icecap of Mars. This one passage stirred up a significant debate:
According to Weather Underground, Vostok, Antarctica is forecast to reach -113F on Friday. That is four degrees below the freezing point of CO2 and would cause dry (CO2) ice to freeze directly out of the air.
It seemed (at the time) a reasonable statement. The freezing point of CO2 is -109.3 degrees Fahrenheit (-78.5 degrees C). There’s been mentions of this supposed phenomenon of CO2 freezing out of the air before on other blogs and websites. One of the best examples was even an entry in the website “ask a scientist” where the question of CO2 freezing out of the air was posed, and the answer from an Argonne National Laboratory scientist seemed to indicate that CO2 could indeed precipitate as a solid from the air if the temperature was low enough at Earth’s south polar ice cap, specifically at Vostok Station, which holds the record for the lowest surface temperature recorded on Earth at −89.2°C (−128.6°F)
Certainly, at least some of the carbon dioxide in the atmosphere at the poles does freeze out during the winter. However, there is not enough frozen out to accumulate to any extent at the present.
David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory
So, it seemed possible. But as WUWT commenters soon pointed out, temperature is only part of the equation needed to deposit CO2 as a solid from the free atmosphere at that temperature.
Soon we were discussing gas laws, phase diagrams, and partial pressures. The debate mainly centered on whether or not this phase diagram for carbon dioxide applied to 1 atmosphere of pressure of pure CO2 versus simply 1 atmosphere of pressure independent of the purity of the gas.
The author of the post, Steven Goddard wrote in comments:
The phase diagram shows unambiguously that the equilibrium state of CO2 at one atmosphere at 113F is solid. The freezing point of CO2 is -109F at 1 atmosphere.
The PDF referenced doesn’t translate well to the blog size format, but this less detailed phase diagram for CO2 does fit and was mentioned in comments also:
Since many of us know from experience that with ice, be it water ice or CO2 (dry) ice, that a phase change can occur directly from solid to gas (sublimation). It seemed reasonable to conclude that the reverse could be possible, going from a gas to a solid as long as the temperature was below the “triple point” of CO2 as well as the freezing point at 1ATM.
The freezing point/sublimation point of CO2 at 1ATM is at -78.5C (-109.3F). In the situation described in the forecast for Vostok station, the temperature was forecast to reach below the freezing point for CO2 at -80.5 C (-113F ). It seemed reasonable then to concludes that CO2 would freeze right out of the air, much like frost does from water vapor. Plus we had a statement from a scientist at a National Laboratory saying it was possible also. What’s not to like?
One small detail: partial pressure.
The concentration of CO2 in the free atmosphere is very small. Thus the partial pressure of CO2 in the atmosphere is about 0.0004 atmospheres. But wait there’s more. Vostok station is at a high elevation, 3288 meters above sea level (10,787 feet) and the atmosphere is thinner. Thus the partial pressure of CO2 is even lower.
Commenter George E. Smith summed it up pretty well with this paragraph:
At -78.5 deg C (-109F), that equilibrium occurs at a partial pressure of CO2 of 760 mm Hg, one atmosphere. Below that pressure, there isn’t enough abundance of CO2 molecules in the vapor phase for collisions with the solid surface to occur at a fast enough rate to make up for the ones that escaped; so the solid CO2; dry ice, will continue to sublimate.
Basically, there are so few CO2 molecules in the free atmosphere, sublimation rules over deposition as a solid. Yes some CO2 may deposit on a surface at at -80.5 C (-113F ), but it would quickly sublimate back into the free atmosphere, and thus accumulation would not occur.
Meanwhile WUWT reader Ric Werme had written to Dr. David Cook of Argonne National Lab to ask about his original opinion he wrote for “ask a scientist” web site. Ric reports he responded with this:
Ric,
You are correct. In my attempts at being simplistic I made a mistake in my answer to “Freezing CO2″ on the Ask-A-Scientist page. -57 C is the boiling point of CO2. The freezing point of CO2 at atmospheric pressure is -78.5 C (-109.3 F). If the temperature reaches -113 F at Vostok, Antarctica, some carbon dioxide might freeze out of the air, assuming that the carbon dioxide vapor pressure drops to its saturation vapor pressure.
The vapor pressure must reach the saturation vapor pressure for dew or frost to form. This happens at the dew point or frost point temperature, which is dependent on atmospheric pressure and the absolute amount of vapor in the air. As atmospheric temperature increases, the dew/frost point temperature increases. As atmospheric pressure increases, the vapor pressure increases. At very low temperatures, the dew/frost point temperature is very low.
When the temperature of the surface (whether grass or a car window) is below freezing, frost will usually form instead of dew, although water can be super-cooled and not produce dew, fog, or clouds in some cases. Surfaces on the Earth cool off sooner than the air, so dew/frost will normally form on them before fog (water or ice) forms in the air.
The temperature being at “freezing” or below does not imply that frost will form on surfaces or in the air. The vapor pressure must be high enough (saturation vapor pressure) and the temperature low enough (the frost point temperature) for frost to form.
So it seems, Dr. Cook (and our own Steve Goddard) made the basic and simple error of not taking vapor pressure into account. Given our human experience with the everyday freezing of water, we don’t often think about it. I didn’t catch it either initially, nor did some WUWT commenters.
It does demonstrate though, how little CO2 there is in our atmosphere, we can’t even precipitate it to solid under any natural condition of earth.
But, even with the debate apparently settled, the CO2 freezing question was still all in the realm of opinions and phase diagrams. Some people really wanted to see some empirical proof. Some thoughts on experiments were tossed about.
Enter WUWT reader Dr. Thomas Thatcher of the University of Rochester who had not only an idea for an experiment, but the means with which to carry it out. He had a lab freezer which would “maintains -80˚C (-112˚F) in my lab, and it can be set as low as -86˚C (-122˚F).”.
He proposed that he could use that freezer to do a test with dry ice:
The argument, as far as I can tell, is that at the atmospheric partial pressure of CO2, dry ice at -113F will sublimate faster than it forms (which may be different than how a pure CO2 atmosphere would behave). I am in a position to test this, as described above.
…
Based on the arguments presented here, the two postulated outcomes are,
1) significant loss of mass, as the sublimation rate exceeds the deposition rate
2) no change, or negligible gain in mass.
(I suspect that any gain in mass will evaporate on the short walk from the freezer to the balance.)
It’s admittedly an imperfect experiment. But I expect the outcome will be rather obvious; the dry ice will be gone in the morning. We’ll see.
He conducted his experiment overnight between Thursday and Friday, and writes:
The freezer is a VWR brand ultralow temperature upright freezer, similar to models shown here.
http://www.vwrsp.com/catalog/product/index.cgi?catalog_number=14230-120&inE=1&highlight=14230-120
It is set to -86C, the temperature typically rises 1-3C when opened, and recovers in about 30 minutes. (Factory temperature calibration was NIST-traceable but it has not been recalibrated since it was installed here.) The samples were loaded at 4:30 pm and removed at 9:30 am, so the freezer will have been largely undisturbed during that time.
The interior is mostly filled with stainless steel racks that hold cardboard boxes for storing biological samples. I placed the test samples in two boxes on the bottom shelf at the rear of the freezer, the coldest zone and closest to the temperature probe.
One sample was placed in an open box with extra holes cut to allow air circulation. The other sample was placed in small zip top plastic bag inside a cardboard box. The samples were weighed by difference before being placed in the freezer and after removal in the morning. Additional weighings were taken to estimate the amount of sublimation during the weighing procedure and the amount of water that might condense on the boxes, but these amounts proved insignificant next to the overall results.
The samples were placed in the freezer at 4:30pm (reading -82C) and removed at 10:00am (reading -83C).
Open container, start weight 36.5g dry ice, end weight 0g, amount sublimated 100%.
Zip-top bag, start weight 27.6g dry ice, end weight 25.3g, amount sublimated 8.3%
Proving, I think, that CO2 will freeze and remain frozen at below -78.5C if the partial pressure of CO2 is near 1 ATM, but the CO2 will rapidly sublimate is the partial pressure of CO2 is near atmospheric normal.
And he concludes:
Bottom line, 40g of dry ice placed in an open container at -82C completely sublimated overnight, while 27g of dry ice placed in a zip top bag retained 90% of its mass. This proves two things, first, that the temperature of the freezer did not exceed -78.5C for any appreciable period of time, and second that yes indeed, the partial pressure of CO2 is the key to the problem.
Best of all, he sent photos of the experiment he conducted:
Thanks to everyone who participated in the debate, including Ric Werme for his correspondence help and especially Tom Thatcher for conducting the experiment and taking photos.
We all learned something, we had a little fun, some online yelling occurred, and some egos were bruised. Overall though it was worthwhile that this myth of “CO2 snow at Vostok station” was finally put to rest.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Flanagan, you insist you are not a troll and then cherry pick your way through a few quotes from a 33 page paper and misrepresent completely what it had to say. Anyone can do that. At the bottom of page 16 of the PDF it also says
“… but when temperatures are hotter than usual, the least educated become those most likely to agree that there is evidence for climate change.”
to cite that phrase out of context would also be a gross misrepresentation of the paper. That would be the behavior of a troll and that is exactly what you have been doing. To repeat: the paper said nothing, I repeat, nothing about the relative intelligence of alarmists vs. deniers. What it addressed was the conditions under which perceptions of global warming changed in the face of perceptions about the weather.
Simple syllogism:
Trolls cherry pick quotes, misrepresent conclusions, obfuscate and argue ad infinitum;
Flanagan cherry picks quotes, misrepresents conclusions, obfuscates and argues ad infinitum;
Therefore…..
For anyone interested in reaching their own conclusions, the paper by Egan and Mullin can be downloaded here (the link is, by the way, courtesy of flanagan):
http://politics.as.nyu.edu/docs/IO/4819/egan_mullin.pdf
please weigh in. Does it make any conclusions about the relative intelligence of warmers or deniers?
Re: Paul Coppin
Water can/does sublimate, but not under any natural terrestrial conditions. See following link for details. http://encarta.msn.com/media_461541579/phase_diagram_for_water.html
Mike
And yet we are told that comets are frozen balls of water ice and CO2 ice in the Vacuum Of Space… (Just what IS the partial pressure of CO2 in a hard vacuum?…)
So, while I think the issue of pure CO2 freezing out has been settled, I think the issue of “CO2 Clathrate Snow” is still a bit, er, open…
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-472SWX0-4Y&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=583e769d0c26987de7ad7805b5945f98
Is not about CO2, they used oxygen, but has this little gem in it:
Oxygen clathrate hydrate which was used as a model substance for other clathrate hydrates with highly volatile guest species was formed from microporous vapor-deposited amorphous solid water prepared at 77 K, and from O2 enclosed in the pores during heating and sintering of the amorphous deposit up to ≈120 K, with “external” O2 pressures during the sintering and gas enclosure process of 10, 100, 200, and ≈ 1700 mbar. Clathrate hydrate formation occurred between ≈170 and 210 K as seen by X-ray diffraction. If was stabilized by layers of ice and decomposed completely on heating at a rate of 10 K min− only between 240 and 250 K, which is much higher than anticipated from dissociation pressure/temperature curves.
Notice we have pressures as low as 10 mbar and formation as high as 210 Kelvin for O2 clathrate in water… Last time I looked oxygen had a boiling point of about 90K and a critical point 154K 5.4 Mpa so having it form a “solid” in a Clathrate at 210K is, um, “interesting” …
Other interesting bits are in:
http://www.sciencemag.org/cgi/content/abstract/254/5031/548
http://ppeppd07.chemeng.ntua.gr/manuscripts/366.pdf
You can get a great deal of interesting reading with a google search such as for “clathrate formation elevated temperature CO2 -methane”.
At the end of a bunch of hours of wandering I’m left with these conclusions:
1) We don’t have a good handle on clathrate formation nor decomposition.
2) Decomposition is not always symmetric with composition.
3) Clathrates do screwy things to the temperature of deposition of species.
4) It is related to a physical crystalline cage capture of each atom or molecule, not so much to physical properties of the bulk materials (i.e. the degree of fit and atomic charges / attractions inside the “cage” relative to the trapped species matter most.
5) Small “contaminants” can alter things a great deal, including contaminants such as salt and biological / organic materials.
6) It’s going to be incredibly hard to figure this out without an actual on the ground test with the specific mix of “stuff” at the pole in the polar air.
7) The low CO2 statistic for the south polar air is, um, “interesting”…
This abstract looked really interesting:
http://pubs.acs.org/doi/abs/10.1021/je034260i
Where the google “tease” had:
Measurements were taken up to the point of clathrate formation. …. They measured only the isotherm at the critical temperature of CO2 up to 10 MPa. …
and the abstract:
Density data of the water + carbon dioxide system were determined using a calibrated vibrating tube mass flow meter with a uncertainty below 0.15%. Measurements were performed in the pressure and temperature regimes (1 to 30) MPa and (284 to 332) K, respectively. The water-rich phase density showed a pronounced dependence on pressure and temperature whereas the CO2-rich phase density did not change from the pure density within the measuring uncertainty. A regression function was developed which describes the experimental data in the range studied.
But the article was paywalled and I don’t have enough “credentials” for whatever they think are deserving minds… (and / or I’m just too damn cheap… 😉
Even the wiki article
http://en.wikipedia.org/wiki/Carbon_dioxide_clathrate
is slightly helpful (though dismissive of CO2 clathrates on the surface of the planet) with statements like:
Carbon dioxide hydrate is a Type I gas clathrate (Sloan 1998). However, there has been some experimental evidence for the development of a metastable Type II phase at temperature near the ice melting point (Fleyfel and Devlin 1990, Staykova et al. 2003).
The article might be this one buried in the references:
Fleyfel, F. and Devlin, J. P. (1990) Carbon Dioxide Clathrate Hydrate Epitaxial Growth: Spectroscopic Evidence for Formation of the Simple Type-II CO2 Hydrate. J. Phys. Chem. 95, pp. 3811-3815
And it has these bits of temperatures for dissociation and pressures for decomposition, but not both together and not for formation. Sigh.
Later on in 1894, Villard deduced the hydrate composition as CO2·6H2O. Three years later, he published the hydrate dissociation curve in the range 267 K to 283 K (Villard 1897). Tamman & Krige (1925) measured the hydrate decomposition curve from 253 K down to 230 K and Frost & Deaton (1946) determined the dissociation pressure between 273 and 283 K. Takenouchi & Kennedy (1965) measured the decomposition curve from 45 bars up to 2 kbar (4.5 to 200 MPa). For the first time the CO2 hydrate was classified as a Type I clathrate by von Stackelberg & Muller (1954).
What’s a budding Kitchen Scientist to do… I go do the test at the south pole myself if I had the money. I’d do it in the kitchen if I had a super freezer. Just chasing the papers is getting tedious…
At any rate, I can smell an interesting effect going on here in a temperature regime that is not within the normal intuitive range of people and involving surface and crystallization chemistry that is way outside the ken of most folks (and many / most chemists…). I’m certain there is something of importance inside this box; I just can see how to get the darned thing open… 8-}
Don’t know nuthin about clathrates or CO2 sublimation, but the ice cubes I froze in my ice trays last October were a lot smaller when I decided I needed some in April.
rephelan (08:44:46) :
uhhh… in my diatribe above, please replace “intelligence” with “level of education”. The paper did not use “intelligence”.
Jeremy (13:42:45) : They used to teach this in Grade 11 in Canada and even I can remember Dalton’s, Charles and Boyle’s Laws. Please let’s not make a mountain out of basic stuff.
I got it in Grade 10 IIRC of my hick farm home town of 40 years ago… but from inspection of my kids homework while “helping them” it looked like the present High School Chemistry was, er, very lacking in critical thinking skills and heavy on memorizing how to do equilibrium calculations… (In other words “Don’t think about what’s going on, just follow the formulas you have been taught”…
I asked the teacher on “open house night” what he did to make chemistry interesting, did they have any fun “hands on chemistry”. He looked at me blankly. I gave a couple of examples I remembered from my (Excellent) chemistry teacher. His response was, with a deeply derisive tone of voice, “Oh, you mean demonstrations. Not much.” He clearly felt that actually doing chemistry was meaningless when compared with the ability to play with word problem sets. This was in a well laid out chemistry room with sinks and gas outlets at each station. A brief inspection showed a fair amount of dust and dry/aged hard water deposits (i.e. not much actual use in a very long time…)
Frankly, my kids would have learned more chemistry in the kitchen with common household items in a long weekend than they actually learned in high school. (I did teach them some this way). THAT is why most of the folks “doing the science” today (and almost everyone who is NOT a trained scientist, IMHO) have this so horridly backwards. They have spent a young lifetime being taught that “science” is a word game, that actual experiments are “demonstrations”, and that computer models can give you the right answer to things much more quickly than you can find it yourself… Oh, and don’t think. Just do the formulas as you have been taught.
It is a special person who can rise above that and move against that tide.
George M (19:16:50) :
William Sears (11:54:01) :
but it would be nice if you had a printer format option, as some topics deserve to be read at leisure.
William:
Simply highlight the text or article of interest, copy and paste to Wordpad or almost any word processing program and print. Read at leisure.
Maybe it’s a Mac thing… but when I want to save a piece to read later, I just choose “print” in the “file” dropdown menu and when presented my options choose “save as pdf”. Then I have a PDF file I can read or print whenever.
rephelan (08:44:46) : please weigh in. Does it make any conclusions about the relative intelligence of warmers or deniers?
I don’t see anything about relative intelligence, but it does seem to support my bald assertion from extensive personal observation that the very intelligent are more likely to believe their own BS even in the presence of physical evidence to the contrary.
One can most easily see this manifest at places like Mensa gatherings where there is always someone or other arguing for a completely whacky favorite belief despite all the world around them to see… It is common enough that I think it may be a general property of the over educated and highly intelligent: They just have a harder time getting a grip on reality, here and now.
Nope. I offer no proof. It’s just an early stage observation of 40+ years running total.
BTW, this “rule” has stood me in good stead for a very long time. I first started by applying it to my own BS quotient (about 35 years ago). Part of my “keeping a tidy mind” process. I do a “reality check” on things whenever possible. Computer programs especially (where we used the phrase “reality check” in a more formal sense as part of the jargon in my group of programmers.)
And that, boys and girls, is why I trust the “local weather” (from all over the planet) far more than I will ever trust any computer generated anomaly map from anyone. And why I would put actual experimental results rather close to first in my list of important attributes of science…
So my “vote” on Flanigan would be: Yes, he’s a troll. But a polite and a relatively harmless one who sometimes (accidentally?) can cause an interesting discussion to follow, while the worst of his trollishness just creates easy “softball” points to get warmed up on while having First Coffee. So I’d vote for not tossing him. Even a broken clock can get you thinking about how to make a good clock…
http://chiefio.wordpress.com/2009/06/13/making-an-english-foot/
has a couple of links to some interesting science done while making pendulum clocks very stable. Including using both iron and brass parts in the pendulum so as they differentially expand they cancel out the thermal expansion error in pendulum length…
E.M.Smith (13:11:58) : I’m certain there is something of importance inside this box; I just can see how to get the darned thing open… 8-}
That was supposed to be “I just can’t see”…
Mike (12:22:57) :
How so? Is it possible that you’ve missed the whole point of the partial pressure discussion?
According to this source
, the vapor pressure of ice at -10 C is 1.95 torr, or about 0.0026. So any atmospheric conditions drier than that (i.e. less than 100% relative humidity) should make the conditions right for sublimation.
Should be “0.0026 atm”.
When the suggestion arose that someone should do an experiment to resolve the argument between competing theories, somebody else (forget who but it’s in the record) pointed out that these phase diagrams are the result of a whole bunch of experimental evidence that has already been collected.
In the majority of cases, I believe that is true; but not necessarily always.
It is my understanding that such things as phase diagrams, solubility products and the like can actually be calculated from theoretical considerations; generally quantum theory in nature.
For example the whole issue of atomic structure and electron orbitals, came about because of theoretical attempts to explaing the spectral lines of the Hydrogen atom, and subsequently other atoms.
The Balmer series and Paschen series and other accoutrements of atomic spectra led to the Bohr atom, and ultimately the theory of orbitals. All of this suddenly elevated chemistry from; “mix a dash of this with a pinch of that and you get a whiff of that other thing. Suddenly (well actually after a whole lot of hard work by many), it became possible to predict the outcome of the pinch/dash experiemnts, with surprising accuracy.
In “The Constitution of Binary Alloys”, a standard reference text (now unavailable), the phase diagrams of many binary inorganic systems are chronicled. They range from the simplest gold/silver phase diagram, where the two components are completely soluble in each other in any possible mixture, to that terror of all metallurgical studies; the Iron Carbon phase diagram; better known as the “steel” diagram.
I have no idea how it is possible to unravel the iron carnon binary phase diagram, with all its intermediate compounds and multiple paths. How experimentalists did experiments to unlock those secrets is just beyond my imagination; yet the outcome is key to monerd structural engineering.
Somehwere in the iron/carbon binary phase diagram is the key to why the Titanic sank; something to do with very low carbon (iron) rivets, instead of the steel rivets that the designers called for; which were apaprently unavailable in sufficient quantities to build the ship.
In the cold waters of icebergia Atlantis; those low carbon rivets turned to s***, and popped their heads off.
But apparently it is possible to compute these phase diagrams from fundamental physics and chemistry; well chemistry is just applied physics anyway. Fortunately such studeis are beyond my pay scale, so I am glad that there are those who do understand that.
I used to teach the atomic physics stuff at a freshman level; but much of that is long gone to the vaporous universe of senility or Alzheimers or just time elapse. I know that the s/p/d/f labels assigned to electron energy levels. or at least their quantum numbers, used to have some appearance meaning to spectroscopists. s stood forr sharb, and d for diffuse, as the resulting spectral lines had those appearanceas. Can’t remember what the other two stand for; but I guess if we need four bases for DNA assembly it is reasonable to have four different quantum number labels, regardless of how they originally came to be.
Try to get some modern egg-head Quantum physicist to explain where s/p/d/f came from; and they probably didn’t even know there ever was such a job title as “spectroscopist”.
I once wanted to be one; more than I wanted to be a fireman.
So yest the CO2 phase diagram was already the work of much experimental verification; and most of us don’t have the means or the patience to do all those experiments; so we thank those who constructed the phase diagram; so we don’t have to do the experiment; But Dr Thatcher’s simple overnighter lab demonstration, is a simple way to save thousands of words. Too bad you can’t do that with a stick in the sandy beach though.
George
E M Smith
I like Flanagan and Joel Shore and RW and Phil, and others who do not sing from the same song sheet as the rest of us. It is good to have a (mostly) civilised discussion with people you will never agree with-and who will never agree with you- and who sometimes make good and thought provoking points.
Tonyb
TonyB (16:32:34) :
E M Smith
I like […] who do not sing from the same song sheet as the rest of us.
I agree. Without sand, no pearls…
EM Smith
Did you get my email? Your last post on directions on how to contact you were rather cryptic to someone like me who studiously avoids the crosswords we have in every UK newspaper. If you did get it, can you do a quick ‘return’ and I will send you the information promised.
Tonyb .
“”” E.M.Smith (14:50:18) :
rephelan (08:44:46) : please weigh in. Does it make any conclusions about the relative intelligence of warmers or deniers?
I don’t see anything about relative intelligence, but it does seem to support my bald assertion from extensive personal observation that the very intelligent are more likely to believe their own BS even in the presence of physical evidence to the contrary.
One can most easily see this manifest at places like Mensa gatherings where there is always someone or other arguing for a completely whacky favorite belief despite all the world around them to see… “””
Well in colloquial Mexican, “Mensa” refers to a crazy lady; not to a club for self annointed air heads. Oh I know the name is supposed to relate to a “table”, but remember in Mexican Spanish, that a table is “mesa” not mensa” which as I have said is a crazy lady; well it’s a different Latin root you see, and all the ladies know why it means a crazy lady.
As I explained to Ric when we corresponded, we attempt to keep our explanations simple in Ask-A-Scientist. As I continued to do so in my response to Ric, I didn’t indicate that my statements were to be considered in the context of a constant volume assumption.
So, my re-posting of my reply to Ric onto Ask-A-Scientist will again be modified to try to better clarify that situation.
I’m only too happy for people to point out the mistakes that we scientists make. Indeed we do make mistakes, which is why we go through a peer review process when we seek to publish our scientific results. Even so, we still find errors in peer reviewed publications. As the group that I work in once found, an error can propagate into further publications based on an earlier mistake. On one such occasion, we published a paper to show how three authors had made further errors based on an initial published error. We must be constantly vigilant in looking for and reporting on such situations.
E.M.Smith (14:50:18) :
All in all, I think the crowd here is pretty intelligent – because discussions sound like Mensa meetings. (At least those where the people not interested in climate have fled someplace else. 😉 )