(Note: this originally published on Dr. Spencer’s blog on April 25th, and I asked if I could reproduce it here. While I know some readers might argue the finer points of some items in the list, I think it is important to keep sight of these. – Anthony)
by Roy W. Spencer, Ph. D.
There are some very good arguments for being skeptical of global warming predictions. But the proliferation of bad arguments is becoming almost dizzying.
I understand and appreciate that many of the things we think we know in science end up being wrong. I get that. But some of the alternative explanations I’m seeing border on the ludicrous.
So, here’s my Top 10 list of stupid skeptic arguments. I’m sure there are more, and maybe I missed a couple important ones. Oh well.
My obvious goal here is not to change minds that are already made up, which is impossible (by definition), but to reach 1,000+ (mostly nasty) comments in response to this post. So, help me out here!
1. THERE IS NO GREENHOUSE EFFECT. Despite the fact that downwelling IR from the sky can be measured, and amounts to a level (~300 W/m2) that can be scarcely be ignored; the neglect of which would totally screw up weather forecast model runs if it was not included; and would lead to VERY cold nights if it didn’t exist; and can be easily measured directly with a handheld IR thermometer pointed at the sky (because an IR thermometer measures the IR-induced temperature change of the surface of a thermopile, QED)… Please stop the “no greenhouse effect” stuff. It’s making us skeptics look bad. I’ve blogged on this numerous times…maybe start here.
2. THE GREENHOUSE EFFECT VIOLATES THE 2ND LAW OF THERMODYNAMICS. The second law can be stated in several ways, but one way is that the net flow of energy must be from higher temperature to lower temperature. This is not violated by the greenhouse effect. The apparent violation of the 2nd Law seems to be traced to the fact that all bodies emit IR radiation…including cooler bodies toward warmer bodies. But the NET flow of thermal radiation is still from the warmer body to the cooler body. Even if you don’t believe there is 2-way flow, and only 1-way flow…the rate of flow depends upon the temperature of both bodies, and changing the cooler body’s temperature will change the cooling rate (and thus the temperature) of the warmer body. So, yes, a cooler body can make a warm body even warmer still…as evidenced by putting your clothes on.
3. CO2 CANT CAUSE WARMING BECAUSE CO2 EMITS IR AS FAST AS IT ABSORBS. No. When a CO2 molecule absorbs an IR photon, the mean free path within the atmosphere is so short that the molecule gives up its energy to surrounding molecules before it can (on average) emit an IR photon in its temporarily excited state. See more here. Also important is the fact that the rate at which a CO2 molecule absorbs IR is mostly independent of temperature, but the rate at which it emits IR increases strongly with temperature. There is no requirement that a layer of air emits as much IR as it absorbs…in fact, in general, the the rates of IR emission and absorption are pretty far from equal.
4. CO2 COOLS, NOT WARMS, THE ATMOSPHERE. This one is a little more subtle because the net effect of greenhouse gases is to cool the upper atmosphere, and warm the lower atmosphere, compared to if no greenhouse gases were present. Since any IR absorber is also an IR emitter, a CO2 molecule can both cool and warm, because it both absorbs and emits IR photons.
5. ADDING CO2 TO THE ATMOSPHERE HAS NO EFFECT BECAUSE THE CO2 ABSORPTION BANDS ARE ALREADY 100% OPAQUE. First, no they are not, and that’s because of pressure broadening. Second, even if the atmosphere was 100% opaque, it doesn’t matter. Here’s why.
6. LOWER ATMOSPHERIC WARMTH IS DUE TO THE LAPSE RATE/ADIABATIC COMPRESSION. No, the lapse rate describes how the temperature of a parcel of air changes from adiabatic compression/expansion of air as it sinks/rises. So, it can explain how the temperature changes during convective overturning, but not what the absolute temperature is. Explaining absolute air temperature is an energy budget question. You cannot write a physics-based equation to obtain the average temperature at any altitude without using the energy budget. If adiabatic compression explains temperature, why is the atmospheric temperature at 100 mb is nearly the same as the temperature at 1 mb, despite 100x as much atmospheric pressure? More about all this here.
7. WARMING CAUSES CO2 TO RISE, NOT THE OTHER WAY AROUND The rate of rise in atmospheric CO2 is currently 2 ppm/yr, a rate which is 100 times as fast as any time in the 300,000 year Vostok ice core record. And we know our consumption of fossil fuels is emitting CO2 200 times as fast! So, where is the 100x as fast rise in today’s temperature causing this CO2 rise? C’mon people, think. But not to worry…CO2 is the elixir of life…let’s embrace more of it!
8. THE IPCC MODELS ARE FOR A FLAT EARTH I have no explanation where this little tidbit of misinformation comes from. Climate models address a spherical, rotating, Earth with a day-night (diurnal) cycle in solar illumination and atmospheric Coriolis force (due to both Earth curvature and rotation). Yes, you can do a global average of energy flows and show them in a flat-earth cartoon, like the Kiehl-Trenberth energy budget diagram which is a useful learning tool, but I hope most thinking people can distinguish between a handful of global-average average numbers in a conceptual diagram, and a full-blown 3D global climate model.
9. THERE IS NO SUCH THING AS A GLOBAL AVERAGE TEMPERATURE Really?! Is there an average temperature of your bathtub full of water? Or of a room in your house? Now, we might argue over how to do the averaging (Spatial? Mass-weighted?), but you can compute an average, and you can monitor it over time, and see if it changes. The exercise is only futile if your sampling isn’t good enough to realistically monitor changes over time. Just because we don’t know the average surface temperature of the Earth to better than, say 1 deg. C, doesn’t mean we can’t monitor changes in the average over time. We have never known exactly how many people are in the U.S., but we have useful estimates of how the number has increased in the last 50-100 years. Why is “temperature” so important? Because the thermal IR emission in response to temperature is what stabilizes the climate system….the hotter things get, the more energy is lost to outer space.
10. THE EARTH ISN’T A BLACK BODY. Well, duh. No one said it was. In the broadband IR, though, it’s close to a blackbody, with an average emissivity of around 0.95. But whether a climate model uses 0.95 or 1.0 for surface emissivity isn’t going to change the conclusions we make about the sensitivity of the climate system to increasing carbon dioxide.
I’m sure I could come up with a longer list than this, but these were the main issues that came to mind.
So why am I trying to stir up a hornets nest (again)? Because when skeptics embrace “science” that is worse that the IPCC’s science, we hurt our credibility.
NOTE: Because of the large number of negative comments this post will generate, please excuse me if I don’t respond to every one. Or even very many of them. But if I see a new point being made I haven’t addressed before, I’ll be more likely to respond.
What surprises me most about the comments in this thread, is the number of people who say they have never seen these weak arguments before – if so they have not been paying attention, as all of them are trotted out regularly on this and other sites.
I think you need a point 11.
11. It is all due to the motions of Jupiter and/or Saturn i.e the astrology argument.
climatereason: What does that average tell us? Is it useful? Is it meaningful? Can we learn anything from it?
Is it merely hiding the fact that some of the rooms are distinctly chilly whilst others are just about warm enough?
Is the average the same in summer as in winter? Do the furnace and air conditioner increase or decrease the average? Those latter are measures of whether the appliances are working in the conditions for which they have been designed.
The Earth mean temperature is a result, not a cause, of all the processes that happen. If the mean is increasing across time, especially if it is increasing rapidly, that is important to know. Its value at any single time or any particular region, or globally for a single year is not important. Only in comparisons is it very meaningful.
Whether the mean is accurately measured is a different question: If it is measure accurately enough then it is useful, even if there is estimation error.
mike_la_jolla says:
May 1, 2014 at 3:47 pm
I’m confused. This is, by a wide margin, the largest group of skeptics on the Internet. While lurking, I cannot recall hearing any of the arguments 1-10 with the possible exception of item 9. Did I miss something?
>>>>>>>>>>>>>>>>>..
Yes. I’ve been active on this blog for years and have seen every last one of those arguments many, many times. I’ve debated proponents of them using real world examples that a ten year old ought to be able to comprehend, to no avail.
The worst one is the whole 2nd Law business which drives me batty. You don’t see it on this blog much anymore because the sl@yers and their acolytes have pretty much been banned. Plus Anth_ny published a couple of experiments that are pretty conclusive and which also served to silence much of that nonsense. I actually had an article mostly written based on an experiment of my own design that absolutely crushed the nonsense and could be performed by a 12 year old. I never submitted it because the issue had been done to death and I didn’t want to wake it up again.
But bottom line, every last one of the issues that Roy raises has been argued incessantly at one point in time or another on this and other blogs. It fascinates me that a guy like Spencer has designed and built instrumentation that has been shot into orbit, which can measure temperatures at various elevations in the atmosphere, has been proven accurate by comparing to balloon and other measurement data, and still gets excoriated by neophytes who are certain he doesn’t understand the physics. As a consequence he most likely feels under attack from both sides of the debate, which is a shame. What he has accomplished is nothing short of brilliant and I consider it both an honour and a miracle of modern technology that I can participate in a forum like this or on his own site and see what he has to say on various topics.
He’s also one of the few recognized scientists working in the climate research field that have had the cahoney’s to stand up to the alarmists and call BS. We should be collectively defending him from the moronic attacks of pseudo skeptics who are no better (worse!) than their alarmist-know-nothing-about-science counterparts, even if there is some minor disagreement on some of the finer points of his article.
Yet some of us sceptics are interested in this metric when it comes to the Medieval Warm Period or the Little Ice Age IF we insist it was global and synchronous? No? You can’t have ya cake and eat it.
Again we could ask what is the average temperature during ice ages? I only ask because the usual state of the Earth in the last few million years is…………………………………an ice age. Like I said there it is.
Spencer’s point about comparison and knowing about changes is crystal clear to me.
mike_la_jolla says:
May 1, 2014 at 3:47 pm
Good point, but they’re out there. The Slayers, for instance, who deny that CO2 can warm the air, are banned from this pro-science site, which takes some doing, given the inclusiveness of its host, who in the interest of free speech permits creationist comments, despite giving ammo to CACA advocates seeking to disparage this award-winning science blog.
Some on the list could be in effect straw men, since you find them more on SkepticalScience than from real human skeptics, however.
The Earth has experienced a hot house Earth with crocodiles in the Arctic and a snowball Earth and everything in between. I think this is meaningful. If yes, then would a 2C change be meaningful in global average temperatures? We can’t have our cake and eat it. You have to measure it otherwise you would be sitting in one of your ‘rooms’ nice and comfy while there is an ice age and tell us is this is not meaningful? Sorry for using extreme examples to make my point but you have to measure and compare OTHERWISE OUR ATTACKS ON THE IPCC’S TEMPERATURE PROJECTIONS V OBSERVATIONS ARE NOT MEANINGFUL. I hope you get it.
Nullius in Verba says: May 1, 2014 at 3:52 pm
“What essential physical property has the atmosphere got that water has not, that explains the correct result?”
Length scale, and, oddly enough, opacity. The limiting relation of your subdivisions is called Rosseland transport. It becomes just a diffusion, with diffusivity inversely proportional to absorptivity. In water it is negligible, and so is thermal radiative transport. It is turbulent diffusion, even in calm water, that is quite adequate to bring solar heat back to the surface.
In the absence of that, there can be an issue. Glass has rather similar optics, but of course no turbulent transport. Here is a glassmaker explaining how glass in sunlight actually gets quite hot in the interior, and it can degrade its properties. There is, of course, no way you can feel that, because as soon as a surface is exposed, the surface temperature rapidly drops.
I just had a look at the original article on Spencer’s site. The comments there contain far more nonsense than the comments here. I am not sure what conclusion to draw from that….
rgbatduke says:
May 1, 2014 at 3:18 pm
Yes, the gap is there. However, the weakness in this argument is that it only tells the impedance to IR up to the current atmospheric constitution. What it does not tell us is the incremental sensitivity of IR impedance to increased GHG concentration.
I.e., it is basically the function evaluated at the current abscissa, not the derivative. The slope of a secant line, not a tangent line. For all we know, the actual sensitivity (tangent line) at the current state of the climate may well slope negative, even while the overall sensitivity (secant line) slopes positive.
rgbatduke says:
May 1, 2014 at 3:18 pm
—————————————————————–
Having an atmosphere has an temperature effect, the composition of it doesn’t (clouds aside). None of what you present here shows that the temperature is raised by the presence of any particular gas. Pointing an IR thermometer upwards will just give a proxy measurement of the temperature of the atmosphere, it does not tell you what effect the component gases have.
So this point still remains …
Amatør1 says:
May 1, 2014 at 12:44 pm
Show us the empirical data proving that a ‘greenhouse effect’ caused by CO2 exists
Re #7 – My interpretation of CO2 concentrations and ice ages is that during an ice age there is much less vegetation so much less CO2 formation. So when the temperatures go up and ice retreats plants come back causing CO2 to go up. That guess also means that CO2 had nothing to do with recovery form ice ages.
Neillusion:
“A few comments say that O2 & N2 dont absorb EM. Hasn’t it been established that, not only ‘they do’, but also that they are actually quite significant in the big picture?”
Symmetric small molecules, including N2, O2, and Ar (the three most abundant gases in the atmosphere) are transparent to infrared.
leftturnandre says:
May 1, 2014 at 3:29 pm
“Lets examine #10”
——————————-
Yes let’s do 😉
Blackbody calcs were -90C out for the lunar regolith.
For our oceans it’s around +98C.
Without atmospheric cooling or DWLWIR our oceans would become a giant evaporation constrained solar storage pond with temperatures topping 80C.
However climastrologists and lukewarmers alike claim that without atmospheric cooling and DWLWIR our oceans would be at -18C.
They went and treated or deep transparent oceans as a “near blackbody” instead of a SW “selective coating” over 71% of the lithosphere. This error is so big it negates not just AGW but the entire radiative GHE hypothesis itself.
The sun heats the oceans.
The atmosphere cools the oceans.
Radiative gases cool our atmosphere.
AGW is a physical impossibility.
It really is that simple 😉
For markrust
Standard atmosphere pressure is 10100 kilograms per square meter. If the entire atmosphere had the same density as at sea level at 15C then divide by sea level density of air.
Thats 1.225 kilograms per cubic meter, so 10100/1.225 is 8245 meters. The standard atmosphere would be 8245 meters thick if it had the same density as at sea level.
Since CO2 is .0004 by volume of standard atmosphere, then .0004 times 8245 is about 3.3 meters.
By weight, CO2 is about 6 kilograms of the 10100 kilograms of atmosphere.
Thank you bw
and 400 ppm times your 100000 meters is 40 meters
Carrick says: May 1, 2014 at 9:29 am
“Ironically, Nick Stokes, hardly a climate sciences skeptic, was one of the people making the absurd argument you couldn’t measure the absolute temperature of the Earth.”
Yes, I was wryly noting that I could be a proponent of point 9. But I think Roy must have been talking about global average anomaly, which is what UAH publishes. He should have made that clearer. Carrick is referring to a discussion where people said that climate scientists were wrong in talking about an average absolute temperature, and I asked, well do they? If they do, there must be a number you can quote. What is it? 12°? 15°? I never got an answer. Now, that’s absurd 🙂
In principle there could be an average absolute temperature, but we can’t measure it, because it is too spatially variable, at least on land. It’s effectively a Nyquist issue. No feasible pattern of terrestrial measurement can resolve the spatial variation. We already acknowledge that we can’t usefully resolve the vertical variation in the bottom few metres, and stick to specifying that we measure at 1.5m only.
That’s why only an average anomaly is meaningful. Anomalies are spatially much less variable, over hundreds of km, and that can be matched by station measurement.
This has to be the worst ‘sceptical’ argument. Even if GISS, RSS etc can’t measure it, it does not mean it does not exist. To be fair some say it is ‘meaningless.’ I say the temperature difference between a hot house Earth and a snowball Earth is not meaningless. A 0.8C rise in ‘global average temperature’ since LIA is meaningful and very beneficial. The one downside is the end of ice skating on the River Thames. 😉
Kristian asks: “So what gases are ultimately emitting earth’s IR to space, then, Robert? Since H2O and CO2 are apparently ‘unemitting’ it …”
That’s simple:
* The warm surface emits “bright” IR across the IR spectrum.
* CO2 & H2O near the surface absorb the “bright” IR within certain bands.
* Cool CO2 & H2O high in the atmosphere emit the ‘dim’ IR to space within those same bands.
Without the GHGs, more of the “bright” IR would escape, increasing the total energy loss to space and hence cooling the earth. With more GHGs. the escaping IR would come from even higher in the atmosphere where it is even cooler leading to even less IR escaping to space, and more warming of the surface.
David Ramsay Steele @ur momisugly here
There is a proliferation of comments on this very thread that attempt to refute the points in Dr Spencer’s article, particularly 4, 7 and 9. By my count, there are 70 direct refutations of various points in the top article in this thread alone, and that does not include the number of posts that express doubt about various points as a query.
For anyone doubting that most of the points Dr Spencer has raised proliferate the web, just do a google search using simple terms. Eg, I just googled “CO2 2nd law thermodynamics,” and plenty of entries came up corroborating Dr Spencer’s point that it is prolific. “no such thing global average temperature” generated 4 million hits on my browser, and while some entries didn’t fit the point, plenty did within the first couple of pages, including articles rebutting the notion (inferring someone had made the claim in the first place).
When googling “WARMING CAUSES CO2 TO RISE, NOT THE OTHER WAY AROUND”, copying the phrase directly from Spencer’s post, one of the entries pointed me to the most popular science website on the net, with an article trying to demonstrate exactly that.
But if you’re in doubt have a search with a few term permutations for the points above, and see what titles you get in the first 5 pages or so. Included will be articles rebutting those points, which corroborate that the points are being made.
A couple of the points in the article are not so prolific, but Dr Spencer said as much.
ZombieSymmetry says:
May 1, 2014 at 4:58 pm
In effect, you are correct, but O2 weakly absorbs in the borderline IR/visible spectrum.
Konrad says “Without atmospheric cooling or DWLWIR our oceans would become a giant evaporation constrained solar storage pond with temperatures topping 80C.”
80 C corresponds to ~ 880 W/m^2. So you would be right if the ocean were heated 24/7 by midday sun in the tropics. 🙂
mark rust,
If the atmosphere were 100km at constant pressure and temperature and segregated into layers by component, then the CO2 layer would indeed by ~40 m thick. 0.0004 * 100,000m = 40. But for the mass/m² of the Earth’s atmosphere, the pressure would be more than an order of magnitude less than the surface pressure we observe. The standard way the composition by thickness as if the components were separated into individual layers is to assume that the total mass/m² is at Standard Temperature and Pressure (STP) which is 0C and 1 atmosphere or 1.0135hPa. Then the column height is about 8 km and the thickness for 400 ppmv CO2 is ~3.2m, The standard way for expressing this value is 3.2 atm m.
Dobson Units, which are used for total column ozone are 10μm atm.
Nick Stokes,
If you have gridded anomalies, then you also must have gridded temperatures that are used to calculate those anomalies. One can then average those gridded temperatures over one year and the entire surface and come up with an average, even if it doesn’t mean a whole lot. I did that once, but it’s not worth looking up. Where the average temperature might mean something is for climate models. The global annual average temperature for a model spin up can be several degrees C from this calculated value. But you almost never see that because the standard method for reporting is anomalies and their trends.
If CO2 causes temperatures to rise, why haven’t temperatures risen for 17 years?