(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.
John: No question that Dick’s tolerance for frustration is much higher than mine. I am who I am.
Thanks to Roy Spencer for the airing of these issues. Also thanks to Richard Courtney for a well-considered comment. This is a very worthwhile posting.
…actually, the way Dick handles this is to avoid engaging people. My downfall is engaging them, repeatedly, hoping they can at least understand what they are talking about before trying to debunk it. This leads to frustration, and then to bad manners.
I was a “true believer” in #5. Thank you for the clarification.
I think you wrote an excellent article, Dr. Spencer. We should now be looking for a follow up article, entitled the 10 top valid skeptic arguments against AGW.
Dr Spencer,
I still have a problem with #7. There are numerous charts showing that ∆T is the cause of ∆CO2. Can you please post a similar chart, showing that ∆CO2 is the cause of ∆T?
Causation is central to your #7 argument. If there is empirical evidence that the added CO2 causes a rise in temperature, then there should certainly be a chart showing that. I’ve looked, but I can’t find one. It would help my understanding if I could view such a chart. As someone upthread said:
The world has done a real experiment and in that experiment CO2 levels rise after temperature; I trust that experimental result far more than any theories. What we are all getting excited about is a very very short term record of events that we do not fully understand, However the Earth has given you experimental proof of what the relationship is.
CO2 causes global warming. But not much at current concentrations. And there appears to be no evidence that CO2 causes measurable warming. Please correct me if that is wrong. A chart like this would be very helpful.
It’s all driven by the sun and Earths orbital parameters, except for human CO2 production, which is a benefit to the planet.
If human CO2 production was compared to a volcano in terms of CO2 production , What scale would this hypothetical “human volcano” be, would it be equivalent to a large or small active volcano?
I’ve been thinking about this sort of comparison for awhile… Any Ideas?
Dear Dr. Roy and Anthony,
I am a Hero of the Workers Soviet (i.e. Simple Red Neck Union Worker, now retired) and don’t have the education to comment on the technical side. However, I enjoyed your post and think that it is a valuable addition. The only way I have to let you know how I feel is to make a reply although it adds little to the discourse. I would find it a convenience if Anthony re-instated the “Like” button. Besides, it would save your gentle readers the time of reading a reply that adds little.
Regards,
Steamboat Jack (Jon Jewett’s evil twin)
engage us with #7……causation vs correlation
I’m not going to be convinced with a say so….
When you can pump CO2 into a greenhouse, in the thousands ppm, without oceans and everything else, and watch CO2 levels drop to limiting in one day….
When you have to constantly pump CO2 into tanks to grow aquatic plants….or they strip all of the CO2 out in minutes
Both of those simple real life examples….show how fast CO2 levels can drop
…and we are not pumping no where near that much CO2 into the atmosphere
“9. THERE IS NO SUCH THING AS A GLOBAL AVERAGE TEMPERATURE”
Ok, well “there is no such thing” as any average. Taking an average is a statistical tool. Assuming we can caluclate it accurately, the question is: does an average tell us something meaningful or useful?
Does global average temperature tell us any meanginful or useful information?
Maybe, maybe not. I’m not sure. It’s something I’ve been pondering.
BTW……..just so we’re all clear on where our money is going
This is what all the screaming is about…….this is what all of global warming looks like…plotted on a red line alcohol thermometer
http://suyts.wordpress.com/2013/02/22/how-the-earths-temperature-looks-on-a-mercury-thermometer/
Agree with Mosh.
Well
If you don’t want a response
Why post highly contested statements?
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.
Not strictly true, the energy lost to outer state is equal to the energy received from the sun, if that doesn’t increase then the loss doesn’t change. What changes is the temperature distribution in the atmosphere and where the energy is lost from.
But temperature as a metric on its own is not a measure of heat. Even from a simple basis surely humidity is a vital factor. Unless it is assumed that humidity is constant at each measuring point over the years, the record of temperature does not necessarily mirror changes in heat. The data is incomplete.
ups I realise my error
I should have shown respect and used Dr and not Mr when describing Roy Spencer, I do apologise and no disrespect was intended 🙁
My only problem with this post is that I haven’t considered anyone making these arguments to be a skeptic; I think there are more appropriate terms for them. Good post though, we don’t need people claiming to be skeptical saying these things. Now how about a top 10 list of debated hypotheses that the AGW cultists confuse as facts.
If someone on this planet shall see the contradiction in seeing CO2 causing ocean acidification and CO2 being an ideal gas.. Or explain if i’m wrong?
Picking at scabs only makes the condition worse.
Are there no hypothesis previously considered “ludicrous” which later became mainstream and accepted thought?!
In climate science, I would be careful, at which glass houses… I throw stones at. GK
“pokerguy says: May 1, 2014 at 7:49 am
One that really annoys me is the “trace gas” argument, as in “how could a trace gas necessary for life etc etc…?”
Your sentiment on that point is regrettable. Is there a better argument to protect the fundamental rights and democracy in this era of anti-CO2 (=anti-life)? After all, CO2 is not the only thing we (=skeptics and alarmists alike) are blamed for, but it’s the first we can falsify.
I’m sorry, but I can’t agree with this list. It “has issues”. Some large, some small.
Largest, IMHO, is the notion that the temperature of a bath tub means an average of 1000 thermometers “has meaning”. It doesn’t. Temperature is an intrinsic property. As such, averaging it loses meaning.
https://chiefio.wordpress.com/2011/07/01/intrinsic-extrinsic-intensive-extensive/
So measuring “a bathtub” is measuring one thing, not an average of 1000 different things. The Global average of thermometers is devoid of meaning. It may still have some (very limited) use, in that there will be some correlations with some other things; but that is not the same as a temperature. Just isn’t.
For others, my quibbles are smaller. Take “no greenhouse effect”. Two quibbles. A real greenhouse is a convection block, not an IR effect. There is no greenhouse effect from CO2, though there might be an IR effect. Then, in the IR effect, the interactions rapidly have complexity that exceeds the ability to compute. It ends up in philosophical hand waving. So lower CO2 warms, then convection moves the air up and dumps heat at altitude, where CO2 cools. Net? More mass flow not higher temperatures. Hand wave away…
For #2 and #3, your argument depends on that heat transmission to non-CO2 to have no subsequent heat dump. We know convection will move it away rapidly. Other modes? How about water evaporation? Air is NOT a dry medium. So is there NO possibility for CO2 absorbed heat to be removed via some other molecule radiating? In other bands and perhaps at other altitudes? I know, not quite the same as the CO2 itself doing the deed, but your dismissal also dismisses the question of what DOES happen. It doesn’t just heat up and lay there…
BTW, your argument per the 2nd law (clothing) is also confounding convection blocking with IR. Bogus example, IMHO. Instead, stand naked in an Alaskan winter surrounded by IR mirrors 2 meters away. Surely all that reflected IR will keep you warmer… (Maybe a smidge, but it will be hard to measure with all that convection freezing your bottom…) So aside from the example of clothes being bogus, it ignores the magnitude relative to convection / conduction… Looking at the bits in isolation isn’t very useful. So yeah, IR goes both ways, but clothing it isn’t…
On #4 the missing word is net. That’s the whole question. Is it a NET warmer or cooler? IMHO it is a net cooler. In the stratosphere is radiates away heat. Below that point, it just changes the rate of evaporation / convection and the IR behaviour is not relevant. See the graph here:
https://chiefio.wordpress.com/2012/12/12/tropopause-rules/stratosphere-radiation-by-species-1460/
Note that CO2 is radiating like crazy in the stratosphere but below that, in the troposphere, it is near zero. Notice that water does the deed in the troposphere. The simple fact is that H2O drives tropophere physics, CO2 works in the stratosphere, where it is a NET cooler. (No idea if that net cooling matters in the long run, though…) That graph from this posting that contains the attribution:
https://chiefio.wordpress.com/2012/12/12/tropopause-rules/
For #5, you ignore altitude. A critical flaw. See the diagram just above. At troposphere altitudes, the CO2 IR is not relevant, broadened or not. At stratosphere altitudes, it is not pressure broadened. Another example of using a hypothetical argument based on physics principles instead of looking at the actual activity (see chart…)
In general, my “complaint” about this kind of “put this discussion off limits” mandate is that it hides more than it illuminates. Yes, in many cases folks make a broken form of argument from the points you raised, and things would be better off if they didn’t. But, no, that does not mean those arguments are void and empty of use or interest. Frankly, the Global Average Temperature one is a great example. How many of you really realize / understand the difference between an intrinsic and extrinsic property? How many know that an average of temperatures is devoid of meaning? Yes, you can average them. Yes, it MAY correlate with some things. But a temperature it isn’t… Like the average of phone numbers by State will have an artifact of Area Code that vaguely correlates with geography, but is meaningless as a phone number…
I do agree it would be good to make a “best arguments” list, and even a “weak arguments” list (where the defects in some of the things you listed could be laid out); but calling them off limits is, IMHO, over the top. It’s too easy to substitute one appeal to authority for another and miss things like intrinsic / extrinsic or actual behaviour of CO2 IR with altitude…
Roy,
I am a big fan of yours—in fact you might say I’m a very big fan of yours. I pore over your regular postings of satellite temperatures and read your blog regularly—all really good stuff. But the logic in your #7 seems to be way off base so I’m hoping you will amend it appropriately. #7 says:
“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. “ The logic here seems to be that if warming causes CO2 to rise and CO2 is rising rapidly, we need a 100 times faster rise in temperature to account for the elevated CO2. What’s wrong with this logic? Think about it. No one is saying that today’s elevated CO2 was caused by warming because there is a totally unrelated cause of higher CO2 that has nothing to do with warming as a cause!! IT’S CLEAR THAT THE TODAY’S HIGHER CO2 LEVELS ARE DUE TO INCREASED HUMAN EMISSIONS, NOT GLOBAL WARMING so we don’t need to look for 100 times global warming. Your argument seems to say that warming does NOT cause CO2 to rise and that is clearly not correct. The chemistry of CO2 equilibrium in sea water clearly shows that warming of sea water releases CO2 into the atmosphere and since three fourths of the globe consists of oceans, that means warming causes a lot of oceanic CO2 to be released into the atmosphere. This is confirmed in ice cores where CO2 lags temperature by hundreds of years as interglacial climates warmed from ice ages (see Jo Nova’s post on this). Here is what I wrote in Chap 5 of the NIPCC 2013 report (Easterbrook, Ollier, and Carter, 2013):
“Changes in carbon dioxide content lag their equivalent temperature events by between several hundred and 2,000 years in Antarctic ice cores (see Figures 5.7.1 and 5.7.2). Changes in carbon dioxide level cannot be the proximate cause of the warmings and coolings seen. Fischer et al. (1999) established CO2 lagged temperature by 600 ± 400 years as the climate warmed from an ice age. Monnin et al. (2001) found warming from the last major ice age preceded rise in CO2 by 800 ± 600 years. Caillon et al. (2003) documented that rise in temperature preceded rise in CO2 in the Vostok core by 800 ± 200 years. Mudelsee (2001) recognized temperature over the past 420,000 years preceded changes in CO2 by 1,300 years ± 1,000 in the Vostok core. Petit et al. (1999) analyzed 420,000 years of the Vostok core and found as the climate cooled into an ice age, the CO2 decrease lagged by several thousand years. Measurements of recent and modern temperature and CO2 changes show the same lead-lag effect (Figure 5.7.3).” Humlum, Stordahl, and Solheim, J. (2012) showed that even short warming intervals from 1982-2012 were followed by increased atmospheric CO2.
So, Roy, I hope you will amend your statement #7 to acknowledge that your argument there would be true only if warming was the ONLY cause of elevated CO2 (which is clearly not the case), and to add that both ice core and recent evidence indicates that warming does indeed cause increased atmospheric CO2, but it isn’t the only cause of increased CO2.
With best regards.
I see pokerguy beat me to it, but can I go all Spinal Tap and suggest a #11?
The claim that because CO2 is a trace gas, comprising only 400 ppm in the atmosphere, so therefore cannot do all the things it is claimed to do, is an argument that drive me bonkers.
If you really believe that, would you mind drinking this water, laced with 400 ppm of arsenic? After all, how can it possibly be enough to do anything to you?
Dr. Spencer has done a great job of stabbing strawmen. I have challenged on points 1, 4 & 10 at his site. I would not expect him to respond. After all his error in point 10 is a 98C error with regard to the oceans totally destroys both the warmist and lukewarmer arguments. Without atmospheric cooling or DWLWIR, our oceans would be at +80C not -18C.
Instead of repeating my full rebuttal of points 1,4 & 10 I will post my top 9 list of games and tricks used by AGW believers and lukewarmers to show CO2 causing warming instead of cooling of the atmosphere –
1. THE TWO LAYER GAME.
The claim – SW heated sphere surrounded by a SW transparent shell of lower emissivity will be driven to a higher temperature by IR exchange between the shells.
The tricks – Conductive coupling between the shells never solved simultaneously. Tmean for the inner shell in absence of the outer always incorrectly calculated.
2. THE EEH / ERL GAME
The claim – Atmospheric OLR can be assumed to be being radiated from an Effective Emission Height or level and the temperature of this can be determined and surface temperature back calculated via lapse rate.
The tricks – EEH is a mathematical fiction with no basis in reality and no supporting empirical measurement. (NO, satellites looking down and ground looking up won’t do.) The atmosphere is provably not radiating 255 w/m2 from a shell or layer. It is radiating in 3D from different altitudes, in differing amounts at different times. Radiative gases present a far greater surface area that vertical dimension only IR opacity assumptions indicate.
3. IR OPACITY ABSORPTION/EMISSION LEVEL GAME.
The claim – Due to IR opacity radiative gases warm at low altitude and cool at high attitude.
The trick – Speed of vertical circulation held constant for increasing concentration of radiative gases to show surface warming.
4. THE FROZEN OCEANS GAME.
The claim – black body calcs show a -18C Tmean for the oceans without DWLWIR to warm them or atmospheric cooling.
The tricks – black body calcs are out by 98C. DWLWIR cannot heat or slow the cooling rate of liquid water that is free to evaporatively cool. Empirical experiment shows SW heated water reaches >80C in the absence of atmospheric cooling or DWLWIR.
5. THE NON-RADIATIVE ATMOSPHERE GAMES.
The claims – A non-radiative atmosphere would have its temperature set by surface Tmean
The tricks – Diurnal cycle and atmospheric circulation ignored (surface Tmax would drive the temp of such an atmosphere not Tav). Conductive cooling and heating of the atmosphere by the surface held equal despite gravity. Loss of effective conductive cooling ignored in calculating surface temp.
6. THE CLOUDS DON’T COOL GAME.
The claim – clouds reduce incoming solar SW but increase DWLWIR for no net effect.
The trick – DWLWIR has no effect on ocean temps, therefore no effect over 71% of the planet.
7. THE “AVERAGES” GAME
The claim – calculating incoming solar as constant 240 w/m2 is just fine.
The trick – It only works for superconducting materials of zero volume. Incoming solar peaks at ~1000 w/m2 and not using the correct figure or diurnal cycle for the heating of transparent materials with slow internal non-radiative energy transports will always give the wrong answer. That would be 71% of the planets surface.
8. THE “CHOKED RADIATOR” GAME.
The claim – Initially radiative gases cause cooling and drive convective circulation, but after a “certain concentration” they start to become less effective radiators. (yes, Pierrehumbert actually tried this one).
The tricks – there is no fixed ERL in the atmosphere. Gases cannot be treated as solid in terms of a radiator re-radiating its own fins.
9. THE TRENBERTHIAN POLE-WISE ENERGY FLOW GAME.
The claim – Atmospheric circulation is primarily driven by equator to pole energy flow, with OLR being just a feedback from adiabatic compression in the descending leg of circulation cells.
The tricks – Massive buoyancy changes due to evaporation ignored. Vertical circulation is the shortest route for energy escape to space from the surface. Empirical evidence shows IR emission from ascending translating and descending air masses in Hadley circulation.
Ultimately it is Dr. Spencers fist-biting mistake in his point 10 that invalidates not just AGW but the entire radiative GHE hypothesis itself. Using IR emissivity alone and treating the oceans as a near blackbody instead of a SW selective coating results in a 98C error for the surface of the oceans in absence of atmospheric cooling and DWLWIR. The physics behind this is old news. Researchers at Texas A&M found that black covers on solar ponds worked far worse than clear covers in 1965. But I suppose the basic physics of selective coatings is just a little too basic to be included in the “settled science” 😉
kowalk @ur momisugly here,
CO2 is virtually transparent to short-wave radiation from the sun, but opaque to infrared radiation upwelling from the Earth’s surface. Little incoming solar radiation is “caught” (absorbed) by CO2, the bulk of absorption occurs from the Earth radiating heat it has accumulated from the sun.