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Aerosols, Chemistry and Climate

Filed under: — gavin @ 12 July 2008

Everyone can probably agree that the climate system is complex. Not only do the vagaries of weather patterns and ocean currents make it hard to see climate changes, but the variability in what are often termed the Earth System components complicates the picture enormously. These components – specifically aerosols (particulates in the air – dust, soot, sulphates, nitrates, pollen etc.) and atmospheric chemistry (ozone, methane) – are both affected by climate and affect climate, since aerosols and ozone can interact, absorb, reflect or scatter solar and thermal radiation. This makes for a rich research environment, but can befuddle the unwary.

I occasionally marvel at the amount of nonsense that is written about climate change in the more excitable parts of the web, and most of the time, I don’t bother to comment. But in relation to the issue of aerosols, chemistry and climate, I read yesterday (h/t Atmoz) probably the most boneheaded article that I have seen in ages (and that’s saying a lot).

The hook for this piece of foolishness were two interesting articles published this week by Ruckstuhl and colleagues and a draft EPA report on the impacts of climate on air quality. First, Ruckstuhl et al found that as aerosols have decreased in Europe over the last few decades (as a result of environmental standards legislation), the amount of solar radiation at the ground has increased while the amount reflected to space has decreased. They hypothesize that this may have helped Europe warm faster in the last few decades than it would have otherwise done. Or equivalently, since the aerosols are anthropogenic, that European temperatures had been subdued due to the cooling effects of the aerosols – and since they are now decreasing, the full effects of the greenhouse gases are starting to be felt. This is just an update to the ‘global brightening‘ story we have touched on before. The EPA report is concerned with the impacts that climate change can have on atmospheric chemistry, and in particular the summertime peaks in urban ground-level ozone which are a well-known and serious health hazard. These are affected by local temperatures, cloudiness, temperature sensitive biogenic emissions and patterns of weather variability. Again, it is a story we have discussed before.

But the NewsBusters article succeeded in getting almost every aspect of these stories wrong. How do I correct thee? Let me count the ways.

  1. Aerosols are not smog:

    First they confuse aerosols with photochemical smog. Both are pollutants, but the first is dominated by sulphate emissions from coal burning power plants, the second from ozone precursors such as NOx, volatile organic compounds, and carbon monoxide mainly emitted from vehicles. (Note that ozone is not directly emitted, but is created by chemical reactions from the precursors with the addition of a bit of photolysis – i.e. sunlight-driven chemistry). The effects on climate are very different: ozone is a greenhouse gas, so increases cause a warming, while sulphate aerosols are reflective, and so increases cause a cooling. The air quality issues in the EPA are almost all focused on ozone.

  2. Europe is not the Globe:

    The next error is to equate changes in temperatures in Europe to the globe. While it would be true that if global aerosol levels declined it would lead to increased global warming, aerosol trends in Asia are increasing strongly, even while those in the US and Europe are dropping. The net effect is possibly a slight drop, but the impact on global temperature is as yet unclear. This regionality matters in both the sulphates case and for ozone. The relevant chemistry is sensitive to water vapour and temperature in varying ways as a function of the pollution level. In remote ocean areas, surface ozone will likely decrease as the globe warms for instance (due to increasing water vapour). In polluted environments increased temperatures and larger temperature-sensitive emissions of isoprene cause enhanced ozone levels.

  3. Surface ozone is not in the stratosphere:

    Next, NewsBusters asserts that the ozone story is confusing because of the

    .. treaty called the Montreal Protocol. This was designed to reduce and eventually eliminate the production and release of a number of substances thought at the time to be depleting ozone.

    Ummm…. those substances (chiefly chlorofluorocarbons – CFCs) are still thought to be depleting the ozone layer – which is in the stratosphere, some 30km above the ground-level ozone that people shouldn’t be breathing. CFCs have no impact on ground-level ozone at all (since their reactive chlorine is only released in the stratosphere).

  4. The final inanity:

    Wouldn’t it be fascinating if such efforts [such as the Montreal Protocol] lead to cleaner air around the world which ended up warming the planet, and that additional warmth is now breaking down the very ozone we thought we could save?

    Every part of this sentence is wrong. The Montreal Protocol had no impact on cleaning the air, it stopped the growth of CFCs which are powerful greenhouse gases (in addition to their role in depleting stratospheric ozone), therefore it slowed global warming, rather than increasing it, and we aren’t trying to save ground-level ozone. Had any of this been true it would indeed have been fascinating.

What should we make of this? Unfortunately one must conclude that no mistake is too dumb for someone, somewhere to make if they think they can spin it into supporting their anti-science agenda. For them complexity is something to be abused rather than a challenge to be understood, underlining quite clearly (again) the difference between science and propaganda.

356 Responses to “Aerosols, Chemistry and Climate”

  1. 151

    #104 Clear Thinker

    I made the mistake of correcting what you said from “five years”, to 8 years (meaning the 9th data point backwards),

    so that it made at least a little sense. But let’s take you at your word for the sake of argument.

    Besides, the last five years have shown a cooling cycle not a warming one. Before you go off on my last sentence I would like to ask a question of Mr. Schmidt.

    To illustrate how wrong he is, I should have taken him at his words

    “the last five years have shown a cooling cycle not a warming one”

    I realize it means nothing, since five years does not amount to a hill of beans in this argument, but it does illustrate the arrogance associated with his lack of knowledge. I’m not confident he is as humble as he claims, though I hope he proves me wrong.

    5 data points shows a slight warming trend, statistically insignificant but warming nonetheless

    6 data points shows more warming

    7 data points shows more warming

    8 data points shows slightly more warming

    Again, insignificant, but illustrative of the fallacy of the argument.

    Mr. Clear Thinker, you may be great at critical thinking but that just means that you are ignoring relevant information or dishonest.

  2. 152
    Clear Thinker says:

    Dear Mr. Schmidt,

    You wrote: 1. “…Since science doesn’t deal in truth, but only likelihood, you assert that everything is therefore debatable.”

    Why on earth would you want to get into semantics when you very well knew what I meant? When I write something I do my very best to write it in a manner so that anyone can understand. No semantics and no cognitive existentialism. Let’s just keep it real and down to earth. And I don’t understand the arrogance you showed in the very first line of your response. Have I been rude to you?

    2. “…but I don’t see you querying gravity, the heliocentric model, the big bang etc. and I doubt very much whether your concerns are over the ultimate truth value of science as a whole.”

    Again, why would I want to query gravity, the heliocentric model,or the big bang theory on this particular thread? Although there are some that are starting to question big bang… Anyway, I am most certainly interested in the ultimate truth value as a whole as it applies to the subject at hand, AGW, Climate Crisis, etc. If either side of this debate is wrong and we as a civilization accept one side over the other we could see disastrous effects. Just like alcohol, food, sex, etc… everything in moderation (sex may be open for debate as to how much is too much) should rule the day. For now.

    3. “You will notice if you spend any time with scientists (I recommend it to everyone), that they are very particular what they debate over – they don’t bother with the things (like the radiative impact of CO2, heliocentricity, the roundness of the Earth) where the evidence is already overwhelming, or on questions for which there is no evidence (what’s the point).”

    This I find almost dishonest. Would you be willing to accept, that when these theories were first suggested that there was no debate by contemporaries of the day? I doubt you would, and I’m hoping I’m right.

    4. “Coming here with meaningless talking point cliches like ‘the debate is not over’ is not however useful. Do at least try to be constructive. – gavin]”

    Are you unwilling to debate the subject? There are many credentialed naysayers out there that would love to disagree with you and they have their facts to back-up their findings. One of the posters at RC has asked who these people are, and wants to know “where’s the beef?”. To your suggestion that I at least be constructive, I will post a list with follow-up info, and I hope you will appreciate my effort. Please let this debate continue by allowing my list to be posted when I have it ready.

    As always, I appreciate your time and effort.

    [Response: Don’t bother posting lists – it never serves any purpose since there is always more nonsense than can possibly be addressed. However, if you want to pick one or two of what you consider the best arguments or most credible positions I’d be happy to engage. I apologise if you didn’t care for my previous tone, but unless you have been living under a rock, you will realise that we are daily assaulted by those who wish in debate, not resolution, but noise. I’ll suspend judgement for the time being. – gavin]

  3. 153

    Re #147 Rob B

    Ok, I reread your post #133 Rob B again. Let me know if I’m on the right track?

    When CO2, CH4 or N2O and GWP’s including H20 (all GHG’s) increase there is an absorption lag.

    The forcing is there for example we are at 1.9 W/m2 mean estimate. That forcing does not heat the planet right away though. It is regulated by multiple factors positive and negative and oceanic thermal inertia is probably the biggest thermal regulator on the planet. Marcus #144 mentioned the ocean before, in that he said:

    Isn’t the short answer to your question “thermal inertia”? Basically, adding more CO2 turns the burner up, but it takes a while for the pot to warm.

    The ocean acts like a speed break, so while the forcing is there, it needs to attain equilibrium with all other factors and the main one is the ocean. In other words, the ocean absorbs heat, or releases heat, more slowly than land and air.

    This can take some time and that causes a lag in temperature increase. We should all be thankful, if it were not for all that water we would be warming even faster.

    of course there is still the Arctic Amplification Effect which causes the Northern hemisphere to warm more than the southern. That is caused by the fact that northern hemisphere has a lot more land which radiates and absorbs heat faster than water. Southern hemisphere is mostly water, which keeps the region cooler, for now at least.

    #142 Tamino

    I like that blanket analogy.

  4. 154

    Re #147 Rob B

    On your second point, I’m not up on IR absorption and transfer, I just saw Hank Roberts is on it though, so I hope that helps.

  5. 155
    Ray Ladbury says:

    Rod B., I’ll take a stab at this. First, remember that the only way energy gets out of the climate system is via outgoing IR. Also, we only have equilibrium when outgoing IR = absorbed solar energy (mainly visible). Now if we add CO2, less IR escapes to space, and this will warm the planet until the temperature is high enough that the IR energy emitted by and escaping from the planet again equals incoming solar energy. In other words–the old “blackbody” curve gets bites taken out of it, and evolves into a new blackbody curve with similar bites, but having the same area under it as the old curve (without bites). It takes time to heat up the atmosphere this much. Does this help?

  6. 156
    David klar says:

    Newsbusters have no credibility on climate science matters. A recent article posted July 18th on their site referred to Gavin as a “climate alarmist” and the realclimate site as the premier site on climate “hysteria”. Nowhere in Sheppard’s article are any references to science papers. Such attempts to disparage a legitimate site for understanding climate science shows that both NB and Sheppard are unqualified to speak on climate science matters.

  7. 157
    kevin says:

    @Rob B.
    I have another amateur’s perspective to chip in, although it seems like Tamino, Hank, and JPR have covered it pretty well–but I get the sense that you, like me, can sort of feel your level of understanding…and until you “grok” it, so to speak, there’s always that slightly unsettled feeling…so here’s how I “grok” the issue I believe you’re asking about:

    The keys to my understanding are the signal to noise ratio, and thermal inertia in different parts of the system. In this case, I’m labeling as “noise” all processes other than heating by the greenhouse effect or direct feedbacks of that heating. It is my understanding that most of these processes are pretty much like noise in that over the long term they are expected to average to a zero net effect (approximately); for the most part they don’t affect the total energy budget of the planet, they just represent a lot of energy moving around within the planet system.

    One form of noise is simple weather. Think about the temperature change you can get at a given location when a storm front rolls through. The noise also happens at other time scales, like ENSO and whatever the hell happens in the deep oceans as huge masses of water slowly swirl around. The amplitude of the temperature changes in these processes can be titanic compared to the amplitude of the temperature changes from a day’s, or decade’s, or even century’s worth of accumulated CO2. But they average out.

    So I think the instant heating you’re talking about does happen, and it gets swirled up into this big cauldron of stew–different processes in heterogeneous environments happening on much bigger amplitudes than the signal, and various timelines, sometimes quite long ones. A slow “noise” process can easily pull temperatures down–in the areas where we’re able to make direct measurements–enough to cancel(and then some) an immediate greenhouse process. In reality, this is just the noise of energy moving around inside the system swamping–again, in the locations of our thermometers (and sattelites, etc.)–the tiny signal of energy being added to the system through greenhouse warming. Our current monitoring is limited to a collection of points in certain strata of the total system. If you had an omniscient monitoring apparatus, I believe you would find that the total energy content of the planet does increase instantly.

    In practice, though, our tiny instantaneous warming signal gets stirred into the stew, and even that bit of warming is buffered by some of the colder stuff like the cryosphere or deep oceans, where its small impact builds up over time, and as these reservoirs of coldness warm enough to absorb less heat from their surroundings, the warming propagates, slowly, through the system. This is the thermal inertia that other folks have mentioned.

    So, much like an ion drive, the greenhouse effect slowly overcomes the thermal inertia of a big, chaotic system–an eensy weensy bit at a time, relative to the amplitude of the noise. As inertia is overcome, the tiny constant push creates a more and more noticeable effect (until the system reaches equilibrium, so the ion drive metaphor breaks down if you try to extend it too far, but hopefully you see what I mean).

  8. 158

    Responding to Chris Colose, #140; Chris was answering my #134

    I know the numbers. I also know different ways to get an approximate calculation. What I don’t have a good handle upon is why one approximation is better than another as a way of getting a ball park figure for the non-feedback sensitivity.

    Assuming Ts = 288, and Te = 255, corresponding to 390 W/m^2 at the surface, and 240 W/m^2 at the TOA:

    I hold the lapse rate fixed and the mean emission height fixed, so that the temperature difference is fixed at 33K. In that case, one more degree at the surface is one more degree at the TOA, and thermal emission from TOA becomes about 244. This gives around 0.27 K/(W/m^2); a commonly cited number for the simple blackbody calculation.

    Or, I treat the atmosphere as fixed layers of a certain emissivity. If there are n slabs of atmosphere all with emissivity e, then the upwards longwave below n slabs is Q(2+n.e – e)/(2 – e), where Q is the shortwave input. (Usually people do one layer with a certain emissivity, or else n layers with unit emissivity; I put it together just to help nut it out for myself a bit.) In any case, the surface emission becomes some fixed fraction of Q, and in this case an increase of 1 degree at the surface gives about 396 W/m^2 at the surface; and so about (396/390)*240 = 243 W/m^2 at the TOA. The method gives about 0.3 K/(W/m^2) base sensitivity; much closer to what is used by Soden and Bony and other such references.

    I appreciate that Soden and Bony and others don’t use my simple zero-dimensional approximations. As it turns out, I have also done some simple integration across latitudes with available lapse rate and temperature data, and the difference seems to be minor by comparison with the difference in choice of method. I think I’m on the right track here with the second method; but it just niggles at me a bit that there is (implicitly?) a change in the mean emission height or lapse rate involved in the non-feedback case. I’m just hoping for a pointer from the experts on the best intuitions or approximations for the zero-order estimates; or if zero-order estimates like this are okay

    Thanks for any free tutorials!

    [Response: The original Hansen calculation was with a radiative-convective model and delta T was the surface temperature change combined with a corresponding shift in the atmospheric T profile (based on the adiabat) that was required to balance the tropospheric flux. Therefore the ‘formula’ you want is a weighted integral of SB over height, weighted by their contribution to the tropospheric flux. The ‘uniform temperature’ approximation is similar and is a uniform delta T applied over the troposphere. – gavin]

  9. 159
    Clear Thinker says:

    Dear Mr. Schmidt,

    Thank you. I would like to take a very recent event of what you call
    “most credible positions” and ask you and your readers to explain the findings here…,25197,24036736-7583,00.html

    You will notice that this Dr. is no hack, so I take him very seriously. Do you?

    Again, I thank you.

    [Response: No. If this recycled nonsense is the best you can do, we are not going to get very far. – gavin]

  10. 160

    Re #152

    Dear Clear Thinker,

    You are playing an interesting game being so polite. It reminds me of family arguments when kids pretend not to be upset and try to out-polite the other to get them upset so they get in trouble with the parents rather than the instigator that is standing there smiling with a cheshire grin.

    In case you are wondering why it takes so long for Gavin to answer you, this may help you understand:

    “Next week will be a little quiet – it is mid-summer after all – so apologies in advance if the moderation is a somewhat slow.”

    And I don’t understand the arrogance you showed in the very first line of your response. Have I been rude to you?

    I think you are rude to ask Gavin to engage you when you have clearly not read up on the relevant science. That is of course clear because you have not posed an intelligent question as yet.

    Again, why would I want to query gravity, the heliocentric model,or the big bang theory on this particular thread?

    While it’s possible you don’t understand what Gavin is saying I hope not. What Gavin is saying is that if you question Co2 as an anthropogenic climate driver then you might as well question gravity, the heliocentric model and the big bang, because it’s the same thing. The science on the GHG’s and their forcing is settled. The rest of your argument here is merely diversionary noise.

    This I find almost dishonest. Would you be willing to accept, that when these theories were first suggested that there was no debate by contemporaries of the day? I doubt you would, and I’m hoping I’m right.

    How obtuse. Again merely diversionary noise; no science argument.

    Are you unwilling to debate the subject?

    Noise. Gavin made the point quite clearly. The debate on the main parts of the AGW are over. The evidence is clear. The results are quantifiable. The isotopic signature of the Co2 is from fossil fuel. It is not possible to have originated from the natural sink. CH4, N2o and high GWP’s are quantified. The GCM’s have differentiated the signal to noise. TSI remains rangebound. GCR’s and SI do not correlate with T increase. The GMT is rising outside of natural variability.

    If you really want to debate the subject, before you do, read and study the relevant material and at least make an attempt to comprehend it in context. Then bring your questions.

    The credentialed naysayers you are referring to have nothing contextually relevant. You choose to indulge in pop science from people who for the most part cherry pick their data and misrepresent significance by presenting outside of the accepted GCM’s. Meteorology has little to do with climatology; Mckintyre Mckitrick were examined and found irrelevant because their argument only altered the data by a few hundredths of a degree; Singer lobbied for the tobacco industry and also wrote papers saying CFC’s are not a problem. The UAH satellite data has been corrected for errors by NASA… et cetera.

    I’m going to say this one more time and please understand, I am not attacking your character but the substance of your understanding. You are ignorant of the context and relevance of the various arguments surrounding the subject of anthropogenic global warming. It’s as simple as that.

    Bring some science arguments not diversions and noise. If your going to argue at least bring some meat to the discussion. Context and relevance are key.

    Gavin, I’d love to see him bring a real substantial argument in here. That would be refreshing.

  11. 161
    chrispydog says:

    Another day, yet another denial:,25197,24036736-7583,00.html

    Dr David Evans was a consultant to the Australian Greenhouse Office from 1999 to 2005.

  12. 162

    Rod B writes:

    I’ve said before, I’m perplexed over the conservative/liberal right/left split over the issue. I find no rationale for that — though I admit it seems to be the case in many instances…

    It has become a left-right issue because measures to deal with AGW threaten the profits of fossil fuel companies, and the GOP exists largely to represent large corporate interests. People like Rush Limbaugh and Ann Coulter have made it their mission in life to fight against any environmental regulation whatsoever — hell, Limbaugh wants to repeal the Clean Air Act. And Limbaugh is the protege of Roger Ailes. He may claim to be a disinterested conservative, but he is a creation of the GOP.

    Dealing with AGW will cut heavily into the profits of oil, coal, natural gas, and automobile companies. Those profits amount to $30 billion a year for Exxon-Mobile alone. It’s not surprising that they’re trying to delay dealing with AGW as long as possible. That’s why E-M subsidizes denier think tanks like the Heartland Institute.

    Follow the money.

  13. 163

    Jesse Brown writes:

    I see the same thing happening in Cosmology where any work that might shake the foundation of Big Bang Cosmology is barred from publishing even as more and more evidence is emerging that the BB just doesn’t work

    I can remember just offhand a paper in Physical Review A which tried to explain the cosmological red shift in terms of photon tidal interaction with curved space. Your assertion that papers challenging the Big Bang are kept out of cosmology journals is simply wrong. There aren’t many such papers because the evidence for the Big Bang is so overwhelming, not because anyone is being suppressed.

    If you’re talking about the specific case of Halton Arp, the journals in the US stopped publishing him because he stopped submitting anything new. All his papers for years have been ones showing juxtapositions of celestial objects with different red shifts, an argument against the cosmological red shift which works only if you completely ignore perspective. Papers in peer-reviewed journals have to contain significant new information. Arp’s do not. He was a respected astronomer once, but because of his obsession with overturning the Big Bang, he has become a crackpot.

  14. 164
    Chris Colose says:

    Clear thinker,

    you should read my post on The Scientific Basis for Anthropogenic Climate Change.

    Then, you might want to read scientific documents, but if you feel the need to go through these random websites, anytime you hear the following arguments, the article is not worth it:

    AGW is wrong because,
    – CO2 lags temperature in Vostok
    – it ended in 1998 (or January 2008, or whatever the newest fad is)
    – Anyone challenging the basic radiative physics of greenhouse gases and their impact on planetary temperature
    – There was 1940-70 cooling when carbon emissions were high
    – Specfic sites (like the Antarctic interior) are growing/cooling, so global warming is wrong.
    – “it always happens”
    – water vapor swamps the effect of CO2
    – Climate sensitivity is too low to matter

  15. 165

    A ‘consultant’ you say, eh?

    Here’s an interesting one :

    Viscount Christopher Monckton of Brenchley is a Nobel Prize winning contributor to IPCC reports. Viscount Monckton has been an outspoken critic of the Kyoto Treaty and the IPCC scientific process. He was science advisor to Margaret Thatcher, his articles have been published in many prominent papers worldwide, and he is presently a member of the House of Lords.

    Dr David Evans has six degrees in Maths, Stats, and Electrical Engineering, including three from Stanford.

    Christopher Monckton +44 7980 634 784,

    Others include ‘Carbon Emissions Don’t Cause Global Warming’ and an article for the ‘Ludwig von Mises Institute’.

    I think we can safely disregard his ‘maths’.

    [Response: It’s worth pointing out that Monckton is not a member of the House of Lords (he stood for election among his peers and got zero votes) and is not a ‘Nobel Prize winner’ – the only people who are acknowledged as such are the lead authors of IPCC chapters. – gavin]

  16. 166
    Arch Stanton says:

    Re: 79 (update)

    For the record, I received my membership to NB yesterday. It took 7 days.

    I don’t see much point in going over there and taking on Godzilla hiding behind secondary sources and technicalities.

    I will take Hank’s advice.

    Gesundheit Hank.

  17. 167
    LEON says:


    I for one would enjoy the prospect of several science-minded individuals joining the Newsbusters site.

    While I understand there’s no reason for a legitimate science site, such as real climate, to wallow in the mud with blatant propagandists, unfortunately, in the age of the blog, it’s unavoidable. The Denier Clan has espoused it’s insanity for long enough.

    I’ve read the Newsbusters site for years and am consistently amazed at the viewpoints embraced there. I am still learning the fundamentals of AGW so I never felt fully comfortable engaging in technical AGW debates at Newsbusters. As such, I always looked forward to the time when real scientists would finally pick up on the propaganda and simply dismantle it.

    Noel Sheppard has gone unchallenged for too long. Like it or not, the MRC does reach a sizable audience, so it would be in the better interest of humanity to expose him for the hack that he truly is.

    Arch, give it a shot. So long as you argue with the facts, what can they say?

  18. 168
  19. 169

    In reply to my #158, Gavin says: [Response: The original Hansen calculation was with a radiative-convective model and delta T was the surface temperature change combined with a corresponding shift in the atmospheric T profile (based on the adiabat) that was required to balance the tropospheric flux. Therefore the ‘formula’ you want is a weighted integral of SB over height, weighted by their contribution to the tropospheric flux. The ‘uniform temperature’ approximation is similar and is a uniform delta T applied over the troposphere. – gavin]

    Thanks; but I’m still a bit unclear. Sorry to be a pest…

    I have read Hansen et al. (1984); and his method seems to be what gives a 3.76 W/m^2/K response. Take the fixed lapse rate (same adiabat moved sideways?) and the same mean emission height, and you get 33K less at the TOS. Hence the zero order approximation dR/dT = d/dT (σ(T – 33)^4) = 4R/(T-33) = 4*240/255 ~ 3.76

    [Response: This is roughly correct, but the effective integral is over the whole troposphere – weighted by the efficiency of the emitters over the column (in particular, more water vapour lower down). – gavin]

    This also has the same ΔT all the way up the atmosphere. I can follow that. My problem is that these days, papers like Bony et al or Soden et al (both 2006, Jour. C. vol 19) use numbers around 3.2, based on inferences from climate models. The GISS models, for example, which are what you work on I believe, have values given by Soden et al as 3.24 to 3.26 (table 1).

    [Response: Yes. That takes into account the spatial variation of forcing, temperatures, clouds and water vapour. – gavin]

    A footnote in Bony et al (2006) says: Note that in GCM calculations, the Planck feedback parameter is usually estimated by perturbing in each grid box the tropospheric temperature at each level by the surface temperature change predicted under climate warming. Therefore this estimate does not correspond exactly to a vertically and horizontally uniform temperature change.

    So they DON’T have a uniform temperature change, if I’m reading this right; and hence (I guess) neither do your models?

    [Response: It’s uniform vertically in the troposphere – not horizontally. – gavin]

    I’m guessing that corresponds crudely to my “multiple slabs of atmosphere method” of comment #158, based on SB for each slab, which ends up in approximation as dR/dT = d/dT (0.61 * σ T^4) = 4R/T = 3.33 It also means that ΔT at the surface is a bit larger than ΔT at the top of the atmosphere, which corresponds to a slightly different lapse rate. The difference between 3.33 and 3.25 is small enough that it might be accounted for by integrating over the surface of the Earth.

    But I’m not yet confident I’ve got it right. If there was a reference which actually works through a zero dimensional one line approximation it would be great. I’ve been explaining the basics of forcings and feedback in some discussions; and in my analysis at my blog of some errors in Monckton’s recent paper. But I tread lightly around the 3.2 value, because I don’t feel confident to explain it as yet.

  20. 170
    Nick Gotts says:

    Chris Colose@164 – I’ve bookmarked and downloaded the post – thanks very much.

  21. 171
    Peter Backes says:

    Something a little more on-topic:

    Smoke From Wildfires May Block Warming of Arctic, Study Says

  22. 172
    William N Mitchell says:

    Leon, Baby, if you think there are no credentialed, scientific skeptics, your reading is in real need of expansion.

  23. 173
    Rod B says:

    Thanks to all for your assistance. But here’s what still troubles me, which admittedly is basic Freshman Physics level, and I haven’t done the math… because I don’t know the physics… which is way I’m asking. I understand the blanket analogy but adding a cover on a cold night and waiting , what, 10-20 minutes to warm up? My impression is that putting the CO2 blanket on takes weeks, months, years to warm up the bed, and so not very useful.

    There is much discussion/assertion here and elsewhere of the delayed heat storage of oceans. A quote from the abstract that Hank referenced is typical. “…The thermal inertia of ocean and ice is thus among the key factors that cause lags between increases in concentrations of greenhouse gases and observed atmospheric temperature changes. Such lags have been variously referred to as unrealized warming, residual warming, or committed warming…”

    This seems backwards. The very first thing in the process is CO2 is added, then absorbs some (earth-cooling) terrestrial or oceanic infrared radiation, then transfers that absorbed energy to heat (temperature increase) via a collision with likely an N2 or O2 molecule. (Bear with me — the single molecule is just a simplified example; it’s easy to visualize even though the numbers are ridiculous and it is not practical). (The net temperature exchange, gram for gram, is close to the same between ground and air, but air is about four times the ocean.) The atmosphere’s temperature has increased within a few microseconds and probably within meters of the surface, the accurate numbers depending somewhat on the previous concentration. All of this before the ocean can put its pants on.

    Next the air molecule transfers its increased energy back to an emitting molecule, but in any case radiates directly or indirectly after a jillion bounces back to the earth surface where its reabsorbed and reheats the surface, or radiates out of the system with both atmosphere and surface ending with a net cooling, or hangs around as a hotter atmosphere. Eventually another option is possible and that is a conduction/convection exchange between the air molecule and either an earth or a water molecule. The water would remove temperature from the air faster than it “absorbs” and would now store this supposedly for a relatively long time — with an ocean temperature increase that’s only 1/4 of the air’s temperature loss. But, it seems to me, this process is highly problematic and slow, which tells me that the low altitude air and to a smaller degree the ground experience a direct, almost immediate, and somewhat long lasting increase in temperature after the added CO2. It might not be linear because, with some lapse, the ocean will pick up a little of the energy/temperature.

    None of this explains the charts which show: 1. increase in CO2; 2. wait a few years or decades; 3. get temperature increase.

    Maybe there is something in my “all other things being equal” as Kevin implied, and the temperature increase gets masked by temporal climate or even weather variations (which by themselves average out to zero over the long term). But (gut reaction) this ought to work both ways — hiding (delaying) temperature increases sometimes, enhancing them other times.

    I have the impression that this all just might be “the way it is”, and stem from deductive logic: 1. temperature rise has been kinda unnaturally lagging CO2 increases the past 150 years; 2. the only thing different from the “natural” process is human induced CO2 (and it seems significant, not just a wobble); 3. therefore the anthropogenic nature must be [somehow] causing the lagging temperature increase. This could be correct, I suppose, but I’m looking for a little physics to back up the statistical correlation.

    Sorry for belaboring this. Thanks again for your help anyway.

  24. 174
    Nick Gotts says:

    BPL@70 – Thanks for your links also – clear and succinct.

  25. 175
    Jim Galasyn says:

    Kinda OT, but interesting:

    Amazon powers Atlantic Ocean’s carbon sink: study

    Nutrients carried by the Amazon River help create a carbon sink deep in the Atlantic Ocean, a study released Monday has found.
    The key ingredients transported by the river are iron and phosphorus.

    These elements are all that an organism called a diazotroph needs to capture nitrogen and carbon from the air and transform them into organic solids that then sink to the ocean floor.

    Researchers from the United States, Greece and England found that the Amazon carries these elements hundreds of kilometers into the ocean and has an impact on the carbon and nitrogen cycles much farther afield than previously thought.

    It is likely that other rivers also help seed carbon sequestering in the world’s oceans, wrote senior author Doug Capone of the University of Southern California.

    The findings may help scientists find the best places to test seeding the ocean with iron, a controversial practice that some biologists believe could help mitigate climate change.

  26. 176
    Arch Stanton says:

    RE 167, Thanks for the encouragement LEON, but I have already wasted too much of my life arguing with people that are as adept at the classic techniques of propaganda as Joel is (he can now claim that I love Wikipedia LOL). It doesn’t matter how many facts you have there is always some come-back that gets your supporters cheering.

    And then is his fan base…It’s kind of like fighting an octopus with one hand tied behind your back. One liners are the bane of intelligent discussions on the internet. Notice how now that they have discovered that you can’t ask the same question over here over and over after it has been addressed, they are giddy with glee at uncovering some great weakness of RC? With all respect to Andy and his open policy (God Bless you Andy) I am thankful we don’t have to wade thorough the same tripe from the same people over and over here like one does at Dot Earth. As it is, the same questions do get answered repeatedly here, but that’s okay, this place is about climate science education. I don’t believe that is the goal at NB.

  27. 177
    Guenter Hess says:

    Rod B,
    It is interesting that you come up with this question. I try to answer a related question for a while, but didn’t find an answer yet.
    I found that in the literature it is assumed that local thermodynamic equilibrium (LTE) holds in the earth’s atmosphere up to a height of about 60 km or 75km.
    However, LTE to my understanding requires that the energy levels in the medium are occupied according to the Maxwell-Boltzmann distribution. This assumption is usually justified since at 1013hPa, the mean free path is about 70 nm, which in turn means that a excited state will be thermalized very fast due to collisions, which in turn guarantees occupation of the energy states according to the Maxwell-Boltzmann distribution.
    Moreover the lifetime of a vibrational state is about 0.001 s. The rate of collision at 1013 hPa and 288K is approximately 109-1010 collisions per second. Indeed, LTE is justified.
    At about 300K this means per example for the CO2 bending mode at 15 µm that the population of this state in LTE is only about 4%.
    BPL calculated on his excellent homepage the optical path length for CO2 to about 0.18/m.
    This in turn should mean that the radiative heat transfer by absorption between ground and the first atmospheric layer takes place within the first 10 to 20 meters, considering CO2 only.
    In texts about radiative transfer in the atmosphere I usually find the following line of reasoning:
    1. LTE holds
    2. Therefore you can apply Kirchhoff’s law
    3. Which in turn means the emission coefficient is equal to the absorption coefficient
    This means then in turn that a slab of atmosphere under steady state conditions radiates a significant portion of the absorbed energy isotropically and establishes the lapse rate via radiative transfer
    However, I think that under LTE I have to multiply the absorption coefficient with the Boltzmann factor (0.04 for the CO2 bending mode to get the emission coefficient), meaning that only 4% of the absorbed Photons get emitted from the vibrational state.
    All the others transfer their energy to translational modes of other molecules, including Oxygen and Nitrogen. This will of course warm the layer of atmosphere and provide an explanation for global warming.
    But for global warming, which is your question, I concluded that it does not matter how you establish the steady state lapse rate, by radiation or collision or a combination of both.
    The steady state lapse rate together with the feedback mechanism will drive the earth to the new steady state. The time constant for the whole process should be different from the microscopic time constants for absorption, collision and emission.
    However, as a scientist I would be curious why under LTE, the emission coefficient for a CO2 band can be estimated using Kirchhoff’s law, while the energy transfer is collision dominated.

  28. 178
    Arch Stanton says:

    Oops my hyperlink for “classic techniques of propaganda” didn’t work:

  29. 179
    Hank Roberts says:

    Smoke plumes from wildfires mapped.

  30. 180

    For Rod B #173.

    To keep it simple, think of a planet covered in one large ocean. Imagine everything is nicely balanced, with energy coming in equal to energy going out, at every point. The ocean is at 15 C, and the atmosphere is absorbing some of the warmth radiated from the surface, which makes it warm as well, though as you go up higher in altitude, the temperatures fall. Because the atmosphere has a temperature, it also radiates heat; some back down to the surface, and some on out into space. Being in balance, the atmosphere radiates the same amount of energy as it absorbs. The ocean is receiving energy from sunlight, and also from heat coming down out of the atmosphere; and radiates all of the received energy back up into the atmosphere. Everything is at just the right temperature to keep all the energy flows balanced; there’s no accumulation of energy anywhere and temperatures remain constant.

    Now consider a series of steps. Step 1. We add a lot of some gas, which is good at absorbing warmth radiated from the surface.

    Step 2. The atmosphere starts to absorb more of the energy from the surface. This heats up the atmosphere a bit. This occurs pretty quickly, because the atmosphere is thin, and does not hold a lot of heat.

    Step 3. Because the atmosphere has increased in temperature, it starts to radiate more heat of its own. Some of that goes on out into space; some goes back down to the surface again. The atmosphere is now in balance again, radiating out the same amount of energy as it absorbs. Its a bit warmer than before.

    Step 4. The ocean is now receiving more energy from the atmosphere. This means it starts to heat up also. But a watched pot never boils. An ocean has a huge hear capacity; it takes a LOT of energy to raise the temperature. So for now, the ocean is NOT in balance. Its temperature is (at first) unchanged, and it merely absorbs the extra radiation.

    At this point, the atmosphere has warmed up, but the surface has not. It takes a long long time for the ocean to warm up. As it does so, over the next few years, it starts to radiate more energy also, which heats up the atmosphere even more. The atmosphere heats up almost at once; but the ocean takes a long time to heat up.

    After ten years, the ocean has finally warmed up so much that everything is back in balance again, as far as we can measure.


    Now Earth is actually a bit more complicated than that. The surface of the ocean may warm up faster than the depths; but the surface is still kept a bit cooler by being in contact with the depths, until balance is eventually restored. Also, we have land. The land heats up almost at once, like the atmosphere…. but the ocean is slow to heat up. This means that the ocean will (initially) be cooler than the land, and winds and currents will transfer some heat from the land to the ocean… cooling the land a bit, and helping heat the ocean a bit more quickly… until it is all in balance again.

    That’s really all there is too it. It takes a bit of time to warm up a large body of water.

  31. 181

    Re #159

    (repost, I think the other one glitched out)

    [edit – too ad hom, please stick to issues not people]

    #172 William N Mitchell

    There are many credentialed people in the world, the question is relevance of the credential and experience in the relevant field and scope of knowledge and experience. Just because someone has a credential does not make him/her relevant pertaining to the argument at hand. Likewise, a non scientists can still have a relevant point of view if it is considerate enough to consider the relevant data, perspectives and understanding, i.e. context.

    Those I consider highly relevant are those that work in the field every day and are involved in the larger scope of understanding the inter-dynamics, that do not cherry pick data or limit their view to a few data points that when tied together still can’t compete with the overarching understanding of the complexities involved in this global warming event.

    #173 Rod B

    I’m not a physicist by any stretch so I am trying to interpret the question and give the simplest answer. Also, I’m not sure I fully understand the question. I don’t understand IR in relation to N2, O2 (not GHG’s either) because I’m not well read in that area at this time. There are all sorts of photochemical processes that I’d like to learn more about as time allows.

    So at risk of having missed your point on the lag, will give it one more try. I think what you are asking is why, with all the GHG’s in the atmosphere are we not warmer, faster; because the GHG’s are there and they should be warming us more?

    I think the answer you may be seeking may be explained by the feedbacks. They are positive and negative. The positives are winning though. So the GHG’s are there and they raise the atmospheric temp a bit. That needs to be absorbed into the ocean, then the ocean responds by releasing more H2O, which is a GHG which causes additional positive and negative feedbacks. The aerosols are helping to cool things but not enough to counter the positive, so the future heating from the current GHG levels will be realized through the positive feedbacks.

    Here is what I understand at this time: Air heats and cools rapidly. Land heats and cools less rapidly and oceans heat and cool very slowly. So there is an order of precedence.

    The oceans warm slowly and then the feedback increases. It’s not all GHG though. It’s also aerosols, and albedo changes such as losing the summer ice in the Arctic. That’s a positive feedback, then the darker Arctic ocean absorbing more heat energy, also positive… those are only a couple examples, there are lots of links in the chain.

    I’m trying to look at the big picture here and hope that helps a bit, but I’m not sure I have the question right.

  32. 182
    Guenter Hess says:

    Correction to my #177:
    I meant 10^9-10^10 collisons per second

  33. 183
    LEON says:


    Arch, understand completely. I’ve been reading scienceblog for a while, but I’m new to Real Climate. Hoping to learn as much as possible so I can finally join in the AGW discussion with a bit more confidence in my understanding (I have a science background but not in anything related to climate or weather). I’m certain this website will be extremely helpful in that regard. The FAQ section has been great for me. Still trucking through, but it’s arguably one of the most succint and efficient introductions to climate change that I’ve found.

    You are correct, there is no need to waste your time with one liners. I suppose my suggestion was mildly selfish in that a part of me takes great pleasure in the public dismantling of an arrogant blowhard.

    Regardless, looking forward to spending some more time at Real Climate. So far, it’s been informative.

  34. 184
    Clear Thinker says:

    Dear RC enthusiasts,

    Ok, let me ask a question so we can ‘maybe’ get a little daylight towards resolution. Question to follow after a few remarks.

    I have made myself perfectly clear that I do not believe the AGW theories that are promoted on RC. I think we can all agree on this one, right? However, I also want you to know that I do not dispute some of the science featured on this site. It’s the conclusions that I disagree with. In order for me to understand what you consider good reliable science, I would like to know the following…

    If a person, or persons were to debate the science either for, or against, the AGW argument, in what fields of science should these persons be educated and proficient in?

    This is a serious inquiry that may help seperate the wheat from the chaff. I am trying my best to piece together the science from both sides to see who is more likely correct with their conclusions.

    I look forward to reading serious responses.

  35. 185
  36. 186

    Clear thinker #184; IMO to start with you need physics. Especially thermodynamics.

  37. 187
    Rod B says:

    guenter says, “…Correction … I meant 10^9-10^10 collisons per second.”

    Whew! That saved a large flame :-)

  38. 188
    David B. Benson says:

    Clear Thinker (184) — I recommend reading “The Discovery of Global Warming” by Spencer Weart:

    Review of above:

  39. 189
    Arch Stanton says:

    Clear Thinker (184), ask Rod B, or Erik (skeptic), I believe both of them fall into your catagory (?).

  40. 190
    Rod B says:

    JPR, to oversimplify the basic absorption physics to maybe clear the stage: 1. the earth radiates infrared based on its surface temperature, and this by itself cools the earth. 2. Some of this radiation can be absorbed by certain gases (not including N2 or O2). 3. The IR radiation gets absorbed into internal molecular energy stores, vibration and/or rotation; this does not increase the temperature of the absorbing molecules. [NB! some might disagree with this…] 4. the absorbing molecules relax by either A] a collision transfer to N2 or O2 translation energy, which does increase gas temperature (Guenter (177) (and others…) says this accounts for 96% of the relaxation), or B] emits the energy (a new photon) directly, up or down (4% of the cases) 5. repeat. Is this what you were looking for?

    I’m not at this juncture (but without prejudice) questioning increasing CO2 causing increasing temp. I’m questioning (actually wondering about) why temp lags CO2 by decades sometimes? Why not just a few minutes, say?

    A quicky minor response to JPR, Guenter, and duae while I continue to digest: Isn’t the exact boundary between surface and atmosphere the exact same temperature? (Though this might be an insignificant distinction — 2mm up it might be a lot different…???) Aren’t the temperature readings for all of those graphs since 1860 or so, that show the lagging behind CO2, overwhelmingly (at least until the past few decades) of the atmosphere, around 1-2 meters above the ground?

  41. 191
    Jim Galasyn says:

    Clear Thinker, I’d like to reiterate David’s suggestion: please do read Spencer Weart’s excellent history of climate science. It will answer all your questions.

  42. 192
    tamino says:

    Re: #190 (Rod B)

    Take a liter of water which is presently at equilibrium with its surroundings, so the energy coming in equals the energy going out. Now add 1 watt to the energy going in. How long will it take the temperature to rise by 1 degree? “Why not just a few minutes, say?”

    Do the same thing, but replace that one liter of water with one million liters of water. Now how long will it take the temperature to rise by 1 degree in response to the extra 1 watt of energy input?

  43. 193
    Clear Thinker says:

    David B. Benson Says:
    22 July 2008 at 4:03 PM
    Clear Thinker (184) — I recommend reading “The Discovery of Global Warming” by Spencer Weart:

    Thank you Mr. Benson for the above link. I found this statement from Mr. Weart interesting…

    “We don’t know exactly which geophysical forces are most important for climate change, nor which scientific approaches point toward the best explanations. Some controversies have remained unresolved for decades. Matters now considered minor (as carbon dioxide once was) may eventually loom large, and vice-versa.”

    And he did mention some of the areas of study that are involved.

    Once again, thank you.

  44. 194
    David B. Benson says:

    Clear Thinker (193) — You are welcome. Kindly encourage others to read that fine presentation of the history.

  45. 195

    Re #184 Clear Thinker

    If a person, or persons were to debate the science either for, or against, the AGW argument, in what fields of science should these persons be educated and proficient in?

    I would say it’s less about the origins of the “educated” part and more about the resultant education from experience, meaning more about the “proficient” part. Experience counts for a lot in something this complex.

    So my vote would be for those that work in the field of climatology as opposed to those that work in the field of meteorology for example, generally speaking.

    The actual field of science one was educated in may have less relevance than the experience in the field. So in that respect, I vote for “proficiency” in the field by virtue of experience in the field.

    There are so many components to the study of climatology though, so one can not limit strictly. Many scientists contribute to the data set and modeling from multiple fields. Context and relevance is key.

    Re #190 Rod B

    Thanks, I need to do a lot more reading in this area. I’m open to recommendations links, books.

  46. 196
    Chris says:

    Re #173/#190


    While the temperature starts to rise soon in response to the enhanced forcing, the new equilibrium temperature takes a while to be achieved due to the heat capacity of the system being forced.

    Why not do an experiment….you need a room….a thermostat..and a thermometer…

    Turn the thermostat from 15 oC to 20 oC…measure the temperature at the back of the room. It will start to rise quite soon after raising the temperature of the thermostat, but it will take a while for the room temperature to re-equilibrate to 20 oC.

    Now fill the room half full of water (sorry!). Stir the water a bit to represent ocean currents. Repeat the experiment. Again the thermometer will respond quite quickly to the enhanced forcing driving the temperature from 15 oC to 20 oC….however it will take substantialy longer for the new equilibrium temperature to be achieved.

    For added reality, light a bunsen burner for a few minutes occasionally to represent El Nino’s……switch on an air conditioner set at 17 oC to represent atmospheric aerosols, and switch this to 18 oC mid way through the experiment to represent various “Clean Air Acts” and the demise of the Soviet Union…..but switch it back up towards the end to represent Asian brown clouds..

    …and so on….

    ..the lag relates not so much to the temperature rise, as to the new equilibrium temperature, and the progression to the new equilibrium temperature will be modulated by various stochastic (and not so stochastic) elements intrinsic and extrinsic to the climate system.

  47. 197
    Clear Thinker says:

    Ocean temps. I see suggested experiments that try to show how the oceans
    temp changes. Do these experiments take into account any heat added to the water by underwater volcanic activity or fumeroles or even fresh water runoff?

    I will get back to my first question later.

    Thank you.

  48. 198
    Chris says:

    Re #190 Rod

    3. The IR radiation gets absorbed into internal molecular energy stores, vibration and/or rotation; this does not increase the temperature of the absorbing molecules. [NB! some might disagree with this…]

    Everybody should agree with that, since a molecule doesn’t have “a temperature”. Temperature is a property of a collection of molecules (their average kinetic energy).

    In ay case molecule don’t really have “internal molecular energy stores”. Molecules aren’t chipmunks! Molecules have molecular energy levels (electronic, vibrational, rotational) transitions between which can be stimulated by absorption of EM radiation of appropriate energy.

  49. 199
    David says:

    Clear thinker, you ask whether people have considered the impact of underwater volcanic activity on ocean temperatures. This type of question illustrates a common problem in discussing science (or public policy for that matter) : people commonly greatly overestimate their own intelligence and underestimate the intelligence of others. As a result, they commonly believe that with a few minutes consideration they can come up with an idea which has for years escaped the attention of experts in the field.
    If you really investigate any field of science you will invariably find that there is both a great deal more known AND a great deal more unknown than you could possibly have imagined initially.

  50. 200
    Hank Roberts says:

    > I see suggested experiments ….

    Where do you see suggested experiments? Source please?

    These are difficult without a control planet. This is why measurements and models are used, we don’t have spare planets to do proper controlled experiments.

    Try looking the question up. For example,
    tells us, with citations to his sources”

    1) The heat has already been measured as part of overall work done on sea water temperature at depths

    “… volcano input is comparable to the background geothermal flux, which in turn is much less than the fluxes through the pycnocline from the warm Atlantic water, and to a lesser extent, the Pacific inflow.”

    2) If there were more it’d become obvious quickly:

    “we have primary evidence that heat from the bottom is not reaching the ice. Temperature profiles from virtually everywhere in the Arctic Ocean display a maximum temperature at a depth from 200-400 [meters]. This is associated with the Atlantic Water entering the basin from the Norwegian Sea. Fundamental laws of physics require that below the depth of this maximum, the heat flux is downward. Very near the bottom temperatures have been found to increase with depth indicating a small upward heat flux from geothermal sources, which help to heat only the very deepest water.”

    and 3) You can do the math, even approximately, and look up numbers for yourself:

    “… the average heat added from volcanoes to the ocean is of order 0.1 Watt per square meter. But the heat added (or removed) to the ocean from the sun and atmosphere is of order 100 Watt per square meter. So it is very hard for volcanoes to compete. Someone probably has much better estimates than these.”

    Click the link for the context and sources.