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CO2 is not the only greenhouse gas, and greenhouse effects are not the only CO2 problem

Filed under: — gavin @ 7 July 2008 - (Español)

The title here should strike a familiar theme for most readers. Climate forcings do not just include CO2 (other greenhouse gases, aerosols, land use, the sun, the orbit and volcanoes all contribute), and the impact of human emissions often has non-climatic effects on biology and ecosystems.

First up last week was a call from Michael Prather and colleagues that the production of a previously neglected greenhouse gas (NF3) was increasing and could become a significant radiative forcing. This paper was basically an update of calculations done for the IPCC combined with new information about the production of this non-Kyoto gas.

Most of the media stories that picked this up focused on the use of this gas in a particular manufacturing process – flat screen TVs. Thus the headlines almost all read something like “Flat-screen TVs cause global warming”! (see here, here, here etc.). Unfortunately, very few of the headline writers read the small print.

NF3 is indeed a more powerful greenhouse gas than CO2 (as are methane, CFCs and SF6 etc.), but because it is much less prevalent, the net radiative forcing (as with other Kyoto gases) is much smaller. Unfortunately, no-one has any measures of the concentration of NF3 in the atmosphere. This is likely to be increasing, since production has stepped up rapidly in recent years, but the amount of gas that escapes to the air is unknown. Manufacturers claim that it is only a very small percentage – but historically such claims have not always been very reliable. However, it is almost certain that NF3 has not caused a significant amount of global warming (yet).

The one issue that many stories did get wrong was in the comparison with coal. Prather’s paper compared the effect of the entire global production of NF3 being released into the atmosphere with the CO2 impact of one coal-fired power station. Since that is the maximum estimate of the current effect, and only matches a single power-station, the subtlety of the comparison got a little lost on the way to “Flat screen TVs ‘worse than coal’” story….

Needless to say, no-one should be throwing away their flat screen TVs because of this (it’s not in the use of the TV that causes a problem), but manufacturers will likely need to step up monitoring of NF3 leakage or switch to an alternative process which some have already done.

The second story getting some attention, is the ocean acidification issue. As we’ve discussed previously, the increased take up in the oceans of human-released CO2 is rapidly increasing the acidity (lowering the pH) of the oceans, making it more difficult for many carbonate-producing organisms to produce calcite or aragonite. These organisms include corals, coccolithophores, foraminfera, shell fish etc.

Both of these issues are relevant to the ongoing climate change discussion and it’s good to see the media picking up (albeit imperfectly) on these ancillary discussions. But as with the “North Pole” lightning rod discussed last week, there always needs to be a hook before something gets wide press (the ‘tyranny of the news peg’ as ably described by Andy Revkin). In the first case, there was a link to a popular consumer item and in the second, there has been a concerted effort to get the ocean acidification issue higher up the agenda.

The fact of the matter is that most of what goes on in the sciences is completely (and usually correctly) well below the radar of the public at large. But when there are discoveries and issues that do have public policy ramifications, getting the public to pay attention often requires finding just these kinds of resonances. Now if there was only a way to make sure the story underneath was accurate….

232 Responses to “CO2 is not the only greenhouse gas, and greenhouse effects are not the only CO2 problem”

  1. 101
    pft says:

    Gavin- “all of which is due to human emissions. Your calculations are wrong because you are neglecting that the ocean/land sources are almost in balance with the sinks, but that the real sink out of the land/atmosphere/upper ocean system is the flux into the deep ocean, which is much slower.”

    Thanks for the reply, but I still can’t quite get it. Looking at it another way, annually, man emits CO2 into the atmosphere that is equal to 1% of the total CO2 in the atmosphere. It seem that the solubility pump could handle this additional loading of CO2 in the cold waters, assuming a well mixed atmosphere, and CO2 not being saturated in the cold waters. My understanding is carbon sinks into the cold water oceans in the Antarctica, transporting it deep and undersaturated at high pressure, returning it to the surface 1000 years later, where it is heated and at atmospheric pressure, to be unloaded from saturated water in the Pacific.

    I guess what bothers me, is that given that man has contributed to higher levels of CO2 in the atmosphere, how is it that 50% of mans CO2 is left behind, while natures CO2 gets absorbed into the sinks, and it seems the models are assuming a very inflexible climate system that is intolerant to small changes in CO2 sources and sinks.

    [Response: Your guesstimate is pretty much the state of science circa 1950. But then Revelle and Suess discovered the buffering ability of seawater which meant that the ocean would not absorb as much CO2 as everyone thought. – gavin]

    #80. Can you direct me to a current source which provides man made emission of CO2, total atmosphere CO2 content, uptakes and sinks? I find it difficult to get all from one source.

    Annual Input to Atmosphere/Output from Atmosphere:
    Ocean: To Atm.: 88, From Atm.: 90, Difference: -2
    Vegetation/Soil (Natural): To Atm.:119, From Atm.: 120, Difference: -1
    Vegetation/Soil (Man): To Atm.:1.7, From Atm.: 1.9, Difference: -0.2
    Industry: To Atm.: 6.3, From Atm.: 0, Difference: +6.3

    Total: To Atm.: 215, From Atm.: 211.9, Difference: +3.1


    #87. I do not need to prove anything and am not trying to prove anything, just trying to understand. When people want to increase energy costs and change lifestyles due to Global warming, the burden of proof is on them.

  2. 102
    Aaron says:

    #100 Tom

    The earth is a thermal system in contact with a heat reservoir in the form of incident radiation from a star, namely the sun. I think we can agree on this fact. The earth also has internal variables like different physical phases, an optical thickness and life. So far so good. Such a thermal system can be characterized as a grand canonical ensemble, meaning that the number of particles and the energy (for a given incident radiation input) are fixed. Now, such a thermodynamical system fluctuates. These fluctuations take all kinds of forms, one of them being volcanic eruptions, but I would even throw in large weather events like tornadoes and hurricanes since they are far from day to day weather. For a grand canonical ensemble in equilibrium (and I would argue that for all intents and purposes that the earth is in equilibrium because there is only a very, very small amount of the possible phase space for the atmosphere being used right now, we are very close to a global attractor in other words) there are stable fluctuations that will allow the system to change internal energy slightly, with respect to total energy, and then return to the pre-existing equilibrium. There are also fluctuations that will take the system to a new equilibrium. That’s how we got here. But back to the point, these fluctuations can last different amounts of time. The question is, after integrating over the time that they last, are they larger than the average relative fluctuation and is that enough to get the system to a new equilibrium position. Its pretty basic stat mech. I understand that CO2 emissions have lasted longer, but after integrating over the time that they have been happening, can you say that their effect is greater than that of a volcano? Since volcanoes aren’t taking us far from the attractor, how is changing the optical thickness of the atmosphere with CO2 taking us away from it as a long time fluctuation? I don’t know. That’s why I was asking.

    There was also some comments of equating these types of fluctuations with noise. I think that is a misnomer and should be clarified. If pull a pendulum away from its lowest point and let go, in the end it will return to equilibrium. In the earth’s gravitational field lifting this pendulum even 6 inches is changing its total potential energy very slightly relative to the center of the earth. As a microcanonical ensemble, this would be considered a stable fluctuation because the system is still returning to equilibrium, albeit a very simple example comparatively. I just wanted to illustrate the point I was making. I’m not talking about flickers unless we would consider a volcanic eruption or CO2 emission a flicker.

    As for your no global equilibrator argument, of course there is an equilibrator. If there wasn’t there would not stable weather patterns or a livable earth. The atmosphere would be testing all the possible configurations of its particles throughout phase space randomly. The laws of physics, specifically statistical physics, are the global equilibrator. Now if you have a serious answer to this question I would very much like to hear it. If you are just trying to derail this train of thought because you think you know my motivation, please stop. I am just trying to get my scientific questions answered on what I thought was a scientific forum. Thanks

  3. 103
    Aaron says:

    #99 Ray

    Sorry I just read the link you left. Thanks. I also think that you have me confused with that other Aaron. I’ll try to use a different name next article.

  4. 104
    tamino says:

    Re: #101 (pft)

    I hope you reach the understanding you seek regarding the science.

    Regarding policy, I believe it’s a serious mischaracterization to state “When people want to increase energy costs and change lifestyles due to Global warming, the burden of proof is on them.” Try “When people want to trigger mass extinctions and ecosystem collapse by ignoring global warming, the burden of proof is on them.”

    I would also mention that the changes most often suggested involve a transition to renewable energy. This will be necessary whether global warming is true or not.

  5. 105
    John Mashey says:

    re: #101
    “increase energy costs and change lifestyles”

    Even if there were no such thing as AGW, energy costs are going to increase and lifestyles going to change, given that we already appear to be on the Peak Oil plateau, will likely *never* have substantially higher production of conventional oil, and then, sometime in the next decade, we can expect the world production to fall. Likewise, but a decade or two later, comes Peak Gas.

    For useful discussions, see The Oil Drum, or read David Strahan’s “The Last Oil Shock” or Kenneth Deffeyes “Beyond Oil”, or see what a friend of mine who used to run Shell says.

    We’ll use all the oil & gas we can get, as they are just too handy. The more efficient we get, the longer we stretch oil&gas and the better we *invest* the one-time inheritance of high-EROI convenient fuels into building sustainable energy supplies, the better *both* economy and climate are.

    The big disconnect is over coal, of course.

    If we do our best to burn fossil fuels fast and inefficiently, we get both a broken economy and a broken climate, leaving some descendants the ugly task of building sea walls and dikes, and rebuilding major infrastructure, not with $20-$30/bbl oil, but with $300++/bbl.

    Kharecha and Hansen is well worth reading.

  6. 106
    Tom Dayton says:

    Re #100 (me):

    Sorry, I mis-edited the paragraph that starts “But suppose the Earth,” so it was backward. It should have read:

    Suppose the Earth was already cooling from other influences. The precipitation of the volcanic sputum would work against that cooling trend, thereby reducing the Earth’s net change–pulling the Earth toward “equilibrium.” But suppose the Earth was already warming. The precipitation of the volcanic sputum then would exacerbate the global, net warming trend, pulling the Earth further away from “equilibrium.”

  7. 107
    Guenter Hess says:

    As I mentioned before, my opinion: The earth is an open system that is far away from thermodynamic equilibrium, which is a good thing for life.
    The key driver here is the sun, which provides low entropic energy that can be used by living things to do work.
    Plants used that when they appeared. They reproduced and produced oxygen molecules, which drove the earth system into another state and they fortunately continue to produce oxygen molecules. Right now this is a dynamical stationary state with about 20% oxygen. You could call that an attractor I guess.
    If the plants would not produce oxygen molecules anymore then another attractor would appear, thermodynamics would remove the oxygen molecules, and the oxygen atoms in the molecules would access a state with a lower oxidation number. This would take a while but the thermodynamics will ultimately prevail.
    Unfortunately us humans can use that low entropic energy as well to do work and change the state of the system and also keep it there. However, we cannot control the feedback of the system.
    Moreover, it might not go back to the original state, but go to a different state as it did after the appearance of the plants.
    From a statistical thermodynamics view I guess one could say the low entropic energy from the sun makes it possible to reach microcanonical ensembles or non-equilibrium states that would not be accessible by a thermodynamical driven process.

  8. 108
    Tom Dayton says:

    Re #102, Aaron wrote:

    As for your no global equilibrator argument, of course there is an equilibrator…. The laws of physics, specifically statistical physics, are the global equilibrator.

    I didn’t realize you were talking at that very high level of abstraction. I’m not a climatologist, but I’m pretty sure that climatologists have not managed to model climate so well that they can quantitatively describe temperature’s deviation from its current attractor in the unitary and tidy way you are asking for. Instead, they model at the level of the individual physical processes and their interactions, run those models with several versions of the parameters, then describe the range of outcomes. So when you asked for comparison of the effects of volcanoes to long-term CO2 increases, the most appropriate way to answer is as Jim answered.

    (By the way, there was no need to get snippy (your last paragraph). I was not in the least bit trying to derail the train of thought. After reading your snippy reply I did look for a relevant quote from Maxwell Smart, but it turns out that his KAOS is spelled differently.)

  9. 109
    Thomas says:

    I think we have some confusion about what a system in equilibrium means. For a strict definition, the time derivatives of all quantities would be zero. For a complicated dynamical system like the earth this will never be identically true. Since you are primarily concerned with warming, lets simplify our discussion to include some measure of the average temperature of the atmosphere, which in some system of units is the total thermal energy of the atmosphere divided by the total heat content of the atmosphere. We can add in a similar measurement for the liquid and solid earth (oceans and solid ground). Now we have shortwave radiation input, solar, and longwave radiation output. Any difference must be accounted for by a change in the heat content of the atmosphere, plus of th solid and liquid components. At any point in time I can say that the probability that they exactly match up is vanishingly small. The biggest known variation has to do with the noncircular orbit of the earth. We just passed our furthest point from the sun (July 4th IIRC), and six months laer we will be a minimum distance from the sun. The differene in insolation is roughly 7%. So ignoring possible changes in the earths reflectivity (albedo), and in the net longwave radiation we would expect the earth to be heating and cooling off on a yearly basis. In a stable climate averaged over a number of years the shortwave energy in and the longwave energy out will balance out, and the heat content of the components will fluctuate around their average value. Now we we add a slowly varying additional forcing to the system, the system is no longer in a time-averaged state of equilibrium, the heat content is changing. That is where we are at today. Now the total heat required to raise the temperature of these components by say a degree C is orders of magnitude smaller than the total amount of sunlight absorbed over a century (and longwave emitted). So the degree of imbalance is actually pretty small, and perhaps the earth is today cooling 49% of the time and warming 51% of the time.

    As a different analogy consider your bank account. Say you deposit $1000 every month, and on average spend $1000, but your spending varies a bit. Your balance varies up and down, but there is no long term trend to it. Now you get a $10 a month raise, but don’t change your spending. Your balance still goes up and down, but after a decade will increase by $1200.


  10. 110
    Tom Dayton says:

    Re #102, second paragraph, Aaron wrote:

    There was also some comments of equating these types of fluctuations with noise. I think that is a misnomer and should be clarified. If pull a pendulum away from its lowest point and let go, in the end it will return to equilibrium…. I’m not talking about flickers unless we would consider a volcanic eruption or CO2 emission a flicker.

    A volcanic eruption and a sporadic CO2 emission are considered “flickers,” insofar as they are not like a pendulum being pulled back from its gravitational equilibrium position. The eruption of a volcano does not wind up a counter-process that then undoes the atmospheric effect of the eruption. The inevitability of the volcano’s ash and sulfuric acid precipitating has nothing to do with the volcano. If aliens flushed their spaceship toilet’s load of the same ash and sulfuric acid into the atmosphere, it would precipitate the same way at the same speed.

    Regarding “noise” in general: Noise is defined with respect to some signal that interests you. Noise can be systematic, or it can be random. It can appear random just because we don’t understand how it is systematic, or it can be truly random. But what really matters is just that noise is what we are not interested in, in this particular inquiry.

    The particular inquiry at hand is change in climate, which by definition is long term, meaning 30 years or so. 30 years was not pulled out of a hat; it was chosen (and not just by global-warming-believing climatologists) because it is long enough to exceed most of the known shorter cyclic and non-cyclic events. So anything shorter than a 30-year trend (the signal — climate) is, by definition, noise (weather).

    In the narrower case of global temperature rise (i.e., a subset of global atmospheric behavior), the size of the signal and the size of the noise are such that 15 years might be adequate to start to get a hint of the signal. (At least, I think I read that by some climatologist or statistician. Gavin? Tamino?)

    So yes, these fluctuations of volcanoes are indeed noise.

  11. 111
    Dustin says:


    You’re needlessly obfuscating your ‘scientific questions’. You might get a better response if you simplify and stop saying canonical.

  12. 112
    Chris Colose says:


    I’d like to comment on the correspondence you have been having considering an “equilibrium condition” of the atmosphere.

    For simplicity, the global mean temperature can be thought of as a function of the solar energy input to the planet, and the outgoing infrared energy which cools the planet. You can set the incoming solar radiation at the top of the atmosphere as “S” and then account for the spherical geometry of the Earth by dividing by 4. You have to account for the amount of solar radiation reflected from the planet, the albedo (α), which is about 30% of what comes in and so that doesn’t really matter. Adding the greenhouse effect (G), and from Stefan-Boltzmann, you have

    S/4 (1-α) + G = σ T^4

    where T is temperature and sigma is just a constant. When you have a volcanic eruption, you increase the amount of particles in the atmosphere that reflect incoming energy, thereby making the value of α larger, which reduces T. When the volcanic particles in the stratosphere precipitate out, then α will come back to its previous value and so will T, not because the atmosphere has some state that it inevitably returns to, rather it’s just because ΔT was a result of Δα. If you increase greenhouse gases, then G becomes larger. If the sun gets much brighter and stays in that state for long periods of time (S gets larger), it will get warmer, and stay warmer for long periods of time all other things being equal. If ice cover declines as it gets warmer then α will reduce, and that further raises T. CO2 is more of a concern then volcanoes because it has a much longer residence time in the atmosphere (ranging from hundreds to thousands of years), while volcanic ash and sulfate ejecta is removed relatively rapidly. Mt. Pinatubo caused a large cooling, but only for a year or two.

    Concerning internal variability (like ENSO), to a large degree you’re mainly just redistributing heat around the globe, and that has large regional implications but much smaller over the global average. Though, you can affect cloud cover and water vapor in the atmosphere which effects α and so you do change the radiative balance a bit on short timescales. During an El Nino, heat is clearly “mined” from the ocean to put into the atmosphere, so if you look at a plot of global temperature vs. time, El Nino years do appear to be anomalously warm. Such variations can dampen global warming on short timescales as well, such as during conditions where you can bring enough colder, deeper water in the oceans up to the surface and you now use the extra energy to heat the colder waters. But you can’t do that forever since it will heat up eventually.

    It isn’t exactly intuitive that the global mean shouldn’t be a bit more noisy then it has been over the Holocene. During a positive AO for instance you can rapidly export ice from the arctic, and that should affect albedo…or you’d think that cloud cover changes might be more pronounced on decadal timescales. This is kind of what Roy Spencer is trying to get at with his “internal radiative forcing” concept, but as it happens, such things tend to cancel out over the long-term and external forcings matter more.

    When you add greenhouse gases you increase the amount of total energy available to the system. The “equilibrator” you’re trying to find is the outgoing longwave radiation (OLR). As you turn up CO2, the planet takes in more solar energy than it gives off to space as infrared, and as a consequence the planet warms. The way the planet comes back to radiative balance (but at a higher temperature) is through increasing the outgoing infrared energy.

  13. 113
    Alastair Brand says:

    #84 & #98 (Mike & Steve) In answer to your comments (yes, I know it’s off topic) I do not have figures for all of Europe, but I have just checked back on the Met Office figures for UK over the last few years.

    The problem is one of perception. Ask the man in the street, and he will interpret a wet spell of weather as being cold as well. Most people would assume that last year was cold (not true) because the summer was wet. The figures, though, show a different picture.

    If you take it as read that 2003 was a hot year, then just look at the data for subsequent years an the figures are surprising. EVERY year since 2003 has been between 1.1 to 1.4 deg C above the long term average. More to the point, since January 2004, there have only been 3 months where the UK temperature has fallen below the long term average. Yet you always have to fight the perceived “facts”.

    On the other hand, this risks falling into the same trap as some of the contrarians. Never rely on the figures for a region in order to evaluate global trends. Bottom line is, look at the gobal – not regional figures. I only used the regional figure here to illustrate a point.

  14. 114
    Richard says:

    Ray Ladbury made a comment about people who have an “incomplete understanding of the science”. However I find it quite astounding for anyone to claim a complete understanding of climate science.

    Climate science involves so many different highly complex physical interactions that no single person could possibly claim to understand the whole multi-disciplinary system.

    I am therefore instinctively sceptical of anyone who claims to be able to have a “complete understanding of the science”.

    I have a PhD in turbulence simulation and 10 years post doctoral experience. Despite this I would be extremely foolish to declare a “complete understanding of turbulence”.

    I understand there is a little turbulence involved in climate science too?

  15. 115
    Mark says:

    Tom Dayton, #83

    Maybe we can use the “Think of the Children!!!” meme.

    They don’t care that it is a one-in-a-million chance their child will be abducted. However, if it saves just one life…

    So why when reducing CO2 emissions and working to stop or reverse climate change must it be a one-in-a-milion-chance we are wrong before you try to save just one life by changing your lifestyle?

    Is your childs life worth less than your SUV?

  16. 116
    Mark says:

    Re #100 The earth is a thermal system in contact with a heat reservoir in the form of incident radiation from a star, namely the sun. I think we can agree on this fact.

    No. We can’t. The earth is decidedly not in contact with the sun.

    You also have a problem with your statements in that the radiation from the sun is black body radiation at 6000C. The earth intercepts this and absorbs it and comes to a black body temperature I think we can all agree is NOT 6000C. So the radiation is not the same.

    CO2 acts differently based on the frequency of the light passing through. Solar light is hardly affected. Earth radiation highly affected.

    So the earth warms up until its temperature rise is enough that the power radiated is enough to overcome the blanketing power of the atmosphere.

    As an example: put a too-high TOG rating duvet on tonight. You will be warm and toasty. But you will not immediately be *too* toasty, will you. Therefore adding a thicker blanket does not immediately change your surface body temperature. There’s a delay. And if you don’t take the duvet off, your core temperature will rise and if you still do nothing, you can die of heat stroke.

    But not immediately.

    Same with the earth.

    Are we going to be able to take the blanket off, though. That’s the question.

  17. 117
    Pete Best says:

    Once again its all talk in the UK papers about the G8s seeming commitment to a 50% CO2 reduction by 2050. Some papers are still arguing that its all a hoax anyway and down to the Sun and that last winter and this summer are cooler than expected and that climate experts are at a loss to explain it. Well what about La nina then!! Anyone told you about that.

    I mean the other night on the UK radio station Talksport was a environmental special with a bloke ringing in with a double first from Oxford (although he would not say what in) stating that climate change was nonsense for two reasons and that no one would come to his University and debate the issue with them

    His first objection was water vapour (I groaned) being the most potent greenhosue gas and it not being mad made. I just could not believ my ears on this one and his other argument against was the fact that humans only release 0.5% of all annual GHG emissions. Once again I groanded. The bloke from the environmental group gave the bath analogy but it did not appease him as he liked the sound of his own voice.

    I just despair at times.

  18. 118

    Joseph writes:

    Out of curiosity, how do we know that we’re not completely out of balance right now? In other words, what if temperature is rapidly increasing primarily because we’re not in equilibrium, regardless of whether green house gases continue to accumulate in the atmosphere? Can this scenario be discounted? If not, is there a reliable way to know when equilibrium should be expected to be reached?

    Earth only ever warms or cools because it’s not in equilibrium. The greenhouse gases are why it’s not in equilibrium. But the amount of the imbalance is tiny or we’d see a rapid change in Earth’s temperatures.

  19. 119
    Mark says:

    “As for your no global equilibrator argument, of course there is an equilibrator. If there wasn’t there would not stable weather patterns or a livable earth.”

    These do not try to get back to an equilibrium. They act blindly.

    Water does not try to form a level surface. It just obeys the forces upon the molecules.

    To get on to your original volcanic point, the volcano spews a lot of grunge out that affects the weather. It isn’t trying to make it cooler, it’s just spewing. The stuff it emits gets washed out and that stops it affecting the weather. The system isn’t trying to get back to an equilibrium, it’s just that the thing forcing itself out of equilibrium is gone.

    Now, if that forcing were big enough or at the exact wrong place (or time), we may move abruptly into a new climate and not get back to what we were. Look up “Chaos Theory” to find out how this can happen.

    There’s no equilibrator, there’s the lack of forcing out of equilibrium.

  20. 120
    mz says:

    Well, I guess if there were constant ash-spewing volcanic eruptions for a long enough time so that the ash would stay in the atmosphere and cool the Earth so long that oceans would start freezing over, then “the system couldn’t handle it”. Don’t know about ash on ice or the CO2 from the eruptions though and their effects.

  21. 121

    Aaron — if you’re asking whether GHGs can cause the Earth to go past some kind of inflection point where its temperature rises out of control, the answer is no. Energy is conserved.

  22. 122
    Luke Silburn says:


    I’m a layman but I’ll take a stab at discussing your slightly OT point.

    The weather you are describing is sometimes called the ‘European Monsoon’ and is a well understood regional weather pattern. Basically it arises as we pass the northern summer solstice and the high angle of the sun causes the relative temperature of the Atlantic and the Eurasian landmass to shift, with the land warming relative to the ocean. This causes air to heat and rise over the land and suck moist low pressure systems in from the ocean – as such it is indeed a monsoonal pattern, albeit much weaker than the Asian version.

    Because the phenomenon is fairly weak, most years the weather produced isn’t pronounced enough for people (other than meteorologists) to notice – although it’s sufficiently reliable for people to grumble about ‘typical Wimbledon/Glastonbury weather’ without necessarily knowing anything about the underlying causes. The track taken by the Atlantic lows is also somewhat variable year to year and so approximately 30% of the time the rains hit areas with few or no inhabitants and, again, don’t get noticed.

    Every now and again however the phenomenon produces a strong, regular sequence of Atlantic lows that track in at the latitude of the Channel Approaches and give Southern Britain and Northern France a thorough soaking from late June until late July (or even into early August). The flooding in central England last year occurred as a result of one such year and the lousy weather experienced by the armies in Normandy during the summer of 1944 was another. This year doesn’t seem to be shaping up to be as bad as last, but certainly the weather in London over the last few days has been fairly typical of the phenomenon.

    As to whether the European Monsson might become more pronounced as a result of AGW, I am most definitely not qualified to answer (or even speculate). However I will point out that as a regional/seasonal weather pattern it is subject to the various teleconnections that operate at the regional/seasonal scale (these underlie the variability in strength and track previously mentioned) and that predicting the way that these various regional scale effects will respond to AGW and combine to produce regional/seasonal weather is, to say the least, a hard problem.

    Which is a longwinded way of saying I don’t know and I strongly suspect that nobody else knows either. Sorry.

    Doubtless I’ve got various things wrong – if the errors are egregious then someone with better knowledge will correct me and we’ll both learn something.


  23. 123
    Ray Ladbury says:

    Aaron, re: equilibrium and climate. I think you are a little confused about the relation between equlibrium and thermodynamic state. Equilibrium does not correspond to a single state, but rather a range of states in the phase space with similar macroscopic properties. There is nothing that “forces” the system back toward equilibrium–it’s just that there vastly more “equilibrium states” than nonequilibrium states. Now if we add energy to the system, we change the volume of phase space available to the system and may introduce states with very different behavior.

    In any case, whether one treats the system as a single system or as multiple systems that interact to various degrees on different timescales becomes ultimately a matter of convenience–and the latter is often more convenient.

  24. 124

    In re 70 and 91 —

    The electric demand in Texas, which has its own separate electric grid (ERCOT) is typically in the range of 30 to 50GW (it’s 36.3GW at this particular instant in time — get back to me later in the afternoon when it’s higher ;) ), of which up to some 6GW is capable of being generated by wind (and 1.8GW of which is currently being generated by wind).

    Pickins’ proposed wind farm won’t be producing at rated capacity (they are rated for stronger than average winds, just because that’s how capacity is rated), so it remains to be seen what the actual production of a 4GW farm would be. The economics have their own set of issues, but I believe the current environment is favorable.

    If my reading of the shift to renewable power is correct, there’s presently a shortage of green production relative to green demand. My conversations with Green Mountain Energy last Fall showed me that there was a shortage of wind production versus customer demand. My recollection is that they were oversubscribed on wind power and the renewable electricity they were committing to customers was hydro or something else — when I found out they couldn’t sell me wind I told them thanks, but no thanks. I think wind is where the smart money is at.

    However, the grid isn’t a charity and unless wind can compete in the energy market, it isn’t going to be put on the grid in the first place, and this is where consumers have to lead. Most of my CO2 offsets come from NativeEnergy (, and I’d gladly give them more money, and I wholeheartedly encourage everyone here to give them more money.

    What you, as a consumer, can do to insure that Pickins’ windfarm, and the ones being built by the folks NativeEnergy partners with, are commercially viable is switch to a renewable provider, if your area has one, and offset whatever other CO2 emissions you have through a high quality offset provider, such as NativeEnergy. What this will do is create a direct demand for renewable power, and the market will respond by producing more, and an indirect market to supply the Renewable Energy Credits for the offset market. The way the REC market works is pretty simple — you drive your car, you emit CO2, the wind farm sells power as “dirty” and keeps the “clean” attributes of its power which it then sells as RECs as a secondary source of income to folks like you who want to offset your CO2 emissions. You can also question businesses you deal with about their use of renewable power and make it clear that you expect something of a higher quality for carbon offsets (if that’s how they are claiming “renewable power”) than a million seedlings planted on an obscure piece of land in a far away place that won’t make a dent in CO2 concentrations for years to come.

    I think that issue — low quality versus high quality RECs — is the defining issue on projects such as Pickins’. If people begin to understand that something like a solar electric or wind farm are actually reducing fossil fuel usage NOW, and planting trees in Africa and won’t reduce net CO2 emissions for many years to come, the economics will become viable. It’s the shysters out there selling RECs from low quality sources, or dubious “energy efficiency” projects, that need to be avoided. Reforestation and energy efficiency improvements should be mandated — someone cut down the forests, so someone needs to put them back, and expecting that one has the right to be however wasteful they feel like is just dumb. That leaves building out a renewable energy infrastructure — what Pickins is doing — as the only meaningful alternative.

    Economically we can’t survive planting seedlings and burning oil and coal. It’s probably cheaper that way today, but the longer we put off the shift to renewable energy, the more economic damage will be done, and the harder it will be to shift when demand for construction outstrips ability.

  25. 125
    Ray Ladbury says:

    Richard, Note that I said an incomplete understanding of the SCIENCE, not an incomplete understanding of the climate. The science reflects our understanding at a given point in time. No one claims to understand everything there is to understand about climate. However, the science is sufficiently advanced that we can state with high assurance that the role of CO2 is understood. We can also state that future developments are very unlikely to overturn that understanding. If you’ve modeled turbulent system, you are no doubt familiar with such a situation. We will never understand everything there is to know about turbulent flow around an object. We do understand it well enough to know the plane will stay airborn. Likewise, we’ll never understand every nuance of climate. We do know enough to state that if we add CO2, it will be hotter than it would be otherwise, that the change in temperature will be of order 3 degrees per doubling and that the effects of the added carbon will persist for centuries to millennia.

  26. 126
    Mark says:

    “#144 Richard Says:
    10 July 2008 at 4:45 AM

    Ray Ladbury made a comment about people who have an “incomplete understanding of the science”.”

    This is more “incomplete understanding” in the vein of “H2O is a greenhouse gas and we don’t produce H2O, so climate warming is incorrect”.

    Would you accept someone like me saying “well, turbulence makes the bee fly, so therefore you should fly better when there’s turbulence, so all that CAT scare is bull”.?

  27. 127
    tamino says:

    Re: #114 (Richard)

    I very much doubt that Ray Ladbury thinks he, or anyone for that matter, has a complete understanding of climate. What he’s objecting to is those who pontificate on the subject, but don’t even know a tiny fraction of what the experts know. It’s not that they lack a complete understanding of science, it’s that they lack even a basic understanding of what *is* known.

    You say you’ve worked extensively on turbulence. Suppose I suggest that the real cause of turbulence in atmospheric dynamics is galactic cosmic rays. You probe me with questions to find out more about my theory, only to discover that I’ve never done any experiments on the subject, I’ve never studied physics, and I don’t know enough mathematics to understand calculus. But I continue to insist that I understand turbulence better than you do — despite more than a decade of intense study, you’re wrong because you’re just trying to promulgate a “turbulence hoax” in order to get more research money.

    That’s an analogy for what we see all the time from climate “skeptics.” I believe that’s what Ray was referring to with his comment.

  28. 128
    Joseph says:

    But the amount of the imbalance is tiny or we’d see a rapid change in Earth’s temperatures.

    I take it what we see now is slow. Compared to what?

  29. 129
    Richard says:

    #125 No aeroplane has ever been developed based on any kind of turbulence theory or simulation even today. Aeroplanes have always been designed based on extensive repeatable experimentation.

    Turbulence simulations are done to provide as much information and understanding as possible. Even today despite the ever increasing super computer capabilities no industrial company would ever complete a design process without large scale experimental testing.

    #126 I understand that H2O is processed in vast quantities both industrially and naturally.

    #127 I know nothing of galactic dynamics, however a turbulence model can be tested under controlled conditions and compared with equally controlled experiments. In this way each proposition can be tested.

    As I understand it climate science has too many unknowns to be able to provide such a controlled environment to properly test each proposition.

    I think that Roger Pielke Sr has presented an interesting view regarding climate change:

    While natural variations are important, the human influence is significant and involves a diverse range of first-order climate forcings, including, but not limited to the human input of CO2.

    [Response: No one will dispute that, and I don’t know why Roger thinks it controversial. The problem is, that while that statement is true, it is also true that CO2 is the fastest growing forcing and the only one that is forecast to grow sufficiently to cause multi-degree changes in global mean temperature in the future. Hence the dominant focus on carbon. – gavin]

    The view of Hendrick Tennekes regarding climate simulations is also interesting

    climate runs made in the past should be analyzed, restarted with the latest version of the stochastic feedback paradigm, and calibrated with accumulated observational evidence. Perhaps the latest versions of climate models cannot be investigated this way, but the great advantage is that working in a retrospective mode offers falsification prospects. Looking back, all data needed for calibration do exist. So do the computers and the software.

    To my knowledge climate models have not yet been tested in this way?

    [Response: I have no idea what he is talking about. Hindcasts of the models are downloadable by anyone and have been analysed in hundreds of different ways. If he has a new methodology he should go for it.
    – gavin]

  30. 130
    Tom Dayton says:

    Re #102, Aaron’s equilibrium and attractors:

    Ray said it better in #123 than I did in #100 and #108. Ray said:

    In any case, whether one treats the system as a single system or as multiple systems that interact to various degrees on different timescales becomes ultimately a matter of convenience–and the latter is often more convenient.

    Aaron, your question from the perspective of chaos theory (#102) was perfectly reasonable. The responses you’ve gotten are not dismissive, they are just indicating that such a chaos-theoretic perspective is not very useful in climatology. In fact, it rarely is useful in most fields of science. (Back off, fluid dynamicists, I said “most”!)

    Chaos theory scores poorly on several of the criteria of the goodness of a theory. It explains poorly, as it does not give a person a satisfying gut feel of understanding the phenomenon. It is not very fruitful, meaning it does not much help people concoct better theories of the phenomenon. It is parsimonious only by hiding all the messiness inside a box. It is poorly predictive, insofar as it is mostly descriptive after the fact; it’s easier to recognize the existence of a particular pattern (e.g., an attractor) than to predict the existence of other patterns.

    Perhaps Richard (#114) can tell us how much he uses chaos theory to study turbulence. That might be one area where that level of description is useful, but maybe not even there.

  31. 131
    Aaron says:

    #123 Ray
    I don’t understand how a thermodynamic state is different than a point in phase space. You can define a point in phase space with x and p and define the same system using thermodynamic quantities like internal energy and chemical potential and the like. That’s how you can go from the idea of there being more volume therefore more energy in the system and then deductively relate it to increasing temperature. Right? How does the volume of phase space change with increasing amounts of GHGs in the atmosphere? Does anyone know if this volume is near the attractor we find ourselves around now? I would think first that these gases already were part of the system or systems, depending on your point of view, and would not need to have phase space added to accommodate their presence in a different physical phase, gas that is. If the volume of phase space changes, I would expect it to change randomly, not adding volume in any place in particular. Is this the right way of viewing this?

    #112 Chris

    Its nice to see some physics equations here. I thought it was interesting that your explanation necessitated the sun getting brighter and staying brighter. I would agree that this is the case for warming to increase, but would this not be the case with or without greenhouse gases? This is not an argument to dismiss global warming, but the amount of incident flux of radiation from the sun in the determining factor in temperature dynamics, right? I mean if the sun diminishes the incident flux, the temperature would go down because the percentage of absorbed radiation when compared to the emitted radiation, which is pretty much constant, would go down even if there was a bunch of CO2 in the air. I just would like some clarification on this point. Thanks.

  32. 132
    Richard says:

    #127 I do know some people who have more years of research behind them than I do who nevertheless continue to promote fundamentally flawed theories in turbulence modelling. I remember one conference where this was exposed however that has not affected their funding.

    It is reasonable to argue that the money spent on numerical simulation of turbulence has not generated a proportional increase in the actual prediction of turbulence flows for practical problems.

    A lot of people are interested in maintaining research funding despite the rather poor results so far. It is not for nothing that CFD is often known as Color Fluid Dynamics!

    It is my field and I am merely being honest!

  33. 133
    Rod B says:

    FurryCatHerder (124), I appreciate your analysis.

  34. 134
    Mark says:


    Yup. We don’t CREATE water much, though.

    And, as Ray said, it is only one, very small, part of what “Greenhouse Gasses” do.



  35. 135
    Mark says:

    Aaron #102.

    OK, I’ve finally digested what you’ve said. [edit]

    Great attractors are NOT equilibriators. They show you where a chaotic system is stable and where a chaotic system is unstable. And by “stable” in chaos terms means “insensitive to errors in measurement”.

    But any chaotic system will move from a stable description of the phase space (the “realm of the possible”) and move to an unstable one. All that stable means is that the next time the occupied phase space repeats, it will be fairly close to the occupied phase space it occupied last time.

    NOTHING puts it back in the same phase space.

    [edit – mark, please calm down, there is a already too much venting here]

  36. 136
    Ray Ladbury says:

    Aaron, there is not a 1:1 correspondence between the thermodynamic states of a system and its physical states in phase space–far from it. In fact, the thermodynamic equilibrium state is the most probable precisely because it corresponds to the greatest number of states in phase space. Keep in mind, though that phase space can be quite complicated in terms of who a system state evolves. Chaos is one example.
    If you increase the energy of a system, you increase the volume accessible to it in phase space. Not only does this make its dynamics more difficult to predict, it means that some of the newly accessible states may have very different macroscopic consequences than those previously accessible.

    Given the fact that different parts of the climate system interact on very different timescales and with different couplings, a phase space type of treatment may not be particularly fruitful for the climate.

  37. 137
    David B. Benson says:

    Regarding life and thermodynamics, I recommend reading “Into The Cool” for an unusual, thought-provoking perspective.

    Perhaps it is useful to think of the globe as a heat redistributor, mostly warmed at low latitudes with heat flowing toward the poles. One a rotating body, this gets complicated right away!

    Still taking a temperature gives some idea of the local system state: it will fluctuate. W.F. Ruddiman’s “Earth’s Climate: Past and Future” is organized around the differing scales of fluctuation. I found it the best beginner’s book (out of a sample of three).

    Looking at the Holocene through the lens of the GISP2 temperatures by Alley for central Greenland, one sees these fluctuations at scales from decadal to millennial; the only overarching tend is that provided by orbital forcing, first up to HCO and then down. Until 1850 CE. That begins the Anthropocene and by 2007 CE it is clear that the statistics of the Holocene are now longer in force; the only comparable temperature increase during the Holocene was the recovery from the 8.2 kya event.

    That said, W.F. Ruddiman makes a good argument in his popular “Plows, Plagues and Petroleum” that humans have influenced the climate throughout the Holocene, more towards the end than the beginning. Indeed, some of the CO2 fluctuations (Vostok ice core) agree well with the timing of known, massively deadly epidemics.
    Despite this, I find it reasonable, even useful, to say that the climate was in near-equilibrium until 1850 CE, but not since.

  38. 138
    David B. Benson says:

    Oh. In comment #137 I menat to say that except for

    the Holocene climate was in near-equilibrium.

  39. 139
    Andrew says:

    Re: 84,98 European Heat

    Heat waves in Norway and record forest fires don’t seem to be congruent with your statements about a cold Scandinavia.

  40. 140
  41. 141
    Eli Rabett says:

    Meant to get this in earlier, but the furor about NF3 is, well let me be kind, ignorant. As John Mashey pointed out, NF3 is used in plasma processing and for thermal cleaning. Why you ask, you cute young things, because in the plasma and with very hot surfaces, the NF3 decomposes to give fluorine atoms, which are very aggressive for cleaning stuff up and eating stuff away that you want to eat away (when a materials scientist invites you up to see his etching, don’t go).

    In other words


    So releases are limited to accidental releases during synthesis and transport and poor scrubbing of the small amounts left after being used. Bah humbug

  42. 142
    Robert Stenson says:

    In view of the present discussion of the role of carbon dioxide in effecting global temperature I would like to know of any laboratory or bench experiments that show a temperature- CO2 concentration curve within the range of currently measured atmospheric CO2 levels.
    You would think it fairly easy to set up multiple containers with different gas concentrations and similar incident radiation.

    Some crude runs have been reported with 100% CO2 or with increased but unreported or unmeasured CO2 concentrations but I know of none with a precise CO2-temperature relationship in the climactically important range.

    I realize that the laboratory scenario is simple in the extreme but it would prove useful in thinking about atmospheric CO2 effects. I would appreciate any comments, references, or help.

    [Response: Try Tyndall (1865). Unfortunately, lab experiments only deal with the direct radiative effects of CO2 – they can’t deal with feedbacks or the eventual climate sensitivity. – gavin]

  43. 143
    Richard says:

    Gavin thank you for your comments.

    CO2 is the fastest growing forcing and the only one that is forecast to grow sufficiently to cause multi-degree changes in global mean temperature in the future.

    The part I struggle most with is the word forecast.

    In my field I think it is fair to say there is no real consensus on turbulence modelling. Different models can get wildly different results. The only agreement comes when the simulations are so well resolved that no model is needed but this is frighteningly expensive (grid sizes the order of mm, time steps very much smaller than 1s)

    Climate models have much more physics involved than just turbulence and so it seems to me a little premature to confidently claim to be able to carry out long term forecasts?

    I study very detailed and controlled problems and still feel unable to provide such a level of confidence in my results.

    It is worthwhile trying to understand what Tennekes is saying in more detail because he is extremely well respected in the fields of turbulence and meteorology.

    As I understand it he is proposing blind runs starting from say 1970 to see if the detailed evolution up to today can be correctly predicted. For example in figure SPM.5 of the IPCC report summary , the different scenarios could be run between 1970-2000 and examined in detail. We have a lot of data for this period and 1970 should provide a quite detailed initial condition?

    [Response: But that is exactly what is already done in the IPCC runs. There is no climate information contained in those hindcasts – only information about the changes in boundary conditions (greenhouse gas amounts, volcanoes, etc) are input. If they aren’t, you don’t get the changes actually seen. The information contained in the initial conditions dissipates quite quickly – the atmospheric information within a few weeks, oceanic information within a decade or so. Therefore the predictability that there is, is contained in the forced response to the changing boundary conditions, not through any tracking of the details of the turbulent flow. – gavin]

    Two important quotes from Tennekes

    From my background in turbulence I look forward with grim anticipation to the day that climate models will run with a horizontal resolution of less than a kilometer. The horrible predictability problems of turbulent flows then will descend on climate science with a vengeance.

    I worry about the arrogance of scientists who blithely claim that they can help solve the climate problem, provided their research receives massive increases in funding. I worry about the lack of sophistication and the absence of reflection in the way climate modellers covet new supercomputers (….) My worries multiply when I contemplate possible side effects. Expansion of research tends to support the illusion that science and technology can solve nearly every problem, given enough resources. Research supports the progress myth that pervades modern society, but that very myth seduces us into ignoring our responsibility for the state of the planet. Therefore, I want to restrain myself. I want to avoid making promises I cannot keep. I want to keep my expansive instincts in check. Above all, I try to be a scientist: I wish to think before I act.

    I suggest reading one of his books before trying to criticise his scientific credentials.

    [Response: Who did that? But focusing on his comments above, it is not arrogant to show that increasing levels of greenhouse gases affect the climate and pointing that out. Additionally, there appear to be an implication that modellers don’t act like scientists, and that would be a very wrong conclusion to draw. We are very aware of what level of approximation we are dealing with here, and we are very aware that while climate modelling has been quite successful, it is not a complete representation of the real world and thus there are large and significant uncertainties remaining – and those uncertainties cut both ways! – gavin]

  44. 144
    Richard says:

    #134 I guess our complete knowledge of climate science and SCIENCE in general allows us to assume a straightforward linear dependence between CO2 and H20?

    [Response: Clausius-Clapyeron would suggest an exponential dependence of WV on temperature, and temperature is related to the log of CO2 change, and so that might be relatively linear at equilibrium and at saturation – but real life is more complicated. – gavin]

  45. 145
    Anne van der Bom says:

    Re #101, pft:

    When people want to increase energy costs and change lifestyles due to Global warming, the burden of proof is on them.

    It is a matter of definition. We are dealing with two changes: Change of lifestyle and change of the composition of the atmosphere (which by the way is the only atmosphere we have).

    I have always found your point of view a very undefendable one.

    I think man producing CO2 is comparable to a farmaceutical company that must prove what the side-effects of new medicine are and whether they are acceptable or not, before they can bring it to market.

    The problem we are currently facing is the fact that we started the large scale burning of fossil fuels more than 2 centuries ago, and didn’t think about it then. We missed that opportunity. But does that change the principle?

  46. 146

    Chris — Please note that in your equation, T has to be the surface temperature rather than the planet’s radiative equilibrium temperature, the latter being the T you get if G = 0.

  47. 147

    Joseph writes:

    “But the amount of the imbalance is tiny or we’d see a rapid change in Earth’s temperatures.”

    I take it what we see now is slow. Compared to what?

    Compared to the variation of several degrees every day. Global warming is proceeding at a long-term trend of about 0.02 degrees per year, too small to be noticed in one day.

  48. 148

    Up here in Alaska our own Katey Walter is talking about the tundra methane releases as a source of energy for nearby communities. Understanding that nobody is going to build giant capture devices, still I would think burning methane would result in less damaging gases. Any calculations on that?

    [Response: Definitely. Methane is much better off burnt than released. (say hi to Katey if you see her). – gavin]

  49. 149
    Mike Donald says:

    Even Zipper knows the four main greenhouse gases.

  50. 150
    Hank Roberts says:

    Eli, thanks for the reality check on NF3. It’s also a nitrogen donor as well as a cleaning agent. Prather’s point seems to be that it should be watched because it’s so stable and long-lived in the atmosphere even small amounts will add up. I recall when CFC refrigerant was vented to the air — systems flushed before being refilled routinely. It wasn’t worth recapturing, and as long as nobody was smoking around it it just went away.