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  1. Speaking of getting the details right, you say plasma TVs, but the articles you cite say LCD if they specify at all. Which is correct?

    [Response: Not sure – this press release simply says ‘flat panel displays’, as does the Prather article. NF3 is used in plasma etching, but I have no idea if that is connected specifically to plasma TVs. To be on the safe side, I deleted the ‘plasma’ reference above. If anyone has more information, please let us know. – gavin]

    Comment by S. Molnar — 7 Jul 2008 @ 9:44 PM

  2. The bad thing is that it has a radiative forcing of 0.21 W/m^2 per ppb and we do not have atmospheric measurements, the good thing is that its release is being looked at in terms of picomoles per mole. I’m curious as to where this gas cuts off outgoing radiation (definitely must be in the atmospheric window), but I can’t find anything on HITRAN.

    Comment by Chris Colose — 7 Jul 2008 @ 10:11 PM

  3. Only slightly off topic… but how extensive this kind of rhetorical attack is…


    The time you take from your real work is appreciated more than you can possibly know.

    Thank you, for what you do, and for keeping us informed.

    Comment by Jacob Russell — 7 Jul 2008 @ 10:45 PM

  4. A third one, which as far as I know, has gotten little attention, since it’s more local, is that of the negative health effects of higher CO2 concentrations in already-polluted areas, i.e., like some cities here in California.

    Stanford Prof. Mark Z. Jacobson has a bunch of interesting papers, but in particular, it’s worth reading:

    Testimony to House April 2008.

    Comment by John Mashey — 7 Jul 2008 @ 11:16 PM

  5. Exactly.
    By Rick Shenkman,
    Millions of Americans are embarrassingly ill-informed and
    they do not care that they are.

    [edit – please stay on topic and off politics.]

    Comment by Edward Greisch — 7 Jul 2008 @ 11:48 PM

  6. I sometimes post to, or RealClimate.I’m going to review whar I’ve said before.The oceans have absorbed so much co2 that they have masked the true extent of the climate crisis.We had plenty of warning as much as 10 years ago about the increasing acidification of the oceans. I’m glad it is getting some press, but for those of us who have followed the news closely it is old news.Also, as I’ve said, most people seriously underestimate the danger of the methal(frozen methane) hydrates at the bottom of the worlds oceans melting.Along with massive expulsion of methane and co2 from melting peat and tundra in the Arctic, but especially in Siberia, the methal hydrates meling will indeed seal our fate.The Greenland ice sheets and Arctic ice, as well as the Antarctic major ice shelves, are all in real, real, danger of melting completely. The floods in the Midwest are jut a start.Desertification is increasing on a logarithmic scale upward, and the oceans have begun serious upwelling current changes, especially in the salinity levels off Greenland, a key downward force on the North Atlantic current.My research indicates that the North Atlantic current has already begun to change.
    And yet, at the current G8 summit, the US continues to obfuscate, minimize, and dimiss the severity of the problem.Now,finally, there is a call for an 80% reduction in manmade co2 by 2020. Finally. If you look at my posts, I said an 80% reduction must occur right now, for there to be any chance at all of averting real catastrophe for the planet.Finally, some are saying 80%, by 2020.
    I want the entire internet community to understand the way I feel.

    [edit – this is not the place for partisan politics, no matter how heartfelt]

    Mark J. Fiore
    Boston College Law School,1987 and Harvard University, 1982

    Comment by Mark J. Fiore — 8 Jul 2008 @ 12:16 AM

  7. Mr Schmidt, I have read the links and understand the principal points. Thanks for the always interesting comments on this site.

    There has been an agreement to agree, at G8 today, to reduce emissions by 50% by 2050. Assuming all agree to reduce by 50% and achieve it (an heroic assumption), what affect will that have on ocean acidification. I tried to find out for myself the answer to this question by reading the original paper but it is a pay website. But perhaps the original paper doesnt contain enough information anyway.

    Comment by Eachran — 8 Jul 2008 @ 2:27 AM

  8. Indeed. For many years in dealing with policymakers I have pointed out that the lowering of seawater pH alone, via atmospheric CO2, justifies significant emission reductions.

    Comment by Nick Riley — 8 Jul 2008 @ 2:52 AM

  9. a very interesting line of thought, pegging (with only minimal condescension :-) the issues to both the media and to the public consciousness (or unconsciousness as the case may be) – there is another thought, that homo sapiens has split into two species, one moral and one immoral, you come across the notion now and then

    anyway, I appreciate your digression, thought provoking, well done, thanks.

    Comment by David Wilson — 8 Jul 2008 @ 2:54 AM

  10. Probably explains why it is best to just stick with global warming and CO2 with some reference to rain forest destruction and land use changes. after all Al Gore and others have done enough work in this arena to get the momentum going and even the G8 have committed to 50% CO2 cut by 2050.

    Is this enough of a cut to stop AGW from being the disaster it is reported it is goign to be with BAU scenarios?

    Comment by Pete Best — 8 Jul 2008 @ 4:03 AM

  11. I note that the Press Association report states, “Scientists have calculated that it [NF3] has a half-life in the atmosphere of 550 years.”

    I assume this half life may relate to the reaction of NF3 with, presumably, oxygen and/or water to form more stable end products that are either not GHGs or are rapidly washed out of the atmosphere, such as N2 and HF respectively. Maybe NF3 also slowly spontaneously decomposes. Its iodine analogue, the solid NI3, easily prepared by adding conc. ammonia solution to iodine crystals, does so: it explodes with a loud bang and a puff of violet smoke if sprinkled on the floor and trodden on. It was beloved of miscreant sixth-formers in the days before health and safety took the pleasure out of chemistry lessons.

    I have often wondered why the duration of CO2 (and other GHGs) in the atmosphere is not generally expressed in terms of half lives. Rather, it is usually stated that ‘CO2 lasts for a century or more in the atmosphere.’

    Can anyone shed some light on this question of half lives?

    [Response: For NF3 the half-life is dominated by photolysis (presumably in the stratosphere) and the reaction with the O(1D) radical. Since these reactions depend on the concentration of NF3, an exponential decay process with a well-defined half-life is a good fit. For CH4 or CO2, the chemistry is more complicated (much more so for CO2) and half-lives less useful a concept. For CH4, 12 years for the perturbative half-life (longer than the ~8 year residence time) is reasonable, while for CO2 the best approximation is a combination of 5 different exponential processes with half lives that range from 3 to 100,000 years. Thus there is a component of CO2 emissions (roughly 15%) that is effectively in the atmosphere forever. – gavin]

    Comment by Slioch — 8 Jul 2008 @ 4:43 AM

  12. “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)…”

    Isn’t the higher energy use of plasma screens the biggest problem here? Or is that mainly because the newly bought screens are usually much larger than the old ones? See for example:

    Comment by Lennart — 8 Jul 2008 @ 5:06 AM

  13. “Now if there was only a way to make sure the story underneath was accurate….”

    Well. For a start, it could help if the IPCC and the real climate scientists made a commitment to tell the truth. One example:

    And in your response, please don’t just ad hom me. How about a reasoned response showing why this reference is actually incorrect.

    [Response: Well since you seem convinced that we are dishonest already, what is the point? However, a moment’s thought should tell you that the whole article is based on false premise: When reviewing an article, do you comment on the 90% of the paper you think is ok, or on the 10% you think is wrong? Thus parts of the IPCC text that people agreed with were generally not commented on – for instance, I read the SPM and did not comment – because I was in agreement. Hundreds of scientists read the various drafts of the SPM, and only a few raised relatively minor issues. If it was one of my papers, I’d have been pretty happy. But even if you don’t think the IPCC reviewing is rigorous (even though it is, and it is certainly a lot more rigorous than anything peddled by Harris and company has undergone), how about all the reviews by the National Academies, and professional societies and special committees? The number of scientists who have explicitly endorsed the central IPCC conclusions is legion – as anyone who has ever gone to the AGU or EGU meeting will see and as anyone who reads the literature will see. It’s a valid argument to say that consensus does not guarantee correctness, but it’s complete nonsense to argue there is no consensus. – gavin]

    Comment by Fair and Balanced — 8 Jul 2008 @ 5:38 AM

  14. The fault for climate change having been “well below the radar of the public at large” for decades has been with NOAA National Weather Service (NWS) headquarters, NWS weather and NWS river forecast offices – not with the media and others not “finding just these kind of resonances”.

    Comment by pat n — 8 Jul 2008 @ 6:34 AM

  15. Mark,

    I don’t think it’s a good idea to attack Republicans per se. I know the GOP has become significantly far-right in recent decades and that almost all the loony public attacks on AGW theory have come from GOP apologists like Rush Limbaugh and Ann Coulter, not to mention the egregious James Inhofe. Nonetheless, there are Republicans, even Republican office-holders, who recognize the problem and want to do something about it. In addition, half the audience is Republican, and we don’t want them to think this is a Republican/Democratic issue. That way lies endless gridlock. The issue must be non-partisan or it will not get solved.

    Comment by Barton Paul Levenson — 8 Jul 2008 @ 7:42 AM

  16. A quick question from a relative layman: if we reduce the concentration of CO2 in the atmosphere will the oceans then start releasing CO2? Or is the absorbed CO2 in the oceans basically there to stay until it’s used by some biological process (reef building, shell formation, etc)?

    If it’s the latter it’s tough for me to see how a (much needed!) reduction in atmospheric CO2 mitigates the oceanic PH level.

    Comment by The Carrot — 8 Jul 2008 @ 7:46 AM

  17. Now if there was only a way to make sure the story underneath was accurate….

    The story does not need to be accurate. It only needs to be true!

    If there is a there is a theat to humanity from NF3 then whether the current production is equivalent to one, one thousand, or one million coal power stations is irrelevant. The public only need, or want, to know that something should be done about it.

    Meanwhile, the scientific truth is being severely compromised by scare stories about ocean acidifcation. How can those species be under threat when they have survived much higher levels of CO2 in geological past? Levels of atmospheric CO2 far higher than even those predicted for the next century? That sort of story does much more to sap the faith of the intelligent layman in scientists, than any confusion by journalists about numbers of power stations.


    Cheers, Alastair.

    Comment by Abbe Mac — 8 Jul 2008 @ 8:05 AM

  18. In addition, half the audience is Republican, and we don’t want them to think this is a Republican/Democratic issue. That way lies endless gridlock.

    Or, perhaps they’ll stop voting Republican, as I did when Reagan hit the national scene and it became clear that the socially responsible, science literate, and fiscally conservative bits of the party I grew up with was doomed to irrelevance.

    Now, I didn’t vote for Nixon because of character issues and his bullshit “secret plan to end the war” which was transparent baloney meant to win votes of those uncomfortable with the notion of withdrawing from Vietnam while at the same time being tired of it. (brings to mind John McCain’s recent claim to have a plan to end the conflict in Iraq, harumph).

    But his administration was great measured by its environmental and conservation accomplishments.

    He’d be tarred and feathered by today’s party. And my own state’s Tom McCall was, in essence, tarred and feathered by the Reagan-era rabid right who’d taken over the Oregon Republican party when he attempted to make a comeback and regain the governor’s office.

    [Response: No more partisan politics – gavin]

    Comment by dhogaza — 8 Jul 2008 @ 8:16 AM

  19. OK, I sent an e-mail to one of the authors of the pH paper suggesting that they might like to go a bit further with the general and interested and worried public : worried because the timelines keep getting truncated.

    How about posting something on realclimate, I suggested.

    I am particularly interested in the relationship of muck in the atmosphere to acidity in the oceans.

    I dont much like 1 degree temperature rise (goodness gracious all that energy) in 100 years let alone 2 degrees but the oceans in 40 years?

    Any smart scientists out there to help Joe Public and me?

    Comment by Eachran — 8 Jul 2008 @ 9:07 AM

  20. Gavin,

    You state that the increased take up in the oceans of human-released CO2 is rapidly increasing the acidity (lowering the pH) of the oceans. I understand the pH of the ocean had dropped 0.1 units in the period between 1750 and 1994, and that the current pH of the ocean varies from about 7.9 to 8.4. What data support your contention that the oceans are acidifying rapidly?

    [Response: Direct measurements of ‘rapid’ (this is on a geological timescale) acidification, and a sufficient understanding of ocean seawater carbonate chemistry to know why, plus the almost certain continuing increase in atmospheric concentrations of CO2. See the wikipedia article for references. – gavin]

    Comment by B Buckner — 8 Jul 2008 @ 9:26 AM

  21. How can those species be under threat when they have survived much higher levels of CO2 in geological past? Levels of atmospheric CO2 far higher than even those predicted for the next century?

    I’m not sure whether this was sarcasm or not, but just in case… Current ocean species have spent hundreds of thousands of years evolving under a certain range of ocean pH. If that pH suddenly plunges, there will absolutely be a shakeup of the various ocean ecosystems, as different species have different responses to increased acidity.

    Comment by Goedel — 8 Jul 2008 @ 9:58 AM

  22. Just a quick (and probably irrelevant) clarification: I was using a common figure of speech and meant no denigration of real Softball. The fastest and best pitcher of any kind of ball, Eddie Feiner, threw softballs

    Comment by Rod B — 8 Jul 2008 @ 10:21 AM

  23. It seems that one important response to shoddy science reporting is to contribute letters to the editor. They might set a portion of readers straight, as well as demonstrate to the newspaper staff that there are people paying attention to the accuracy of their science stories.

    Comment by Milan — 8 Jul 2008 @ 10:23 AM

  24. For purposes of legislative action, dire rhetoric is not usually all that effective because everybody cites worse case scenarios for every issue and legislators get used to dismissing it. Environmentalists have cried wolf more than most and that has given opponents a lot of ammo and leverage.

    To quickly get rid of an apparently dangerous product like NF3, it is necessary to show the practical alternative. The car companies got a reprieve for several years on taking asbestos out of brakes because they claimed that the alternatives were unsafe (they weren’t, but it took time and effort to show that). VOCs from auto paint shops were a demonstrable health and environmental harm on many levels but lawmakers had to actually see that water-based paints and drying sheds were a viable alternative before they pulled the trigger.

    I know from conversation with lobbyists, hill staffers and members over the years that consumer and environmental advocates are often ineffective because of compulsive self-righteousness and a strange pride in economic ignorance. Taking the position that everyone who disagrees is both immoral and stupid is rarely a winning tactic in any social setting.

    I am not a chemical engineer but I assume there is probably an alternative to NF3 or a way to create closed process for vapor collection that could be mandated, probably even with express industry cooperation in formulating the details. When the choices are concrete, the costs known and the rhetoric deflated, things can get bi-partisan in a hurry.

    Comment by George Tobin — 8 Jul 2008 @ 10:24 AM

  25. Lordy lord lord, a great initial post and most every response is either tangential, a digression, or from another planet. Focus, people.

    Gavin, you asked for a reference, here’s one — NF3 was a trivial chemical a few years ago, it’s becoming widely used very quickly.
    Here’s why:

    Comment by Hank Roberts — 8 Jul 2008 @ 10:28 AM

  26. Wasn’t the recent G8 result a “loose” goal, not a commitment? Wouldn’t such agreements mean more if they include China and India?

    Comment by Rod B — 8 Jul 2008 @ 10:28 AM

  27. A sandbox 101 question: What is it that makes methane and others “much more powerful” greenhouse gases? Is it because their internal makeup allows considerably more IR absorption, molecule for molecule? Or is it because they absorb in bands like the window that are “virgin territories”? For example if we had no GHG in the atmosphere, then added say 50ppm of both CO2 and CH4, which gas would contribute more toward warming? Or is it related to the relative lifetime of the various gases? Or some combination?

    [Response: All of the above. Different bands are differently absorbed depending on what the resonance is (vibrational, stretching etc.) and that depends somewhat on the strength of the bonds (which is obviously molecule specific). Concentration matters a lot – absorption is linear at very low concentrations and flattens out to logarithmic at higher values. And overlap is really important. If a molecule absorbs in the atmospheric window region, it is much more important than one that overlaps with water vapour. – gavin]

    Comment by Rod B — 8 Jul 2008 @ 11:00 AM

  28. And an even more holistic approach would include (aside from all the effects from GW and GHG releases), the various other harms from doing the things that entail GHG releases; for example:

    1. the other, more local pollutants from driving I.C.E. cars & their harms;
    2. the money lost from not being energy/resource efficient/conservative, which at the macrolevel weakens our economy (never mind threats to the economy & livelihood from GW harms)
    3. the health benefits lost from driving rather than cycling & walking.
    4. increased crime because people drive rather than walk or cycle (there was a study that neighborhoods with heavier pedestrian and cycling traffic experienced less burglaries).
    5. the physical/psychological stress of commuting long distances, bec one chose to live far from work, when closer comparable houses were avaiable, plus the lost family time, leading to various family dysfunctions….
    6. War and conflict to secure our resources
    7. Destruction of rainforests to get the bauxite for aluminum coke cans, bec we didn’t recycle our cans (which saves 95% energy & reduces GHGs).

    And so on.

    Of course, to be fair, we must balance harms against benefits to some extent (as long as it’s not a case of “I beneift, others are harmed”).

    But in cases of desired benefits that entail harms, we should be looking for harmless or less/least harmful alternatives. This has not been done enough, since the industry-gov-media-military complex, focused and dependent on oil/coal profits, sort of makes it difficult for us to perceive problems they don’t want us to perceive, like GW and its many, many ramifications, and difficult to work on solutions (I’m still waiting for my plug-in-hybrid).

    Comment by Lynn Vincentnathan — 8 Jul 2008 @ 11:02 AM

  29. Pat N. at #14:
    ‘The fault for climate change having been “well below the radar of the public at large” for decades has been with NOAA National Weather Service (NWS) headquarters, NWS weather and NWS river forecast offices – not with the media and others not “finding just these kind of resonances”.’

    It would appear that politics has played a part in what you report. But politics (and big money) has probably also played a part in how science is reported through the media and in the very selection of those who write for and appear in the media stories about climate change.

    To borrow a phrase, this is the politics of minds suffering from ‘Nature Deficit Disorder’. Education can help stamp out this ubiquitous disease.

    Comment by catman306 — 8 Jul 2008 @ 11:03 AM

  30. > How can those species be under threat when they have survived
    Many did not, as you’d know if you looked it up. Rates of change….

    Comment by Hank Roberts — 8 Jul 2008 @ 11:13 AM

  31. In relation to the article, the Plasma TV’s have NF3. What do we know of NF3 and in technical matters what other choices do consumers have? In a greener ethical matter, don’t all companies find this as a concern? If these are being sold in the market at a higher demand rate, do we even have to think about the greatest number of the greatest good of everyone trying to buy into the companies products of plasma TV’s? I think so. This happens to be a main focus and a larger issue that should be discussed to the manufacturers. I believe that the research that has been brought up to this matter should be open for the public to learn and understand the information given.

    Comment by Matthew Newman — 8 Jul 2008 @ 12:01 PM

  32. re #17 Abbe Mac

    You have to go back an awful long way to get atmospheric CO2 levels that are that much higher than current ones. Around 20 million years. That’s a very long time even on evolutionary time scales (humankind has only been around for around 200,000 years and the tree-dwelling apes from which the h-ominid line descended were around about 10 million years ago).

    It’s the rates of change that are important. The current set of sea-dwelling creatures, and specifically calcite/aragonite-fixing species, have evolved under conditions of relatively constant or extremely slowly changing ocean pH, and so have a relatively limited som-atic adaptability to changes in ocean pH. Ocean pH just doesn’t change much on the many 1000’s of years time scale (barring catastrophic events). So these creatures are rather sensitive to what seem to be relatively small changes in pH of only a few tenths of a pH unit (remember the pH scale is a logarithmic one). This is easily demonstrated in the laboratory.

    So the answer to your question “How can those species be under threat when they have survived much higher levels of CO2 in geological past?”….is that they haven’t survived much higher levels of CO2 in the geological past. Either their evolutionary predecessors were adapted to higher CO2 levels in the past, or (as happened during some of the major extinction events) they didn’t survive the insults (raised global temperatures/ocean acidification etc.) of greatly enhanced atmospheric CO2 concentrations..

    ..that’s the concern…

    Comment by Chris — 8 Jul 2008 @ 12:10 PM

  33. There has been an agreement to agree, at G8 today, to reduce emissions by 50% by 2050.

    I think this goal implicitly assumes that (a) methane clathrates will not be problem, (b) CO2 & methane release from melting permafrost will not be a problem, and (c) a melting of 50% or more of the Greenland Ice Sheet is something we can adapt to. While it’s still possible that these three assumptions will turn out to be true, the impact of one or two of them being wrong could be awfully high ….
    As for ocean acidification, this goal seems likely to cut the rate of acidification by about half. Ocean acidification is like global warming in that zero CO2-emissions are a prerequisite to a turn-around.

    Comment by llewelly — 8 Jul 2008 @ 12:44 PM

  34. The industrial use explained (see also the link I posted earlier which leads to much on industrial volume and production):

    “… forming an amorphous silicon nitride (a-SiN) deposited film … N-supplying raw material gas … examples are nitrogen (N2), ammonia (NH3), hydrazine (H2 NNH2), hydrogen azide (HN3) and ammonium azide (NH4 N3). Besides these, nitrogen halide compounds such as nitrogen trifluoride (F3 N) and nitrogen tetrafluoride (F4 N2) can be used. …”


    “… if the chemical industry had developed organobromine compounds instead of the CFCs … then without any preparedness, we would have been faced with a catastrophic ozone hole everywhere and at all seasons during the 1970s, probably before the atmospheric chemists had developed the necessary knowledge to identify the problem and the appropriate techniques for the necessary critical measurements. Noting that nobody had given any thought to the atmospheric consequences of the release of Cl or Br before 1974, I can only conclude that mankind has been extremely lucky, that Cl activation can only occur under very special circumstances. This shows that we should always be on our guard for the potential consequences of the release of new products into the environment.”

    Time to accept the precautionary principle?

    Comment by Hank Roberts — 8 Jul 2008 @ 1:00 PM

  35. Rod B,

    I’m going to quote a couple exerpts from raypierre’s climate book, and this is partially in line with what gavin said (particularly the fact that methane is stronger on a molecule-by-molecule basis because of lower background concentrations), but I’m not so sure it is in 100% agreement:


    //”There is, however, a widespread misconception that methane is in some sense an intrinsically better greenhouse gas than CO2. A few simple calculations will serve to clarify the true state of affairs….

    The common statement that methane is, molecule for molecule, a better greenhouse gas than CO2 is true only for situations like the present where methane is present in far lower concentrations
    than CO2. In this situation, the greater power of a molecule of CH4 to reduce the OLR results simply from the fact that the greenhouse effect of both CH4 and CO2 are approximately logarithmic in concentration. Reading from Fig. 4.35, we see that for methane concentrations of around 1ppmv, each doubling of methane reduces OLR by about 2W/m2. On the other hand, for CO2 concentrations near 300 ppmv, each doubling of CO2 reduces the OLR by about 6 W/m2. Hence,
    to achieve the same OLR reduction as a doubling of CO2 one needs three doublings of methane, but since methane starts from a concentration of only 1ppmv, this only takes the concentration to
    8ppmv, and requires only 7/300 as many molecules to bring about as was needed to achieve the same reduction using a doubling of CO2. Equivalently, we can say that adding 1ppmv of methane yields as much reduction of OLR as adding 75ppmv of CO2…..

    If methane were the most abundant long-lived greenhouse gas in
    our atmosphere, and CO2 were present only in very small concentrations, we would say instead that CO2 is, molecule for molecule, the better greenhouse gas. “//


    Hope that helps.

    Comment by Chris Colose — 8 Jul 2008 @ 1:11 PM

  36. And there are other ramifications from our GHG emissions. (I’ve just been reading Mark Bowen’s CENSORING SCIENCE: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming.)

    I also think we should reduce our GHGs, bec:
    They cause GW, which leads to scientists finding out, which causes lots of politicos to lie, cheat, deceive, and do other dastardly deeds in their attempts to cover up, censor, and distort the science, which may cause them to end up in a much hotter place than a globally warmed world. At the very least it increases cynisim toward government (and toward industries which fund the gov and media, and hire the politicos after/before their gov jobs), which feeds into increasing societal demoralization. Not to mention, helps thwart action to address GW — both bec the public isn’t getting the truth and bec they’ve been demoralized by such cover-ups and distortions.

    Comment by Lynn Vincentnathan — 8 Jul 2008 @ 1:15 PM

  37. The article linked in #13 is paroting the nonsense from Vincent Gray, who worked in the coal industry (and thus must not have a “vested interest” according to the article) and has never published anything about climate change, and basically knows nothing about climate change in general. He is one of those people who uses the title “expert reviewer of the IPCC” to claim some kind of qualifications, when, of course, anyone can be an expert reviewer.

    The Canadian Free Press article is talking about the second order draft of chapter 9, not the first draft, and it doesn’t take much thought to realize that the first draft is going to have more comments than the second. The reason why 60% of the reviewer comments were rejected is because 50% came from one person, Gray. And the reason why they were dismissive is because his comments were incompetent. He has around 70 comments asking not to use the word “anthropogenic” and similar word changes. Other comments were basically wild declarations with no supporting evidence.

    Anyone who doubts this can read the comments for themselves and search for Gray’s name:

    Comment by cce — 8 Jul 2008 @ 1:24 PM

  38. Re # 17 Abbe Mac:
    ‘the scientific truth is being severely compromised by scare stories about ocean acidifcation. How can those species be under threat when they have survived much higher levels of CO2 in geological past?’
    Why don’t you read the scientific literature on ocean acidification and find out for yourself? Then, please come back and tell us who is compromising the scientific truth. The following will get you started:

    Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers (NSF, USGS, NOAA)

    Ocean acidification due to increasing atmospheric carbon dioxide (Royal Society, UK)

    Evidence for Upwelling of Corrosive “Acidified” Water onto the Continental Shelf
    Richard A. Feely, Christopher L. Sabine, J. Martin Hernandez-Ayon, Debby Ianson, Burke Hales
    Science 13 June 2008: Vol. 320. no. 5882, pp. 1490 – 1492 DOI: 10.1126/science.1155676;320/5882/1490

    You might also check out NOAA’s Pacific Marine Environmental Laboratory Carbon Dioxide Program Ocean Acidification website:

    For more general discussions of this topic, check the Wikipedia reference Gavin provided in # 20, or, this article by a couple of the leading scientists studying ocean acidfication:
    Carbon Dioxide and Our Ocean Legacy, by Richard A. Feely, Christopher L. Sabine, and Victoria J. Fabry

    Comment by Chuck Booth — 8 Jul 2008 @ 2:28 PM

  39. The Carrot (16) — Suppose we found some means to rapidly remove excess CO2 for the air. Then the shallow ocean would degas to follow along, lowering pH. The CO2 already committed to the deep ocean will be there still, for a long, long time.

    That’s my amateur take on it.

    Comment by David B. Benson — 8 Jul 2008 @ 2:44 PM

  40. As an emissions market analyst, I spend endless hours scanning every article that pops up on Google when you search for the words “greenhouse gas.” For all of the occasional slightly off-topic digressions, it was truely refreshing to read a genuinely intellectual, scientifically literate discussion on the topic. I will definitely come back to this site when I need to feed my brain something healtier than the rubbish that passes for journalism these days.

    Comment by Sherry Orton — 8 Jul 2008 @ 3:16 PM

  41. RE: Greenhouse gases other than CO2

    Is there any discussion of a regulatory framework to control the use of volatiles that have “bad” IR absorption spectra? In other words, it seems that industrial chemicals could be quantitatively ranked based on how well their IR absorption spectra overlap with that of H2O. This could be coupled with the lifetime of the gas in the atmosphere. The worse this coupled ranking, the more tightly the chemical would be regulated. That would effectively price poor “greenhouse gas” performers out of the marketplace.

    Given the vast number of volatile chemicals in use in the world, such an approach would at least provide a general means for judging the use of these chemicals in industry.

    Comment by Jamie — 8 Jul 2008 @ 3:29 PM

  42. Thanks Gavin for trying to keep politics to a minimum.

    Comment by Sean — 8 Jul 2008 @ 3:44 PM

  43. Re #38, its the speed at which it is hapenning I believe is a major factor, 30x previous events.

    Comment by pete best — 8 Jul 2008 @ 3:51 PM

  44. Previous response:
    “How can those species be under threat when they have survived? Many did not, as you’d know if you looked it up. Rates of change…”

    Those that did survive still have the genes left over from more acidic times. The phenomenally fast reproduction rate of most of these organisms ensures that they can adapt to changes.

    Nature is pretty impressive. Don’t trust me though I believe in life on Mars.

    Comment by Sean — 8 Jul 2008 @ 3:57 PM

  45. Re #39

    Did you mean “Then the shallow ocean would degas to follow along, raising pH”?

    When CO2 dissolves in water it equilibrates with a hydrated form (H2CO3) which dissociates into bicarbonate and carbonate according to the pH:

    CO2(air) {- – – – } CO2(aq) (+H2O) {- – – -} H2CO3 {- – – -} HCO3- + H+ {- – – -} CO3- – + H+

    where {- – – -} represent reversible arrows (equilibria)

    Knowing the total hydrated CO2 concentration, the concentrations of carbonic acid (H2CO3), bicarbonate (HCO3-) and carbonate (CO3- -) are easily calculated since the pKa’s defining the various equilibria are known.

    So the pKa’s (the pKa is the pH at which there is 50% of each species on either side of any of the individual equilibria are):

    H2CO3 {- – – – } HCO3- + H+ (pKa = 6.4)

    HCO3- {- – – – } CO3- – + H+ (pKa = 10.3)

    one can see that at pH 7.5 (sea water-ish) there is very little carbonate and most of the hydrated CO2 is in the form of bicarbonate

    [the actual proportions of the species can be calculated from the Henderson-Hasselbalch equation:

    pH = pKa + log ([base]/[acid])

    so for the carbonate (base)/bicarbonate{acid) equilibrium:

    [carbonate]/[bicarbonate] = 10^(pH-pKa)

    and at pH 7.5 [carbonate]/[bicarbonate} = 10^(-2.8)

    which is about 0.016]

    I believe that this is the problem for ocean species that use carbonate to build their skeletons/shells. There is already a limited amount of carbonate in the oceans due to the high pKa of the bicarbonate-carbonate equilibrium, and as the pH drops the equilibrium is shifted even further away from the already very small dissociation of bicarbonate to carbonate.

    Note that if CO2 were to “out-gas” from the oceans the equilibrium would be pulled in the direction of de-acidification (since bicarbonate needs to be protonated before it can dissociate into CO2 and H2O).

    Interestingly this identical CO2-carbonic acid-bicarbonate-carbonate equilibrium maintains the homeostatic pH in our blood (pH 7.4)…a relic of our evolutionary deep oceanic past.

    Comment by Chris — 8 Jul 2008 @ 4:05 PM

  46. Re #20
    You state that the increased take up in the oceans of human-released CO2 is rapidly increasing the acidity (lowering the pH) of the oceans. I understand the pH of the ocean had dropped 0.1 units in the period between 1750 and 1994, and that the current pH of the ocean varies from about 7.9 to 8.4. What data support your contention that the oceans are acidifying rapidly?

    I hope you realize that the pH scale is logarithmic?
    A change from 8.1 to 8.0 is a rise in hydrogen ion concentration of ~21%.

    Re #44
    Why do you assume that the acid resistance genes remain, particularly in an organism with a fast reproduction rate?

    Comment by Phil. Felton — 8 Jul 2008 @ 4:22 PM

  47. So this is what I sent to Mr Zeebe this morning (CET).

    “Dear Mr Zeebe

    I read ScienceDaily’s report on your work following up from a link on

    I understand the implications of ocean acidification but it is the first time that I have seen easily understandable numbers.

    What interests me are your forecasts for pH changes by 2050 on the usual global warming scenarios. It wasnt clear from Science Daily’s report what the basis for your upper range forecast of 0,35 is.

    I have posted a question to Mr Schmidt on the realclimate site but I wondered if it would help if you or one of your colleagues could yourselves post further explanatory information.

    Best regards and dont weaken


    Now, I am not a professional scientist but I am thinking about it even at my advanced age, but I would like to know what the number is and why.

    This is the same issue as sea level rise or sea-ice extent or temperature rise, or the recent discussion about probability density functions.

    It all boils down to the same thing : what is the number.

    I posted on ice sheet mass balance and sea level rise on this very point and eventually two posters offered something.

    My background is science, social sciences, and law and when I used to do law I worked with some pretty smart people in the profession. My instructions to them were, I am never going to sue you because if a decision is made it is my decision.

    So all you scientists out there, there’s a challenge, no more ifs and buts or maybes or perhaps. I wont sue you.

    What’s the number on pH by 2050 and why, and what are its implications?

    I would add that I am impressed by Messrs Annan and Connelly for putting their money where their mouths are on climate issues.

    Comment by Eachran — 8 Jul 2008 @ 4:30 PM

  48. #44 Sean:

    [“Those that did survive still have the genes left over from more acidic times. The phenomenally fast reproduction rate of most of these organisms ensures that they can adapt to changes.”]

    Not really. I don’t think that’s a supportable assertion without some evidence in its support! It’s more likely that the absence of selection pressure (more acidic oceans) will have resulted in the loss of the acid-adaptated genotype. Unless organisms have som-atic physiological adaptability (of the sort that lets us humans adapt to variations of altitude through the adjustment of the oxygen affinity of haemoglobin, for example) it’s unlikely that evolutionary adaptation could occur sufficiently quickly to allow adaptation to rapidly acidifying oceans..

    …so it’s a question of time scales again. If atmospheric CO2 concentrations were to carry on increasing at current rates for another 100 years or more it’s rather likely that a large number of oceanic species would succumb, however “phenomenally fast” the little critters tried to reproduce. One/two hundred years is likely to be far too short a period for adaptive evolutionary responses, and the situation would be more akin to the previous extinction events in Earth’s history, many of which are associated with raised greenhouse gas levels/warming/ocean acidification/anoxia etc.

    Comment by Chris — 8 Jul 2008 @ 4:36 PM

  49. From an expert’s point of view, was the earth in a thermal equilibrium with the incident flux of sunlight before the industrial revolution?

    Comment by Aaron — 8 Jul 2008 @ 4:44 PM

  50. What was the PH of the oceans at the time the carbonate-based life forms of Trilobites and Ammonites totally dominated the oceans and CO2 levels were 4,000 to 7,000 ppm?

    Comment by John Lang — 8 Jul 2008 @ 5:44 PM

  51. John Lang: Trilobites and ammonites did not live at the same time, except during the Late Paleozoic when the trilobites were few and very much on the decline before their total extinction 245 milion years ago. Also trilobite carapaces aren’t necesssarily made of carbonate. Ammonites became dominant in Mesozoic oceans after the trilobite extinction.

    Comment by Figen Mekik — 8 Jul 2008 @ 6:01 PM

  52. Chris (45) — Yes. Thank you for the correction and the amplification.

    Comment by David B. Benson — 8 Jul 2008 @ 6:03 PM

  53. #49 Aaron:

    You can save the RC folks some time by rephrasing your question as what you already believe. I’m hazarding a guess that your point is “Well, the earth has experienced periods of non-equilibrium in the past, so what’s wrong if it isn’t in equilibrium now?”

    Once you’ve done that, somebody can pipe up with the answer, probably to the effect that avoidably putting the system out of equilibrium in a way that will cause it to restabilize at a sub-optimal point is undesirable. I’m not I’m expert, but that’s probably the general gist of your “answer”.

    Comment by Doug Bostrom — 8 Jul 2008 @ 6:15 PM

  54. A lot of the press reports on NF3 were confused, in the sense that they focussed mostly on flat panel displays, and thought the mention of plasma had something to do with plasma displays…

    Plasma etching is a step in semiconductor manufacturing, and is different from the “plasma” in plasma displays.

    NF3 is one of several choices used with CVD (Chemical Vapor Deposition) processes in general, i.e., in products that include:

    – microprocessors, DRAM, etc
    – flat-panel displays
    – photovoltaic solar cells

    To be clear, it’s one of the substances used in the manufacture of the products, it’s not *part* of the products (and better be long gone before the product ships), and actually, flat-panels may well be the lesser of uses.

    As to why it’s used (it’s only one alternative), see Gas World, which says:

    “NF3 is used as a chamber cleaning gas in the manufacture of semiconductors, flat panel displays and other electronic devices. When compared with competing products, NF3 offers customers significant reductions in emissions, throughput increases of up to 30%, longer chamber life and faster clean rates.

    Nitrogen trifluoride is also used in the plasma and thermal cleaning of CVD reactors, while it is used as a source of fluorine radicals for plasma etching of polysilicon, silicon nitride, tungsten silicide and tungsten for example.

    Although semiconductors remain the principal driver for electronic specialty gases, increased interest in photovoltaics is adding to the push.

    Electronic gases are needed in thin-film deposition, such as chemical vapour deposition (CVD) or physical vapour deposition (PVD), technologies used to make a semiconductor or a photovoltaic cell.

    The three major gases used in semiconductors, liquid crystal displays (LCDs) and photovoltaics are nitrogen trifluoride (NF3), silane (SiH4) and ammonia.

    Demand for electronic gases in the semiconductor and solar cell industries continues to outpace global GDP growth by more than two times. In traditional semiconductor segments such as microchips and flat panel displays, market researchers expect sales growth of around 8% per year between now and 2010 – and for the solar segment, the annual forecast lies at around 30%.

    Experts anticipate that from 2012, photovoltaic producers will spend more on gases than flat-screen manufacturers, and from 2017 they are even set to overtake the chip sector.

    Although only a handful of different gases are used in solar-cell manufacturing – in comparison with more than 20 for semiconductors – the volumes required are significantly greater.”

    SO, as usual, one must be careful with popular press. They whacked flat-screens, which are second to semiconductor chips, and will likely be third to PV cells.

    I haven’t seen the full Prather article, but:

    1) WE certainly do need to be measuring this.

    2)However, if there’s one place where chemicals are *very* carefully controlled, it’s a semiconductor fab, thank goodness. Equipment vendors (Applied Materials, etc) and fab operators certainly need to pay attention to keeping this under control or (maybe) finding alternatives, but it may be a potential problem reasonably kept under control. Again, fabs are at least used to working with witches’ brews of nasty chemicals.

    Comment by John Mashey — 8 Jul 2008 @ 6:29 PM

  55. Re #29

    What you said is probably true, but politics (and big money) does not explain why NWS
    deliberately kept climate change below the radar screen during the Clinton/Gore administration.

    Comment by pat n — 8 Jul 2008 @ 6:42 PM

  56. Re # 45 Chris
    “… this identical CO2-carbonic acid-bicarbonate-carbonate equilibrium maintains the homeostatic pH in our blood (pH 7.4)…a relic of our evolutionary deep oceanic past.”

    As you seem to be quite familiar with aqueous carbonate chemistry, I’m surprised you would end with a statement such as that. The CO2 buffering system in our blood doesn’t involve carbonate to any significant extent, as there is little carbonate at pH 7.4 (as you noted, the HCO3-/CO3= reaction has a pK around 10.3) . Second, the pH of 7.4 is maintained largely by amino acids, such as histidine (mostly in proteins and peptides), having a pK in that range; the pK for CO2/bicarbonate is a full pH unit lower (again, as you noted). Our blood chemistry is no doubt a carry over from our piscine ancestors, but most fish have a blood chemistry (i.e., concentrations of specific ions) very different from that of seawater. However, the CO2/bicarbonate buffer system is a fundamental property of aqueous systems, period – it is not restricted to seawater.

    Comment by Chuck Booth — 8 Jul 2008 @ 6:54 PM

  57. On the subject of ocean acidification, how much CO2 gets dissolved in the oceans on a day to day basis? Also, the Henderson-Hasselbalch doesn’t really apply here because there are other organism that use CO2 for other physiological functions, namely photosynthesis. Even if it was, you would first need a rough estimate of the amount of base to CO2 as an acid to know the effect of the unused CO2. I’m also guessing that most of that base is in high concentrations in reefs and other places where life is most likely found. Since CO2 is just as likely to dissolve anywhere in the ocean, even a large amount of CO2 dissolved would have little impact since its concentration will be much diluted and many orders of magnitude smaller than the concentration of the base say in a crab’s shell or a coral reef. Diffusion is a powerful process.

    Comment by Aaron — 8 Jul 2008 @ 7:20 PM

  58. #53 Doug

    There are stable fluctuations from equilibrium and there are unstable ones. The question is whether or not the earth existed in a stable equilibrium before the industrial revolution. Also, how would one tell if an equilibrium is stable or not other than the usual stat mech definitions of compressibility and heat capacity? I know that there is an attractor the atmosphere, but can the atmosphere venture far from this point in phase space? If so, how far?

    Comment by Aaron — 8 Jul 2008 @ 7:26 PM

  59. #53 Doug

    The question does not have an answer as far as I know. I would not have asked it if I thought I had the answer. I know that some fluctuations in a grand canonical ensemble, like the earth, are stable, meaning that they will return back to the same equilibrium state after the fluctuation. That’s how one knows that as you increase the amount of energy you increase the temperature. It is a stability requirement of the ensemble. I just wanted to know if this picture is applicable to the earth system with a solar sunlight bath reservoir in equilibrium. Its really a statical thermodynamics question.

    Comment by Aaron — 8 Jul 2008 @ 7:43 PM

  60. Re the response to #11: Gavin, I have been trying to get a better understanding of the lifetime of methane than the usually quoted ten years. But can you please explain your statement “For CH4, 12 years for the perturbative half-life (longer than the ~8 year residence time) is reasonable. How can half-life be longer than residence time?

    [Response: CH4 has what is called a feedback on it’s own lifetime. CH4 loss is controlled by the OH- concentration, but if you increase CH4, you use up OH-. The residence time is the total amount of CH4 divided by the loss rate (roughly 8 years), and if the loss rate was constant, then perturbations would decrease with an 8 year time-scale. But since the loss rate actually goes down if you increase CH4, that means that perturbations last a little longer than that (roughly 12 years). There’s more discussion (taken to extremes) in Schmidt and Shindell (2003). – gavin]

    Comment by Blair Dowden — 8 Jul 2008 @ 7:56 PM

  61. The article says 4,000 tonnes of NF3 were produced last year and the CO2 equivalent of NF3 is 17,000 times that of CO2.

    While those numbers sound shocking, the CO2 equivalent of current NF3 production of 68 million tonnes should be compared to the CO2 production amounts of roughly 40 billion tonnes (ie, this is 1,000 times smaller than CO2 or a forcing of let’s say 0.0017 W/m2)

    Comment by Lowell — 8 Jul 2008 @ 8:04 PM

  62. Gavin, Chris C., thanks for the help.

    Comment by Rod B — 8 Jul 2008 @ 9:37 PM

  63. One of the comments claimed the warming effect of the NF3, was similar to that of a single coal plant. If I were to take that statement at face value then the impact of this chemical is pretty small, in fact probably very much less than any CO2 released by the production of the power used by those displays. If that is the case, then this chemical needs a small amount of monitoring just in case either its effect has been grossly underestimated, or its usage grows dramatically. It hardly seems like an issue of general concern.

    Comment by Thomas — 8 Jul 2008 @ 11:14 PM

  64. The atmosphere holds 760 gigatons of CO2. Man emits about 6 gigatons of CO2. The total emissions from all sources are about 200 gigatons (I have seen numbers as low as 150 gigatons so clearly the level of understanding of the carbon cycle is poor), and each year there is a net uptake of about 3 gigatons. So 98.5% (98%) of all CO2 emissions are absorbed into the various sinks. How exactly is mans CO2 emissions due to energy consumption contributing to the 3 gigaton uptake. Shouldn’t our share be 3% (or 4%) of this, or 0.09 (0.12) gigatons? And how does CO2 stay in the atmosphere for 100 years or more when 30% (20%) of CO2 in the air is removed from the air each year. Seems the half life would be 3-5 years?.

    Not saying man is not affecting things, and not saying CO2 is not responsible for part of the warming, or that there is not any warming. Deforestation, urban island effects, agricultural practices and other pollutants certainly must contribute to whatever changes man is responsible for, and natural variation in climate may be a factor. But I want to stay focused on man made CO2 from fossil fuels and why it takes the heat for global warming.

    [Response: Because it has increased ~100ppm (37%) over pre-industrial levels – 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. Think of it like a bath tub that has a tap turned on and a small drain and has reached a stable level. In the bath there is someone sloshing the water from one side to the other. Now you come along and pour in some buckets of extra water – the average level will rise depending on how quickly the small drain responds, but it is doesn’t depend on the sloshing at all. – gavin]

    Comment by pft — 9 Jul 2008 @ 3:13 AM

  65. Re #56:

    Chuck: yes, you’re right that the bicarbonate – carbonate pKa is too high for this equilibrium to make a significant contribution to pH buffering in blood. It’s almost exclusively the carbonic acid-bicarbonate equilibrium that is involved. I used the entire equilbrium (carbonic acid-bicarbonate-carbonate) since, if there’s any hydrated CO2, the full equilbrium is represented, distributed amongst the various species according to the pH (it’s just that there is a minimal contribution from dissociation of bicarbonate to carbonate at blood pH).

    The carbonic acid – bicarbonate equilibrium is an important pH system in blood ‘though, and especially so since the blood is continually coping with changes in CO2 concentration. So just in the same way that outgassing of CO2 from oceans results in a rise in ocean pH, so the “outgassing” of CO2 from blood (through the lungs) “pulls” protons from the blood onto bicarbonate and raises the pH (and if the pH becomes too alkaline, bicarbonate is removed by the kidneys).

    Interestingly, whereas the reversible hydration of dissolved CO2:

    CO2(aq) + H2O == HCO3- + H+

    is quite a rapid reaction (half life around 5 seconds) so that CO2 equilibrates between the air and ocean surface according to the temperature and atmospheric CO2 concentration (and ocean surface dissolved CO2 concentration -equilibration of which with the deeper ocean layers is limited by the physical mixing of surface and deeper layers presumably), this reaction is catalysed in blood by carbonic anhydrase resident in our red blood cells, each enzyme molecule of which can bind and hydrate 1 million CO2 molecules to bicarbonate every second.

    The other buffering components of blood pH are proteins as you say (especially haemoglobin which binds protons), and also inorganic phosphate which has a pKa (6.8) closer to blood pH…

    Comment by Chris — 9 Jul 2008 @ 4:50 AM

  66. The Great Barrier Reef has proved to be an effective ‘hook’ here in Australia. A google news search gives you an idea. The turn-around in the average aussie’s attitude to climate change in the last couple of years has been nothing less than stunning, it and Iraq were the major factors in the recent election.

    Comment by Alan — 9 Jul 2008 @ 5:22 AM

  67. #44

    As a geneticist I thought I should comment on adaptation in general to give a picture of what effect “strong” (whatever means strong) acidification could have.

    Biological organisms have been shaped by their environment, are still shaped nowadays and will still be shaped tomorrow.
    They are, in parallel, shaped by “random drifting” based on their ability to acquire changes (mutate).

    So we have two forces that are specific for each organisms and even (but to a lesser extend) to each individual of a given species:

    1) Speed of genetic changes (intrinsic, species specific & in more moderate way individual specific)
    2) Speed on environmental changes (extrinsic, global, regional,…)

    if genetic changes match environmental changes -> good you survive & proliferate
    if genetic changes fit less well with environmental changes -> well you survive less and you know what ? it’s a competition ! so you should change yourself or the environment otherwise you’ll disappear.

    So it is true that species and some individuals in these species may have kept or re-acquire a greater resistance to acidification allowing them to cope better with acidification changes.
    It should also be noted however that there is even more species and individual that did NOT maintain such resistance or even became very sensitive to acidification. For example all these organisms that were spared from acidic environment for long (evolutionarily speaking) periods of time.

    To simplify, the more brutal the change (evolution scale remember) the more species and individuals will be eliminated (strong selection), the slower the change the more species and individual will be maintained (weak selection).

    I think corals (a lot of coral species but not all) are a good example of organisms that are sensitive to acidification. Many coral species may disappear, very few may survive and even expand reducing diversity until they drift to recreate a certain diversity.
    But the stronger the acidification, the smaller the number of species that can survive and the smaller their possibilities to evolve (strong constraints limits possibilities).

    Hope I haven’t been too much off-topic…

    Comment by Eric — 9 Jul 2008 @ 5:50 AM

  68. Aaron writes:

    From an expert’s point of view, was the earth in a thermal equilibrium with the incident flux of sunlight before the industrial revolution?

    Yes, and on short time scales, it is now. If it weren’t, Earth would heat up or cool down, as required, until balance is restored.

    We’re a bit out of balance now, and staying that way, because the amount of greenhouse gases in our atmosphere is steadily increasing. But to a first approximation you can model the Earth’s atmosphere very closely by assuming radiative equilibrium at top-of-atmosphere.

    Comment by Barton Paul Levenson — 9 Jul 2008 @ 6:34 AM

  69. Somewhat off topic, but speaking of other greenhouse gasses, in this case ozone, Alastair Lewis was interviewed on the very pro-environmental National Public Radio show Living On Earth (see ) broadcast this weekend. It was very upbeat on global cooling from tropical ozone depletion due to bromine and iodine, probably from sea spray. The following exchange was particularly interesting to me:

    ELLERMAN: So I guess this is really gonna change our perspective on climate models and change the climate models?

    LEWIS: Well it certainly shows that we need to keep an open mind, that actually there are some things out there in remote places that are pretty important, that we actually haven’t discovered or accounted for yet, that it’s not a completely done deal in terms of the chemistry of the atmosphere, that there are still some discoveries to come. Understanding how the climate works is still subject to big uncertainties so there are big processes that perhaps we haven’t discovered, or processes that we don’t understand accurately and we need to go to these places to really try

    [Response: What you see is a journalist asking a seemingly important question and the scientist trying to get back to what they know about. There is no ‘global cooling’ from halogens above the ocean, since there is no reason to expect them to be changing. What this does is affect the background state for ozone in chemistry-climate models in some regions, which is likelyl to have little or no effect on changes in ozone due to increased emissions of precursors. It’s obviously better to get all these details in, but the whether this is ‘really gonna to change our perspective on climate models’ – the answer is no. – gavin]

    Comment by Willem Vanden Broek — 9 Jul 2008 @ 6:46 AM

  70. O.K. I’m going to ask low-level question of the day.

    T. Boone Pickens this week announced plans to set up (on private property, minimal governmental approval needed) a network of windmills to generate power. The radio show I was listening to this morning, Brad & Britt on WZTK in Greensboro (not a national show, and usually rather balanced. One of them is conservative and one is liberal, both have shown a lot of leaning towards environmental conservatism), they said the plan was to try to string enough power generation together to power 50 million households.

    Will that amount of power generation reduce the production need enough for some of the other non-environmentally friendly power plants to stop producing so much polution? With the Majove desert solar projects, the current Hydro-electric and nuclear plants online and now the wind project, would that be enough to pull coal out of the equation? Or somewhat close?

    (As was proven on another thread, I’m somewhat new to the game, so asking those who know to see if there might be some hope…)


    Comment by Paul — 9 Jul 2008 @ 8:06 AM

  71. #57 Aaron

    Yes the Henderson Hasselbalch equation applies here. The H-H equation effectively defines the equilibrium distribution of the basic (proton acceptor) and acidic (proton donor) components (conjugate pair) of a titratable group (a buffer). So it can be used to calculate the ratio of carbonate/bicarbonate (or the absolute concentrations of these if the total buffer concentration is known, which I’m sure it is in the oceans – it’s around 27 mM in blood, of which nearly 26 mM is bicarbonate) in the oceans, in blood or in a bucket.

    It doesn’t really depend on other organisms [if a photosynthetic algae uses a bit of dissolved CO2 this will have a tiny effect on the CO2-carbonic acid-bicarbonate-equilibrium, but this will just “readjust” (Le Chatalier’s principle) and (assuming the local sea pH doesn’t change), the equilibrium ratios of conjugate acids and bases (e.g. carbonic acid/bicarbonate) won’t change].

    I’m not sure what you mean with:

    [“Even if it was, you would first need a rough estimate of the amount of base to CO2 as an acid to know the effect of the unused CO2. I’m also guessing that most of that base is in high concentrations in reefs and other places where life is most likely found.”]

    Notice that in the Henderson-Hasselbalch equation “base” means “basic component of the buffer”.

    So in the equilibrium:

    H2CO3 === HCO3- + H+ === CO3- – + H+

    Bicarbonate is the “base” when considering the carbonic acid – bicarbonate equilibrium and is the “acid” when considering the bicarbonate – carbonate equilibrium. So I wonder if you are using the term “base” in the same manner that I, and Mssrs Henderson and Hasselbalch, are! Obviously carbonate is the most basic component of the buffer. So if that’s what you are referring to, I see sort of what you are saying with respect to the reefs/coral etc. However this carbonate is essentially “fixed” (as aragonite or calcite)..the carbonate in equilibrium with bicarbonate in sea water is dissolved carbonate. That’s not to say that the “fixed” carbonate (in shells and skeletons of sea creatures) isn’t also in “equilibrium” with the dissolved carbonate, and of course one of the problems of ocean acidification is that the shift in the carbonate/bicarbonate equilibrium even further towards bicarbonate enhances the leaching of “fixed” carbonate back into solution…..

    …i.e. the shells of the poor sea creatures start to dissolve…

    Comment by Chris — 9 Jul 2008 @ 8:44 AM

  72. Aaron,
    When we speak of nonequilibrium thermodynamics, we are really talking about near-equilibrium thermodynamics. There really aren’t great methods for treating systems that are far from equilibrium. However, most systems do not spend a significant proportion of time far from equilibrium, and this includes Earth. The concept of local thermodynamic equilibrium applies except right at the top of the atmosphere. The boundary condition is tricky, but can be handled.

    Comment by Ray Ladbury — 9 Jul 2008 @ 9:10 AM

  73. Re #72, apart from Life itself perhaps which is far from equilibrium.

    Comment by Pete Best — 9 Jul 2008 @ 9:19 AM

  74. Am I missing something here? At home, I have copies of publications going back to the early 1980’s, which refer to the problem of increased oceanic acidification due to enhanced levels of atmospheric CO2. So why are certain sectors of the media only beginning to take notice of a “new” issue now?

    This ought to be given more prominence; one of the main contentions in “The Great Global Warming Swindle.” last year, claimed that the oceans could be a net exporter of CO2 to the atmosphere, resulting from increased temperatures (entirely natural, of course) But if oceans are acidifying as a result of increased CO2 uptake, they logically cannot be a net exporter of CO2 back to the atmosphere.

    Yet most people I have spoken to, on both sides of the divide, appear not to have even heard of the issue of acidification.

    Comment by Alastair Brand — 9 Jul 2008 @ 9:28 AM

  75. As for other factors contributing to AGW, let’s not forget all that carbon released by all the fires (800 currently in California alone) caused by the extra heat and drought caused by AGW. A vicious cycle that will probably snowball. And drought will unfortunately probably mean less regrowth of carbon-eating trees and more initially of dryland chaparral communities and giving way finally to desert conditions.

    Comment by Ron R. — 9 Jul 2008 @ 9:39 AM

  76. #71 Chris

    But if the Henderson-Hasselbalch equation is applicable after accounting for the amount CO2 has been used to photosynthesize sugars, and concentration of base, from the definition in the equation (either single or bicarbonate), is much, much higher than the trace amount of CO2 that are dispersed throughout the ocean, based on an analysis that would like the Langmuir adsorption isotherm, how can these traces amounts of the acid (CO2) contribute enough to dissolve crabs’ shells which have a much higher concentration of the base? We are taking a small number and dividing it by a bigger number and then taking a log. That sounds like a very small number to me. Also, if there is more CO2 for more algae to make more sugar and then more algae, that puts more carbon to turn into carbonate by crabs and the like. So carbonate may not be truly fixed, but there are definitely competing processes. The question is, once these other factors are accounted for, production of new carbonate from more microorganisms and consumption of CO2 by said microorganisms, what does this do to the relative concentrations of both bases and CO2 at the point of activity?

    #72 Ray

    If the common practice is to treat the earth as a thermal system in equilibrium with a sunlight bath, what is a rough estimate for the absolute magnitude for the largest stable fluctuation in the internal energy of the earth? I would guess that this might be related to the square root of number of particles in the atmosphere as would be the case for a grand canonical ensemble, but I don’t if that is allowable with the different physical phases found in the atmosphere (i.e. gas, clouds and crystals).

    Comment by Aaron — 9 Jul 2008 @ 9:46 AM

  77. We’re a bit out of balance now, and staying that way, because the amount of greenhouse gases in our atmosphere is steadily increasing.

    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?

    Comment by Joseph — 9 Jul 2008 @ 9:52 AM

  78. I thought this was interesting new analysis on methane in the ocean

    It came out on July 4th, seems to be in the positive feedback progression.

    From Article:

    Although the implications for global climate change are still being studied, the warming and further stratification of the ocean seem likely to affect marine methane production. “This is a newly recognized pathway of methane formation that needs to be incorporated into our thinking of global climate,”

    Comment by John P. Reisman (The Centrist Party) — 9 Jul 2008 @ 9:55 AM

  79. #77 Joseph

    Using Kirchoff’s Law one can tell whether or not a graybody like the earth is near or far from equilibrium. This is done by related the amount of incident radiation from the sun is absorbed and how much the earth thereafter emits. If the ratio of these two factors stays relatively constant, which it has for the earth, then one can assume that the earth is pretty close to equilibrium. This is how greenhouse gases play a role in this drama. More CO2, CH4, H2O and other gases there are, the bigger the absorption and an increase in T. But so far, this has been a hard thing to measure so I would say that it is up in the air at best.

    Also, it is very hard to push a system as big as the atmosphere far away from equilibrium. I would even say that the amount of CO2 we put into the atmosphere would not even make the internal energy of the atmosphere fluctuate enough to not have it come back to equilibrium some other way, but this is just a hunch. I mean , if we pushed the atmosphere so far from equilibrium, how have the last three very large volcanic events have not done the same in the other direction?

    [Response: This is extremely confused. Kirchoff’s law says no such thing, the greenhouse effect is not a hard thing to measure and is not ‘up in the air’ in any sense except literally. Volcanoes do have large negative impacts on the TOA radiative balance but they don’t occur frequently enough to have cancelled out the increasing effect of GHGs (see here). – gavin]

    Comment by Aaron — 9 Jul 2008 @ 10:51 AM

  80. Re pft @ 64: “The atmosphere holds 760 gigatons of CO2. Man emits about 6 gigatons of CO2.”

    Out of date figures, human emissions are currently over 8Gt per year.

    “The total emissions from all sources are about 200 gigatons…and each year there is a net uptake of about 3 gigatons”

    That’s 3Gt of human generated CO2 (measuring just the C, again should be ~4Gt currently). As Gavin pointed out in his response, total natural emissions and uptakes by natural carbon sinks are roughly in balance, plus the sinks are also taking up roughly half of human emissions. Hence the rest of human emissions, ~4Gt, account for all of the annual increase of 2+ppm/yr.

    Comment by Jim Eager — 9 Jul 2008 @ 11:14 AM

  81. # 76 Aaron

    Chris was correct about the H-H equation – in its standard form, it relates pH, dissolved CO2 gas concentration, and bicarbonate concentration. If one of those values changes (e.g, bicarbonate is taken up by photosynthetic algae, or excreted by the kidney), the other two will change in a predictable way (once equilibrium is re-established, and assuming there is no change in temperature or salt content, which could alter the pK a bit).

    Chris: The point I was actually trying to make (# 56), but didn’t make very well, was that the CO2-bicarbonate buffering system is an unavoidable consequence of life based on an aqueous environment in the cells and other body fluid compartments. The homeostatic mechanisms that keep our blood pH at 7.4 (and keep fish blood pH at 7.7-8.0, depending on the temperature) are, in large part, those that evolved to regulate the components of that buffer system, i.e., elimination of CO2 by ventilation of gills and/or lungs) and uptake or excretion of bicarbonate and H+ via ion transporters in gills and/or kidneys. Your statement seemed to suggest that it was the chemical buffering system that maintained homeostasis, whereas I would argue that the buffer system merely responds to changes resulting from physiological processes subject to feedback control; homeostasis is (usually) the result. In short, I was merely nitpicking a bit for the sake of clarity and accuracy. You obviously understand the physiology quite well.

    Comment by Chuck Booth — 9 Jul 2008 @ 11:39 AM

  82. Joseph, I’m not sure what you are asking? The climate is not behaving like a system far from equilibrium, but rather like an equilibrium system perturbed from that equilibrium by a forcing.

    Aaron, I’m not sure that your question is a reasonable way to look at a dynamical system with components that interact on very different timescales. That’s sort of the problem Schwartz had with his overly simplified depiction of climate. But basically, the answer to your questions is that different scales of fluctuations will happen with different probability distributions on different timescales. That’s the noise. The thing is that none of the noise has a monotonically increasing character, so the longer the timescale, the more–on average–we expect to see trends due to CO2.

    Comment by Ray Ladbury — 9 Jul 2008 @ 11:42 AM

  83. Re #69, the NPR interview of Lewis:

    When I heard the interviewer ask that loaded question during the broadcast, I started yelling warnings at Lewis as I yell at characters in bad horror movies who are about to open the closet from which blood is dripping.

    Lewis’s response was perfectly adequate for a listener who knows what Lewis knows. Unfortunately, he didn’t preface his response with a sufficiently simple and strong answer for listeners who are less in the know, or listeners who know incorrect things.

    I certainly don’t blame Lewis. He was thinking on his feet, his answer was excellent for some audience members, and he seemed to be giving the interviewer the benefit of the doubt. Unfortunately, nowadays I think all interviewees on any topic that might remotely have a connection to climate change should prepare for interviews by preparing one short, strong, unequivocal, clear sentence about the relation of their topic to climate change. They should write that sentence on a note card that they keep in front of them during the entire interview, so they can read that sentence on a moment’s notice.

    Comment by Tom Dayton — 9 Jul 2008 @ 11:54 AM

  84. I apologise in advance for what I know is a bit off topic – even though it is very much connected with AGW. I am sitting here on an English summer day suffering the dismal drizzle dripping form a grey gloomy sky all brought on by a deep and slow moving mid-latitude cyclone (depression)that has hovered over Britain for near 48 hours. A seemingly endless succession of such depressions have sluiced their way across NW Europe this year – and indeed even the western Mediterranean has not been unassailed by damp and dripping depressions. I am recently back from Tuscany and Rome in not so Sunny Italy where one period the deluge was continuous in a Scottish Highlands sort of way for 36 hours. The dreary summers afflicting Ireland, Britain, France, Scandinavia and Benelux as well as Spain, Portugal and Italy are causing increased scepticism about the reality of global warming.

    There is I believe, research that suggests that the higher temperatures associated with increased levels of greenhouse gases may be reflected in an increase in the intensity (though not the frequency) of tropical cyclones – hurricanes and typhoons etc. Presumably, deeper cyclones with higher winds and heavier rain would ultimately result from the warmer air of the present having a higher maximum possible absolute humidity than the cooler air of before AGW i.e. the warm air has a higher “capacity” for water vapour, than does cool air. When warm air rises and cools adiabatically, the water vapour condenses our, releasing latent heat, encouraging continued rising, cooling, and condensation under conditions of instability when adiabatic lapse rates are higher than the environmental lapse rate. In short, warmer air may provide more energy to the cyclone to result in higher windspeeds, lower barometric readings at the centre of the cyclones, and heavier precipitation.

    Could such processes also be operating in mid-latitude depressions that develope over the west Atlantic and move north west to Europe? Is there any evidence that mid-latitude depressions/cyclones are more intense (and perhaps more frequent) than say 50 or 100 years ago? Does anybody know of any research that has looked into
    1. Possible increases in pressure gradients within depressions
    2. Increased mean windspeeds.
    3. Increased intensity of precipitation.
    4. Increased frequency of depressions.
    5 Increased complexity of frontal systems and occlusions.

    My thought is that global warming may actually increase uptake of water vapour from the oceans and in certain geographical areas – West Europe for example – result in increased cloud and storm, and possibly localised cooling relative to the rest of the globe.

    Comment by Mike — 9 Jul 2008 @ 11:54 AM

  85. Joeseph, #77:

    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?

    As this RC article explains, our planet is indeed out of radiative balance, and the temperature increase is due to not being in equilibrium. This is primary evidence for global warming – and this imbalance is entirely due to human-emitted greenhouse gasses. And indeed, substantial warming remains ‘in the pipeline’, and if GHG levels froze right now, we would still experience about 0.6 C further warming.

    Comment by llewelly — 9 Jul 2008 @ 12:08 PM

  86. Gavin, you’re right. The ratio is described does not have to equal a constant for there to be thermal equilibrium, it has to equal one. In the IR region, this is the case. Now for Kirchoff’s law to really make sense this has to hold true for all the parts of the em spectrum and I don’t know if this has been tested. If you know of data on the absorption and emission of radiation by the earth in regions like x-ray and gamma, please let me know. I would like to look at them. If you would like more information on Kirchoff’s law please see

    As for volcanoes, I was not suggesting that they could somehow offset the contributions of greenhouse gases by people. I was claiming that these large scale volcanic effects provide very large fluctuations to the internal energy of the atmosphere, modeled as a grand canonical ensemble. Despite these fluctuations the atmosphere is able to bounce back and return to the basically the same equilibrium position in a rather short period of time, much less than geological time. It would be interesting to see what the maximum absolute fluctuations in the internal energy would still allow the atmosphere to return to the same equilibrium state with the incident radiation from the sun and whether or not adding so much CO2 or other gas would provide this much of a fluctuation on what type of a time scale.

    Comment by Aaron — 9 Jul 2008 @ 12:26 PM

  87. pft:

    Leaf dies and rots. CO2 released.

    Leaf grows. CO2 sequestered.

    Unless we have fewer plants year on year (by, say, cutting them down…) this is a balance. That there are a quadrillion tons of leaves means nothing. They all grow back.


    We extract the oil and burn it. CO2 released.

    We ????

    Ah. We don’t have a natural sink for this.

    So even 1 ton of CO2 burned needs to be taken up by something else. And you need to PROVE this single ton is taken up because the default is “nothing”. you must prove your assertion to a skeptical crowd.

    When we note that it is trillions of tons of oil, we have problems.

    Comment by Mark — 9 Jul 2008 @ 12:27 PM

  88. Volcanoes do have large negative impacts on the TOA radiative balance but they don’t occur frequently enough to have cancelled out the increasing effect of GHGs (see here)

    If I understand that graph correctly, there’s a clear trend in net forcing, which means we’re not in equilibrium, and getting further away from equilibrium.

    How do we know that, even if GHGs stay at current levels indefinitely, equilibrium will be reached, say, at a 2 or 3 degree anomaly vs. an 8 degree anomaly? In other words, can an assurance be offered that the current level of disequilibrium is not much more catastrophic than normally thought?

    Historically, it seems that an increase of 100 ppmv CO2 has quite a major impact on temperature (although I’m not sure to what extent that’s due to feedbacks).

    Comment by Joseph — 9 Jul 2008 @ 12:35 PM

  89. Regarding the CO2 absorption or release question (posts 16, 39, 45, 46): the oceans absorb CO2 (check the NOAA numbers). Increasing atmospheric CO2 concentrations increase the air-sea flux, which has its most significant impact on the shallow surface waters. This causes increasing acidification in these waters due to the slow rate of deepwater formation, which would transfer the water with increased surface CO2 to the deep abyssal waters. Plus, the major impact is in the Pacific where carbonate saturation depths are shallow, but the significant transfer of water with increased TCO2 (and the associated carbonate system changes) is going to occur in the North Atlantic and the Southern Ocean.

    Slowing down the rate of atmospheric CO2 increase would thus slow down the rate of the increase of the air-sea CO2 flux. Reversing the increasing atmospheric CO2 trend (we can dream) would also reduce the air-sea CO2 flux, but I’m qualitatively sure that even if it goes down to pre-industrial levels, the air-sea flux of CO2 would still be into the oceans. But it would be closer to balance with deepwater formation rates, so there would much less acidification of surface waters.

    Comment by Jimbo — 9 Jul 2008 @ 12:48 PM

  90. #76 Aaron

    That’s very confused – you’re mixing up all sorts of unrelated concepts.

    The Henderson-Hasselbalch equation simply defines the ratio of the acidic and basic components of a buffer according to the pH and pKa. Nothing more, nothing less. It defines the position of a physical equilibrium. It’s got nothing to do with what animals do with CO2, sugars and so on. We’re talking about how dissolved CO2 in the ocean that is hydrated to carbonic acid further partitions between its monobasic (bicarbonate) and dibasic (carbonate) forms, and how this affects the ocean acidity.

    Carbonate-fixing animals in the sea fix various forms of carbonate (CO3- -) usually as CaCO3 (calcium carbonate, which in various forms like calcite and aragonite is the dominant component of shells/coral). The concentration of carbonate in sea water is small (around 230 umol kg-1 or 230 micromoles per kilogram of sea water), because the dissociation of bicarbonate to carbonate is not favoured in sea water (the equilibrium at the pH of sea water is almost 1000-fold in the direction of bicarbonate; see my post #45). As the pH drops further, due to increasing atmospheric CO2 concentrations, the equilbrium shifts even further away from carbonate towards bicarbonate. During the last 420,000 years through several glacial/interglacial cycles, it’s unlikely that the carbonate concentration dropped below 250 umol kg-1, so already the acidification of sea water resulting from our massive CO2 emissions has resulted in a very significant drop in the sea water carbonate concentration.

    This follows directly from the straightforward physical equilibrium described in my posts #45 and #71. As CO2 dissolves and is hydrated in sea water, the carbonic acid releases protons acidifying the water and shifting the bicarbonate – carbonate equilibrium further in the direction of bicarbonate. The carbonate concentration drops.

    It’s really as simple as that.

    How problematic is this phenomenon? Potentially very problematic. The sea water carbonate concentration that was in the range around 310-250 umol kg-1 during the last 420,000 years (calculated from CO2 concentrations from the Vostock ice core), has been reduced to 230 umol kg-1. Experimental studies have shown that carbonate accretion (“fixing”) on coral reefs drops to zero or becomes negative (aragonite leaching back into the water as dissolved carbonate) when the carbonate concentration drops to around 200 umol kg-1. That’s expected to occur at an atmospheric CO2 concentration of 480 ppm.

    These things can be calculated since they are simple physical equilibria. The effects on coral reef growth can be directly observed in field studies and experiments.

    A useful acount of the effects of atmospheric CO2 emissions on ocean pH and coral reefs was published recently:

    O. Hoegh-Guldberg et al (2007) “Coral reefs under rapid climate change and ocean acidification” Science 318, 1737-1742

    Comment by Chris — 9 Jul 2008 @ 12:57 PM

  91. re Paul (70), actually Pickens’ North Texas 200,000 acre wind power project will (hopefully) by 2014 generate 4000MWatts, which is estimated to handle 1,300,000 average homes — about the same as two large nuclear power plants. … at a cost of about $12B (which also includes some transmission lines and a separate water delivery pipeline). This is a bit bigger than the 2700MW wind farm in West Texas and way larger than the 300MW the State is planning for the Gulf of Mexico, but is said to be the largest (planned) in the world to date.

    It’s curiously interesting since, as you probably know, T. Boone made his $billions over the last 50 years from oil and natural gas. It will be interesting to see if 1) he can pull it off (2 installed every 3 days over six years+ for the turbines alone in an area with virtually no infrastructure), and then 2) make any money off it (requires the continuing federal operating (tax) subsidy, e.g.)

    Comment by Rod B — 9 Jul 2008 @ 12:59 PM

  92. @Thermodynamic equilibrium and earth

    Maybe somebody can enlighten me,
    I learned that for a macroscopic body in thermodynamic equilibrium all extensive parameters like pressure, volume, temperature, composition and number of molecules are independent of time.
    I learned also that thermodynamic equilibrium requires detailed balance on a microscopic scale. This means per example for two black bodies in thermodynamic equilibrium that the incoming intensity is balanced with the outgoing intensity in every wavelength interval across the spectrum.
    I also learned that the earth is an open system far away from thermodynamic equilibrium, but of course in a stationary state or close to it with radiative balance.

    Comment by Guenter Hess — 9 Jul 2008 @ 1:23 PM

  93. #77 Joseph

    Slightly out of balance is subjective and relative.

    Maybe the best way to say it is to generalize. We were fairly in balance prior to the industrial revolution. The climate forcing was following the natural cycle and in a slight cooling trend.

    Then we added industrial based GHG’s which added forcing to the system. Now the ocean has to absorb the extra forcing to get a new warmer equilibrium. So getting back into equilibrium is not as favorable as it may sound.

    I’d rather attain equilibrium at a lower lever than where this is headed. But as Steven Colbert from the Colbert report has mentioned in response to Michael Griffins (NASA Director) statement about “who is to say the climate we have is the ideal climate…”, Colbert responding, “who are we to say that pacific islanders prefer their islands above water”

    We really don’t have a handle on the compounding of positive feedbacks, but there is some paleo precedence for an anomaly in the direction of 8 degrees. There is reason to lean toward the upward scenario, in my opinion, given variables, given BAU, given, what we know, et cetera, et cetera…

    Yes we are pushing further away from equilibrium at this point.

    Comment by John P. Reisman (The Centrist Party) — 9 Jul 2008 @ 1:28 PM

  94. Re Aaron @86: “Despite these fluctuations the atmosphere is able to bounce back and return to the basically the same equilibrium position in a rather short period of time”

    That’s because both volcanic ash and sulfuric acid aerosols don’t stay in the atmosphere very long, hence the forcing does not last very long.

    Comment by Jim Eager — 9 Jul 2008 @ 1:53 PM

  95. Paul (70) — Your question probably more properly ought to be asked on

    which is run by energy expert Joe Romm.

    Comment by David B. Benson — 9 Jul 2008 @ 2:37 PM

  96. re #81 Chuck,

    Your nits are well picked….! In my understanding the carbonic acid-bicarbonate equilibrium does contribute to the maintenance of blood pH (as a very weak buffer 1 pH unit away from its pKa – it buffers somewhat against acidification which takes the pH back towards the pKa). However your depiction of a more “passive” role for the carbonic acid-bicarbonate equilibrium around which the physiology of pH homeostasis and O2 uptake/CO2 excretion evolved, is a beter way of considering the broader picture.

    Comment by Chris — 9 Jul 2008 @ 4:31 PM

  97. #94 Jim

    The point I was trying to make with volcanoes, especially the big ones, is that when they erupt, they provide a very large, short impulse fluctuation to the earth’s atmosphere. Despite these very large fluctuations (Tambora created temperature differences of up to 20 degrees at some latitudes and even caused famine all the way across the world!) the atmosphere was still able to find an equilibrium that looked similar to that of before the eruption not long there after. I’m really just asking if there is some kind of estimate for how much the earth’s atmosphere can take it terms of a fluctuation. I know it can take large volcanic eruptions. If you integrate over enough time, does CO2 input from people push the atmosphere passed this fluctuation limit? I don’t know, but it seems like a pretty straight forward question from a pure physics standpoint. As far as I know, there is no reason to believe that this is an overly simplified point of view.

    #82 Ray

    Can you please give me some more information on Schwarz? I would be interested into seeing more of this person’s work.

    Comment by Aaron — 9 Jul 2008 @ 4:39 PM

  98. Re #84: Mike, you make this statement —

    “The dreary summers afflicting Ireland, Britain, France, Scandinavia and Benelux as well as Spain, Portugal and Italy are causing increased scepticism about the reality of global warming.”

    — and then ask if anyone has any statistics about these “dreary summers”? A climate shift along the lines of what you describe would be rather big news, I think. You can use the internet to look at the numbers and see if there’s anything to this. It shouldn’t take you long.

    Also, increased scepticism on whose part? Do you have some sort of survey data to back up this claim?

    Weather/climate and public opinion are two areas where sceptcism should first be applied to seat-of-the-pants personal assessments. Try that, please.

    Comment by Steve Bloom — 9 Jul 2008 @ 5:02 PM

  99. Aaron, you can read about Schwartz here:

    Schwartz is not a bad scientist, but this shows what can happen when somebody with an incomplete understanding of the science wades too deep.

    I am curious about your contention that you are weighing “both sides” of the argument. Where are you getting the denialist side–because it sure ain’t in the peer-reviewed literature. The profession of publishing significant insights into climate while denying that humans are playing a significant role is absolutely moribund. So where is this “other side” you keep talking about.

    Comment by Ray Ladbury — 9 Jul 2008 @ 5:28 PM

  100. Re #97, Aaron asked whether there is “some kind of estimate for how much the earth’s atmosphere can take in terms of a fluctuation.”

    Aaron, I infer you think the atmosphere has some sort of general-purpose equilibrator. It does not have mechanisms that per se strive for equilibrium of all the Earth’s characteristics. (The Gaia metaphor must not be taken too literally.)

    It does have some specific mechanisms that counteract some specific changes. But those mechanisms do not pay attention to whether they are exacerbating other changes.

    Jim’s example (#94) was that volcanic ash and sulfuric acid aerosols cool the Earth by reflecting incoming solar radiation. Those substances quickly precipitate out, thereby counteracting the specific effect of cooling from those specific substances.

    But suppose the Earth was already cooling, and so much so that it was heading into an ice age. The precipitation of the volcanic sputum then would exacerbate the global, net cooling trend from all influences.

    So that precipitation is not inherently a global equilibrator. It just does its own thing, sometimes with the global effect of counteracting net global trends (equilibrating), and sometimes amplifying those trends (disequilibrating).

    So the answer to your question of whether there is “some kind of estimate for how much the earth’s atmosphere can take in terms of a fluctuation” [my emphasis on “a”], is that there is no single answer, because the answer differs depending on the specific causes, directions, and sizes of the fluctuations.

    Back on point of Jim’s reply: Fluctuations due to volcanic eruptions peter out quicker than fluctuations due to, say, chronically increasing CO2 levels in the atmosphere.

    Comment by Tom Dayton — 9 Jul 2008 @ 5:56 PM

  101. 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.

    Comment by pft — 9 Jul 2008 @ 8:03 PM

  102. #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

    Comment by Aaron — 9 Jul 2008 @ 9:05 PM

  103. #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.

    Comment by Aaron — 9 Jul 2008 @ 9:14 PM

  104. 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.

    Comment by tamino — 9 Jul 2008 @ 9:28 PM

  105. 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.

    Comment by John Mashey — 9 Jul 2008 @ 9:30 PM

  106. 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.”

    Comment by Tom Dayton — 9 Jul 2008 @ 9:30 PM

  107. @Aaron
    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.

    Comment by Guenter Hess — 9 Jul 2008 @ 11:04 PM

  108. 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.)

    Comment by Tom Dayton — 9 Jul 2008 @ 11:25 PM

  109. 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.


    Comment by Thomas — 9 Jul 2008 @ 11:37 PM

  110. 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.

    Comment by Tom Dayton — 10 Jul 2008 @ 12:06 AM

  111. #102

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

    Comment by Dustin — 10 Jul 2008 @ 12:10 AM

  112. Aaron,

    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.

    Comment by Chris Colose — 10 Jul 2008 @ 12:19 AM

  113. #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.

    Comment by Alastair Brand — 10 Jul 2008 @ 4:25 AM

  114. 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?

    Comment by Richard — 10 Jul 2008 @ 4:45 AM

  115. 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?

    Comment by Mark — 10 Jul 2008 @ 4:56 AM

  116. 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.

    Comment by Mark — 10 Jul 2008 @ 5:13 AM

  117. 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.

    Comment by Pete Best — 10 Jul 2008 @ 6:14 AM

  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.

    Comment by Barton Paul Levenson — 10 Jul 2008 @ 6:34 AM

  119. “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.

    Comment by Mark — 10 Jul 2008 @ 6:41 AM

  120. 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.

    Comment by mz — 10 Jul 2008 @ 6:51 AM

  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.

    Comment by Barton Paul Levenson — 10 Jul 2008 @ 7:02 AM

  122. Mike@84

    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.


    Comment by Luke Silburn — 10 Jul 2008 @ 7:32 AM

  123. 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.

    Comment by Ray Ladbury — 10 Jul 2008 @ 8:04 AM

  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.

    Comment by FurryCatHerder — 10 Jul 2008 @ 8:16 AM

  125. 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.

    Comment by Ray Ladbury — 10 Jul 2008 @ 8:18 AM

  126. “#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”.?

    Comment by Mark — 10 Jul 2008 @ 8:24 AM

  127. 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.

    Comment by tamino — 10 Jul 2008 @ 9:19 AM

  128. 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?

    Comment by Joseph — 10 Jul 2008 @ 10:12 AM

  129. #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]

    Comment by Richard — 10 Jul 2008 @ 10:23 AM

  130. 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.

    Comment by Tom Dayton — 10 Jul 2008 @ 10:58 AM

  131. #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.

    Comment by Aaron — 10 Jul 2008 @ 11:26 AM

  132. #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!

    Comment by Richard — 10 Jul 2008 @ 11:30 AM

  133. FurryCatHerder (124), I appreciate your analysis.

    Comment by Rod B — 10 Jul 2008 @ 12:36 PM

  134. #129

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

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



    Comment by Mark — 10 Jul 2008 @ 1:22 PM

  135. 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]

    Comment by Mark — 10 Jul 2008 @ 1:29 PM

  136. 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.

    Comment by Ray Ladbury — 10 Jul 2008 @ 2:02 PM

  137. 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.

    Comment by David B. Benson — 10 Jul 2008 @ 2:14 PM

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

    the Holocene climate was in near-equilibrium.

    Comment by David B. Benson — 10 Jul 2008 @ 3:51 PM

  139. 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.

    Comment by Andrew — 10 Jul 2008 @ 4:17 PM

  140. This piece on Mclean is funny:

    Comment by B — 10 Jul 2008 @ 6:16 PM

  141. 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

    Comment by Eli Rabett — 10 Jul 2008 @ 9:34 PM

  142. 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]

    Comment by Robert Stenson — 11 Jul 2008 @ 12:08 AM

  143. 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]

    Comment by Richard — 11 Jul 2008 @ 3:20 AM

  144. #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]

    Comment by Richard — 11 Jul 2008 @ 3:26 AM

  145. 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?

    Comment by Anne van der Bom — 11 Jul 2008 @ 5:57 AM

  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.

    Comment by Barton Paul Levenson — 11 Jul 2008 @ 5:58 AM

  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.

    Comment by Barton Paul Levenson — 11 Jul 2008 @ 6:05 AM

  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]

    Comment by Steven J Heimel — 11 Jul 2008 @ 8:52 AM

  149. Even Zipper knows the four main greenhouse gases.

    Comment by Mike Donald — 11 Jul 2008 @ 10:04 AM

  150. 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.

    Comment by Hank Roberts — 11 Jul 2008 @ 10:39 AM

  151. P.S., stumbled into this while looking up NF3. Discover Magazine does the really stupid about this general topic:

    [Response: very odd. – gavin]

    Comment by Hank Roberts — 11 Jul 2008 @ 10:41 AM

  152. In response to Richard (143),
    While I appreciate the complexities involved with turbulence modeling, I don’t think that it is necessary to understand microscale turbulence features to say something about global climate change. There are many instances where one can predict macroscopic behavior without detailed knowledge of what’s happening on a microscopic scale: for years, chemical engineers have predicted heat flow in pipes containing turbulent fluids; rheology of metals can be predicted without tracking the movement of every dislocation in the material; and electrical flow in conductors can be measured without tracking the tortuous path of electrons in the crystalline lattice.
    I am not trying to say that turbulence modeling has no place in climate models. I think that it could improve regional forecasts of GCMs. However, it is important to remember that turbulence is responsible for the redistribution of heat in the Earth’s troposphere and hydrosphere only; large-scale turbulent flow does not exist within the stratosphere. Since global climate models rely on radiation laws for transfer of heat to outer space and for absorption of heat from the Sun, incorporating turbulence models will have little effect on the resulting global temperature. Regional temperatures may be somewhat different, however.

    Comment by Jeff — 11 Jul 2008 @ 11:07 AM

  153. #152 Thank you for your comments Jeff you have made some interesting points.

    In the case of heat flow in pipes the models tend to be okay as long as the pipes are smooth and straight and the heating is homogeneous (because that is the same problem the models were calibrated for).

    As soon as you make the pipes more complicated such as putting bends in them you suddenly find all the models giving different answers.

    If you want to know any detail about the heat transfer fluctuations at the pipe walls you even have difficulty knowing what’s going on with the smooth straight pipe.

    Macro scale solutions for macro scale problems can be found only under very controlled environments where the forcing and boundaries are all known and well defined. (But even then the micro scale can sometimes encroach on the macro scale e.g. thermal fatigue failure)

    It is okay to separate the macro from the micro scales in turbulence until you realise that transfers really do exist from the small scales to the large scales.

    I really don’t know enough to estimate how important turbulence is in the sun/atmosphere/ocean system.

    Maybe it can just be ignored? Are the mass transfer processes in any way linked to the mixing processes and hence the radiation balance?

    Comment by Richard — 11 Jul 2008 @ 12:13 PM

  154. In response to Jeff(152)
    I think Richard has his point. If I understand GCMs, they contain radiation, dynamic prozesses, surface processes, chemistry and everything as a function of time and space. So the minimal model contains a system of coupled non-linear differential equations.
    If you have such a system of coupled non-linear differential equations it is in general, as I understand it, very difficult to deduct straightforward relations between cause and effect. This is valid for measurements as well as for simulations. And to make predictions within the framework of the Navier-Stokes equation is still part of the millennium problems in mathematics.
    Actually, if an easy model as you suggest would suffice, it would make me nervous .

    Comment by Guenter Hess — 11 Jul 2008 @ 12:48 PM

  155. Guenter (152),
    I did not mean to imply that a simple model involving only radiative processes would be effective for determining global temperatures. My point was that incorporating turbulence in models would not change the TOA radiative flux, which is the primary driver of climate change. The Navier-Stokes equation is certainly important for characterizing fluid dynamics in the troposphere, but it becomes less relevant as one moves higher in the atmosphere, where mass decreases exponentially. On the other hand, the NS equation can have an impact on feedbacks in climate models. Regional heat transport can affect albedo, cloud cover, etc., which will affect global temperatures. However, I am skeptical that incorporating complex turbulence models in GCMs will have a first-order effect on global temperature. You would have to convince me that by incorporating turbulence in models, the feedbacks would be significantly altered. Considering that current GCMs do a reasonably good job of forecasts and hindcasts, incorporating and validating turbulence effects in GCMs would take a lot of work. However, I would be THRILLED if anyone in the turbulence field thought the problem interesting enough (and tractable) to pursue such a model.

    Comment by Jeff — 11 Jul 2008 @ 1:49 PM

  156. Jeff #155:

    However, I am skeptical that incorporating complex turbulence models in GCMs will have a first-order effect on global temperature. You would have to convince me that by incorporating turbulence in models, the feedbacks would be significantly altered.

    But isn’t precisely the problem of cloud formation and aerosols the current greatest remaining feedback uncertainty in climate modelling, and relatively intractable precisely due to being turbulent chaotic processes? IMHO Richard put his finger on a sore spot. Though I am not nearly as pessimistic as the text he quotes — the models are doing remarkably well, perhaps due to the combined effects of ensemble averaging and studying global or large-area bulk quantities.

    The post on Ed Lorentz and chaos theory not so long ago here on RC would appear worth a re-read.

    Comment by Martin Vermeer — 11 Jul 2008 @ 3:01 PM

  157. Discover Magazine blog on NF3

    “The big point for me here, anyway, is just how inexact the science is of global warming. To be sure, it’ occurring. We have some ideas how — but not the whole picture. Hence, we need more research and more of a concerted effort to mitigate the known causes as well as find out what isn’t known. Meanwhile we shouldn’t rush to judgment (or policy, for that matter). Otherwise we may just have another corn ethanol situation on our hands: a lot of time, money and attention being put into something futile.”

    Journalists should have a better understanding of the issues by now. Ethanol production from biomass is not a solution to global warming, but it is a partial solution to the energy supply problem as fossil fuels are phased out (the others are solar and wind).

    The three basic lines of evidence (paleoclimate, climate models, and real-time data) all support the notion that fossil fuel-sourced CO2 is having a large and persistent influence on global climate. International organizations are going to have to come to terms with this – carbon dioxide emissions are not the issue, fossil fuel use is. CO2 emissions have historically been balanced against CO2 uptake, which is why CO2 varied so little over the past few million years. By pulling hundreds of billions of tons of carbon out of multimillion-year old fossil fuel deposits, we’ve increased the size of the active carbon pool. The planet is warming, and the two major culprits are fossil fuel use and extensive deforestation. Thus, the solution is to halt the combustion of fossil hydrocarbons (bury your plastic in a landfill – that’s the right approach!), and halt deforestation (especially tropical deforestation).

    That results in some secondary problems, like a lack of energy supplies and building materials. That’s where the economically viable technical solutions come into play. These are based on reliance on sunlight, wind and photosynthesis as basic sources of energy and raw materials. Replacing existing fossil fuel infrastructure with renewables will cost will require a redirection of perhaps 40% of the world’s economic activity (that’s the current share that energy takes up). Some leading industrialized countries (Japan and Germany, mainly) are following this strategy, while others (the U.S., Australia, and the members of OPEC) are mostly dedicated (for obvious, if short-sighted, economic reasons) to pursuing the status quo.

    That’s all been known for some time, though. For something a bit more interesting, look at the following graph of waper vapour increases over the oceans, 1988-2003:

    The trend is +1.28% per decade – a slow but steady increase. Also note the large pulse of water vapour into the atmosphere during the 1997-1998 El Nino, followed by the return to the normal. A “skeptic” would look at the period from 1998-2000 as proof that global warming was over; an “alarmist” would take the period 1996-1998 as proof that global warming was rapidly accelerating, and a scientist would look at the entire dataset and draw conclusions from that. That conclusion is pretty well summed up in the 4th IPCC – we’ll have catastrophic results under business as usual scenarios within a hundred years, and significant climate changes are unavoidable even with drastic and immediate action.

    Comment by Ike Solem — 11 Jul 2008 @ 4:20 PM

  158. NF3 is just one of the high GWP gases

    Hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) are potent greenhouse gases, and some persist in the environment for thousands of years. These gases, referred to as high global warming potential gases (high GWPs) are from 140-23,900 times more potent than CO2 in terms of their capabilities to trap heat in the atmosphere over a 100-year period. Also, because they remain in the atmosphere almost indefinitely, concentrations of these gases will increase as long as emissions continue.

    Small concentrations but very potent. None of these are getting much play in the media. Maybe NF3 made it into the news cycle because it has to do with TV’s and that makes it a great story somehow?

    Comment by John P. Reisman (The Centrist Party) — 11 Jul 2008 @ 10:48 PM

  159. Re #56 myself:
    correction/clarification. It is not the chaoticness that is the problem, it is the necessity to include a huge range of scales for physical realism, from droplets through cloud systems to the size of the Earth. This is obviously computationally impossible, but if it were, the resulting model would still be chaotic. But with photorealistic cloud etc. feedbacks…

    (BTW thank you RC for banning the use of text-only browsers like lynx. What the about visually impaired?)

    [Response: There is an audio challenge for those who can’t see the captcha, but I don’t see a way for lynx users to have this work. I’m open to suggestions to fix this. – gavin]

    Comment by Martin Vermeer — 12 Jul 2008 @ 2:03 AM

  160. Please allow me to post some recent worrying data here, on which I haven’t seen press coverage:

    In 2007, global emissions of carbon dioxide (CO2) from fossil fuel use and cement production increased by 3.1%, which is less than the 3.5% increase in 2006. The emissions from China, with an emission increase of about 8%, accounted for two thirds of this global increase. Smaller contributions were made by India, the USA and the Russian Federation, in contrast to the European Union (EU-15), where a relatively warm winter and high fuel prices led to a 2% decrease in CO2 emissions. The increase in emissions, in 2007, of about 800 million metric tons of CO2, was mainly due to a 4.5% increase in global coal consumption, to which China contributed by more than 70%. At present, CO2 emissions per person from China, EU-15 and the USA come to about 5, 9 and 19 tonnes of CO2, respectively. In the 1990-2007 period, total CO2 emissions related to the use of global fossil fuel and cement production increased by about 34%.

    These figures are based on a preliminary estimate by the Netherlands Environmental Assessment Agency (PBL), using recently published BP (British Petroleum) energy data and cement production data for 2007.

    Comment by Ark — 12 Jul 2008 @ 3:38 AM

  161. Re John P. Reisman (158) …“Maybe NF3 made it into the news cycle because it has to do with TV’s and that makes it a great story somehow?”


    “…a previously neglected greenhouse gas (NF3).” (Second sentence of the article). The other gasses you mentioned are all discussed by the IPCC and covered at Kyoto.

    Comment by Arch Stanton — 12 Jul 2008 @ 10:39 AM

  162. “At present, CO2 emissions per person from China, EU-15 and the USA come to about 5, 9 and 19 tonnes of CO2, respectively.”

    I shudder to think about what the world would be like if everyone equaled the USA’s 19 tonnes per person.

    Comment by Al Crawford — 12 Jul 2008 @ 11:55 AM

  163. I shudder to think about what the world would be like if everyone equaled the USA’s 19 tonnes per person.

    Except that doesn’t seem at all possible. I’m not sure if peak oil is a problem or a solution.

    Comment by Joseph — 12 Jul 2008 @ 7:27 PM

  164. I’ve put up a longer post with links about why the Prather and Hsu paper should be withdrawn and the authors drawn and quartered. The only semi-reasonable thing is that there should be a watching brief on NF3 concentrations. It should only be put onto the controls list if concentrations grow to the point where they can be measured. Right now the forcing is below 0.001 W/m2.

    Comment by Eli Rabett — 12 Jul 2008 @ 11:21 PM

  165. Joseph, #163:

    Problem is that peak oil means that although demand is going up, we can’t pump it out any faster.

    That doesn’t mean production is going down, just that it can’t go up quick enough to meet demand.

    I don’t think “peak oil” is a solution.

    Comment by Mark — 13 Jul 2008 @ 6:25 AM

  166. Re #163, its certainly not possible with fossil fuels but globally solar engine could be harvested to yield some serious amounts of energy if required to do so. Globally we can power the earth with solar. Once installed we can power all our cars etc from electricity from this source plus wind and other places. We just need globalisation to mean that for everything.

    Comment by pete best — 13 Jul 2008 @ 6:37 AM

  167. re. #142
    Gavin-Thank you for the response.
    Tyndall (1865) is not available either at my library or at Borders.
    Neither is Arrhenius(1896). My understanding is that Arrhenius conclusions on CO2 were based on numerical calculations.
    While it is true that climate and climate change due to any forcing is horrenously complicated, with multiple feedbacks, it would seem that at least somewhere, someone would have a controlled, isolated experiment to measure the effect of varying CO2 concentrations on temeperature changes from incident radiation. While far from a perfect model an order of magnitude figure regarding the relation between CO2 levels and temperature, in the climatically important range, would then be available. After all it is known with other relations such as CO2 solubility as a function of temperature.
    Perhaps this stuff is in some high school or college chemistry text but I do not know of it and have not seen it. There are enough posters, with a lot of knowledge, on these threads that you would think that someone would know of such an experimentally determined relation.

    Comment by Robert Stenson — 13 Jul 2008 @ 10:25 AM

  168. Robert Stenson in 167 wrote:

    While it is true that climate and climate change due to any forcing is horrenously complicated, with multiple feedbacks, it would seem that at least somewhere, someone would have a controlled, isolated experiment to measure the effect of varying CO2 concentrations on temeperature changes from incident radiation.

    Since you are asking for a “controlled” experiment, you need to control for the emissivity of the surface that is absorbing the radiation, the absolute humidity, the pressure, the temperature, etc..

    However, you are asking specifically about carbon dioxide and how it will affect radiation. So perhaps we should ask for the spectral emissivity of carbon dioxide — which is also its absorptivity — assuming local thermodynamic equilibrium conditions under which Kirchoff’s Law applies — at roughly atmospheric pressures of 20 mb and above.

    Here are some posts which show how the spectral emissivity of carbon dioxide varies according to temperature and pressure — and which point you to an online tool where you can create your own graphs:

    Wednesday, July 04, 2007

    Pressure broadening
    Thursday, July 05, 2007

    High Pressure Limit. . . .
    Sunday, July 08, 2007

    Incidentally, the spectral properties of carbon dioxide essentially fall right out of quantum mechanics — although you should mix in some quantum statistical mechanics for good measure as you are not dealing with molecules in isolation, but collisions, bending, etc. where for example, a temporary magnetic diapole may result in some minimal absorption of infrared radiation even by non-greenhouse gases such as oxygen.


    For more of the history and physics, please check out:

    A Saturated Gassy Argument
    26 June 2007

    Part II: What Ångström didn’t know
    26 June 2007

    Comment by Timothy Chase — 13 Jul 2008 @ 11:34 AM

  169. #167 Robert Stentson

    In general
    John Tyndall’s Research on Trace Gases and Climate

    This might be the Tyndall(1865) Gsvin referred to “On Radiation: The “Rede” Lecture” on google books
    It might not be the same work Gavin refers to, but it does discuss the absorption of heat by CO2 and basic experiments showing it.

    Comment by Joseph O'Sullivan — 13 Jul 2008 @ 11:37 AM

  170. Re: #167 (Robert Stenson)

    You’ll find a lot of information about “classic” papers in climate science, including links to full-text articles, at this site.

    Comment by tamino — 13 Jul 2008 @ 11:55 AM

  171. Re #167 Robert Stenson:

    Arrhenius is scanned and on line, link inside:

    Tyndall apparently not, but a description of his measurements is:

    Current knowledge of greenhouse gas spectra is much improved. Play with it at:


    Comment by Martin Vermeer — 13 Jul 2008 @ 12:12 PM

  172. # 167
    Robert try reading Spencer’s Brief History (it’s on-line):

    Here’s a snippet

    Experts could dismiss the hypothesis because they found Arrhenius’s calculation implausible on many grounds. In the first place, he had grossly oversimplified the climate system. Among other things, he had failed to consider how cloudiness might change if the Earth got a little warmer and more humid. A still weightier objection came from a simple laboratory measurement. A few years after Arrhenius published his hypothesis, another scientist in Sweden, Knut Ångström, asked an assistant to measure the passage of infrared radiation through a tube filled with carbon dioxide. The assistant (“Herr J. Koch,” otherwise unrecorded in history) put in rather less of the gas in total than would be found in a column of air reaching to the top of the atmosphere. The assistant reported that the amount of radiation that got through the tube scarcely changed when he cut the quantity of gas back by a third. Apparently it took only a trace of the gas to “saturate” the absorption — that is, in the bands of the spectrum where CO2 blocked radiation, it did it so thoroughly that more gas could make little difference.

    Still more persuasive was the fact that water vapor, which is far more abundant in the air than carbon dioxide, also intercepts infrared radiation. In the crude spectrographs of the time, the smeared-out bands of the two gases entirely overlapped one another. More CO2 could not affect radiation in bands of the spectrum that water vapor, as well as CO2 itself, were already blocking entirely.

    These measurements and arguments had fatal flaws. Herr Koch had reported to Ångström that the absorption had not been reduced by more than 0.4% when he lowered the pressure, but a modern calculation shows that the absorption would have decreased about 1% — like many a researcher, the assistant was over confident about his degree of precision. But even if he had seen the 1% shift, Ångström would have thought this an insignificant perturbation. He failed to understand that the logic of the experiment was altogether false.

    Then you could read through this:

    It might give you some links

    PS. I *love* your thinly veiled assertion that the emperor has no clothes…it’s classic!!

    Comment by Hugh — 13 Jul 2008 @ 12:35 PM

  173. Robert,

    There is paper in The Quarterly Journal of the Royal Meteorological Society vol 67 p. 263 (1941) by G.S. Callendar entitled “Infra-red Absorption by Carbon Dioxide, with special reference to atmospheric radiation”. It summarises the experimental results up until that date.

    There is also this site which contains the latest information on spectral lines in the atmosphere.


    Cheers, Alastair.

    Comment by Abbe Mac — 13 Jul 2008 @ 1:12 PM

  174. Timothy Chase, a quicky clarification: I didn’t think diatomic molecules like O2 could ever have a magnetic dipole… can they?

    Comment by Rod B — 13 Jul 2008 @ 9:11 PM

  175. Rod B,

    I think they can:

    Comment by Paul Middents — 13 Jul 2008 @ 10:38 PM

  176. The National Geographic Channel aired the first part of a new documentary this evening, Earth: The Biography(previews can be seen at The series is narrated by Dr. Ian Stewart, a senior lecturer in geodynamics at the University of Plymouth’s School of Earth, Ocean and Environmental Sciences.
    The first episode was Volcanoes, and near the end of the show, Dr. Stewart discusses the snowball earth hypothesis and the (alleged) importance of volcanic CO2 emissions in re-warming the earth around 630 million years ago (you can view this segment at

    Although Stewart hints that the planet might not have been completely frozen, he doesn’t clearly explain is that it would have taken millions of years for atmospheric CO2 to reach a level sufficient to cause greenhouse warming, and he doesn’t mention any other greenhouse gases; according to a Wikipedia article on snowball earth(, CO2 and methane are thought to have risen over a period of 4-30 million years. I was surprised to see no mention of water vapor playing a role.

    As AGW skeptics and deniers like to claim that volcanoes are the major source of atmospheric CO2, they are likely to seize on Dr. Stewart’s explanation of post-snowball earth warming by volcanic emissions of CO2 to bolster their argument.

    Perhaps one of the RC moderators could comment on the snowball earth-CO2 warming hypothesis and its relevance (or lack of relevance) to current warming?

    Comment by Chuck Booth — 13 Jul 2008 @ 10:46 PM

  177. Chuck Booth wrote in 176:

    As AGW skeptics and deniers like to claim that volcanoes are the major source of atmospheric CO2, they are likely to seize on Dr. Stewart’s explanation of post-snowball earth warming by volcanic emissions of CO2 to bolster their argument.

    Volcanoes did play a role in four out of five of the major extinctions, I believe. The one I am most familiar with (which is to say not very much) is the Permian-Triassic extinction, brought on by a supervolcano in Siberia which erupted for approximately a million years, laying waste to a huge forest and releasing huge quantities of methane from shallow deposits along the continental plate. The major waves of extinction took place during the first 15,000 years — if I remember correctly.

    I am not sure that the AGW skeptics would want to remind people of this, but if they do, it underscores the fact that changes in carbon dioxide levels have in fact preceded changes in temperature. And it doesn’t do them much good — unless they can point to a supervolcano that is currently active. Additionally, we do have levels of oxygen falling in tandem with the rise of carbon dioxide — which is a smoking tailpipe of combustion.

    Comment by Timothy Chase — 14 Jul 2008 @ 1:31 AM

  178. Rod B asked in 174:

    Timothy Chase, a quicky clarification: I didn’t think diatomic molecules like O2 could ever have a magnetic dipole… can they?

    Not even a transient electric diapole (unlike carbon dioxide), but a magnetic diapole?…

    Observations of the Magnetic Dipole Rotation Spectrum of Oxygen
    Nature 212, 66 – 67 (01 October 1966)

    Comment by Timothy Chase — 14 Jul 2008 @ 1:45 AM

  179. PS

    Sorry, Paul, didn’t see your response — and we picked the same article, too!

    Comment by Timothy Chase — 14 Jul 2008 @ 1:48 AM

  180. Re #176 Chuck Bboth: pretty good video, that.

    The problem I see is that it indeed seems to claim that it was volcanic CO2 that ended the snowball episode, and in a trivial sense that is true. The full story is that on Earth, on a time scale of hundreds of thousands of years, there is an equilibrium between these volcanic processes, and the absorbtion of CO2 back into the Earth’s crust by rock weathering and deposition of carbonates. It is the latter processes that came to an abrupt stop under the global glaciation: no rain, no rivers, little exposed rock, no plant roots opening it.

    Water vapour was correctly left out of it: at Snowball Earth temperatures, it is virtually absent, and plays no role in coming out of it either.

    If anybody wants to turn this into denialist propaganda, point out the difference in time scales: sub-century for AGW as against geological time scales for volcanism/weathering. Currently humans are releasing two orders of magnitude more CO2 than the world’s volcanoes combined, and it was no different back then. It was the slow, slow build-up in the absence of weathering that melted the snowball.

    Of the possible relevance to current warming, it could be that it demonstrates that there were conditions in the past where total feedback was (due to albedo) over 100%. Both the glaciation and the deglaciation were “runaway”, due to ice sheets below 45 degs latitude. This particular runaway isn’t going to happen now, but the Earth system isn’t quite as self-regulating as some folks wish to think.


    Comment by Martin Vermeer — 14 Jul 2008 @ 6:03 AM

  181. Re # 180 Martin Vermeer:

    Thanks for your response.

    at Snowball Earth temperatures, it [water vapor] is virtually absent

    That I knew.

    and [water vapor] plays no role in coming out of it either

    I was assuming that as the earth warmed, the water vapor pressure in the atmosphere would increase, and act as a feedback to increase temp further. What am I missing here?

    Comment by Chuck Booth — 14 Jul 2008 @ 9:08 AM

  182. Paul (175), thanks, this was interesting. I’m not terribly versed in this, but in link’s summary hypothesis suggesting (showing evidence of) O2 rotation absorption, they talk of O2’s “permanent magnetic dipole” I can’t visualize how a diatomic molecule with identical atoms can possibly have a dipole, even if it’s one vibration DoF gets excited. Do you have any insight?

    Comment by Rod B — 14 Jul 2008 @ 11:13 AM

  183. Timothy, I’m not sure if it should be electric or magnetic dipole. Electric makes more intuitive sense to me, but the link said “magnetic” dipole. ??

    Comment by Rod B — 14 Jul 2008 @ 11:22 AM

  184. Martin, et al. In the slow but millions of years long release of CO2 way back then, why wouldn’t the CO2 have been absorbed out of the atmosphere into earth and carbonaceous rock (which I understand is far and away the largest carbon store), mitigating the temperature increase?

    Comment by Rod B — 14 Jul 2008 @ 11:32 AM

  185. Chuck Booth (181) — Nothing. Once there was open ocean (and it is not clear that ‘snowball earth’ was ever completely covered with ice) then water vapor plays a role.

    Comment by David B. Benson — 14 Jul 2008 @ 11:43 AM

  186. Rod B asked in 183:

    Timothy, I’m not sure if it should be electric or magnetic dipole. Electric makes more intuitive sense to me, but the link said “magnetic” dipole. ??

    Google Search: oxygen “magnetic dipole”

    Result #9:
    Rotational Lines of Molecular Oxygen

    Comment by Timothy Chase — 14 Jul 2008 @ 12:02 PM

  187. Rod writes:

    Martin, et al. In the slow but millions of years long release of CO2 way back then, why wouldn’t the CO2 have been absorbed out of the atmosphere into earth and carbonaceous rock (which I understand is far and away the largest carbon store), mitigating the temperature increase?

    It is. There’s a dynamic balance between weathering, which removes CO2, and volcanism/metamorphism, which adds it. Weathering goes up with temperature, drawing out more CO2 when it’s hotter, and when it’s colder, weathering decreases and CO2 builds up. This “carbonate-silicate cycle” keeps Earth habitable over the long run. It has failed a couple of times when we’ve had “snowball Earth” conditions.

    Comment by Barton Paul Levenson — 14 Jul 2008 @ 12:31 PM

  188. Chuck (#181):

    I was assuming that as the earth warmed, the water vapor pressure in the atmosphere would increase, and act as a feedback to increase temp further. What am I missing here?

    That it will come too late to make a difference. The glaciation and the deglaciation are both “flip-flops” between two stable climate states, the snowball state and the “normal” one, which are some 60 degs apart for the same CO2 concentration. What happens in the deglaciation is that, as soon as equatorial temperatures rise above zero over a large enough area, a runaway deglaciation driven by albedo starts, and doesn’t stop until the Earth is not only ice free, but a super-tropical hothouse from pole to pole. The transition is very fast, mere centuries.

    It takes a lot of CO2 to melt a snowball… we’re talking thousands of ppmv here. And at the point where the runaway starts most of the Earth is still frozen over and “aquaeous vapour” still well out of the game. But it gets its sweet revenge in the hothouse phase!

    Rod (#184):

    Martin, et al. In the slow but millions of years long release of CO2 way back then, why wouldn’t the CO2 have been absorbed out of the atmosphere into earth and carbonaceous rock (which I understand is far and away the largest carbon store), mitigating the temperature increase?

    But Rod, that reaction requires running water! It works this way, that the rain “leaches” basic substances out of the rock and carries them to sea, where the “carbonic acid” is also dissolved. No rain, no rivers… just ice as far as the eye can see, under an ever-blue, cloudless sky.

    (Are you aware BTW of the theory that the current succession of ice ages (modulated by Milankovic) was triggered by the rise of the Himalayas?)

    Comment by Martin Vermeer — 14 Jul 2008 @ 12:51 PM

  189. Timothy (186), re O2 rotation. Thanks. Very interesting

    Comment by Rod B — 14 Jul 2008 @ 3:03 PM

  190. BPL (187) and Martin (188), Thanks for the insight. Makes sense. Except some of Martin’s I didn’t fully follow: You mentioned the water leaching carbon out of the rocks (and delivering it to the ocean). I understand that process but am not sure the connection with rock absorbing carbon, not giving it up…?

    No, I haven’t heard of the Himalayas effect on ice ages. Sounds intriguing and a little mind boggling! I’ll have to go investigate it.

    Comment by Rod B — 14 Jul 2008 @ 3:18 PM

  191. Thanks to Martin, Tim, and David for setting me straight on CO2 warming of snowball (or slushball) earth. The remaining episodes of Earth: The Biography, on the origin of the atmosphere and the history of the oceans, look very interesting. As always with National Geographic productions, the graphics, animations, etc are outstanding. And its nice to have a narrator who’s a scientist, as opposed to a television or film celebrity.

    Re # 186 Tim C and others: Oxygen as a magnetic dipole

    If I’m not mistaken, this property of oxygen is the basis for measuring O2 concentration in air using a paramagnetic oxygen analyzer (e.g.,

    (Sorry for veering off topic.)

    Comment by Chuck Booth — 14 Jul 2008 @ 3:23 PM

  192. Rod B (#190):

    You mentioned the water leaching carbon out of the rocks (and delivering it to the ocean).

    Not carbon, Rod, but rather, basic compounds like CaO which reacts with acidic CO2 to produce CaCO3, calcium carbonate, then deposited as sediment. (It’s more complicated than that, but that’s the idea.)

    Comment by Martin Vermeer — 14 Jul 2008 @ 3:45 PM

  193. Want to thank posters #168, 169, 170, 171, 172, and 173. for their comments. Working my way through the material and there is a lot of it.

    Specific comment first to Timothy on #168:

    Was not trying to replicate the atmospheric humidity and other potentially confounding factors in my “controlled” experiment but was trying to isolate the effects of CO2 concentration changes and its contribution alone to temperature changes from incident radiation that mimics the solar spectrum.
    Went to the articles that you provided and came across that very neat spectralcalc. Had fun trying different scenarios.
    However, the following comments/questions arose:

    1) If CO2 is opaque to earthly reradiation then it is also opaque to incident radiation of the same wave number. Analogous somewhat to cloud cover which traps warming radiation at night but provides cooling umbrella coverage during the day.

    2) What % of the incident radiation that caues warming whether primarily or secondarily thru reradiation is blocked by CO2 at the climatically important concentrations and how does that compare quantitatively to the energy that is reflected or reradiated from earth. In another words what is the energy balance sheet in the important CO2 absorption range.

    3) My original question was related to temperature changes with changing CO2 concentrations and I am not sure how to take the spectral analysis and determine that.

    4) It appears that my original “experimental” setup question is not valid since it was taking atmospheric gases with 380ppm of CO2 and was not considering the total number of CO2 molecules that would be encountered on a sun to earth trip. However, I am not sure that taking the number of CO2 molecules that would be encountered and stuffing them in a 1.25 or 2.5m tube at 1000 mbar replicates the situation either and as far as I know that is the way the experimental absoption setup is structured.

    Comment by Robert Stenson — 14 Jul 2008 @ 4:39 PM

  194. Robert, did you try the ‘Start Here’ link at the top of the page, and the first link under Science on the right side? You’re asking very basic, frequently answered questions that you may feel better about answering for yourself, since you can read the references and get a better idea of the weight of the evidence.

    This may help. Remember the energy/wavelength relationship.

    Comment by Hank Roberts — 14 Jul 2008 @ 5:04 PM

  195. > opaque

    beware that word, it will confuse you. It absorbs and emits infrared (handing the energy off to surrounding molecules or, if emitted near the top of the atmosphere, having a good chance of losing it into space).

    You’ll find this notional horse reduced to horseburger in several long threads here.

    Comment by Hank Roberts — 14 Jul 2008 @ 5:41 PM

  196. In response to Robert Stenson’s comment 193

    First, I should let you know that I am not a climatologist or even a physics student. Just a coder in an unrelated industry. But I have hung around for a little bit — so I will help where I can.

    Your “questions” 1, 3 and 4 (or 1 for that matter) aren’t exactly questions. However, I will focus on 1 and 2.

    You wrote:

    1) If CO2 is opaque to earthly reradiation then it is also opaque to incident radiation of the same wave number. Analogous somewhat to cloud cover which traps warming radiation at night but provides cooling umbrella coverage during the day.

    True, but largely irrelevant. Carbon dioxide is almost entirely transparent to sunlight — including the infrared. You can see this here:

    Solar Radiation Spectrum

    … and here:

    Atmospheric Transmission

    … and in the first diagram the amount of energy which gets absorbed then re-emitted to space without making it to the surface would be roughly proportional to that small section of yellow directly above “CO2” to the far right. Of course it wouldn’t be exactly equal proportional to it as some energy is getting absorbed by other atmospheric constituents, transmitted via collisions, then radiated by CO2 and other molecules. However, to a first approximation, CO2 is simply transparent to solar radiation and opaque only to certain parts of the earth’s thermal radiation.

    You wrote:

    2) What % of the incident radiation that caues warming whether primarily or secondarily thru reradiation is blocked by CO2 at the climatically important concentrations and how does that compare quantitatively to the energy that is reflected or reradiated from earth. In another words what is the energy balance sheet in the important CO2 absorption range.

    It wouldn’t make sense really to break carbon dioxide out this way. Radiation which gets absorbed by a given carbon dioxide molecule will typically be lost due to collisions with other atmospheric constituents. Above an atmospheric pressure of 20 mb, a molecule will typically suffer a million collisions or more over the half-life of an excited state. However, this is a quantum excitation, and as such excited molecules will have no memory of how long they have been in an excited state, and thus so long as a certain percentage are in an excited state at any given time, a certain percentage will undergo spontaneous decay over any given period of time. This applies as much to water vapour and methane as it does to carbon dioxide — where each atmospheric constituent will be exchanging energy with other atmospheric constituents.

    As such, if you are interested in what is taking place in the atmosphere itself, what you need to do is model it — including this interaction. The following is a fair representation of the results:

    The Energy Balance and Natural Climate Variations

    In net, carbon dioxide is responsible for 1/10 to 1/4 of the greenhouse effect — depending upon how you calculate it, e.g., by removing all other atmospheric constituents and seeing what is left of the greenhouse effect, or by removing it and seeing what of the greenhouse effect is left when you have only the other atmsopheric constituents.

    Comment by Timothy Chase — 14 Jul 2008 @ 6:03 PM

  197. PS to my response to Robert Stenson

    The following might interest you:

    NASA AIRS Mid-Tropospheric (8km) Carbon Dioxide

    The image is carbon dioxide at 8 km. You will notice the plumes rising off the heavily populated east and west coast of the United States. What is being measured is the infrared radiation being absorbed and then reemitted by carbon dioxide at a particular wavelength — 15 μm, I believe. The thicker the carbon dioxide, the more opaque the atmosphere becomes to the infrared radiation in that channel. So in essence, you are seeing CO2’s enhanced greenhouse effect in action when you look at that photo.

    Comment by Timothy Chase — 14 Jul 2008 @ 6:21 PM

  198. re

    I used the term opaque in the sense of no tansmission ie 100% absorption of a specific wavelength as indicated in the spectrum charts on Spectralcalc . Realize that there is reradiation and also that the top of the column will be more likely to radiate into space.

    The original question as to the availability of a CO2 temperature curve and the responses to that request is what has led me off into the deep weeds. I have no desire to review 200 posts. I thought the original question was fairly straight forward and that an answer would be readily forthcoming. Apparently not.

    In any case it is dinner time and we are having horseburger.

    Comment by Robert Stenson — 14 Jul 2008 @ 6:47 PM

  199. Re: Robert #198

    As you go up, you go through the well mixed CO2. At some height, you’re no longer 100% opaque (because the number of CO2 molecules left going up isn’t enough).

    But, if you increase the amount of CO2, the amount you have from any height to the edge of the atmosphere increases too. So the height at which 100% opacity increases.

    Now, when you insulate something like, say a loft or hot water tank, as you add another layer, you increase the insulating properties.

    Does this seem to be familiar?

    Comment by Mark — 15 Jul 2008 @ 1:36 PM

  200. Remember ‘absorbed’ doesn’t mean soaked up and held permanently, taken out of play. That’s one word around which confusion often arises. The infrared from the surface is slowed down by more interactions but eventually does leave the planet.

    Comment by Hank Roberts — 15 Jul 2008 @ 3:03 PM

  201. @4 John Mashey
    I want to flashlight your point
    we are getting to the point where CO2 is simply impairing the air we breathe – a “golden future” for CO2 concentration controlled (and energy consuming) airconditioning – no joke

    -current CO2 level: about 280ppm – this is atmospheric background concentration
    -annual increase 2ppm/year (and this rate is still increasing)
    -so we will reach 500ppm probably much sooner than Yr 2100 (no possible harmful feedbacks assumed)
    the such called Pettenkofer Value calls for 500ppb as target maximum indoor concentration of CO2 in airconditioning
    harmful effects on human health such as headaches and sickness start little above this value at less than 1000ppb

    as urban concentrations are substantially above atmospheric background situation gets worse, there is simply no more of the rare “fresh air” to do airconditioning

    Comment by Andree Henkel — 16 Jul 2008 @ 4:54 PM

  202. Answer to Carbon Emissions May Lie Under the Sea

    By Eli Kintisch
    ScienceNOW Daily News
    14 July 2008

    Scientists may have found a way to chemically lock up a trillion metric tons of carbon dioxide, many times the expected global carbon emissions over the next century. The plan involves injecting the greenhouse gas into huge formations of the porous volcanic rock basalt that lie on the sea floor. The approach would be expensive, however, and a host of questions remain about the technique…

    Now, researchers have detailed the potential for deep-sea basalt formations to provide even more places for humanity to quarantine its carbon waste. A team led by geophysicist David Goldberg of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York, focused on a 70,000-square-kilometer region of the Juan de Fuca plate. This honeycomb of porous basalt lies under more than 200 meters of clay roughly 200 kilometers off the Oregon coast. Analysis of drilling data along with geochemical and seismic studies reveal that this region alone could hold more than 250 billion tons of carbon–more than 120 years worth of U.S. emissions…

    In the group’s scheme, reported today in the Proceedings of the National Academy of Sciences, carbon dioxide would be injected in a liquidlike state into the sea floor, where it would be held below the clay sediments for decades to centuries. There, the carbon would react with the basalt to form chalk, a chemical reaction that laboratory and field tests on terrestrial basalt formations suggest is irreversible…

    Comment by Chuck Booth — 17 Jul 2008 @ 10:06 AM

  203. Interested in comments:

    Comment by Robert Stenson — 18 Jul 2008 @ 12:08 PM

  204. How much is the actual pH changing by? 0.2 units (that’s on a logarithmic scale and implies a very small change in proton concentration doesn’t it? Moreover, if the oceans are absorbing atmospheric CO2 doesn’t that mean there’s going to be less in the atmosphere.

    (Dons asbestos suit for ensuing flame)


    Comment by David Bradley — 18 Jul 2008 @ 2:11 PM

  205. GOAL: No CO2 emissions.

    A fundamental change in our driving habits is now required.

    The Automobile Industry is going to be in the same position as the Airline Industry in the next few months. Unless we get away from gas combustion vehicles, including Hybrids, the automobile industry (as we know it) will die.We need to make drastic moves. America needs to move to ELECTRIC. The vehicles are not as fast, not always as fun to drive, but the move will save Americans money (Billions) and help bring change to our automotive companies. Let’s “Be Green”!!!!!!!!!!!! BG Automotive Group Ltd. has a car that will travel 80-100 miles per charge for $15,995. Finally a car that most Americans can afford. Did you know that 80% of all drivers, drive less than 50 miles per day? This new car will cost an equivalent of $0.20-0.25 cents/gallon (depending on electricity rates in your area). Why send $700 Billion per year to OPEC (now buying up U.S. companies) when we can use this money for our schools, health care, social security for all Americans, etc, etc, etc. We can make the difference if WE change.

    Comment by Barry Bernsten — 18 Jul 2008 @ 4:25 PM

  206. Well, Robert Stenson, the APS has caused the following words to appear as a preface to Monckton’s crap:

    The following article has not undergone any scientific peer review. Its conclusions are in disagreement with the overwhelming opinion of the world scientific community. The Council of the American Physical Society disagrees with this article’s conclusions.

    Elsewhere they point out that this online raglet is not peer-reviewed, is a very minor part of the empire, etc.

    If it were 800 years ago I’d expect to see the editor’s head on a pole by morning.

    Comment by dhogaza — 18 Jul 2008 @ 5:10 PM

  207. Re @204

    A 0.2 drop in pH is actually rather large, a increase of ~58% in [H+]!
    Yes absorption by the oceans does reduce the atmospheric concentration, that’s why the concentration is as low as it is now, unfortunately it’s unable to keep up so they both go up.

    Comment by Phil. Felton — 18 Jul 2008 @ 5:27 PM

  208. > implies a very small change in proton concentration doesn’t it?
    > … (Dons asbestos suit for ensuing flame)

    Your link leads back to your own blog:
    “David Bradley Science Writer” … “ is the website of freelance science writer David Bradley BSc CChem MRSC.” … “SciTech news and views with a healthy dose of skepticism …”

    Posting elementary error, anticipating flames as attention? Eschew!

    Comment by Hank Roberts — 18 Jul 2008 @ 6:14 PM


    Accounting for sea surface temperature, we calculate an average reduction in clear-sky outgoing long-wave radiation for the year 2006 of 0.48plusminus0.14 W m-2 between 45° S and 45° N. This estimate of the clear-sky greenhouse effect from tropospheric ozone provides a critical observational constraint for ozone radiative forcing used in climate model predictions.

    Comment by Hank Roberts — 26 Jul 2008 @ 11:14 AM

  210. > European Monsoon …
    > water vapor …
    > Clausius–Clapeyron

    Compare (I’ve mentioned these elsewhere)

    Excerpts at

    Comment by Hank Roberts — 26 Jul 2008 @ 12:14 PM

  211. Over the last few days I have ventured to RealClimate more regularly than in the past to look at articles on a variety of subjects. One point which shines through many of the articles (and editorial responses to comments) is a presumption that everything was “in balance” before the industrial revolution (for example Mr Gavin’s response to comment 64 in this thread).

    That is a truism if one defines “in balance” as “unaffected by industrialisation”.

    But if one defines “in balance” as “stable” it is palpably untrue. All sorts of changes to the climate have occurred historically, severe heating, mild heating, severe cooling, mild cooling and everything in between. Yet in his response Mr Gavin gives an analogy in which he uses the word “stable”.

    If one takes 1750 as the base year in which everything was exactly as it should be then any effect of industrialisation is necessarily a detriment. But I cannot accept that as a proper starting position because I would have to ask why 1750, why not 1700, or 1650, or 1089 or 1,000BC or any other point in history?

    It will probably not surprise you to hear me say that I approach the AGW debate from the opposite side of the fence from this blog, I hope it will also not surprise you to hear that I make this comment because I want to know whether there is an answer to my concern. Do you start from the position that everything prior to the industrial revolution was “natural” and the industrial activities of one animal are “unnatural”?

    I hope you will not think the way I phrased my question in any way rude, it is not intended to be, it is a genuine question because I have noticed a tendency for articles here to presume that anything humans have done must be a detriment. And that troubles me (just as my opposite presumption might trouble you).

    [Response: I have no idea where you’ve got this idea, but my own science has been completely ecumenical in looking at drivers of climate change. Climate models don’t care why CO2 has risen, or the sun’s forcing has changed, or why volcanoes erupted or ice dam burst or why the orbit wobbles. As to stability, CO2, CH4, N2O were realtively stable for thousands of years prior to the industrial revolution. Since then they have changed faster than at any time for which we have reasonable estimates. You don’t need to have any special attitude to notice things have changed. The same goes for land use change and aerosol emissions. Humans have changed all the rules. None of these elements were absolutely static prior to human interference, and those (much smaller) fluctuations play a role in understanding pre-industrial variability. The attribution problem (did a cause likely give rise to an observed effect) is similar agnostic about whether these things are good or bad or indifferent. It troubles me that this is not obvious to you. – gavin]

    Comment by FB [edit] — 1 Aug 2008 @ 11:16 PM

  212. FB (211)

    It is well known that climate during the last 2,000 years, and the Holocene as a whole has exhbited a fair degree of change(MWP, LIA, Holocene optimum, etc) but in fact all of these events were still very small when compared to other climate changes such as during the glacial times, glacial-to-interglacial transitions, PETM, etc. Some of them may even have been a largely zero-sum game globally, but with larger regional anomalies. Even these very small “bumps” mattered quite a bit for the vikings, the mayans, and others. So you can see why a change that represents as much as going from a full glaciation to our current interglacial can be worrysome!

    It doesn’t look like we have went outside a range of + or – one degree C since the last glaciation, so the current temperature rise is really beginning to separate itself from what nature has been doing. The relative stability of GHG concentrations is also what it is. The fact that ice cores show no CO2 concentration higher in 800,000 years (and probably much longer, but confidence decreases as ice cores go away) and that the rate of GHG change is at least an order of magnitude greater thn glacial-interglacial variability, it doesn’t take a genius to figure out we are changing the atmosphere…and that is changing climate.

    Comment by Chris Colose — 2 Aug 2008 @ 10:00 AM

  213. Thank you Mr Gavin and Mr Colose for your responses.

    I am not, and do not pretend to be, a scientist. I do not have the technical knowledge required to understand every nuance of every article on this or any other blog on this subject. So I have to rely on something I do understand – words.

    The words I questioned were “in balance” and “stable”. Mr Gavin, you were kind enough to explain that you used those words in a specific way, a way that is both logical and, arguably, linguistically correct.

    I had interpreted them more literally. My interpretation led me to suggest that they had been misused. I then asked whether that perceived misuse was caused by a presumption implicit in many of the comments to this thread.

    You explained the meaning you intended to convey and I accept that explanation. There was no need for you to be gratuitously offensive in your final sentence.

    Comment by FB [edit] — 2 Aug 2008 @ 7:39 PM

  214. Re; CH4.
    I am working on a simple model for investors (time challenged, non science, daily money voters who control business) to understand the negative impacts (the cost) of poor investment decisions.
    Profit sensitive investors, fearing money loss, may invest in alternatives, solar power etc. Rather than Co2 intensive production of energy hungry goods.
    Please correct my assumptions.

    a). Total sea ice area in 2007 was 4.13 million km2 and the Greenland land ice was 1.7 million km2,

    b) As the sea ice melts, Daily image update it will reduce by about 2/3’s the total arctic peak summer heat reflection.

    c) The sea ice, formally reflecting 95% of incoming heat, soon melted will absorb 85% of the heat. A 17 fold increase in heat load.

    d) Thus the increase heat load from the sun, over the whole arctic in peak summer is. 2/3 x 17 = 11.33.

    e) There is a -1C buffer between the frozen potential CH4 and it’s emergence.

    f) QUESTION. How many ice-free summers this would take for permafrost to start to melt? (I live in a hot country, Australia)

    g) The pending relese of CH4 equals the effect of man’s Co2 production.

    h) QUESTION How many years will it take for 80% of this effect to engage once it starts to thaw.

    i) The green house effect, from 80% of the available CH4 = 80% more heat load on Greenland.

    j) That although the sea level is rising at 1.7mm per year the acceleration of 0.013mm per year is the danger.

    k) Thus 80% more the green house heat load on Greenland = 1.8 times the annual sea level acceleration.

    l) Multiplying sea level acceleration of 0.013mm by 1.8 = 0.0234mm.

    m) The acceleration is continuous unless stoped. Therefore year 2 sea level acceleration should be multiplied by 1.8 to get the year 3 figure = 0.04212mm, year 3 acceleration by 1.8 = 0.075816mm and so on.

    n) Feed back loops like this multiply each other.

    Hope I have not mangled science.
    I’m in the clear, take a shot.

    [Response: The ice-albedo feedback is reduced through the intervention of clouds – open water is generally more cloudy than ice covered ocean and so the effect on the planetary albedo is less severe than you hypothesise here (still a real factor though!). – gavin]

    Comment by Wally — 8 Aug 2008 @ 1:05 AM

    Sorry this the link to the Daily Image Update.

    Comment by Wally — 8 Aug 2008 @ 1:13 AM

  216. The evidence from experimental observations of CH4 releases from live plants (see sources below) now looks to be fairly compelling, and points to the effect of UV light on plant pectin as a mechanism. This certainly raises some interesting possible connections and feedbacks, i.e.- increasing CO2 = increased vegetative biota = increase in CH4 = enhanced ‘greenhouse’ warming = increase in H2O vapour = further enhancement of ‘greenhouse’ warming = further increases in H2O vapour = further enhancement of ‘greenhouse’ warming, etc., etc.

    Sources: Frank Keppler, John T.G. Hamilton, W. Colin McRoberts, Ivan Vigano, Marc Braß and Thomas Röckmann, “Methoxyl groups of plant pectin as a precursor of atmospheric methane: evidence from deuterium labelling studies, New Phytologist, May 9, 2008”

    Ivan Vigano, Huib van Weelden, Rupert Holzinger, Frank Keppler, Andy McLeod and Thomas Röckmann, “Effect of UV-radiation and temperature on the emission methane from plant biomass and structural components” Biogeosciences in press

    Source: Max Planck Institute for Chemistry)

    Comment by Rando — 8 Aug 2008 @ 10:49 AM

  217. Hi, Please excuse a non climatologist with a simple question. Does increasing CO2 levels have any impact on plant growth, beneficial or otherwise?
    Thank you

    Jeff Temple

    Comment by Jeffrey Temple — 15 Aug 2008 @ 5:25 AM

  218. Jeffrey, Some plants benefit from increased CO2–all other things being equal (poison ivy is one, but some beneficial plants as well). Others do not. The “all other things being equal” however, is critical. CO2 is rarely the limiting factor in plant growth, and if you get more drought or flooding, any benefit is negated.

    Comment by Ray Ladbury — 15 Aug 2008 @ 8:19 AM

  219. Jeffrey, just as an example of why this isn’t simple, putting your question into Scholar just for the year 2008:

    found this among much else:

    “… Elevated CO2 decreased N content and increased C:N ratio of both plant types. ….”

    (excerpt seems impossibl3e due to overprotective spam filter)

    Comment by Hank Roberts — 15 Aug 2008 @ 11:09 AM

  220. Jeffry

    Yes, increases in CO2 will have an effect (even if miniscule) either good or bad on plants.

    The above is an example of why you should be asking a question, not a statement.

    Comment by Mark — 15 Aug 2008 @ 12:11 PM

  221. Hi, Please excuse a non climatologist with a simple question. Does increasing CO2 levels have any impact on plant growth, beneficial or otherwise?
    Thank you
    Jeff Temple

    If all other conditions are right, some plants can leverage increased CO2 levels to achieve greater growth. These conditions include, but are not limited to:
    (a) Temperature. Every plant species has a range of temperature it grows best in. In many cases this range can be quite narrow (for example, the best growth temperature range of corn excludes typical summer daytime temperatures in the North American central plains). The range in which a plant can leverage CO2 for further growth is usually even narrower.
    (b) Water. All plants require water, but too much water can drown plants. Both soil and air moisture must be within a narrow range for a plant to be able to leverage increased CO2 levels.
    (c) Nitrates. Most plants require nitrates for growth. Without sufficient nitrates, plants can’t leverage increased CO2 levels.
    Even if all other conditions are right, the vast majority of plants can only leverage increased CO2 levels only so long as CO2 levels remain with in the narrow range of CO2 levels they adapted to over the course of their evolution. Since CO2 levels were between 160 ppmv and 320 ppmv for about a million years, many plants lack entirely the ability to leverage increased CO2 levels of above 310 ppmv. (Current CO2 level is about 384 ppmv.)

    To bring this into focus, consider the region of North America south of 45N. This region has gotten dryer over the last 50 years, and this is likely due to global warming. It has gotten warmer as well, also due to global warming. It will become still dryer and warmer due to further global warming. But most of the plants in this region are adapated to pre-industrial levels of warmth and moisture. So as global warming causes the region to become dryer and warmer, the warmth and moisture levels will move further away from the optimal warmth and moisture levels needed for leveraging high levels of CO2. As a result, even plants that could theoretically benefit from increased CO2 levels will not, because unsuitably warm and dry weather comes with the increased CO2 levels.
    The end result is that so far only 2 plants, poison ivy and kudzu, have been shown to grow faster in the conditions that global warming is bringing to the areas in which they already grow.

    Imagine a cook who loves salt. Suppose he increases the salt in all of his recipes. Since salt is good, won’t that make all the cook’s recipes better? If you cook, try increasing the salt in a few recipes by 40% or so, and see what happens.

    Comment by llewelly — 15 Aug 2008 @ 2:06 PM

  222. To reduce llewelly’s and others content:

    Plants are not pure carbon.

    Therefore if there’s not enough of the “not carbon” around to be had, more CO2 doesn’t mean a thing.

    And Climate Change has more consequences than just “more CO2”.

    Comment by Mark — 15 Aug 2008 @ 3:22 PM

  223. Guys, I just wanted to congratulate you on this blog, and to thank you for your help. I am a chemical engineer, work in the oil industry (in an oil refinery), but am convinced, like I think the majority of us engineers outside of USA, that we do have global warming, and that it is THE major problem we should be facing. I see letters in our technical journals from people who claim it is an invention by those opposed to the capitalist system, as an example, to which I attempt to respond, and your site is giving me the ammunition I need. Thanks
    Jeff Temple
    PS If you could suggest anyone I could contact for support/assistance in this, I would be grateful

    Comment by Jeffrey Temple — 18 Aug 2008 @ 4:06 AM

  224. Jeff —

    I don’t know how much help they will be, but my climatology pages are here:


    There are eight pages specifically rebutting assorted deniers.

    Comment by Barton Paul Levenson — 18 Aug 2008 @ 8:30 AM

  225. An important point not yet mentioned is that even if increased CO2 does not increase growth in many circumstances, it is likely to reduce transpiration (loss of water from leaves), as the plants need fewer stomata to absorb their CO2, and it is through these that most water loss takes place. This complicates both plant growth responses, if this is water-limited, and feedback effects on atmospheric composition.

    Comment by Nick Gotts — 18 Aug 2008 @ 10:44 AM

  226. Nick, #225.

    True enough. How much of an effect is that is unknown but since they won’t take up more CO2, this isn’t likely to cause more plants to grow worldwide or reduce the CO2 in the atmosphere. It may help in holding off or avoiding minor climate chages causing SOME dessertification, but when you’re in the Sahara, you’re still well limited in water (and just about everything else), so a growing Sahara is still a bad thing.

    Comment by Mark — 18 Aug 2008 @ 12:52 PM

  227. Mark #226,
    Yes, however the claim was made at a talk by Bob Watson, now chief scientist at UK DEFRA (Department for Environment, Food and Rural Affairs), formerly at the World Bank, that this effect does make an important difference in the CO2 level at which (a) the Amazon will die back and (b) crop yields will fall significantly in many areas. Watson is in no way a denialist, but does say, correctly AFAIK, that GCMs’ representation of vegetation dynamics is pretty rudimentary, and of likely land use change in response to climate change, non-existent.

    Comment by Nick Gotts — 18 Aug 2008 @ 5:54 PM

  228. Grim news, and right on the heels of the new permafrost carbon store estimates.

    Exclusive: The methane time bomb
    By Steve Connor, Science Editor
    Tuesday, 23 September 2008

    The first evidence that millions of tons of a greenhouse gas 20 times more potent than carbon dioxide is being released into the atmosphere from beneath the Arctic seabed has been discovered by scientists.

    The Independent has been passed details of preliminary findings suggesting that massive deposits of sub-sea methane are bubbling to the surface as the Arctic region becomes warmer and its ice retreats.

    Underground stores of methane are important because scientists believe their sudden release has in the past been responsible for rapid increases in global temperatures, dramatic changes to the climate, and even the mass extinction of species. Scientists aboard a research ship that has sailed the entire length of Russia’s northern coast have discovered intense concentrations of methane – sometimes at up to 100 times background levels – over several areas covering thousands of square miles of the Siberian continental shelf.

    In the past few days, the researchers have seen areas of sea foaming with gas bubbling up through “methane chimneys” rising from the sea floor. They believe that the sub-sea layer of permafrost, which has acted like a “lid” to prevent the gas from escaping, has melted away to allow methane to rise from underground deposits formed before the last ice age.

    They have warned that this is likely to be linked with the rapid warming that the region has experienced in recent years. …

    Orjan Gustafsson of Stockholm University in Sweden, one of the leaders of the expedition, described the scale of the methane emissions in an email exchange sent from the Russian research ship Jacob Smirnitskyi.

    “We had a hectic finishing of the sampling programme yesterday and this past night,” said Dr Gustafsson. “An extensive area of intense methane release was found. At earlier sites we had found elevated levels of dissolved methane. Yesterday, for the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface. These ‘methane chimneys’ were documented on echo sounder and with seismic [instruments].”

    Comment by Jim Galasyn — 22 Sep 2008 @ 9:33 PM

  229. And more really bad news:

    More methane plumes found in Arctic
    By Tom Peterkin
    Last Updated: 11:01am BST 25/09/2008

    Hundreds more methane plumes have been discovered in the Arctic raising fresh fears that the greenhouse gas is contributing to global warming.

    A British team of scientists found the gas, which is 20 times more potent than carbon dioxide as a greenhouse gas, being released from the seabed to the west of the Norwegian island of Svalbard.

    The findings follow the revelation earlier this week that Russian scientists have discovered vast quantities of methane being released by the melting permafrost from the seabed off Siberia.

    Scientists believe that sudden releases of methane have, in the past, been responsible for increasing global temperature, dramatic climate change and the extinction of species.

    The latest discoveries came from researchers on the British ship the James Clark Ross. They said they had observed around 250 methane plumes in a 30 sq mile area.

    “The discovery of this system is important as its presence provides evidence that methane, which is a greenhouse gas, has been released in this climatically sensitive region since the last Ice Age,” Prof Graham Westbrook of Birmingham University, said.

    Comment by Jim Galasyn — 27 Sep 2008 @ 11:02 AM

  230. Nick #227, “poorly modeled” doesn’t mean “it will counter the model predictions of increased problems with global warming”. It means “it will have an effect on the model predictions, increasing the uncertainty”.


    If you measure by induction the height of the Eiffel tower as 300ft and have an expected error of 50ft, this doesn’t mean the tower is 250-300ft. Errors or uncertainties go up AND down.

    Some effects we can consider but not model mean that water will be less of a problem. Some effects we can consider but not model mean that water will be more limited. They could cancel out. Dessertification is as likely to overwhelm the increased efficiency of plant water use as be overwhelmed by it.

    And since plants are not solid carbon, neither say how the plants are supposed to get the building materials for the other constituents of plant matter.

    E.g. signalling ions of potassium.

    Comment by Mark — 27 Sep 2008 @ 1:46 PM

  231. Expect more waves of starving penguins to wash up on equatorial breaches…

    The krilling fields: study fears catastrophe in Antarctic food chain
    Andrew Darby, Hobart
    October 14, 2008

    THE first evidence suggests that a predicted rise of atmospheric carbon dioxide will wreak havoc on krill, the tiny crustacean at the heart of the Antarctic food web.

    Although public sympathy for the crustacean is undetectable, polar life such as penguins, seals and whales would wither without it.

    Captive-bred krill at the Australian Antarctic Division developed deformities and lost energy when they were exposed to the greenhouse gas at levels predicted globally for the year 2100.

    The damage meant that the krill were unlikely ever to breed, a University of Tasmania investigator, Lilli Hale, said yesterday.

    Polar life, from tiny seabirds through penguins and seals to whales, depend for food on Antarctic krill, Euphasia superba.

    A loss of krill suggested there would be a catastrophic impact on these other species, Ms Hale said.

    The level of atmospheric carbon dioxide now stands at 384 parts per million (up 100 ppm since 1832), according to the Intergovernmental Panel on Climate Change. At a worst case it could reach around 900 ppm in 2100, IPCC models show.

    Carbon dioxide is absorbed by the sea most easily in the colder Southern Ocean, which becomes more acidic, interfering with the formation of calcium carbonate.

    Organisms, including krill, rely on calcium for the formation of their shells.

    In Ms Hale’s study, the division’s world-first krill breeding research facility near Hobart was used to hatch 200 larvae in jars with an artificial atmospheric carbon dioxide level increased to the worst-case 2100 level. “Their anatomy wasn’t quite right,” Ms Hale said. “They were a bit deformed, and they were listless. It’s unlikely they would have survived through to adulthood.”

    When carbon dioxide levels were raised even further, fertilised eggs did not hatch at all. …

    Comment by Jim Galasyn — 14 Oct 2008 @ 9:34 PM

  232. NF3 has also been proposed as an oxidizer for liquid propellant rockets. It’s much easier to handle than liquid fluorine.

    Rocket engineers also looked into tetrafluorohydrazine (N2F4), which gives even better performance. Perhaps the industries that use NF3 should switch to this, if (as I strongly suspect) it has a short atmospheric lifetime.

    Comment by Paul F. Dietz — 5 Nov 2008 @ 2:12 PM

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