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  1. Nice!

    But following up on Michael the Syrian, do green grapes make sour grape wine? :-)

    Comment by David B. Benson — 2 Mar 2008 @ 5:47 PM

  2. Makes you realize how devastating such an eruption would be today.

    Comment by Alex Tolley — 2 Mar 2008 @ 5:50 PM

  3. I am sure everyone has read Sir James Lovelock’s recent interview in the March 1 edition of the Guardian in the UK, written by Decca Aitkenhead, but if somehow you missed it, it is a must-read and also NSFW:

    Comment by Danny Bloom — 2 Mar 2008 @ 6:08 PM

  4. Looking at the references which appeared along with the report in NATURE about the ice cap over Baffin Island, I noticed one about the 1453 CE event.

    Gao, C., A. Robock, S. Self, J. B. Witter, J. P. Steffenson, H. B. Clausen, M.-L. Siggaard-Andersen, S. Johnsen, P. A. Mayewski, and C. Ammann (2006), The 1452 or 1453 A.D. Kuwae eruption signal derived from multiple ice core records: Greatest volcanic sulfate event of the past 700 years, J. Geophys. Res., 111, D12107,

    That event was quite large and also appeared to have resulted in a rather large climate impact. The historical information from China suggests major crop failures and famine. One of the interesting aspects of this report was the differences in dates for an event which might be considered well dated in historical records, even though there were no reports from the actual location.

    I’ve also seen references to an event dated at 1259 CE, for which, last I heard, the location had not been determined. Apparently, the Baffin Island data places this event at a somewhat later date.

    Comment by Eric Swanson — 2 Mar 2008 @ 6:59 PM

  5. This event is well known from the long bristlecone record as well. For those interested in a good treatment of volcanism over the last 50 centuries should look to a paper by Salzer and Hughes last year in QR. Here.

    Here is what they have to say on the subject:

    There has been some suggestion that the AD 536 dust-veil event might be the result of a comet impact, however, rather than a volcano (Baillie, 1994). The AD 536–547 environmental disruption has been observed in multiple proxies and has been characterized as a widespread catastrophic event (D’Arrigo et al., 2001).

    The improved dating of the ice core records via the layers is crucial for zeroing in on these large global events. I’m glad to see that this is moving forward.

    Comment by skepticism_is_a_virtue — 2 Mar 2008 @ 7:59 PM

  6. Beautiful. I was kind of rooting for the comet (I’m a sucker for astrophysical causes) but this is just as good. Any idea how we go about searching for the culprit volcano?

    Comment by Jim Galasyn — 2 Mar 2008 @ 8:13 PM

  7. The report on the Baffin Island ice cap wasn’t in NATURE, as I mentioned above, but in the GRL. Here’s the reference:

    Anderson, R. K., G. H. Miller, J. P. Briner, N. A. Lifton, and S. B. DeVogel (2008), A millennial perspective on Arctic warming from 14C in quartz and plants emerging from beneath ice caps, Geophys. Res. Lett., 35, L01502,

    Comment by Eric Swanson — 2 Mar 2008 @ 8:43 PM

  8. And so another one bites the dust. :) IIRC the cooling related to this event has been used as the main benchmark separating the “Roman Warm Period” from the later “Medieval Warm Period,” which in the absence of enough data on vulcanism were imputed largely to inferred variations in solar irradiance along with various other minor climate regimes of the last few thousand years.

    What’s interesting is how little attention this recent shift in the science has gotten (to the point that I for one had more or less missed it, although it was right there in the AR4 WG1 report).

    Comment by Steve Bloom — 2 Mar 2008 @ 8:49 PM

  9. Anyone interested in looking at a list of major eruptions over the past 12,000 years should look here:

    Comment by Ian Forrester — 2 Mar 2008 @ 9:30 PM

  10. I would not rely on my memory, but there are 2 events that may be related. One is an asteroid impact that wiped out a city in the ancient world and the other was a volcano on an island in the eastern Mediterranean. The asteroid was in something by John Lewis, maybe his book, “Mining the Sky,” but I’m not sure. I hope this helps your search.

    Comment by Edward Greisch — 2 Mar 2008 @ 10:16 PM

  11. There is an excellent book by historian David Keys, who covers the global consequences of this volcanic event. It is called “Catastrophe: An Investigation into the Origins of the Modern World”. (Published in 2000.)

    Comment by Anders Lundqvist — 3 Mar 2008 @ 2:33 AM

  12. Re 3, Jim certainly deserves a knighthood, but he doesn’t have one yet!

    John Gribbin

    Comment by John Gribbin — 3 Mar 2008 @ 5:11 AM

  13. Re #3, Ah what a nice picture he paints Mr Lovelock but his statements are starting to sound like the alarm bells that James Hansen is sounding. Mr Hansen as director of GISS (realclimates boss I believe)has recently in january 2008 started issuing warnings of safe limits for CO2 of 350 ppmv which is of course impossible to achieve in the present global economic economy, well unless we can mobilise ourselves to a level of magnitude that dwarves the second world war mobilisation. Oil copanies are not going to stop providing and producing oil, nor are coal companies coal or gas copanies gas but strategic targets by governments could be set but not 120% of CO2 reductions by 2020/2030 as is being requested here.

    Hansen states that new paleoclimatic evidence leads him to believe that this is teh case and that 450 ppmv is an absolute upper limit but one that coms with enourmous consequences such as desertification and areas of uninhabiatability across the globe. Maybe Lovelock is right, be prepared to adapt for technology can be devised to do that rather than mitigate CO2 emissions as we can start from a clean slate. Build nuclear power plants to provide the adaptation energy to power the technology. Huge swathes of lans will be under water and food will probably need to be synthesized within 20 years.

    It is all very apocolyptic and very doomey but as it comes from these two then I would suggest that we had better start listening. Science is very conservative and very skeptical and when it comes to AGW, it may not have shouted loud enough long enough.

    [Response: FYI. Hansen has no connection whatsoever with RC. – gavin]

    Comment by Pete Best — 3 Mar 2008 @ 5:41 AM

  14. What’s the interpretation for the bigger peak (A.D. 529)?

    Comment by Martin — 3 Mar 2008 @ 7:22 AM

  15. So without derailing the conversation on the actual topic, what is the prevailing opinion on Lovelock and his current thinking? I’m asking from my position as a layman on the topic of Global Warming. Is he out there? Is he the extreme opinion? Or is there some truth to what he says? This is the second article I have read about Lovelock in the last couple of months, and just wondering how much of what he says is informed science, and how much is not?

    Comment by jbroon — 3 Mar 2008 @ 8:20 AM

  16. Sigh! There’s still the odd skeptic in the woodpile I see. I’m afraid you lot are becomming increasingly ‘ODDer’ and rarefied…reason…The OVERWHELMING information that ‘PROVES’ ACC is happening. These are the world’s top, most repected scientists, each one experts and masters in their respective fields..each one has spent the best part of thier lives in the quest to understand how their chosen aspects of science works and interrelates to the other earth sciences. These silly little sceptics armed with all their weath of imaginary intelligence and doctorates seem to think that ALL these brilliant and searching minds have it ALL wrong..why dont you take a long hard look in a mirror so you can see how stupid and ridiculous you sound. I bet you dont work in highrise buildings either because some ‘expert’ of an architect built them and so with just the right wind speed and precipitation and relative humidity etc. they could suddenly come crashing down. So stop advertising your abject ignorance and actually listen to what the IPCC is telling you and accept the consequence that raising the most important greenhouse gas by 30%+ in the relative blink of an eye is having on our climate.

    Comment by Lawrence Coleman — 3 Mar 2008 @ 8:36 AM

  17. Without commenting on whether Lovelock’s assessment is correct in its various aspects, I am most struck by the logical inconsistency in his message.

    On the one hand he states, “Global warming has passed the tipping point, and catastrophe is unstoppable.” As a consequence of that assessment he dismisses ideas such as renewable energy, recycling, avoiding flying etc. as pointless.

    And yet, he strongly advocates using nuclear power as something that “can solve our energy problem.”

    Well, why is saving CO2 emissions by using nuclear power important, but saving emissions by other methods a waste of time because it is already too late?

    Such an inconsistency, it seems to me, renders his message incoherent.

    PS. Sorry this is off topic. I did enjoy the 536AD tale, but then got distracted by #3!

    Comment by Slioch — 3 Mar 2008 @ 11:41 AM

  18. Lovelock is a bit of an eccentric crank.

    Six and a half billion people on the planet, soon to be nine or ten billion people on the planet, and he is suggesting that these people shouldn’t bother to recycle or plant trees. Not very credible.

    He’s also suggesting that technological nations should give every third world nation and jungle militia’s access to nuclear technology.

    The gentleman had some great ideas, but the warranty has expired.

    Comment by Thomas Lee Elifritz — 3 Mar 2008 @ 11:47 AM

  19. Lawrence,

    There is nothing we can do! If I change all my light bulbs to low energy ones, will that save the world? If I sell my car and get a bicycle will that do? What if you join me, can we save the world together? I think not. Even if all the sensible people in the world stopped wasting energy, there is still another 90% who would go on driving the SUVs, jet skis, and monster trucks. Apart from macho men, how are the few remaining housewives going to get the food to feed their families? They need their car to take them to the supermarket to fetch the groceries.

    Our only hope is that the next president of the USA will organise the world to take action. But any presidential candidate who advocates the actions needed will never get elected.

    Let’s face it, GWB admitted that the USA is hooked on oil. Our only hope is if we (USA, UK, Europe, China, India, etc.) go cold turkey. Can you see that? Can you see any of the main three (good) candiates advocating that. Can you see them implementing it?

    Lovelock’s advice was to enjoy yourself while you can. Why should it be that those who are destroying the world should be the ones to have thh fun?

    Cheers, Alastair.

    Comment by Abbe Mac — 3 Mar 2008 @ 12:04 PM

  20. Just thinking a bit more about the Baillie hypothesis, and also Jim G’s comment (#6) above, it doesn’t follow that we are looking for one event or type of causation, nor should we assume that discovery of a volcanic influence disproves a cometry cause, since the latter would not necessarily leave a crater or impact zone. For example, one might consider a combination of vulcanicity and a major cometry burst, somewhere in the upper atmosphere, the latter leaving a large quantity of dust or volatiles (maybe including SO2?) to be circulated in the stratosphere.

    Regarding Edward G’s comment (#10 above), Edward, are you thinking of the eruption of Thera (now called Santorini) when you refer to an island in the Mediterranean? If so, I think the date for that has been fixed pretty well at about 1550 B.C. or thereabouts, so the dates do not match for this as a cause (1550 BC vs 536 AD). Do you know of any other Med. eruptions around 540 AD, as there are a number of other possible culprits, otherwise we shall probably have to look farther afield (e.g. Krakatoa, or maybe something in the southern hemisphere?).

    Comment by Nick O. — 3 Mar 2008 @ 12:08 PM

  21. For a broad overview of reconstructing past climates, including creating an accurate chronology and how the different proxies are combined with models, see:
    Walker M and Lowe J (2007) Quaternary science 2007: a 50-year retrospective. Journal of the Geological Society, London, vol 164, pp. 1073-1092.

    We are nearly at the stage of having annual climate and environmental data over the last few thousand years and extending into prehistory. Events such as volcanic explosions are very useful for correlating different climate proxies. Written records are an under-exploited source of past climate information, in my opinion.

    To jbroon: Lovelock emphasises the worst possible outcome. The main reason for doubting more mild forecasts of climate change is that they fail to adequately consider feedback mechanisms (tipping points). A recent assessment of the dangers of specific tipping elements in the climate system is:
    T. M. Lenton, H. Held, E. Kriegler, J. W. Hall, W. Lucht, S.
    Rahmstorf, H. J. Schellnhuber (2007) Tipping elements in the earth system. ICESM Abstracts, Vol. 1, ICESM2007-A-00032.
    (Tim Lenton has worked with James Lovelock and Stefan Rahmstorf is a contributor to a certain climate blog.)

    Lovelock’s worst case scenario is definitely possible, but by no means certain, and while he may turn out to be right about the broad outcome, I for one do not agree with his views on energy and agriculture. For instance, nuclear power will obviously be part of the world’s future energy mix, but the expansion required to cover all our future needs is unlikely and risky in its own right, whatever the drawbacks of lifestyle change and renewable energy. It would also probably be fair to say that he enjoys scaring the cccp out of hapless interviewers, and it is easy to forget how widespread is the requirement on paid scientists to speak in measured terms or risk their job. James Hansen, because of his senior scientific post, can speak out while only running the risk of contradicting political bosses (who can’t argue with him on the science) as opposed to scientific superiors who might take a different view from him and cut off his grant money.

    In the UK, politicians are examining whether to increase the 2050 emissions cut target from 60% to 80-90%, so the Hansen view of the science is filtering through.

    Comment by Ed Sears — 3 Mar 2008 @ 12:38 PM

  22. #13 Pete Best, having read much of Hansen’s published work and all of Lovelock’s Revenge of Gaia, I really don’t see Hansen and Lovelock’s alarm as being about the same consequences. Lovelock is much more pessimistic.

    #17 Slioch, Lovelock’s fear now is that what is coming will be so massive we (in the UK) must be as self-sufficient as possible. He’s quite clear about his reasons in the article, and if he’s right about what’s coming it makes strategic sense.

    I don’t know what to make of Lovelock, I think he’s probably overestimated the impact. But his top down arguments appeal to the electronics graduate in me, my fear is “For want of a nail” type cascades. I hope people in 2100 will be able to look back and say “It could have been worse, just look at 536AD.”

    Thanks for another interesting essay Gavin.

    Comment by CobblyWorlds — 3 Mar 2008 @ 1:36 PM

  23. Thanks to Ian for the great link in 9.

    These look like the best candidates, judging only on proximity to 536AD:

    PAGO – New Britain, C 530 AD ± 150 years, VEI 5
    VESUVIUS – Italy, 536 AD, VEI 4?
    RABAUL New Britain, C 540 AD ± 100 years, VEI 6

    Comment by Jim Galasyn — 3 Mar 2008 @ 1:48 PM

  24. On the subject of Lovelock’s interview, a couple of thoughts come to mind. One, a person should have more modesty than to dismiss the thoughts of someone with one of the world’s greatest minds. Second, one shouldn’t expect too much consistency in a topic as complex as climate change.

    Besides, Lovelock doesn’t argue that renewables wouldn’t be beneficial, rather that they’re not practical because of the enormous manufacturing and construction effort required for them, compared to their output. Elsewhere he has pointed out that their part-time nature requires that backup energy be available. So one supposes that if the backup energy were environmentally sound there’d be no point in having the renewables.

    My own view is different, but I’d hesitate to disagree with Dr. Lovelock. I think it will take a mix of renewables and nuclear to minimize the problem.

    Comment by Red Craig — 3 Mar 2008 @ 2:01 PM

  25. From

    suggested as a reference by Ian Forrester in comment #9,

    here are some suspects:

    PAGO New Britain C 530 AD ± 150 years 5
    VESUVIUS Italy 536 AD 4?
    RABAUL New Britain C 540 AD ± 100 years 6

    But even Rabaul has only a VEI of 6 and the dating is uncorrected radiocarbon (as is that for Pago).

    Comment by David B. Benson — 3 Mar 2008 @ 2:05 PM

  26. More reading:

    Supporting evidence from the EPICA Dronning Maud Land ice core for atmospheric CO2 changes during the past millennium

    Tellus B, Volume 57 Issue 1 Page 51-57, February 2005

    Click the link there to follow forward:
    Search ISI for citing articles (12 or more)

    Among those citing articles, this is interesting:

    The early anthropogenic hypothesis: Challenges and responses
    Ruddiman, William F.
    Source: REVIEWS OF GEOPHYSICS 45 (3): Art. No. RG4001 OCT 31 2007 Document Type: Review

    Abstract: Ruddiman ( 2003) proposed that late Holocene anthropogenic intervention caused CH4 and CO2 increases that kept climate from cooling and that preindustrial pandemics caused CO2 decreases and a small cooling. Every aspect of this early anthropogenic hypothesis has been challenged: the timescale, the issue of stage 11 as a better analog, the ability of human activities to account for the gas anomalies, and the impact of the pandemics. This review finds that the late Holocene gas trends are anomalous in all ice timescales; greenhouse gases decreased during the closest stage 11 insolation analog; disproportionate biomass burning and rice irrigation can explain the methane anomaly; and pandemics explain half of the CO2 decrease since 1000 years ago. Only similar to 25% of the CO2 anomaly can, however, be explained by carbon from early deforestation. The remainder must have come from climate system feedbacks, including a Holocene ocean that remained anomalously warm because of anthropogenic intervention.

    Comment by Hank Roberts — 3 Mar 2008 @ 2:18 PM

  27. In the late 1970s and early 1980s, there were many speculations that a full-scale nuclear exchange would create a “nuclear winter” – but the science at the time relied on simple models, and aerosol effects were poorly understood, so there were many unanswered questions. For a modern take on the question (which is similar to a volcanic eruption in some respects), see:

    Robock et. al, Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences, JGR 2007

    The modern update isn’t any more encouraging, but it does mean that the effects of aerosols, particulates like dust and smoke, are now far better understood, giving more robustness to climate model predictions.

    The Pinatubo eruption of June 1991 also provided a rare modern-day test case for climate models. See:

    Global Cooling After the Eruption of Mount Pinatubo: A Test of Climate Feedback by Water Vapor, Soden et. al Science 2002

    Potential climate impact of Mount Pinatubo eruption, Hansen et. al GRL 1992

    Radiative Climate Forcing by the Mount Pinatubo Eruption, Minnis et al Science 1993

    So, why does this slightly obscure topic matter? Quote:

    “If you plug in volcanic eruptions, El Niños, solar variations and other natural causes and try to simulate past climate changes, you can do a pretty good job of modeling climate change until the end of the 19th Century,” the researcher said.

    After that period, he said, natural causes alone don’t account for the amount of warming, about 0.6 degrees Celsius (1.1 degrees Fahrenheit), that has taken place in the last century.

    “But when you factor in Pinatubo and other eruptions along with anthropogenic (human-caused) emissions,” said the scientist, “it accounts for the observed record of climate change for the past century, including the overall warming and episodic cooling, and validates the climate models.”

    Comment by Ike Solem — 3 Mar 2008 @ 2:23 PM

  28. Abbe Mac
    Going fossil fuel cold turkey would mean economic suicide.
    If you want to see misery, death and destruction, then implement
    the nonsense proposed by Gore and Co.
    Fortunatelly, it won’t be allowed to go that far. When people start paying through the nose for this hysteria, they’ll use their votes run ya’ll out of town.
    Already with the high energy and food prices, we’re beginning to see social instability.

    Comment by Pierre Gosselin — 3 Mar 2008 @ 2:28 PM

  29. @Solem
    How do you explain Jan 08’s massive global temperature drop?

    Comment by Pierre Gosselin — 3 Mar 2008 @ 2:30 PM

  30. Pierre Gosselin Says:

    “How do you explain Jan 08’s massive global temperature drop?”

    Pierre, how do you explain massive global temerature raise in ’98?

    Comment by Petro — 3 Mar 2008 @ 2:44 PM

  31. Pierre Gossilin (29) — You mean, back to average? Here are some links to proper analyses of recent temperatures:

    Comment by David B. Benson — 3 Mar 2008 @ 2:54 PM

  32. Re #12: Oil copanies are not going to stop providing and producing oil, nor are coal companies coal or gas copanies gas but strategic targets by governments could be set but not 120% of CO2 reductions by 2020/2030 as is being requested here.

    Oil companies have an absolute financial incentive to continue driving oil ever further into scarcity. With today’s new record of $104/bbl, once can see the scarce oil is a lot more valuable than if we reduced demand by conservation.

    Re: #28: Going fossil fuel cold turkey would mean economic suicide.
    If you want to see misery, death and destruction, then implement
    the nonsense proposed by Gore and Co.

    I’m already personally “carbon positive” (or whatever is better than “carbon neutral” and I’m not going broke. The people who go broke are going to be the ones who, like my DI1K (double income, one kid ;) ) friends who likely gross north of $150K and “can’t afford” a hybrid.

    Economic suicide is what people do when they persist in buying new cars that run on gasoline. Which the car companies would love people to do since we’re going to be forced to by yet another brand new car when our gasoline bill exceeds our new car payment.

    ObTopic: Fascinating stuff. I remember when Pinatubo blew up and the sky slowly changed from infrequent red sunsets to the far more common just about every day sort of red sunsets. I’ve been waiting ever since for “Red sky in morning, sailors take warning. Red sky at night, sailors delight” to have some manner of predictive ability.

    Comment by FurryCatHerder — 3 Mar 2008 @ 3:09 PM

  33. #28 I dont think cold turkey on fossil fuel is even remotely feasible within a 30-50 year span, but Gore wasnt advocating that – rather a whole series of small measures which together bring down CO2. You can use your votes to live in a pretend-world where global warming isnt happening but that wont stop temperatures rising. Can we put your country down for say 2 million refugees? You think anti-CO2 measures will cause instability but that nothing on what climate change will bring. Oh, and every natural cycle is still working bringing ups and downs with it. Will you scream global warming has stopped with cycle or look at the long term trend? Note also the prediction that 2007, 2008 would be steady (and thats without the La Nina) but 2009 would see business as usual.

    Comment by Phil Scadden — 3 Mar 2008 @ 3:15 PM

  34. Re Pierre’s question in 29:

    How do you explain last night’s massive global temperature drop?

    Comment by Jim Galasyn — 3 Mar 2008 @ 3:16 PM

  35. How do you explain Jan 08’s massive global temperature drop?

    Answer – Weather

    The one degree F in global heating is not going to eliminate winters, for cying out loud.

    Comment by d. beck — 3 Mar 2008 @ 4:09 PM

  36. RE: comment #25 (quoted below):

    Huyanaputina in 1600 also had a VEI of 6, so Rabaul would seem to be an excellent suspect (caldera-former). Vesuvius seems unlikely.

    “suggested as a reference by Ian Forrester in comment #9,

    here are some suspects:

    PAGO New Britain C 530 AD ± 150 years 5
    VESUVIUS Italy 536 AD 4?
    RABAUL New Britain C 540 AD ± 100 years 6

    But even Rabaul has only a VEI of 6 and the dating is uncorrected radiocarbon (as is that for Pago).”

    Comment by Nigel — 3 Mar 2008 @ 4:28 PM

  37. FurryCatHerder (32) — Biopact

    calls what you have accomplished carbon-negative.


    Comment by David B. Benson — 3 Mar 2008 @ 4:31 PM

  38. Another point in Rabaul’s favor is that the caldera formed in the 540 +/- 100 event was flooded by the sea (this contributes greatly to aerosols):

    Note that the caldera encompasses the whole bay–the more obvious volcanoes are smaller vents around its periphery. These have been known to erupt simultaneously in recent years–exciting place to live!

    Comment by Nigel — 3 Mar 2008 @ 4:51 PM

  39. I have heard of the Krakatoa theory accounting for the 536 eruption. In his book “Krakatoa”, Simon Winchester used anecdotal evidence to claim that there was an eruption of the devilish island that helped the peasants of Sumatra overthrow their abusive rulers. Winchester then used the 1883 to help account for the overthrow of the Dutch in Indonesia and the rise of Islam in the region to its current. Its a very interesting read if you are not familiar with geology.

    Comment by Maxwell — 3 Mar 2008 @ 5:10 PM

  40. Great post.

    RE Lovelock & wind power. He lives out in the countryside, where they are proposing to build massive wind farms, which would destroy the view & kill birds. I think Robert Kennedy Jr (with Natural Resource Defense Council) is also opposed to wind for the same reasons.

    As one on 100% wind I do feel a bit guilty that birds get killed and my power source may be ruining someone’s country view out in West Texas.

    Maybe over time inventors will come up with wind and solar solutions that are smaller and less obstructing, ones households could employ to generate all their electrical needs (which could be reduced through efficiency/conservation measures, green building, passive solar, etc), and also use that electricity for recharging their EV or compressed air EV, so they could drive on the wind or the sun. That would mean living off-the-grid, freedom from the matrix.

    Oh yes, I forgot, we’re already there. The tech is available.

    Now, if we could just get the government to cut back on those huge subsidies and tax breaks to oil and coal….which we pay for on April 15th, regardless of whether we’re off the grid and driving on wind/solar power.

    Comment by Lynn Vincentnathan — 3 Mar 2008 @ 6:02 PM

  41. It appears that the weather events were world-wide:

    and that the hypothesis of Rabaul was already made in 1984.

    (The problem with Krakatoa is that there is no definitive evidence of a super-eruption in the years in question.)

    Comment by David B. Benson — 3 Mar 2008 @ 6:10 PM

  42. Re #14

    The bigger peak in 529 could be the one corroborated by the DML cores. 529 is within the range 542 +/- 17.

    Comment by Andy Simpson — 3 Mar 2008 @ 7:26 PM

  43. #24: Linus Pauling was one of the 20th century’s finest. Two Nobels in his own right (granted one not for science), and a whisker away from another with the DNA structure. Yet in later life he was plain wrong about vitamin C – to the point of nutty – though his standing meant that many assumed otherwise (some still do!).

    Lovelock is wrong about nuclear and wrong about renewables. He misses the power of distributed generation. Photovoltaics on every roof and a grid extending across time zones are all that’s needed. Do-able now and affordable now. Four decades (to 2050) will be more than enough to get it done.

    Comment by GlenFergus — 3 Mar 2008 @ 7:29 PM

  44. Lynn Vincentnathan (40) — … my power source may be ruining someone’s country view out in West Texas. I’m sure that out there they think the view improved. :-)

    Regarding bird strikes, I am under the impression that this is not (much of) a problem for the newer, slower turning, windmills.

    Comment by David B. Benson — 3 Mar 2008 @ 7:50 PM

  45. I’ve read the book Catastrophe by David Keys. The central theme is the 535-536 AD event was a volcanic eruption. Keys’ conclusion, based partly on local evidence, is that the culprit was Krakatua, and the 535-536AD eruption was more severe than the 18th century one.

    Re. 3. Lovelock is a defeatist, although he claims to be an optimist. He does tend to blow his own trumpet – he attributes himself more prescience than I think is warrented. And it’s all very well for him to “Enjoy life while [he] can”. He’s 88.

    On the other hand, I’m a pessimist. I doubt we’ll adequately deal with global warming before it starts to hurt, at which point more and greater pain is inevitable. In this case the cost will be huge, but saying we’ll be reduced to a single “breeding pair in the arctic” is delusional.

    Yet I believe that it is possible for us to avoid the worst, although some effects of climate change are now inevitable. I just don’t believe we’ll do it – too many vested interests. However, I’m determined to do my bit to help minimise the damage.

    Re 9 The list of major eruptions in the alst 12,000 years is clearly incomplete. Half occur after 1000AD and 25% after 1800AD. It’s very easy to image a few VEI 7s (i.e. Tambora-sized eruptions) being missed.

    Comment by Bruce Tabor — 3 Mar 2008 @ 8:07 PM

  46. Pierre Gosselin claims that trying to address global warming (GW) can only be done cold turkey? Get real. NO one, and I mean NO major scientist or Government or major agency has ever claimed that we must go cold turkey on all oil/coal power sources to solve GW. So what is the person’s point besides stupid alarmism to attack other peoples ideas? Yes, there is a range of options that people propose, some more aggressive then others but none even remotely that extreme but to make a false straw man to attack GW and other people’s thoughtful idea’s is a typical, immature response to an otherwise intelligent forum.

    Comment by DBrown — 3 Mar 2008 @ 8:45 PM

  47. RE: Volcano Tours

    For all the latest info on volcanos and tours to them: GO: Lots of useful info here. If you happen to have a few grand in spare change, a tour to a volcano would be a really nice alternative to the standard vacation to tropical resorts. Be prepared to rough it, however. The tours go out to the volcano where you camp out for 4-5 days while you explore the volcano and hike around the area.

    What’s really interesting is the list of active volcanos. Pretty scary since any one of them could undergo a major eruption, like The Son of Krakatoa.

    Comment by Harold Pierce Jr — 3 Mar 2008 @ 9:39 PM

  48. Re: Abbe’s true what Pierre says that suddenly going cold turkey will be economic suicide. We cant go cold turkey anyway..the infrastructure just isn’t there and wont be for decades. We can’t even decide upon a tough carbon trading scheme. We are still stuck in the committe level of progress. Logically I share your sentiments but I also realise that I must do my level best as well- I’ve got a 2 year old son who deserves a decent future. Either way our ship has reached the other reaches of one hell of a hurricane..a ‘perfect storm’ whether we come out the other side or not depends on our united stewardship..not many disparate captains pulling the ship in all directions. We have to realise also that whatever we do to mitigate CC we will still get sucked helplessly towards the eye of the’s going to get progressively worse and worse for a hundred years or more and the oceans for another thousand plus.. What we do need ‘NOW’ is definite emmission goals set by every country. I believe the world bank will have to compensate poorer countries to meet their short/medium and long term goals. We must also allow flexibily in those goals as more up to date reports in the future from the IPCC and other bodies saying we must do more to but the brakes on..this must be heeded by world govs to bring forward their goals…there is going to be an enormous economic cost..not too many are denying that..but what’s the point of maintaining a robust economy if the world’s dying?

    Comment by Lawrence Coleman — 3 Mar 2008 @ 10:20 PM

  49. 13: I personally thought Lovelocks predictions 2020 and 2040 to be beyond the pale doomster stuff. I think I understand Hansen, and I don’t think he says that post tipping point feedbacks would be anything near that rapid. Hansen is more concerned with what will happen in say 50 to a few hundred years.

    I don’t think we are looking for a super-eruption. My understanding of the term is that supereruptions are Yellowstone or Toba sized events involving roughly 1000 KM**3 magma. The world probably only sees a supereruption about once per hundred thousand years. 536, is probably much less significant.

    Comment by Thomas — 3 Mar 2008 @ 10:51 PM

  50. Why does the presence of sulfates rule out impacts (iceballs or hardballs)? I mean I understand reasonably well enough that volcanic eruptions produce sulfur compounds that would show up in the ice cores. But why couldn’t an impact produce the same compounds? Massive fires of either peat or forests resulting from an impact would seem to create similar releases of sulfur. From the massive fires over Indonesia recently – we saw the impact of that on the atmosphere.

    I’m not questioning the conclusion – purely interest on my part. I’ve always had a passing interest in the time period – from Arthurian legends, collapse of civilization, Plague of Justinian, etc. And so whether or not the critical event of 535-6 was a comet or volcano would seem interesting – I’ve always been fond of the theory that a comet struck Western Europe.

    Comment by Robin Johnson — 3 Mar 2008 @ 11:45 PM

  51. Robin, I think — I’m not an expert, I just did a quick browse of what Google Scholar offers — that the distinction is based on the quantity of sulfur. I can’t think of any source that would produce a really large amount from a meteor or from a biological source hit by one.

    Just a quick look found me this quantity estimate for example:

    “During the steady-state period of activity of La Soufriere Volcano in 1979, the mass emissions of sulfur dioxide into the troposphere amounted to a mean value of 339 ± 126 metric tons per day. This value is similar to the sulfur dioxide emissions of other Central American volcanoes but less than those measured at Mount Etna, an exceptionally strong volcanic source of sulfur dioxide.”

    I don’t know how many days those volcanos were in steady-state activity, but the total adds up fast.

    Comment by Hank Roberts — 4 Mar 2008 @ 12:43 AM

  52. RE#48 “We cant go cold turkey anyway..the infrastructure just isn’t there and wont be for decades.”

    “Car-Free, Solar City in Gulf Could Set a New Standard for Green Design.”

    “Renewable Energy: Desert Dreams”

    Thus, the time required to transition to a renewable energy basis could be measured in years rather than decades – it’s all a matter of how many resources are devoted to it.

    Comment by Ike Solem — 4 Mar 2008 @ 1:09 AM

  53. #29 # Pierre Gosselin asked

    “How do you explain Jan 08’s massive global temperature drop?”

    Firstly, remember that January 2007 was the warmest January on record (anomaly 0.87C NASA GISS), so that obviously amplifies the current fall. (Jan 2008 0.12C)

    Secondly, there is presently a strong La Nina (negative temperature anomaly) in the Pacific (caused by an upwelling of colder water from the depths). The cooler waters of the Pacific absorb large amounts of heat from the atmosphere and are probably (partly) responsible for the cold events witnessed recently in many parts of the world.
    La Nina events are the flip side of El Nino: during the latter the Pacific surface waters become abnormally warm. An El Nino event was responsible for the positive spike in global temperatures in 1998, and we appear at present to be getting a negative spike from this La Nina in 2008.

    Here are graphs of sea surface temperatures in the Pacific for Feb. 7th 2007 and Feb. 8th 2008. The lower graph in each set is the interesting one since it shows the anomaly relative to 1971-2000:

    Feb. 7th 2007:

    Feb. 6th 2008:

    If you doubt the cooling effect of La Nina, try taking a hot-water bottle filled with cold water to bed with you!

    Finally, Tamino’s articles (linked to in #31 above) should settle any remaining doubts you may have about if we are now experiencing global cooling: we are not.

    Comment by Slioch — 4 Mar 2008 @ 3:32 AM

  54. James Lovelock is being more visionary than scientist in the quoted interview. When asked

    if he attributes the conflicting predictions to differences in scientific understanding or personality, he says: ‘Personality’.

    Put the 2020 and 2040 dates on one side and his views on the possibility of future disaster are not substantially different from James Hansen. The difficulty is that he has a track record of being on the mark with earlier, seemingly wild forecasts. Perhaps we should file these predictions but not forget them.

    The interviewer tells us

    He fears we won’t invent the necessary technologies in time, and expects ‘about 80%’ of the world’s population to be wiped out by 2100.


    Eventually we’ll have a human on the planet that really does understand it and can live with it properly.

    Even if he’s right then to fulfil his hope, we will need renewable sources of power. Nuclear can only be a temporary expedient in his scenario.

    Comment by Ian Perrin — 4 Mar 2008 @ 4:25 AM

  55. From the reports from Rome on the 535 event it would appear fairly certain that the present food supplies would fail totally with anything like that scale of impact on insolation. An aggressive natural disaster of the cataclysmic kind we don’t need right now. There are quite enough convergences in the pipeline.

    The recent cold snap at ground level will play havoc on food production. What is the impact of the southern USA weather on corn production? With USA producing about 8% of its fuel from corn and with the now-solid relationship between food and fuel any reduction in the corn harvest will increase the stress between food and fuel supplies – the oil shock of a few decades ago was only a 5% dip in supply.

    I think Lovelock is right in his general view. I admire the way Hansen et al say that everything will be sort of OK if only we can do X, Y and Z. But we wont and it is becoming increasingly clear that we cannot. So while Hansen et al are correct in their estimate of what is needed to keep us safe; their comments about “all we have to do is…” are simply to keep them in the loop as part of a socially acceptable run at the solution.

    I agree that we might as well stop messing about with mitigation. For example we have no idea how to sequester CO2 at any sort of commercial scale that would make a difference. There will be twice the volume of liquid CO2 as there is oil and handling that amount of CO2 product is impossible. The infrastructure will never be built, and if it does it would require twice the energy input to the system to get both the current energy output and the CO2 sequestered. Biofuels don’t add up – or rather they do:– to more CO2 than fossil fuels. Carbon taxes wont be spent anywhere useful, etc etc… Its all rubbish.

    But like Lovelock I think there is hope for a great adventure. Like the start of war there will be the opportunity for euphoric pursuit of new goals and new systems that will – to a degree – see the survival of some of us. We wont be building tanks or fighters – we will be building sustainable power supplies, local MASH units, self contained farms and running railways around the 100m above sea level contour to provide a simple old-world transport route that will last past the time the seas stop rising.

    There will be opportunities for good old commercial interests to prevail in the production and operation of new systems. But the old systems will surely fail. Energy and food are now inextricably intertwined, and we will find – perhaps before the middle of this year – that the world will move into a hoarding phase where citizens and nations start building stores not as short term buffers against variations in commodity prices but as reserves for the long term future – until until.

    The variations in climate, the stagnation in oil production, the increased demand for food, the imposition of export levies in numerous countries to halt export of foodstuffs, droughts and climate extremes, trembling commodity markets, failing banks, collapsing ice sheets, melting glaciers and the increased rate of extinctions in amphibians, insects, sea life and small mammals (not to mention the coming demise of our primary predator the Polar Bear!) are all indicators of a convergence of forces against the survival of modern society in its present form.

    In the main any opportunity for useful control of these forces has already slipped beyond the control of any man or country.

    For those of us left standing these will definitely be exciting times! It will indeed be “…life Jim, but not as we know it!”

    Comment by Nigel Williams — 4 Mar 2008 @ 5:55 AM

  56. Re #49, Yellowstone is every 600,000 years and one is over due by 40,000 years I believe. As for Lovelock, I agree that his message appears very starck but he sees earth science differently to te majority. For one he is a true systemesist and laments the lack of the true complex modelling in terms of the biosphere as well as physical processes which he belieevs is sigificant.

    His predictions are based on additional factors which makes them more dire than the majority of climate scientists but who is to say that he is not right rather than misguided.

    Re. Re#13, Sorry RC. I i no way meant to associate James Hansen with RC, only with GISS.

    Comment by Pete Best — 4 Mar 2008 @ 6:19 AM

  57. Pierre Gosselin writes:

    [[Going fossil fuel cold turkey would mean economic suicide.]]

    True. We’ll have to do it gradually, say, in a couple of decades.

    [[If you want to see misery, death and destruction, then implement the nonsense proposed by Gore and Co.]]

    What nonsense would that be?

    [[Fortunatelly, it won’t be allowed to go that far. When people start paying through the nose for this hysteria, they’ll use their votes run ya’ll out of town.]]

    The contraction is “y’all” from “you all.”

    [[Already with the high energy and food prices, we’re beginning to see social instability.]]

    We’ve seen social instability for a long, long time.

    Comment by Barton Paul Levenson — 4 Mar 2008 @ 6:31 AM

  58. Robin Johnson, Having been near both volcanos and forest fires, I can say without a doubt that forest fires cannot touch volcanos for production of sulfur. Sulfur melts at a relatively low temperature, and so will dissolve into the superheated water associated with a magma body. When pressure is released by the eruption, it will flash to vapor and react with the water to form sulfuric acid and other sulfates as it is dispersed at high altitudes–even into the stratosphere.
    Forest fires, because carbon is the dominant element, tend to form a lot of CO2 and ash. Not the same at all.

    Comment by Ray Ladbury — 4 Mar 2008 @ 8:01 AM

  59. Re: 46. You’re wrong! Our Gov in australia has just been advised rather strongly by a leading and respected economist Prof. Ross Garnaut about the economic impact of global warming and he advocates just that. well..a 90% reduction in greenhouse gasses by 2050 anyway. More and more reports are coming in saying that the only way to stabilise climate and then reverse the damage done is by going almost completly carbon neutral ASAP. Sorry DBrown..get your facts straight first!

    Comment by Lawrence Coleman — 4 Mar 2008 @ 8:28 AM

  60. Just read a bio of James Lovelock’s life and achievements..what an incredible man!! His insights into life itself and the atmosphere as an extention of everything that has ever breathed to me were based on buddhism..well I’m buddhist so I’m biased..hehe! We wont destroy the earth..only us and virtually every animal and plant on this planet for a heck of a long time. The earth WILL recover maybe in a million years..but it will recover!
    Here’s the link of one of his bios…

    Comment by Lawrence Coleman — 4 Mar 2008 @ 8:50 AM

  61. Thanks Hank and Ray.

    Comment by Robin Johnson — 4 Mar 2008 @ 8:55 AM

  62. On the subject of renewables:

    There really is very little reason we can’t do more to deploy renewable sources of energy. The incremental cost is measured in pennies per KWH, and the total cost differences in many instances is dollars per month. For some sources, such as wind, there is now a financial incentive to use wind rather than coal — the “all wind” electric plans here in Texas are fractionally cheaper than the mixed coal-nuke plans.

    I wish I could say my electric costs are going down, but at something like 300KWH for January (they misred my meter last month by 100KWH, so I’ve not updated the image the link off my name references, but last month was 408KWH or so according to them), that monthly customer service fee starts to show up in the cost of electricity as pennies per KWH.

    On the subject of distributed generation:

    Sorry, not a solution. I’d love it if it were, and the solar array on my roof would also love it if it were. But, alas, I have the graphs of power output to prove that distributed generation is a really BAD idea. What distributed generation is a good idea for is surviving the coming problems the electric grid is going to face as ever increasing amounts of load are shifted from carbon-based to electron-based sources. I’m not interested in being without electricity because 1/3rd of the population decides to plug their electric cars in on a Sunday night so they can drive the next day and the grid collapsed because the load exceeded that of the hottest summer afternoon.

    Distributed generation is needed so we can survive the end of the oil era, not so we can cut carbon emissions at the coal-fired plants. ERCOT, the grid where I live, produces somewhere around 35GW on a day like today — maybe a bit higher if we dip below freezing tonight. But 35GW is a whopping 18 nuclear plants at 2GW each. Toss in some landfill natural gas or landfill reclaimed biomass powered generators for frequency and voltage regulation and all of Texas is off the carbon addiction for electric generation. Time to realize that? Ten or 15 years. Doubt my math? You can check the ERCOT load / generation numbers at . Current generation — 39,400MW.

    The solution isn’t distributed generation, which has to be the dumbest idea anyone ever dreamt up (yes, really — managing ERCOT is no simple feat. Imagine all 17 million or so Texans all poking their fingers in ERCOT’s interconnect), it’s large scale storage technologies such as compressed air and pumped hydro. Several more GW of wind out in West and North Texas, pump the Lower Colorado back into the Highland Lakes during the periods of high wind, or air into salt dome down south, and we’ve got our regulation abilities from wind sources.

    The main obstacles are not the techology. The entire automobile fleet is already being replaced on a shorter timescale than we have to end our oil addiction (I’m a “we can’t cause global warming because we can’t afford the price of fossil fuels” skeptic, for those of you who don’t know me). We know how to build electric motors. We know how to build batteries. Toyota’s system (Hybrid Synergy Drive) is now very well proven and leds itself to conversion to plug-in hybrid. All that remains is the will to pull the trigger, and people don’t want to give up their giant oil swilling SUVs or their cutsie dimmable lights to avert what, for themselves, is going to be a financial disaster.

    Comment by FurryCatHerder — 4 Mar 2008 @ 9:30 AM

  63. George Monbiot has got it in the best perspective. He says small is not beautiful anymore. It will take a gargantuan effort such as Iceland developing enough thermal generating facilities to power nearly the whole of Europe. Do-able but far off.

    Think of how much electricity Yellowstone could produce (don’t think too much about that super eruption though, cause no one knows how to avoid that. In my dreams I see Bill Gates buying a hundred automatic drilling machines placed 20 miles away drilling a low angle to intersect the magma chamber well below center, and slowly venting it). Sorry for getting off topic.

    Here is Monbiot’s speech in Aug. ’07 at the Camp for Climate Change in London. He is the second speaker in at approx. 15 minutes. Best keep the volume down. It was recorded from the audience and their applause is quite loud.

    Comment by d. beck — 4 Mar 2008 @ 10:17 AM

  64. I’m not sure what James Lovelock’s doing in this thread, but since he does not appear to be going away, I fear I must dissent from the general tone of reverence. There’s no doubt Lovelock has considerable achievements to his credit, but he’s far from infallible in his judgements on environmental matters – as he, again to his credit, recognises (in “Homage to Gaia”, 2000). A pioneer of measuring trace atmospheric gases, in 1974 he declared that the CFCs in the atmosphere posed “no conceivable hazard” (Lovelock, J.E., Maggs, R.J. and Wade, R.J. (1973). Halogenated Hydrocarbons in and over the Atlantic. Nature ‘241, 194-196). More generally, he was for a long time very confident of “Gaia’s” ability to deal with human-caused pollution – a confidence which I am sure was quite sincere, but was very convenient to the large companies, such as Shell, who financed his work. The “Gaia Hypothesis” is certainly brilliant, if only as a “meme” extraordinarily well adapted to its cultural environment. Aitkenhead’s interview says Gaia theory “forms the basis of almost all climate science”. I do not know whether Aitkenhead acquired this view from Lovelock, but I would be interested in the contributors’ views on the statement itself. The interview also makes clear that Lovelock makes absolutely no effort to limit his own GHG emissions or other impacts on the environment.

    Comment by Nick Gotts — 4 Mar 2008 @ 11:16 AM

  65. A smart grid ensures that people don’t overload the grid at any particular time. Set the price high enough, and people will find different times to charge their cars.

    Comment by cce — 4 Mar 2008 @ 11:50 AM

  66. RE #48 “what’s the point of maintaining a robust economy if the world’s dying”

    That got me thinking, we really don’t have a robust economy, if we’re consuming & destroying the capital. It’s like selling the building and machines of a factory part by part. On the books it looks like we’re making a good profit, but once the capital is all gone, there will be a collapse. And I’m just speaking of using up and polluting finite resources, on which economies ultimately depend. If you include the effects of GW, the situation is even more dire… you sell the roof of your factory, which makes your books look great for the moment, then the next moment a flood and hurricane strike and destroy an even greater portion of your capital, plus killing some of your workers. Then you have to sell all the more capital to cover up the losses.

    We’re in the midst of a close-out fire sale, which simply gives the illusion of a robust economy.

    Comment by Lynn Vincentnathan — 4 Mar 2008 @ 12:42 PM

  67. Re. #58 (Ray L.) Ray, do we have any data on comets releasing SO2, just pursuing the air burst (as opposed to full impact) idea? Or would they produce other volatiles that might have the same climate effect as that indicated in the c. 536 AD data?

    Comment by Nick O. — 4 Mar 2008 @ 1:24 PM

  68. You are right. Not a super-eruption:

    Comment by David B. Benson — 4 Mar 2008 @ 1:50 PM

  69. Nick O., We have to ask where the sulfur would come from. There is no process I can think of for a comet to be particularly enriched in sulfur. So, it would have to be a direct hit on a site on Earth where sulfur was enriched. You might have a somewhat high sulfur content in a bog, but there would be lots of organic matter to burn along with it–not the sort of event we’re looking for. For high-sulfur/low-organic, you are looking at a geologically active area with lots of hyhdrothermal activity (e.g. Rotorua in N. Zealand or Yellowstone in the US). Such sites are a lot more likely to supply their own explosive potential rather than requiring a cometary impact.

    Comment by Ray Ladbury — 4 Mar 2008 @ 2:49 PM

  70. This topic ought to make anyone thinking of the global engineering strategy of injecting aerosols into the stratosphere, to mitigate the effects of AGW, give it another look and go back to the drawing board.
    If we overshoot the planned upon levels of sulfates and the fruits and other food products don’t ripen, at our current levels of population, for a season or two, we’re in big trouble.

    Comment by Lawrence Brown — 4 Mar 2008 @ 5:43 PM

  71. RE: Age of Fossil Fuels Will Last Forever!

    I have said this many times here and elsewhere, I will say this once again here, and I will say this at RC for the very last time. We will always use increasing amounts of fossils fuels because there are no subsitutes with the requisite chemical and physical properties, and there never ever will be any reduction in the emission of carbon dioxide.

    For example, boats, planes, freight trains and trucks, construction, mining and agricultural machines, most cars and light trucks, motorcycles, snowmobiles, ATV’s, all military vehicles, go-carts, golf course and sports field grass mowers, etc will require and use liquid fossils fuels becasue these fuels have high energy density and are easily prepared from crude oil by fractional distillation and blending, low energy processes that do not require the breaking of chemical bonds. Even catalytic cracking of heavier distillate fractions is a low energy process.

    The “Fuels of Freedom” are chemically inert (except to reaction with oxygen. halogens and several highly reactive chemicals such as singlet oxygen) noncorrosive, highly portable, and can be stored indefinitely in sealed containers (e.g., steel drums) and under an inert atmosphere (e.g., nitrogen) in large tanks.

    Fossils fuels will always be required for lime and cement kilns, metal smelters, steel mills, foundries and metal casting plants, metal cutting and braising torches, all factories that make ceramics (e.g., bricks, tiles, china, glass, etc), all food production, processing and distribution, space and water heating, cooking and baking, BBQ’s, manufacture of porcelain-coated metals, harvesting of wood and lumber manufacture, isolation of essential oils by steam distillation for prepartion of fragrances and flavors, etc.

    The reasons we use thermal plants for generating electricity is that these plants have a small footprint, can be located close to consumers, and produce electricity reliably and at very high energy-densities.

    Fossils are the feedstock for the petrochemical
    industries (sometimes called the chemical process industries), which manufacture everything from A to Z, such as synthetic fibers. There is not enough suitable land for growing cotton, flax and sheep to meet world demand.

    If you guys have any schemes that will replace fossil fuels for the above applications and uses, I’m quite sure the engineers will glady welcome your suggestions.

    We will always have lots of fossil fuels because we can always use coal for manufacture of synthetic hydrocarbons. Germany did this on amassive scale during WW II and South Africa use the process and it supplies about 40% of liquid hydrocarbons which can be
    manufactured into a wide range of useful materials.

    Google “SASOL” for more info.

    Comment by Harold Pierce Jr — 4 Mar 2008 @ 7:20 PM

  72. Well, I have no doubt that every last barrel of oil, ton of coal, and cubic meter of gas will be extracted as soon as commercially feasible, no matter the harm to the environment, but…”always” ? That’s hard to picture.Always is such a long time.

    Comment by Paul — 4 Mar 2008 @ 8:42 PM

  73. Re 60 Lawrence Coleman,
    My understanding is that going “cold turkey” means you immediately stop doing something, in this case using carbon based fuel sources.

    A reduction or 90% in the per-capita CO2 emissions over the 42 years between now and 2050 proposed by the Garnaut Review here in Australia is not the same as “going cold turkey”.

    Yes it’s a rapid transition, but the idea is to use our current sources of wealth and energy (fossil fuels) to leverage us into new sources of wealth and energy, just as has happened whenever the form of energy that underpins society has changed.

    Comment by Bruce Tabor — 4 Mar 2008 @ 8:50 PM

  74. Re Harold Pierce @ 71: “I will say this once again here, and I will say this at RC for the very last time. ”

    Is that a promise?

    Comment by Jim Eager — 4 Mar 2008 @ 9:03 PM

  75. Re 64 Nick Gotts.
    I agree on Lovelock. His recent book “The Revenge of Gaia” was probably the most unscientific book on global warming I’ve ever read, with the possible exception of Michael Crichton’s State of Fear. The books are from opposite ends of the spectrum, but only one pretends it is not fiction.

    He is justly famous for the Gaia Hypothesis, which has led to Earth Systems Science. But he continues to encourage the religious overtones of the concept, that Gaia is somehow teleological or purposful. And the concept that Gaia is a homeostatic organism, striving to maintain a constant environment is over the top. A better concept might be a broad scale corollary of Le Chatelier’s Principle: that when an equilibrium is disturbed the equilibrium shifts to partially counteract the change. There is nothing unique to living systems about this behaviour.

    Comment by Bruce Tabor — 4 Mar 2008 @ 9:16 PM

  76. Re 71 Harold Pierce,
    I could go through and refute your argument case by case, but ultimately what you have said is a statement of religious belief, and one that is demonstrably a mathematical impossibility. On a planet where we “will always use increasing amounts of fossil fuels” the “Age of Fossil Fuels” cannot possibly last forever, as the reserves of fossil fuels are finite – even coal, oil shales, tar sands etc. This is even more the case when you consider EROI – energy return on investment. The only fossil fuels that are worth recovering are ones that ultimately yield more energy than they cost to recover and process for their ultimate purpose.

    Comment by Bruce Tabor — 4 Mar 2008 @ 9:33 PM

  77. Harold Pierce, Jr., According to the World Coal Institute: “At current production levels, proven coal reserves are estimated to last 147 years.”

    That assumes current production levels, but of course energy demand will continue to grow. I had hoped that forever would be further off than 1.5 centuries. So, when the coal runs out, do you propose to mine Titan?

    Fossil fuels are finite. They threaten the continued viability of civilization. Accept it and let’s find a way to cope without them.

    Comment by Ray Ladbury — 4 Mar 2008 @ 9:41 PM

  78. Re 55 Nigel Williams,
    I largely agree. You have the optimists view of what I view with great pessimism. To me “interesting times” – war, famine, depression, genocide – are better read about in books or perhaps seen from afar. Unfortunately we will be building tanks and fighters as this is an inevitable response in times of stress like this, along with the rise of tyrants and demagogues. A world population crash to around 1 billion, which is a realistic worst case, will not be pleasant for the 6-7 billion “missing”. Will the survivours consider they have lived through “interesting times” or a holocaust, as that is the only comparable magnitude of loss – the almost complete loss of European Jewry.

    On a minor point, I think you’ll find that 65-70 metres is the highest retreat needed and quite possibly only 12-25 metres will be required, but picking where sea level will stabilise will be difficult.

    Comment by Bruce Tabor — 4 Mar 2008 @ 9:48 PM

  79. Harold, Re 71,

    Google “SASOL” for more info.

    Just for sh*ts and giggles try googling Peak Oil and Peak Coal.

    Comment by Fernando Magyar — 4 Mar 2008 @ 10:24 PM

  80. As stated in Hansen 1981, and elsewhere, one of the main tenents of AGW is that as the atmosphere becomes more opaque the effective radiating level will rise and that because of the lapse rate will emit at a lower temperature, I suppose assuming that that level stays within the troposphere. In 1981 Dr. Hansen put the height at 6.5km/5.5km for tropics/poles. First, I would like to know where he got this number, was it by calculation or observation. And secondly, it has been 25 years, has that level moved higher? Or if that is an ill formed question, at what height did the earth emit from before we perturbed the natural order?
    Thank you for any insight.

    [Response: It’s based on the mean emitting temperature (i.e. the T at which SB emission would equal absorbed solar) which is around 255 K. If the mean surface temperature is 288 K and the lapse rate is around 6 K/km then you end up with a mean emitting height of 5 to 6 km. This does not mean that this is where all outgoing LW comes from – you can see from the spectra that for different wavelengths the emissions come from different temperatures (heights) – that is of course how satellites can sense different parts of the atmosphere. Since it is a little bit of a convenient fiction, changes in this height are more useful as a pedagogic device than as a tool for diagnosing climate change. – gavin]

    Comment by Ellis — 4 Mar 2008 @ 11:26 PM

  81. It would be nice if the AGW Catastrophists could actually measure some observations that give credence to the Hypothesis of Anthropogenic Global Warming…. That shows it has a SIGNIFICANT effect and affects climate. To the extent that it is clearly visible beyond the background noise of natural variation…. they can’t.

    So… Ten years now, there has been no warming trend. Despite the Hypothosis that Increasing CO2 drives warming… Now we have a cooling…. No mechanisms explained… Nor for the 40’s until 70’s cooling period either…

    We also just happen to have the lowest activity of sunspots…

    Sunspot activity makes a better fit than does Athropogenic CO2.

    Trying to fit Volcanoes into your bits and pieces here is not going to help… We’ve had large modern eruptions and a heap of data from them… The effects don’t stay in the atmosphere for any significant period.. The affects would not last centuries… What about St Helens and Pinotubo…

    Comment by J.Hansford. — 5 Mar 2008 @ 1:27 AM

  82. Re #75 Bruce Tabor

    He is justly famous for the Gaia Hypothesis, which has led to Earth Systems Science. But he continues to encourage the religious overtones of the concept, that Gaia is somehow teleological or purposful. And the concept that Gaia is a homeostatic organism, striving to maintain a constant environment is over the top.

    My suspicion is that the Gaia Hypothesis is just a special case of the Anthropic Principle: the Earth appears to have all these self-restoring tendencies because we are around to talk about it :-)

    That doesn’t guarantee that it will last though, does it. A world population crash due to a sudden collapse of the agricultural production base, somewhere in the 2030-2060 time frame, is a worst case scenario, but unfortunately not one that seems entirely over the top — most people have no idea of the fragility of the ecological base of our production system.

    And when comparing with the Holocaust you’re missing three orders of magnitude.

    Comment by Martin Vermeer — 5 Mar 2008 @ 2:13 AM

  83. Nigel Williams writes:

    [[For those of us left standing these will definitely be exciting times! It will indeed be “…life Jim, but not as we know it!”]]

    What makes you think you or your descendants will be among those left standing?

    Comment by Barton Paul Levenson — 5 Mar 2008 @ 7:14 AM

  84. Harold Pierce Jr writes:

    [[We will always use increasing amounts of fossils fuels]]

    That’s physically impossible. There aren’t infinite amounts of fossil fuels. Using increasing amounts means the more we use, the faster we run out. Do you understand how a compound-interest expansion works?

    If the entire upper 10 kilometers of the Earth’s surface were pure anthracite, and use rises 2% per year compared to this year’s equivalent of about 3.9 x 1012 kilograms equivalent, we run completely out of fossil fuels in 688 years (and God knows what the surface temperature of the Earth would be like by then). If, a little more realistically, only one part in 1,000 is fossil fuels, we run out in 339 years. Either way, we run out.

    Comment by Barton Paul Levenson — 5 Mar 2008 @ 7:56 AM

  85. Re J.Hansford @ 81: “It would be nice if the AGW Catastrophists could actually measure some observations that give credence to the Hypothesis of Anthropogenic Global Warming….”

    Such measurements have been addressed here at RealClimate repeatedly, as has been your assertion that there has been no warming trend for ten years. Don’t blame others for your inability to pay attention.

    J.Hansford: “Sunspot activity makes a better fit than does Athropogenic CO2.”

    Then how, exactly, do you explain the divergence of sunspot activity from temperature rise after the late 1970s?

    What you fail to understand is that solar variation and greenhouse gases are entirely separate and independent phenomena that may offset or reinforce each other. Should solar activity lessen, cooling of Earth’s surface and atmosphere will result, but greenhouse gases will continue to make it warmer than it otherwise would be. Likewise, any increase in solar insolation will be amplified by greenhouse gases. Either way, adding more greenhouse gases will make it warmer yet.

    Comment by Jim Eager — 5 Mar 2008 @ 10:13 AM

  86. RE: 536 eruption

    “here are some suspects:

    PAGO New Britain C 530 AD ± 150 years 5
    VESUVIUS Italy 536 AD 4?
    RABAUL New Britain C 540 AD ± 100 years 6”

    Instead of a single, massive eruption, would a series of smaller, closely spaced eruptions have the same effect? Would all of the particulates from the first be cleared by the time any smaller “after-eruptions” came by?

    The list above shows two smaller eruptions within 10 yrs (I know, there’s a +/- 150 yrs). How much would have been in the air when the second one, IN THE SAME AREA, went off? Or a second one “down-wind” of the first?

    Speaking of the “dating”, would particulates from two, closely spaced (time and location) eruptions compound the dating errors?

    Just curious.

    Comment by henry — 5 Mar 2008 @ 11:20 AM

  87. “Instead of a single, massive eruption, would a series of smaller, closely spaced eruptions have the same effect? Would all of the particulates from the first be cleared by the time any smaller “after-eruptions” came by?”

    I suspect that it needs a big one, sufficient to put a lot of particulates and water in the stratosphere where it will linger for years, small ones will wash out of the troposphere much more rapidly.

    Comment by Phil. Felton — 5 Mar 2008 @ 12:39 PM

  88. Note: Volcanic eruptions of any type can be treated as Poisson events. The probability of having 2 in close succession will generally be small. Moreover, a large volcanic eruption is more efficient at throwing material high into the atmosphere, where it stays longer and has more effect.

    Comment by Ray Ladbury — 5 Mar 2008 @ 12:52 PM

  89. RE: #74

    Yep! I promise! And not only that, I’m not going to rebut my critics.

    I’m wasting too much time on these climate blogs. I still have to process about 100 temperature records from my favorite weather station and lightstation at Quatsino, BC. I just finished a multi-decadal analysis of the min temperature for Fall Equinox Interval (FEI, Sept 16-26) and have obtained some inexplicable results. Here is a brief synopsis. The data are reported for the mean min temp +/- AD, where AD is the classical average deviation. The results are: 1900-29, 280.5 +/- 1.5 K; 1930-89. 281.8 +/- 1.5 K; and 1990-2005, 283.1 +/- 1.5 K.

    The temperature jump of 1.3 K between the intervals is significantly different by the t-test (p less than 0.05). I compared the yearly means for each decadal interval on either side of the jump point using the t-test for unpaired data. I have no explanation for the long intervals of constant temperature for the 1900-29 and 1930-89 intervals. The total jump of 2.6 K applies only to this interval and not to the Spring, Summer and Winter intervals (i.e, 11 days centered on the soltice or equinox). I didn’t do a multi-decadal analysis on these intervals. However, I did compare the 1900-06 interval to the 2000-06 interval for min temperature for these four sampling intervals, but I still working on this for the max temp. I still have to do the multi-decadal analysis for the max temp for the FEI to see if the temp jumps occurs for this metric. So stayed tuned for more “hot” results from the Pierce Climate Research Center (aka the basement rec room!).

    Attn: Gavin! Is it OK to do a t-test on the yearly means for each decade when comparing two decades or do I have punch in 110 numbers (Groan!) for each data set? Please don’t say, “No!” BTW, I will send you hard copy when I get this project done.

    Comment by Harold Pierce Jr — 5 Mar 2008 @ 12:58 PM

  90. Is there a reason why Europeans are so shy in declaring 2 consecutive none winters? Surely something which was read about the medieval warm period, from my Euro contacts it was/is quite astounding. What is remarkable about 536 AD event is that it was reported in Europe, also recorded by trees in Arizona, a truly world wide phenomenon, an easier to explain climate event. With retrospect this past winter shows climate in its true esoteric nature. , as some contrarians are celebrating what they call an extremely cold winter, an end of a long spell of NH warming. Climate is not so simple, does not turn on an impredictable dime, it has many 3 dimensional facets transposed in a time morass.

    Comment by wayne davidson — 5 Mar 2008 @ 1:08 PM

  91. Re J Hansford @ 81 wrote: “…No mechanisms explained… Nor for the 40’s until 70’s cooling period either…”

    No mechanism only if you have blinders on or refuse to look for it. The mechanism is likely simple. 1998 was an anomalously warm year due to ENSO. This year is shaping up to be anomalously cool, also likely to ENSO. Reasons like these are why “climate” is averaged over many years, and is not based on a cherry picked start date. Weren’t you talking about background noise a moment ago? And then you go on to cite a short cycle! The 40’s-70’s were explained by increasing fossil fuel sulfates and other aerosol particles at that time.

    Re J Hansford @ 81 wrote: “…Sunspot activity makes a better fit than does Athropogenic CO2…”

    Then why don’t we see a significant trace of an 11 year periodicity in global temperatures? Check out what temps were doing 11 years ago when we were at a similar place in our solar cycle. Temps were rising. What happened to your imaginary sunspot correlation? If you knew much about sunspots and the current (semi-popular in skeptical circles) theory of GCRs you would know that Svensmark would expect the exact opposite correlation that you seem to from the sunspot cycles. Funny thing…his expectations don’t seem to correlate with measured temps either….

    Comment by Arch Stanton — 5 Mar 2008 @ 1:59 PM

  92. henry (86) — Even the super-eruption of Mt. Toba about 74–71 kya left sulfates in the stratosphere for only about 3, perhaps 6 years. Tambora (VEI 7) produced a single year without a summer.

    So to obtain eighteen months of effects, the hypothesized two or more eruptions need to be one right after the other, so to speak. But yes, this might be the best accounting for the observations that we can have, baring more evidence. Nicely thought out, thank you.

    The dating is via radiocarbon. Unless one eruption causes fires in the forests of the other, I fail to see how the datings could be confused.

    Comment by David B. Benson — 5 Mar 2008 @ 2:08 PM

  93. RE #78 & “65-70 metres is the highest retreat needed”

    About how long (how many decades or centuries) would it take in a worse case scenario for the sea to rise 60 meters? I need this info for a story I’m writing.

    Comment by Lynn Vincentnathan — 5 Mar 2008 @ 2:36 PM

  94. What I got from this article is that it reinforces my belief that the primary threat from climate change is in our ability to produce food; sea level rise and other effects are merely add-ons.

    Most people in the developed world have no idea how sensitive farming is to weather patterns, because they aren’t farmers. Farmers are pretty good at optimizing what they can get from the land under the weather patterns they have adapted to locally. Almost any difference from ‘normal’ weather patterns will result in less food production. The devil in climate change is not the periods of equilibrium at either end; it’s the period of instability in the middle.

    We’ve all become concerned about the price of fuel; we’ve no idea what it will be like when the price of a loaf of bread becomes a significant portion of your income. If you are reading this, you are affluent enough to afford a computer and an internet connection and that pretty much means that getting enough food is not a daily struggle for you.

    From a very broad term perspective, fossil fuel energy is merely solar energy that has been stored. In the long run, the earth’s people are limited to the energy coming into the system, and that means solar, or its derivatives, wind and wave. (Or possibly geothermal or fusion, that would last a blessed long time if we can ever get it figured out, but then there would be only food production and living space to limit our population and the end result of that doesn’t have a good feel to it either.) Solar energy will not sustain the current world population at the level required by our industrialized societies. Eventually, something will have to give; either the world population decreases or our energy consumption dramatically drops. With current and foreseeable technology, a dramatic drop in energy use would mean a lot of people die; there is connectivity there. It’s very close to a catch 22.

    Paranoia warning, read on at your own risk.

    Do you think that the current administration is all stupid? I don’t think so. Do you think that they are power hungry? I think almost all people who seek positions of authority are. Do you think that they weren’t aware a few years ago that a continued military presence in the middle east would likely cost them the coming election? They must have been aware of the risk. So, what really motivated the war(s) and has kept us there? I don’t know, but it had to be more important than ensuring the politicians’ positions of power. It wasn’t WMD and it wasn’t bringing democracy to the region. My prediction is that whoever wins the election will have access to information they currently don’t, and we will stay. Best guess: Whatever nation has control over the most (energy) resources will be at a significant advantage in the coming decades.

    “May you live in interesting times.” is a curse, not a blessing. There will be tanks and planes. I fear for my children’s future.

    Comment by Chris Golledge — 5 Mar 2008 @ 3:26 PM

  95. henry, I’m no expert, but looking quickly with terms I recall, there’s been a lot of work done identifying the chemicals and isotopes that can tell one layer of volcanic ash from another — they can be traced back to specific volcanos, by what’s in them, very often.

    This is quite an old cite but if you click the ‘citing sources’ link on the page it’ll lead you forward following other papers that referred to it, and you can see some of how this area of science developed:

    Comment by Hank Roberts — 5 Mar 2008 @ 4:27 PM

  96. Volcanic Eruptions Cool the Earth – Yeah, We Knew That

    Regarding Henry’s post, I would be much more impressed if we could account for the Little Ice Age with volcanic events.

    This eruption I heard about through PBS (I think) a few years ago in a show on the Keys book. It’s nice the time scales on the ice cores can be lined up. Nevertheless, we are talking about a blip of few years of cooling.

    So this doesn’t amount to anything like disproving solar variation as a cause of some climate change as some posters have seemed to suggest.

    Comment by Jim Cross — 5 Mar 2008 @ 8:00 PM

  97. The site is great and I enjoyed the post about the 534 anomaly. Unfortunately, the “(more)” link doesn’t work in Firefox 2. I was forced to use IE instead. For reasons I don’t understand, this comments feature doesn’t work in Firefox. My apologies for posting this here, but I couldn’t find anyplace else.

    Comment by Cline Frasier — 5 Mar 2008 @ 8:14 PM

  98. Lynn 93. Reading between the waves, Hansen is betting on multi-metre rise by 2100 – especially if we do BAU, and even if we do get back to 350ppm CO2 in the next few decades.

    I understand Greenland ice sheet is 8m of sea rise, West Antarctic is 7m rise gives a first round total of 15m. The other 55m comes from the rest of the Antarctic ice sheets plus glaciers etc. That gets us to around +70m above present high tide. After that there will be on-going thermal expansion of the ocean until we (oops we wont be here will we) until Mother Earth reaches thermal equilibrium. Probably (unless I am contradicted) +80m is a good number to look at for the new high tide mark. I believe if you are planning any sort of ‘sustainable’ structure you shouldn’t get closer than +100m, as the process of the coastal hills settling down to a natural angle of repose will take a while, and depending on slope will chew the cliff-edge back quite a way.

    How fast? Well emissions will slow a bit as we die off, but its unlikely we will get away with less than 450ppm CO2 as a peak because there will be a bit of a flurry of emission-related activity as we try and build our way to some sort of safe future using our existing infrastructure. Faint hope. But 450ppm and the combination of peak oil and peak food will see demand ease in say 50 years, and anything like BAU will see all the predicted social turmoil of climate and sea level rise refugees heading for the pie shop on the top of the hill. The rise will happen in a sine-wave style – slow at first (we’re seeing the beginning of the beginning now) increasing to a peak rate of change as we pass thru about +30 to +40m, and then slowing as the decreased volume of ice remaining contributes less per year.

    So if we get +5m by 2100 (perish the thought) then a sketch of 80m on a sine-like curve finds 5m at about 25% of the time (100 years), so peak at 50% (the next 100 years). So peak rate of rise is at around 2200CE, and then you are looking at maybe 5m in 20 years. Draw the curve yourself and see how it looks to you. If its less by 2100 (say only 2m) then that flattens and extends the whole thing. We hope. Since the tail will be due to the warming of the deep ocean the tail will be very long – millenia. So it will probably be C4000CE before coasts will start to settle down and develop, and once again shallow water shell fish, coastal spawning grounds and the like will begin to re-establish. In the intervening period the coastal waters will be a turgid mess of freshly eroded land swirling among rough bedrock and collapsing sea-cliffs. As the fishing reports say – it will definitely be ‘muddy and un-fishable’ for quite a while.

    Comment by Nigel Williams — 5 Mar 2008 @ 11:19 PM

  99. #80

    As a follow up to Gavin’s response for further clarification, the tropopause has actually increased in height (See for example Santer et al, Science, 2003; 479-483). This reduces the stratosphere, and so you get much more cold air above you to radiate downward. If you did want to confine an “Effective radiating level” to a single altitude though, it would be much lower than the tropo-strato boundary anyway. If you increase the height of the effective radiating level, you extrapolate along a greater distance using the appropriate adiabiat and the surface is warmer.

    Comment by Chris Colose — 5 Mar 2008 @ 11:58 PM

  100. in #93 Lynn Vincentnathan said:

    About how long (how many decades or centuries) would it take in a worse case scenario for the sea to rise 60 meters? I need this info for a story I’m writing.

    During the sort of interglacial period that we currently inhabit, if the Eemian example MIS-5e is any guide, 2°C suffices to raise global sea level for the next hundred years and many centuries to come by an average of 1.6 meters, or about 5 feet, per century. That may be the best case that we can, on average, expect. During MIS-5e, some centuries suffered a sea rise rate higher than average, others a lower; a few centuries knew some stability or even a sea level drop.

    The worst sea rise rate I can recall seeing in studies of paleoclimate is 5m per century but such a rapid rate has never been sustained for more than two centuries as far as I know. However, the worst-case total sea rise may be worse than you think, closer to 80 meters than 60. Either way, getting there at the 1.6m rate would obviously take a few thousand years. Hope that helps!

    Comment by Meltwater — 6 Mar 2008 @ 7:14 AM

  101. Re. 93 Lynn Vincentnathan, 65-70 metres

    The most rapid known rise in sea level occurred at the end of the last ice age during the so-called Meltwater Pulse 1A. I’ve seen various estimates, but a typical one is a 25 metre rise in 500 years or 5 metres per century, 0.5 metres per decade.

    The actual forcing that triggered this was small compared to current climate forcings – initially only about 0.25 W/m^2 – we currently have 0.75 +/- 0.25 W/m^2 and rising. Somehow this initial trigger led to the build up of GHG’s and albedo changes (and more forcing) that resulted in this rapid rise in sea level. I don’t know exacly how soon after the trigger it occurred, I suspect it’s unknown.

    You could theoretically calculate a maximum rate based on climate forcings and some albedo feedbacks, and an assumption of how much of the forcing went into melting ice. Let’s assume 100% of the forcing went into melting ice.

    Lets say 1 W/m^2 forcing – thats 5*10^14 W over the globe.
    The latent heat of melting for water is 334J/g or 3.34*10^17 Joules/km^3 water equivalent – i.e. water volume once melted.
    Over the whole globe over a year, 1 W/m^2 corresponds to:

    Dividing these two results gives:
    1.58*10^22Joules/3.34*10^17 Joules/km^3=47,000km^3 melted water per year.
    This is distributed over 350 million km^2 of ocean
    47,000km^3/350 million km^2=0.13*10^-3km/yr=0.13 metres per year.
    (For comparison each of Greenland and West Antarctica is estimated to be losing about 150 km^3 per year, for a combined sea level rise of a little under 1mm per year.)

    So if all that 1 W/m^2 forcing went into ice melting it could raise sea level by 1.3 metres per decade or 13 m/100yrs. This is unlikely in itself as a good proportion of heat must go into warming the ocean, although this may stop if large amounts of ice spread through the oceans as ice sheets break up – creating an efficient way to transfer heat from ocean to ice, which incidentally is half of the key to the whole process – the other half being albedo changes on the ice itself (eg. meltwater ponds, soot), which transfer heat straight to the ice.

    If you wanted to speed things up for fictional purposes you could double the forcing due to albedo changes, eg loss of the polar sea ice, formation of large meltwater lakes on ice. You could then add release of CO2 and methane from permafrost. In addition, in some areas, especially West Antarctica, the ice won’t need to melt – it will just flow off the surface it rests on once enough lubrication and buoyancy is present – this could happen in a decade or less (5 metre rise). Almost as rapid collapse is possible in Greenland – 7 metre rise. The stable ice sheet is East Antarctica – equivalent to about a 55-58 metre rise.

    In short, I’ve no idea of the maximum possible rate. I could believe extreme conditions could do it within a century, but a number of worst-case positive feedbacks would have to be present.

    What do others think?

    Comment by Bruce Tabor — 6 Mar 2008 @ 7:20 AM

  102. J. Hansford writes:

    [[So… Ten years now, there has been no warming trend.]]

    Not true. Look again:

    [[ Despite the Hypothosis that Increasing CO2 drives warming… Now we have a cooling…. No mechanisms explained… Nor for the 40’s until 70’s cooling period either…]]

    Industrial aerosols.

    [[We also just happen to have the lowest activity of sunspots…
    Sunspot activity makes a better fit than does Athropogenic CO2.

    No, it doesn’t, actually. There’s a fairly good relation between solar activity and temperature up to about 1940, but sunlight has been essentially flat since 1950, so it can’t explain the present sharp upturn in global warming.

    Comment by Barton Paul Levenson — 6 Mar 2008 @ 8:22 AM

  103. Well, scientists are often myopic too. Really. Some latch onto something they are certain is rock solid and then tectonics or KT gets reasoned and evidence observed, and the raft floats around and the sky occasionally falls, and catastrophic terminations and punctuations rule.

    Gavin, and Ray Pierre know clearly and well enough that there is an effort to fund and seriously study the “Sulfate Aerosol Shield,” and more and more people are starting to realize this workable scheme will be supported by Big Carbon Inc., with lots of money, since it would “allow” much more CO2 to be pumped and dumped in the Commons of our Air, as Ray noted, in Science article quote. NCAR has done recent work. As well as a solid body of “modeling.”

    The “quote” probably Ray to Eli Kintisch in a phone interview. . .
    The Work.

    Paul Crutzen is Author #2, above paper.

    You can do this in your head.


    Pulverize to 1 micron thickness a cubic meter of sulfur. That single pulverized cubic meter of sulfur will cover a million square meters of stratosphere surface and it would take ~555 billion cubic meters to make a 1 micron thick sulfur shield over the entire earth. If a pre-pulverized cubic meter of sulfur weighs a ton (density ~1) then 1.5 GtS, could make an aerosol shield 3 microns thick, and cool the planet enough to counteract some of the global warming for a while. That would get you lots of Big C Inc. funding.

    Ray points out that once started there is a global stability issue, and a maintenance issue that lasts a long time. I do NOT like the shield idea, without a simultaneous mechanism to suck 10 to 25% of the atmosphere into a device to remove and sequester the CO2. Nature can’t do this or we would not have AGW.

    Lag Time

    The “lag” time for 385-390 ppm CO2 thermal equilibrium with its 25 F temp rise is 143 years (according to Carl Johnson, who computes the length of time it takes to use air to heat a column of rock 3000 feet deep, to the temperature 83F) Carl’s wrong “of course” (but where?) and the rise is only . . .?

    (This is the website that needs holes punched in it, legitimate holes with straight-forward physics. )

    This line of analysis, leading to some real disturbing conclusions, is part of why James Hansen is hawking 350 ppmv. (I favor 300 ppmv)

    No Matter. The rate at which the new equilibrium is approached, and its value, can be argued (The rate.) But the final temperature is an issue to all of life on earth. Hmmm, “issue” is understatement.

    Poke some honest reasonable holes in Carl’s approach. Please. (Ignore his 1353, Solar constant from way B.C. I thought the ocean could moderate, but water vapor only may not be enough. Aerosol shield any one?)

    I don’t know if the image here will make it into the comments section, but here is an illustration of a global “sulfate aerosol shield” that reflects 70% of incident solar irradiance, and keeps the temp down to about 900 F. uniformly. Of course, there is some CO2 that keeps the temperature that high.

    The 536 AD event is relevant, especially WRT the agricultural output. Too cold or too hot? The deniers need rope for support. The real point is this: The system is critically balanced. WE humans have screwed that up. We have the rope, not the will. Sea change coming. Billions die. Species time could be over. But doesn’t have to be.

    Comment by Les Porter — 6 Mar 2008 @ 8:41 AM

  104. Re. 93 Lynn Vincentnathan,
    Further to my earlier comments. Prehistorically, sea level rise at the end of glacial periods was rapid, in contrast to the slow build up of ice sheets over tens of thousands of years. Current GCMs almost certainly do not capture the break-up of ice sheets accurately. It has become obvious that ice sheet collapse is a rapid, nonlinear and “wet” process. Rapid breakdown in the past coincided with Heinrich Events, where armadas of glaciers broke off from ice sheet glaciers:
    Some process or processes had to destabilise these ice sheets before this happened and we are beginning to see some sign of this in the Greenland and West Antarctic ice sheets (GIS and WAIS). Once breakup of an ice sheet proceeds far enough it generates its own positive feedbacks and is virtually unstoppable.

    To understand the mechanisms of ice sheet collapse it is worth looking at some of Jim Hansen’s publications:
    Some are quite technical, but others are more readable:
    Hansen, J., 2007: Climate catastrophe. New Scientist, 195, no. 2614 (July 28), 30-34.

    Hansen, J.E., 2005: A slippery slope: How much global warming constitutes “dangerous anthropogenic interference”? An editorial essay. Climatic Change, 68, 269-279

    This one is a bit more technical, but it looks at the mechanisms underlying previous rapid sea level rises and specifically, how “paleoclimate evidence [shows] how sensitive climate and sea level are to even weak climate forcings”:
    Hansen, J., Mki. Sato, P. Kharecha, G. Russell, D.W. Lea, and M. Siddall, 2007: Climate change and trace gases. Phil. Trans. Royal. Soc. A, 365, 1925-1954, doi:10.1098/rsta.2007.2052.

    Another good Hansen source are his mailing list posts and presentations – see:

    Comment by Bruce Tabor — 6 Mar 2008 @ 9:06 AM

  105. Again with the “multiple” theory:

    The following link is to a map showing just the islands of Indonesia, with over 60 eruptions since 1900.

    I can imagine this area was pretty active then, and that’s why I’m asking about smaller eruptions in same area, over short periods of time…

    Comment by henry — 6 Mar 2008 @ 9:13 AM

  106. 98. Engulfment of critical nodes (power stations, refineries, industrial plant, etc) at current coastline in global supply chains with BAU-induced SLR of about 5 metres by 2100 would substantially terminate the global economy by mid-century. Thus, mitigation and BAU scenarios could both lead to large-scale anthropogenic emissions reduction, aleit for very different reasons. In effect, BAU could collapse anthropogenic streams within about 4-5 decades, depending on ice sheet dynamics. Triggered emission flows (under both BAU and potentially subcritical mitigation pathways) unlocked from natural storage would still be present. Urgent throttle back to 300-350 ppm CO2 would seem sensible.

    Comment by mg — 6 Mar 2008 @ 10:32 AM

  107. Global food supplies are already at a historically low ebb. A rerun of 536 AD would probably result in major famine world-wide.

    Comment by SqueakyRat — 6 Mar 2008 @ 11:15 AM

  108. Les, I just glanced over that website you point to, and I’m no expert, but when I see “A very highly respected expert in this field has said…” with no footnote, then an argument against what he says somebody said, I think, he needs to cite his sources.

    The claims I can check — like that nobody’s noticed the thermal mass of the Earth — can be checked and disproved, thus:

    And he writes this: “Using Stefan-Boltzmann backwards, we can easily calculate that … even if the carbon dioxide concentration would only get up to double today’s (around 770 ppm) the average temperature of the surface of the Earth would necessarily become around 45 degrees F hotter than today …”

    That makes me think
    — hmmm, he should be using metric units, and
    — hmmm, he should wonder why he’s an outlier.

    Comment by Hank Roberts — 6 Mar 2008 @ 11:41 AM

  109. Bruce Tabor, in comment #101, said What do others think?

    I’ve been a long time amateur student of the so-called ice ages. I suspect the sea stand maximum rise rates for, say Meltwater Pulse 1A, are under-represented in the paleo-records. Extreme pulses (of anything) tend to be smeared in the geological formations, so appearing to take longer and thus have a lower maximum.

    While I don’t know the extent to which this occured for the sea stand rise from LGM to now, it seems resaonable, at least for a future fiction story, to suppose a doubling to say, one meter per decade averaged over several decades, with a peak year rise of again one meter.

    Comment by David B. Benson — 6 Mar 2008 @ 4:36 PM

  110. Thanks folks – that’s great info re ice melt etc.

    Regarding the ‘wish-list’ of 350 to 300ppm – its not going to be done BY us is it; its going to be done TO us.

    I do not see any sequestration process on the books that will be able to be actively and deliberately implemented across all emission sources that will have any material effect on emission rates. Particularly with the ongoing rate of coal fired power station builds. A similar CO2 extraction system will have to then pull CO2 back from about 400ppm (we’re at what – 384 and rising fast now?) and how many tonnes is that?

    From – the atmosphere weighs about 5.1 x 10^15 tonnes – say about 5,000 Gigatonnes (Gt). Of that the 384ppm of CO2 is just about 2 Gt (ignoring molecular weights etc – for the purists!). Overall we release 27 Gt CO2 into the air each year from human activities and natural sources release about eight times that amount. Fortunately natural sinks absorb most of this, leaving us with the balance in the air to live with.

    This sort of mass-flux of CO2 (say 240Gt per year plus or minus) impresses me with how incredibly fine the difference between increasing or decreasing CO2 levels is. It seems the entire atmosphere contains only about 1% of our annual human emissions of CO2 – the remainder is pulled out by sinks such as plants, dissolution in the oceans and rock formation. And from this it looks like only a tiny change in the absorption or production rate (say +/- 1%) is needed to lead to a massive swing in CO2 content. I assume that the absorption systems are to a degree responsive to changing CO2 levels which flattens the impact of changes – but never the less (if my sums are right) the extreme sensitivity is apparent.

    We recall that recent research has shown the biosphere is not absorbing as much as it did in the past – which is exacerbating the rate of rise. Yet at the same time does this show how a practical reduction in emissions could see the existing natural sinks start to pull levels down at a useful rate? Or am I missing something?

    Comment by Nigel Williams — 6 Mar 2008 @ 6:01 PM

  111. Nigel Williams (110) — You are missing the on-going ocean acidification. The consequences of that are, IMHO, likely to be much worse than sea stand rise, etc.

    The only solution is to permanently sequester all the excess carbon added to the active carbon cycle, mostly by burning fossil fuels. Others have estimated that this is about 500 GtC, with about 8.5 GtC aded yearly just now.

    Big job, but not insuperable nor damagingly expensive to the world economy.

    Comment by David B. Benson — 6 Mar 2008 @ 6:42 PM

  112. > 2 Gt (ignoring molecular weights ….)

    No. No, no, no, no.

    Call Avogadro and ask. I’m sure you have his number.

    Comment by Hank Roberts — 6 Mar 2008 @ 7:30 PM

  113. Opps! My previous post should read “”…about 10% of annual human emissions or 1% of total global emissions of CO2..”. Thanks. N

    Comment by Nigel Williams — 6 Mar 2008 @ 8:11 PM

  114. Nuclear power plants can generate thousands of tons of radioactive waste a year (3,000 tons in 1976, 13,000 tons in 1983). It would be very expensive if not impossible to fly the space shuttle out so often to dispose of this waste. And space shuttles are not fail safe. Uranium has a radioactive half-life of 80,000 years. Where can all this accumulating waste be stored and then guarded (uranium makes a handy weapon of mass destruction) if Lovelock’s proposals were adopted? The health of uranium miners will be threatened as will anyone living near the mines. It takes just one particle entering one cell to cause cancer or genetic mutation. It’s impossible to build a nuclear power plant that does not constantly leak small amounts of radiation into the surroundings. And the Chernobyl explosion released a thousand times more radioactive materials.

    Comment by Nathan Brain — 6 Mar 2008 @ 9:24 PM

  115. Thanks Hank – good to know you’re there!

    Without fretting the detail my point is that the flux of CO2 in and out of the atmosphere is a significant portion of the total mass of the atmosphere – in this case its about 240Gt of 5,100Gt or about 5%.

    CO2 is a fraction of a percent of the atmosphere’s mass, so the persistence of anything like a steady-state CO2 balance is more of a miracle than a certainty. (Thats if my maths is right this time!)

    Anything – either way- that unbalances that can (I suggest) lead to a rather major swing in the CO2 left in the air which in turn will line up all the usual suspects in the case of our untimely (but sadly apt) demise.

    Comment by Nigel Williams — 6 Mar 2008 @ 9:55 PM

  116. Re deglacial sea level rise, we have to be careful to look at conditions that were about similar to the present (i.e. starting with a similar amount of ice that is then subjected to added warming). Looking at what happened during the big melt 12ky ago is thus not useful, but the tail end of the last deglaciation (the Eemian) is more useful since it involved a bit more melting than we have seen so far.

    The recent paper on this subject is here and a perhaps more useful interview with the lead author here (noting that someone linked the abstract above). The upshot is that all else being equal (to the Eemian) we’re looking at 1.5 to 2.5 meters/century (the latter being the worst case).

    All else may not be equal though, since the late Eemian melt was driven by increased high-latitude insolation due orbital changes rather than GHGs and since we could apply more forcing.

    Comment by Steve Bloom — 6 Mar 2008 @ 10:02 PM

  117. Theres a new solar variability article out in physics today: Scafetta & West. I’d be really interested to hear what you think.

    Comment by Alex — 6 Mar 2008 @ 10:02 PM

  118. Re #110:

    The only solution is to permanently sequester all the excess carbon added to the active carbon cycle, mostly by burning fossil fuels. Others have estimated that this is about 500 GtC, with about 8.5 GtC aded yearly just now.

    Nah, better solution — immediately ban discarding (landfill) or recycling anything that contains carbon. Start refining the carbon out of everything we dispose of — the tons and tons of trash and refuse every year — and sequester THAT. Let the sun do the job of converting CO2 to something we can more readily get carbon from.

    Comment by FurryCatherder — 6 Mar 2008 @ 10:05 PM

  119. Re #106:

    98. Engulfment of critical nodes (power stations, refineries, industrial plant, etc) at current coastline in global supply chains with BAU-induced SLR of about 5 metres by 2100 would substantially terminate the global economy by mid-century.

    This and most other Doomsday scenarios assume people are utterly and completely stupid and keep rebuilding the breaking down infrastructure where the water level is determined by the position of the moon relative to the local zenith or nadir …

    A lot of that infrastructure isn’t going to be around in 92 years, and a lot of that infrastructure was BUILT in the last 92 years. Let’s try to remember what things were like 92 years ago. Don’t much recall nuclear power plants being built in 1916, and the number of massive oil refineries and megavolt transmission lines in 1916 compared to today were nil.

    But all this ignores the fact that sooner or later, we’re going to have to face the Next Big Natural Disaster, because they aren’t going to stop happening just because we want them to.

    Comment by FurryCatherder — 6 Mar 2008 @ 10:29 PM

  120. #94 Thanks Chris, very well put. Only one gripe. “Solar energy will not sustain the current world population at the level required by our industrialized societies.” Why not? One Chinese manufacturer is already talking seriously of $2/peak watt photovoltaics. Halve that, and you’d have the cheapest source of peak electricity, bar none. $1000/installed MW. Not coal. Not nuclear. Maybe large hydro on an excellent site. Gas currently goes close, but you have to buy the damn fuel.

    And even if the solar efficiency is only 10%, the total collector area required is tiny, probably less than the existing global roof area(?). As Hansen says, we’ll burn all the oil and gas anyway. It’s coal-fired electrictity that’s the swing emitter. The task is to find a serious alternative.

    Comment by GlenFergus — 7 Mar 2008 @ 12:02 AM

  121. Could any of you answer this question… 3 mil years ago the earth’s temp was 5C hotter than it is today and that caused a sea level rise of more than 80ft or 25m….why then do scientists say that greenland and antartica if they were to completely melt would only constitute a moderate 7m rise a piece for a tot. of 15m..where’s the other 10m coming from? However they did not have 7bil little CO2 producing factories running around the planet 3mil years ago + livestock. They aslo did not have the wanton deforestation going on as we do now..and I bet the ocean’s acidity wasn’t conspiring to kill of CO2 absorbing/O2 producing plankton either. In those days we had plenty of negative feedback mechanisms in place..nowadays these essential feedback mechanisms have failed or are failing by anthropogenic rise to +ve amplifying more and more +ve everywhere you care to look..and a vicious and deadly cycle has begun in earnest with NO escape route. Still back to the original question where does te additional 10m come from?

    Comment by Lawrence Coleman — 7 Mar 2008 @ 3:50 AM

  122. RE: #102

    What cooling from about 1950 to 1975? Print the typical plot of global mean temperature and then get your French curve(s). If you ignore the mysterious “temperature bump” centered on 1940, and few other minor bumps, you will find that there was a very slight rise in temperature until 1975. If you also ignore the “bump” and the “dip” around 1900-10, you can get a really nice curve that from 1880 declines slowly and smoothly to 1915, then rises slowly to 1930 at which point the curve starts the very slow rise until to 1975, where curve rises up quite quickly and linearly to the end of the graph at 2005.

    Anybody got an explanation for this bump? The winters in Europe from 1941 thru 1944 were some of the coldest on record IIRC. Lastly, were there any large volcanic eruption around 1910 the would have cause the temp dip?

    Comment by Harold Pierce Jr — 7 Mar 2008 @ 6:36 AM

  123. #108, Hank Roberts.

    Hank. 1st of all — Thanks!

    I used borehole values trying to correlate his 143-year lag-time to other earlier climate events, but find them smeared a wee bit too much to refute or change his values as smoothed. The correlation is weak since the values are small. Clearly, of course, the borehole information depicts the current characterization of global warming, and does so globally. (I really did dig into the borehole stuff, and can’t refute Carl with that.)

    I re-worked the entire set of values Carl espouses, and I used extant values as proxy data for temperature characterizations.

    I used Sachmann, Boothroyd and Kraemer values for solar fusion over the last 4.567 billion years, trying to see “when” the 1353 value actually existed from an energy production standpoint — and decided that the 1353 to 1367 doesn’t matter for the approximation, and it would be nice to actually understand sunspots and solar variability, (or get big carbon to get an anti-sunspot law through our congress, with fines.)

    Despite his use of engineering “units” (which leads to our logical thought-bottleneck by his not converting the units into metric) — the comparison of the 188 ppmv ice-age value to the 288 ppmv interglacial value and the correspondent temperature rise (Heck, call it the combination of H2O and CO2, and CH4 as the ‘natural’ GHG’s) and a linear expression is not all that much of a “stretch.”

    Meaning, the only possible invalidation of that linear comparison of ice-age proxy temperatures must come from the fact that the orbital changes that end the cold times rely on H2O(vapor) for a major part of the temperature rise — not simply the additional CO2 from the ocean and the thawed biomass decaying from what was ice-age grip.

    —– With a 10% solar flux increase (~1.1 billion years A.D.) our oceans begin to migrate in large quantities into the air. If we some how increase with CO2 blanketing, the surface wattage, I’m not sure haw we can stop the buildup of a runaway greenhouse. But — this is new ground. Even though 1300 ppmv to 2300 ppmv CO2 is implied in the 80 to 100 Mya period (Karen Bice, et. al.) remember the “hot tub ocean” — the solar constant was possibly in the 1270 – -1300 W/meter squared range. —

    Using the simplistic approach Carl uses is not an outlier. But it is repugnant! Bugs the heck out of me. And Hank, what can you suggest (forget boreholes) that can refute the proposition?

    To make a nice little world everyone can “believe-in” really requires this approach be fully, and doubly (by a second line of data) refuted.

    The highly respected fellow he mentions is James Hansen. And lots of people are afraid Hansen is right. 350 ppmv. The aerosol shield? As raypierre points out, a shield means a species commitment. You can’t just to it for a few years. I say on top of the shield we must commit to generation-long removal of the CO2, and its interment.

    Thanks so very much. It is a real challenging road we leave the future next 5 generations — with species self-termination a real possibility — and in so short a time!

    If you don’t do a solid refutation, hmmm, this is going to bother you, hmmm? (Smile)

    Comment by Les Porter — 7 Mar 2008 @ 6:46 AM

  124. You misplaced 3 zero’s. 5.1 x 10^15 tonnes about 5 million gigatonnes.

    Comment by Wim Benthem — 7 Mar 2008 @ 7:14 AM

  125. – the atmosphere weighs about 5.1 x 10^15 tonnes – say about 5,000 Gigatonnes (Gt).

    Try 5,000,000 Gt. 1Gt = 10^9t, not 10^12.

    Comment by S2 — 7 Mar 2008 @ 7:55 AM

  126. re: 118 FCH…nice idea, there is a way to utilise the carbon in plastics and rubber products ie: old tyres and mix that with iron ore to supplement the carbon content of the ore. Works quite well! The process of refinement however also produces one hell of a lot of CO2 and other greenhouse gasses..unless the iron refinary is directly over an area where geo-sequestration is possible.

    Comment by Lawrence Coleman — 7 Mar 2008 @ 9:51 AM

  127. re:114 Lovelock did mention the wide spread use of nuclear power was the ‘best of the other evils’. However, wide spread nuclear use should have been adopted at least 20 years ago, we have left it a little late at this stage we are at. It would have been a good interim source of power while ‘cleaner’ ways were being developed 20 years ago. Even we were to suddenly embrace the virtues of nuclear tomorrow it would still take 10-15 to get enough plants up and running to make any significant impact on north american let alone global energy efficiency. I still believe it is possible to increase the energy efficiency of photo-voltaics to above 20% and mass production wil keep the cost low. One example..on a street corner with say-4 houses, if one house agrees to cover their entire roof with solar panels, that house could supply the other 3 with power and they would get paid by the occupants of the 3 houses for monthly power consumed. Solar is so very versatile and with the cost falling buy the day, it should be the preferered energy source.

    Comment by Lawrence Coleman — 7 Mar 2008 @ 10:25 AM

  128. Re:#123 on the subject of an aerosol shield,in addition to a long term commitment problem,I don’t believe we know enough about the complex interactions between all the systems involved to experiment this way. What will be the effects on agriculture and on marine biota,for example, of a screened out Sun? We might do more harm than good or as they say ‘the cure could be worse than the disease’.

    The objejctive should be to mitigate the anthropogenic effects of climate change,not possibly add to them. This can best be done by radically reducing the human component of GHGs.A good example is the wedge approach proposed by Pacala and Socolow of Princeton University.

    Comment by Lawrence Brown — 7 Mar 2008 @ 11:17 AM

  129. Lawrence — rate of change, and rate of change of rate of change.
    We’re putting CO2 into the atmosphere very fast.

    Natural geological and biological processes change — slowly! — but rapid changes cause extreme outcomes.

    We’re provoking one now. Ward’s argument, from the geological record, is that this has happened before, at times CO2 increased a hundredth as fast as we’re increasing it now.

    See Ward’s book; audio interview here.

    Comment by Hank Roberts — 7 Mar 2008 @ 11:41 AM

  130. Les — see all the work done on climate sensitivity. The guy with the Physicist page has a number so extreme that it doesn’t match anything from the geological record, and he’s getting it by logic.

    If his number were right, the past geological record would be wrong.
    I don’t believe the strata are unreliable to that extent. Yes, we’re changing the world far faster than any past event short of an asteroid impact or “Deccan Trap” basalt flow. But that’s not what he’s talking about.

    The “Physicist” illustrates the old way of doing science, reasoning what the world must be like from a few basic truths. It’s the “founder” approach — this is why people try to find “founders” for evolution and climate science, because logical pyramids often become logical houses of cards built on a foundation that can be shaken.

    Our brains didn’t change 200 years ago. Somehow, though, people began to think beyond founders and logic to empirical science.

    Look at the geological record, read at the current estimates from the IPCC, read

    Comment by Hank Roberts — 7 Mar 2008 @ 11:54 AM

  131. Lawrence Coleman (121) said why then do scientists say that greenland and antartica if they were to completely melt would only constitute a moderate 7m rise a piece for a tot. of 15m..where’s the other 10m coming from?

    They don’t. Greenland completely melting, about 7 m sea stand rise; West Antarctic Ice Sheet completely melting, again about the same. East Antarctic Ice Sheet is assumed not to melt.

    Comment by David B. Benson — 7 Mar 2008 @ 1:10 PM

  132. 121 see for a breakdown of the constituent elements of an 80 metre sea level rise

    Comment by mg — 7 Mar 2008 @ 3:35 PM

  133. Thanks! My passion and maths dont mix well eh! From wiki total mass of atmosphere 5.1361×10^18 kg = 5.1e15 tonnes = 5.1 Petatonnes = (as you correctly say) 5,000,000 Gigatonnes. That drops the percentages in my CO2 calcs by 1e-3, BUT it retains the relationship between the annual flux of CO2 of 240Gt and the content of CO2 in the atmosphere of about 2Gt and that’s my point.

    So the ins and outs are (I think!) 100x the residual we breath, and so marginal changes in either the emitter or the sink could have drastic effects on the CO2 content. It appears that the amount of CO2 in the atmosphere is about the equivalent of around 3 days total (all sources) emissions and about a month’s worth of anthropogenic emissions.

    At present we are pushing in the wrong directions with both ends of the deal – we are trashing the sinks by destroying forests and other natural sinks, while we are continuing to increase emissions by burning oil at peak production rates and steadily increasing coal burning as we open a new coal powered generation plant every two days. It would not be hard to see a situation where over a relatively short period (months) atmospheric CO2 could double! The impact of that forcing would be impressive to say the least!

    Is this sensitivity real – if not what is it that’s acting as the buffer here?

    Comment by Nigel Williams — 7 Mar 2008 @ 5:34 PM

  134. RE: # 130,#123,#108,#103

    Thanks Hank.

    You took a look. You missed.

    There is “no comparable geological period” to refer to. None. Ever, and the reason? The reason is this is new ground. The sun’s irradiance, the solar constant, has never been here before, except during the era of solar fusion ignition. CO2 has been up and down. But the sun brightens inexorably, steadily, and where we are now on its projected main sequence burn is about halfway to red giant. The solar constant has not been as high as it is now, for 4.567 billion years. When the sun ignited, for a brief time it 17 times its current luminosity. Then within 50 million years it settled down and burned at about 70% of what it is now. It has been a nice linear burn from 70% to 100%. But never has the solar constant been as it is now.

    There are no comparable geological times past.

    Use some simple numbers to show the error of Carl’s ways.

    Thanks! You may have what I assume is the last word. If you comeback with something in the numbers and easy, hey!

    Comment by Les Porter — 7 Mar 2008 @ 6:07 PM

  135. Re #117: The Scafetta & West Physics Today article (pdf here) is just a review of their prior work. Why it got published is a mystery to me, although perhaps PT was making a point when they categorized it under “opinion” (see table of contents here). Giving them plenty of rope?

    One can but stand back and admire this paragraph:

    “Thus, the Sun’s influence on Earth’s temperature is subtle because it is not just an energy transport process but also an information transfer. According to linear response theory in statistical physics, a network S responds to a perturbation P by means of a linear transfer equation, whose kernel, the response function, is determined by the fluctuation–dissipation theorem given that the perturbation is sufficiently weak. When S and P are non-Poisson renewal processes, the response of S is maximal when the complexity of the two networks, as measured by the inverse power-law indices, is matched. For the Sun–Earth one-way linking, S is the Earth and P is the Sun. The complexity-matching effect in the Sun–Earth network is evident in the equality of the inverse power-law indices.”

    Chasing solar butterflies?

    Comment by Steve Bloom — 7 Mar 2008 @ 6:08 PM

  136. b>Comparable geological period?

    There is “no comparable geological period” to refer to. None. Ever, and the reason? The reason is this is new ground. The sun’s irradiance, the solar constant, has never been here before. CO2 has been up and down. But the sun brightens inexorably, steadily, and where we are now on its projected main sequence burn is about halfway to red giant. Although ignition and settling on the main sequence appears to fit best with 70% of present value, Sachmann and Bothroyd tried to fit a slightly different model to something that would give you a young wet Mars. (I never accepted that model, but it gives you a shot at a wet Mars.)

    I have a good understanding of the IPCC stuff.

    I enjoy the links, they are illustrative of your approach, and mine.

    I’ve used a few of the NCAR models, read all the IPCC stuff, especially their extremely accurate characterizations and estimates relating to the vanishing polar sea ice. The preferred IPCC models are off one standard deviation, 1 sigma.

    I addressed Carl’s hypothesis directly to him — he thinks I have attacked him, so I am not on a good footing with him. But have not completed my complete reanalysis of what he has done. So I could refute it.

    Thanks Hank. Just do the numbers. Or do some numbers, using his approach and refuting the whole idea.

    Use his numbers or your numbers to show he is wrong; point out precisely where his numbers are wrong and by how much. (I have used your arguments already.)

    Granted. He is pretty irritating in his manor and means of pronouncement. He has some practical works if you explore the rest of his postings, and he has made some money on wood stoves, I guess several million, he has an interesting abode, he is greener than most. But I ask you to attack the preposterous conclusion with numbers and extant empirical, observational data, and there is nothing wrong with working Stefan Boltzman backwards, that is how we first determined the energy output of the sun, blackbody thermodynamics, absolute zero, things like that.

    Try to do some numbers. I can cite a thousand places and papers, and none of them refute either his approach or conclusion. As I said, the most likely contributor to the Temperature at 188 and the warming Temperature at 288 is a larger quantity of H2O vapor aloft at the ice-age terminations.

    That H2O really helps with the warming — so I am suggesting that adding nearly 1/4 more CO2 to the 288, or when the CO2 rises from 188 to 288 then 388 the temperature change is not linear. (yes, I know we are right at 385 now, and we passed the 350 in 1989)

    When do you reach equilibrium? How do you plainly and easily compute it? That is, how long does it take to reach equilibrium with 385 -390? That is what (my supercilious friend) Carl is getting at. How soon do we cook, and how well-done do we get.

    Comment by Les Porter — 7 Mar 2008 @ 6:32 PM

  137. Thank you Gavin for your response to 80. It provided an impetus to research further the idea of an energy imbalance. Before I get to that, just one question about your response. Was the 255k you quote as the mean emitting temperature based on an equation derived from the fact that outgoing emission has to equal incoming absorption? The reason for the this question is pretty obvious, as you, yourself point out, with others, the earth is in an energy imbalance. Specifically, how does that imbalance effect the equation
    πr²(1-a)So=4πr²σTe. Secondly, or more importantly, if the earth is emmitting less energy than what is absorbed, due to the ocean, would that not imply that the atmosphere is cooling. I mean think about it, if energy is going into the ocean than it would not be available to the atmosphere. Of course, I realize that science has a history of proving the most counter-intuitive theories as plausible, and in no way doubt the veracity of Hansen et al 1(2005), but still, when the same person tells me that

    However, the cool Pacific Ocean only enhances the planetary energy
    imbalance [Hansen et al., 1997, 1999] which tends to increase surface temperature.

    and then states,

    Confirmation of
    the planetary energy imbalance can be obtained
    by measuring the heat content of the
    ocean, which must be the principal reservoir
    for excess energy (3, 15). Levitus et al. (15)
    compiled ocean temperature data that yielded
    increased ocean heat content of about 10 W
    year/m2, averaged over the Earth’s surface,
    during 1955 to 1998 [1 W year/m2 over the
    full Earth È 1.61  1022 J;

    I belive you can understand why I am confused. As I said, from an intuitive perspective, the ocean cooling i.e. shedding energy, would imply to me an atmospheric warming, whereas an ocean warming would mean less available energy for the atmosphere, and thus atmospheric cooling. Fortunately, I accept that you know more about this paradox than I, and can only hope your response will not include the heads I win, tails you lose argument found in the published papers.

    Comment by Ellis — 7 Mar 2008 @ 10:39 PM

  138. Re #133 Nigel Williams:

    Thanks! My passion and maths dont mix well eh! From wiki total mass of atmosphere 5.1361×10^18 kg = 5.1e15 tonnes = 5.1 Petatonnes = (as you correctly say) 5,000,000 Gigatonnes. That drops the percentages in my CO2 calcs by 1e-3, BUT it retains the relationship between the annual flux of CO2 of 240Gt and the content of CO2 in the atmosphere of about 2Gt and that’s my point.

    Oops indeed. The content of CO2 in the atmosphere is also 1000x larger, 2000 Gt (or 3000 Gt with correct molecular mass), so… the annual flux is only 8% of this. It takes ten years for full recycling.

    Often you see the argument that these natural fluxes are so much bigger tham our industrial output of CO2, that the latter can be ignored by comparison. The misconception is due to missing that the biological carbon cycle preserves carbon: what is taken out by plants is put back, precisely, by digestion, decay etc. sooner or later. Atmospheric (+oceanic) CO2 can only change if some non-biological process either adds or removes carbon from the cycle.

    Only three mechanisms come to mind:
    1) volcanism and rock weathering + carbonate deposition — small capacity, long term (tens of thousands of years)
    2) deposition of fossil fuels — slow.
    3) release of fossil fuel carbon — very fast. This overwhelms the first two.

    You can think of the metaphor of a company with a large turnover, but a small but constant loss year-over-year. It will go bankrupt.

    Comment by Martin Vermeer — 8 Mar 2008 @ 5:52 AM

  139. re: 118 FCH…nice idea, there is a way to utilise the carbon in plastics and rubber products ie: old tyres and mix that with iron ore to supplement the carbon content of the ore. Works quite well! The process of refinement however also produces one hell of a lot of CO2 and other greenhouse gasses..unless the iron refinary is directly over an area where geo-sequestration is possible.

    I’m talking about refining things that contain carbon into a more pure form of carbon, not using carbon for stuff. That’s a fairly simple process involving heat and not so much air. That giant ball of fire in the sky provides plenty of heat. Just take the leftover charcoal and bury it in the ground, instead of pumping massive amounts of CO2 into the ground for generations to come to have to deal with.

    Comment by FurryCatherder — 8 Mar 2008 @ 9:19 AM

  140. Les Porter (136) — The natural climate system takes thousands of years to reach a quasi-equilibrium.

    FurryCatHeader (139) — Either biochar or biocoal, about which more can be found at

    will certainly be sequestered for thousands to millions of years. However, preliminary studies indicate the same is true for various forms of sequestering liquid CO2.

    Comment by David B. Benson — 8 Mar 2008 @ 1:15 PM

  141. Whew! Thanks Martin 138 for getting us the right numbers. Thats helped my understanding of the mechanisms I was fretting about a lot. 8% in and out a year in total and so I guess its about 1% per year that’s anthropogenic.

    Gives us an idea of how much difference say a 10% reduction in our emissions would make to the overall flux. Not much in time. Interesting.

    Comment by Nigel Williams — 8 Mar 2008 @ 8:17 PM

  142. in #101 Bruce Tabor said:

    The most rapid known rise in sea level occurred at the end of the last ice age during the so-called Meltwater Pulse 1A. I’ve seen various estimates, but a typical one is a 25 metre rise in 500 years or 5 metres per century, 0.5 metres per decade…. The actual forcing that triggered this was small compared to current climate forcings – initially only about 0.25 W/m^2 – we currently have 0.75 +/- 0.25 W/m^2 and rising. Somehow this initial trigger led to the build up of GHG’s and albedo changes (and more forcing) that resulted in this rapid rise in sea level. I don’t know exacly how soon after the trigger it occurred, I suspect it’s unknown.

    Current climate forcing is indeed more extreme, but Meltwater Pulse 1A (thanks for the link, Bruce) occurred as an ice age was ending, when there was greater extent and quantity of ice and snow vulnerable to rapid melting and other destabilization. I consider it likely, therefore, that the melt which human unburied carbon emissions are provoking will not be as fast for as long as Meltwater Pulse 1A probably was. Which may have been down to half as fast and up to twice as long as the estimate you cite, within the uncertainties, IIRC.

    in #116 Steve Bloom put it like this:

    … look at conditions that were about similar to the present (i.e. starting with a similar amount of ice that is then subjected to added warming). Looking at what happened during the big melt 12ky ago is thus not useful, but the tail end of the last deglaciation (the Eemian) is more useful…. The recent paper on this subject is here and a perhaps more useful interview with the lead author here (noting that someone linked the abstract above).

    That was I, Steve. Thanks for the URLs. My own link to the article from when I first read it was no longer working, and I had never seen the Scitizen interview with Rohling before. I’ve cited both now in my blog entry.

    The upshot is that all else being equal (to the Eemian) we’re looking at 1.5 to 2.5 meters/century (the latter being the worst case).

    If I may quibble I think the .5 in both numbers is a .6 in the original. In any event sea rise at that rate would be disastrous even though it would not match Meltwater Pulse 1A.

    All else may not be equal though, since the late Eemian melt was driven by increased high-latitude insolation due orbital changes rather than GHGs and since we could apply more forcing.

    Aye, there’s the rub.

    Comment by Meltwater — 9 Mar 2008 @ 7:56 AM

  143. Could someone separate out the different topics in this stream of responses? Each could be a separate discussion. thanks

    Comment by dick roman — 9 Mar 2008 @ 12:20 PM

  144. Related to the speculation of what would happen when another 536 CE type event occurs, here is some commentary regarding the current world food shortage:

    Comment by David B. Benson — 9 Mar 2008 @ 2:36 PM

  145. Re #141 Nigel Williams:

    Thanks Martin 138 for getting us the right numbers. Thats helped my understanding of the mechanisms I was fretting about a lot. 8% in and out a year in total and so I guess its about 1% per year that’s anthropogenic.

    Gives us an idea of how much difference say a 10% reduction in our emissions would make to the overall flux. Not much in time.

    But, read also what I wrote about the carbon cycle balance. The 8% is indeed in and out, the 1% is in, but not out. It’s “profit” (or from the human viewpoint, loss), not turnover. The 10% of 1% reduction appears on the bottom line, never mind the turnover.

    Comment by Martin Vermeer — 10 Mar 2008 @ 3:48 AM

  146. # 140
    referring to my #136 but apparently not doing the background reading. . . RE: # 130,#123,#108,#103
    David Benson??? (Tongue in cheek! Thanks. Are you kidding?)

    What is really obvious is that “this” is not a “natural climate situation” that will take thousands of years to gradually arrive at and reach equilibrium.

    It may be hard to think in punctuated terms. Like the period at the end of a sentence. The gradual acceptance of tectonics and the gradual recent grasp of the KT impactor are two different ideas.

    Tectonics is long and continual and gradual, but we in the community accepted it once we saw the mechanisms. (Sea floor spreading, magnetic pole reversals in the tracks, mapping the continental shelves, identifying the exact same rock groups in Africa and South America.) Tectonics is almost as geologically gradual as erosion.

    Differentiation in the mantle must still be the mechanism carrying the rafts of light rock around on the surface. . .?

    Uniformitarianism is still a nice way to look at tectonics, but there is some understanding the earth is old enough for 30,000 foot tall mountains of granite to have had time to be scraped or weathered to dust.(sedimentary rock) The Canadian shield was unlikely ever that tall and it is good to see some of the old (crust) still around.

    The AD 536 sulfate cooling did affect Ag around the world. It was a punctuation kind of event. The KT impact was definitely a punctuation event, and life really went a different direction at the end of that sentence.

    If we are unable to prevent the serious consequences of the massive amounts of CO2 we have floated into the Commons, this period of human presence in the geologic record will look like a period at the end of a sentence? Or a layer like the KT boundary layer?

    How long do YOU think it will take for the Atmosphere and the Land beneath it to reach equilibrium? Carl suggests 143 years for 390 ppmv, IPCC and some NASA models suggest as long as 500 years. I think more than 143 years, but not as much as 500 years as per the performance of the Arctic Sea Ice.

    But the question really is: How long would it take nature to remove what we have added, or can it do so by itself? Were we gone tomorrow, all of us in a flash, would life accomplish the adaptations needed to survive what we have done — if the temps reach 12C to 15C (22F to 27F) above our current average. Could life adapt in time? Some could walk north or south and high.

    But would the plants of the tropics survive 150 to 160 F or more, so things that eat the things that eat plants that we and other things eat could survive. Plants run slowly. We would lose many. And if we lose too many we die.

    If the time to reach “quasi-equilibrium” is 143 years or 500 years — does that enhance the running speed of plants?

    I think we are looking at more than a million years to begin to recover life aplanet without us, or without our help. If we are the best-brightest life form on earth and can survive, I think we can’t do BAU.

    Thanks for your comment — and realize, neither you nor I are likely to live to experience what is coming.

    Comment by LesPorter — 12 Mar 2008 @ 1:58 PM

  147. LesPorter (146) — Not only do I read all the comments on every thread, I actually read some of the climatological literature. One paper, of several, which treats the current pulse of global warming (so-called greenhouse) gases being added by human activites is the Archer/Ganopolski 2005 paper. I’ve posted about it before, but in any case it is easily obtainable from David Archer’s publications web page.

    Another is a recent paper (possibly still a preprint) by Hansen et al. demonstrating effects continuing for over 1500 years.

    Comment by David B. Benson — 12 Mar 2008 @ 5:42 PM

  148. #147,

    David, thanks

    Just pop out those web locations and I’ll read what is available with out elsevier and ingenta or such.

    If Jim did the work with NASA connections support, etc., it should surely be available soon. If he did it at home, I used to do that too.

    In leiu of that — when and if most of the land plants are gone with a temperature higher than they can adapt to, how long does it take to return to lower than 350 ppmv?

    I again need to clarify. Without reduction down to Jim Hansen’s 350 ppm — what will the temperature be in 1500 years? If a sufficient quantity of plants still exist in a warmer ocean, but few plants are able to reclaim the land, how long does it take to cool the planet so that some kinds of lush plants can gobble CO2 from land?

    My concern is what happens if we do loose control and we may have passed that point — so that the equilibrium is 20 to 30 F higher — and stays that way?

    I’d be interested in reading those papers. You cite no locations, but I’ll see if I can find them anyway, yes, starting with Dave Archer’s page.

    Thanks again.


    Comment by Les Porter — 14 Mar 2008 @ 12:06 AM

  149. Les, good clues to how long it takes in a Science paper a while back, I mentioned it in an earlier thread here and elsewhere.
    and on how the PETM started

    Comment by Hank Roberts — 14 Mar 2008 @ 9:03 AM

  150. Les Porter (148) — Google search is your friend. For example “David Archer Chicago” gets you there. Probably also works for “James Hansen NASA”, but here is the link which contains .pdf files of interesting papers:

    Also, here is a summary & commentary on a recent paper in Geophysical Research Letters which you will find of interest:

    Comment by David B. Benson — 14 Mar 2008 @ 12:25 PM

  151. # 147 David — see below. Thanks!
    # 149 Hank — thanks.

    Hank, also see:
    The Lovelock Interview:

    And from 1998, ten years earlier, in “Essays on Science and Society,”
    Science Essay:
    “a book for all seasons.”

    # 147, David B.Benson took me rightly to task, read on. . .

    David B. Benson,

    I just now scanned Archer/Ganopolski’s paper, and am printing it out for leisurely reference and to chase references, etc.

    What little I have digested in the last few minutes makes me wonder which plants survive the temperatures that will/would be forthcoming with another 5000 Gt C in the air.

    I will read the paper completely but 5 trillion tons C combines with O2 to make 44/12’s times that much CO2, such that we add another 18.3 trillion tons or 18,300 Gt CO2 to the atmosphere. It takes a fire (combustion) to join the C to the O2, and it gives off some chemical reaction heat, which I will ignore for this back of the envelope approach.

    . . . .[Come on! Imagine — Air/ fuel explosive! Finely powder 5,000 Gt C spread it as a powder in the appropriate volume of air, throw in a match or spark and . . . locally that is quite an explosion, and changes a lot of carbon dust to CO2. . . Slow burn also produces some BTUs. . . or maybe CH4 . . .( Filmmaker’s, we’ll get back to “The Day The Arctic Burned” (Sensational!-low-budget climate-change-film in the spirit of The Day After Tomorr . . . ). . .methane rises, bubbles to the surface, froths the Arctic Ocean, Shiphand Seaman First Class Jureska Novograd, who’s still trying to quit smoking, stands in the almost chilly arctic summer air on the bow of the Progresso an open Arctic Ocean-crossing ice-breaker-freighter, bound for Portugal, sees ahead where the ocean looks like it has a new layer of ice, but as the freighter gets closer, Jureska sees the white color is the Arctic Ocean boiling bubbling, seething — and light’s his last smoke. . . .and finally quits smoking. . . but the Arctic Ocean’s surface burns and flashes for weeks and months as the methane rises. . . the Arctic Communities are heavily. . .] . . .

    Back to the Earth-CO2, on the recovery track. . .

    5.0 x1012 x 44.01/12.01 = 18,322 billion tons CO2 That’s what 5000 Gt C + 02 weighs as CO2.

    The atmosphere weighs 5135.2 trillion tons (NCAR before Bushed)

    44.01/28.96 = 1.5197 (how heavy CO2 is WRT “average” air.)

    So we take 5,000 billion tons C combined with O2 for 18,322 billion tons CO2, and add it to the current (385ppmv) 3004.53 Gt CO2 in air “now” to yield a total of 21,327 Gt CO2 in air, and what would that do to the Model Temperatures and length of time to remove from the air?

    I’ve done this below showing that the extra 5000 Gt C as C02 corresponds to a value of approximately 2,733 ppmv, or 7 times the current concentration of CO2. That is a possibility (my low budget film above) and no matter how long algae that survive a hot ocean take — we lose a lot of land plants.

    (I believe Land plants are perhaps more efficiently exposed to CO2 quantities via immersion in air with the available CO2 than plants in the top couple of meters water — and can capture larger quantities of CO2 on land than plants in water. I grant that some mosses do really well, and will check this assertion (My Act of Faith assertion) out, but for the moment. . .)


    Ice age CO2 x ratio x weight of atmosphere = weight of CO2 in atmosphere.
    0.000280 x 1.5197 x 5,135.2 x 1012 = 2,185.11 billion tons CO2 ice age
    0.000385 x 1.5197 x 5,135.2 x 1012 = 3,004.53 billion tons CO2 now
    0.002733 x 1.5917 x 5,135.2 x 1012 = 21,326.76 billion tons CO2 (5000 Gt C new)


    My remarks, Off the Cuff. . .since I have not delved into the full set of references and am only “remarking” on the “conservative approach . . .”

    Archer and Ganopolski, in their results section, pgs 4, 5, 6, have serious fun and do not stretch the modeling at all. (Now these models have not at microtime scales real accurately reflected the current arctic sea ice situation.) And I therefore question the average 4.7o C positive perturbation for 500 kyr . [-15] (i think it might be over 8o C).

    I realize the Delta T for a CO2 doubling giving 3o C is used, but point out that 2733 ppm is a lot more than doubling-and-a-half and corresponds to more than 7 times the current 385 ppm for which we have no easily antecedent proxy for temperature and near current solar constant.

    (We ain’t been here before, exactly. . .just do the best we can from the past record to turn it ahead like a mirror, using our rearview mirror to drive this unknown road; yeah we stumble a lot.)

    Karen Bice, et al, (Woods Hole) with the hot tub ocean from 91o to 107o F. 33o to 42o C from foraminifera, and proxy CO2 values from 1300 to 2300 ppmv in the 80 — 100 Mya range (before K/T) had solar constants logically in the ~1356 range. (Solar Constant just whipped out here as a linear function from Earth current to 4.5 Gya at ~970 W/m2, then back to 100 Mya.)

    Read the paper here:

    Or the easy version here:

    The Archer paper and Bice paper only intersect in my mind in the realm of comparative CO2 ppmv’s and terrestrial temperatures. I have recently counted on the ocean’s solubility and temperature as per solubility as a “place” for the CO2 to go, to save us from the death of land/food plants.

    Now, it doesn’t look that good. I don’t think the ocean is going to absorb this excess we have now, let alone what Archer and Ganopolski provide caveat to real disaster — which is only cacti and far north phytoplankton as means of re-capturing the CO2 we’ve exhaled to the air. Karen Bice’s 42o C ocean provides one example of past high temperatures and proxied high ppmvs CO2. Oceans don’t get that warm now, according to NASA, NOAA, and I reference this:

    Also relevant:

    (from work of Maura Rabbette)

    If the “Day the Arctic Burned” (5000 Gt C) arises as a punctuating step with methane release, the temperatures ought to be scaled up to a Delta T (for CO2) of 7.13x instead of 2x, or 4x. Which is a criticism of Carl Johnson’s simplistic linear approach as well. (Not Archer, et al)

    Carl Johnson does not really address the ocean contribution, except obliquely. Why, for example, do the ocean depths stay so cool when it is obvious that the ocean basin basalts should be conducting some of the earth’s geothermal through the ocean basins to warm the oceans. Yet Carl only wants to use the top 3000 feet of continental rock to equilibrate with 390 ppmv CO2 temperatures. (Don’t think about this unless you just can’t help it.)

    But it does not look good ahead of us.

    David B. Benson, I won’t pick on you for “not reading the thread posts” — or thinking you haven’t — ever again! Also want to thank you for the head’s up for the two papers, and I will look for Jim Hansen’s 1500 year extrapolation.

    I really really enjoyed the Archer and Ganopolski paper, think they are conservatives, and will dig through the paper again.

    I find that I started out totally downplaying the “sulfate aerosol shield” a few months ago — and still do not like it for all the obvious reasons, the main one being that it will be funded by Big Carbon Inc, and possibly be used to extend the use of Fossil C for everything but lubricants, and transportation. Now I am starting to feel P. Crutzen and others have a piece of our only salvation with the way this planetary emergency is playing out.

    Huge “moving/running” plants, like the Trifids (original written) version trained genetically to gorge on CO2 in un-ending quantities to their own extinction might be better. . . we could do the same on fossil carbon, huh?

    What plants are going to save all creatures, great and small?


    Comment by Les Porter — 14 Mar 2008 @ 2:58 PM

  152. Les Porter (151) — You are welcome. See also my comment #150.

    In figuring these out, please take into account that Peak Oil, followed not long thereafter by Peak Oil, will limit the ability to attempt to exploit deep ocean methane (strictly natural gas) hydrates. So it is probably more sensible to calculate with smaller figures than 5000 GtC. Use the Peak Oil+Coal figures plus whatever CO2 equivalent for the methane being expressed from bogs and tundra appears to be a sensible estimate as temperatures rise.

    You might also wish to study more about PETM. The Wikipedia page provides a starting point and you can also use the search feature at the top of the Real Climate page.

    Comment by David B. Benson — 14 Mar 2008 @ 4:51 PM

  153. Minor note: the 280 ppm is end of Ice age, beginning of the warm. You can plug in 0.000188 to get the tons of CO2 airborne in a full fledged Ice Age. I meant to put that in there. It is 1466.29 Gt C.

    That is what keeps the planet from a snowball with recent insolation. My Quick and Dirty, taken back to say 700 Mya changes the Solar Constant to ~1305 W/m2, which to me is in equatorial wet fluctuating snowy ball range, but obviously with also the possibility of a band of tropical or equatorial zone oceans — where large areas either side of the equator are fluctuating sea ice. That is a while back, the linear extrapolation is from ~1368 “now” to solar ignition ~960 W/m2 4.5 Gyr back “then” in time.

    Sorry if I misled anyone. The table figure should have started off with the 188 ppm value, and the others are back of envelope despite the digits.

    The 536 AD event, unlike the K/T just cooled things down a little. Warming can also make it hard for crops to transpire and lots of water will be consumed to keep a plant alive in the heat. To exhaustion, demise, exceeding what it has adapted to.

    Comment by Les Porter — 14 Mar 2008 @ 5:23 PM

  154. OT, posted here because the original article is by Gavin, to whom this is relevant. In New Scientist for 22 March, p.11, there is an article “Rising Temperatures bring their own CO2”. Fine, you might think, we all know about this feedback. However, in the contents page, the article is pointed to using the words “Climate sceptics may have a point”, and in the article itself, Fred Pearce begins:
    “Climate sceptics are right. Temperature increases do precede rises in atmospheric carbon dioxide – the opposite of what you would expect if changes in CO2 were really driving climate change. That’s the verdict of leading atmospheric modeller Peter Cox, a climate expert at the University of Exeter.”
    Pearce does go on to say Cox stresses this does not mean we do not have to worry about GHGs, but quotes him as saying:
    “People on both sides want a one-way link, but the historical record shows the causality goes both ways”.
    No papers by Cox are cited – the most recent relevant one I can find is “Positive feedback between global warming and atmospheric CO2
    concentration inferred from past climate change” by
    Marten Scheffer, Victor Brovkin and Peter Cox, published in Geophysical Research Letters in 2006 (I can’t find an exact reference). This paper stresses that the historical work on the Little Ice Age agrees with climate model results.
    Is Cox given to saying stupid things for publicity, or is this (as I suspect) a misquotation or out-of-context quote by Pearce? (At the end of the article, Gavin is quoted as saying “We are headed into unknown territory and the only things we have to guide us are physics and our knowledge of the past.”) I intend to complain to NS about this irresponsible rubbish, which we are bound to see cited by denialists for the indefinite future, but it would be useful to know who is at fault.

    Comment by Nick Gotts — 20 Mar 2008 @ 2:30 PM

  155. Lawrence Coleman is a pompous ass! There are as many learned neurons on both sides of the AGW or ACC or whatever you wish to call it argument. The IPCC is political and deserving of immense skepticism.

    Admit that you will apologize and quit science if you are wrong and only then will you have shown the humanity to be believed by others just as intelligent as you are.

    To believe you alone have wrested sense from chaos is laughable. You invite argument by your impudent denunciation of opposing voices.

    You are a fool.

    John lagace


    Comment by john lagace — 31 Mar 2008 @ 7:09 PM

  156. John Lagace, OK, so you are skeptical of the IPCC. Fine. So start with the peer-reviewed scientific literature. The number of published studies is a pretty good metric. The number of studies that support anthropogenic causation of climate change outnumber those that do not by roughly 2 orders of magnitude–a pretty good sign of consensus. But don’t stop there. Look at how often the papers are cited once they are published. Here the consensus for anthropogenic causation is even more stark–nearly every study that questions anthropogenic causation pretty much falls flat. They simply do not point to fruitful new avenues of inquiry–being cited only by refutations or when the authors subsequently “update” the cycle a few years hence. Look into the backgrounds of those publishing the “dissenting” studies–virtually none of them are actual climate scientists. Finally, look at the position statements taken by professinal organizations of scientists. Not one actually dissents from an anthropogenic mechanism for climate change. To make the claim that there are “as many learned neurons” on either side of the question of anthropogenic causation is sheer ignorance–the neurons that claim we aren’t behind the changes have never studied climate change.
    Finally, might I suggest that you will get much further on this site of you confine yourself to the details of your opponents’ arguments rather than launching ad homenim attacks.

    Comment by Ray Ladbury — 3 Apr 2008 @ 10:37 AM

  157. I’m not sure how much to rely on Keys. Reviewing Keys’ book in British Archaeology, the British archaeologist Ken Dark commented that “much of the apparent evidence presented in the book is highly debatable, based on poor sources or simply incorrect” and that “Nonetheless, both the global scope and the emphasis on the 6th century AD as a time of wide-ranging change are commendable, and the book contains some fascinating and obscure information which will be new to many. However, it fails to demonstrate its central thesis and does not offer a convincing explanation for the many changes discussed.

    Comment by Doug Weller — 12 Jan 2009 @ 11:01 AM

  158. Somewhere I read of a claim that a meteorite impact in northwestern Australia gave rise to 536 AD and all that.

    Comment by David B. Benson — 12 Jan 2009 @ 12:55 PM

  159. David, you may be thinking of Plimmer? Odd duck. Google for +536 “dust veil” “cometary dust” — lots of stuff out there.

    “… 535 AD Krakatoa exploded, as did Rabaul in 536 AD. The Earth passed through cometary dust in 536 AD. The dusty atmosphere reflected heat and darkness prevailed and, as a result, the climate cooled….”

    Comment by Hank Roberts — 12 Jan 2009 @ 2:04 PM

  160. Hank Roberts (159) — Definitely not Plimmer.

    Comment by David B. Benson — 12 Jan 2009 @ 2:35 PM

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