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Is the ocean carbon sink sinking?

Filed under: — david @ 1 November 2007 - (Español)

The past few weeks and years have seen a bushel of papers finding that the natural world, in particular perhaps the ocean, is getting fed up with absorbing our CO2. There are uncertainties and caveats associated with each study, but taken as a whole, they provide convincing evidence that the hypothesized carbon cycle positive feedback has begun.

Of the new carbon released to the atmosphere from fossil fuel combustion and deforestation, some remains in the atmosphere, while some is taken up into the land biosphere (in places other than those which are being cut) and into the ocean. The natural uptake has been taking up more than half of the carbon emission. If changing climate were to cause the natural world to slow down its carbon uptake, or even begin to release carbon, that would exacerbate the climate forcing from fossil fuels: a positive feedback.

The ocean has a tendency to take up more carbon as the CO2 concentration in the air rises, because of Henry’s Law, which states that in equilibrium, more in the air means more dissolved in the water. Stratification of the waters in the ocean, due to warming at the surface for example, tends to oppose CO2 invasion, by slowing the rate of replenishing surface waters by deep waters which haven’t taken up fossil fuel CO2 yet.

The Southern Ocean is an important avenue of carbon invasion into the ocean, because the deep ocean outcrops here. Le Quere et al. [2007] diagnosed the uptake of CO2 into the Southern Ocean using atmospheric CO2 concentration data from a dozen or so sites in the Southern hemisphere. They find that the Southern Ocean has begun to release carbon since about 1990, in contrast to the model predictions that Southern Ocean carbon uptake should be increasing because of the Henry’s Law thing. We have to keep in mind that it is a tricky business to invert the atmospheric CO2 concentration to get sources and sinks. The history of this type of study tells us to wait for independent replication before taking this result to the bank.

Le Quere et al propose that the sluggish Southern Ocean CO2 uptake could be due to a windier Southern Ocean. Here the literature gets complicated. The deep ocean contains high concentrations of CO2, the product of organic carbon degradation (think exhaling fish). The effect of the winds is to open a ventilation channel between the atmosphere and the deep ocean. Stratification, especially some decades from now, would tend to shut down this ventilation channel. The ventilation channel could let the deep ocean carbon out, or it could let atmospheric carbon in, especially in a few decades as the CO2 concentration gets ever higher (Henry’s Law again). I guess it’s fair to say that models are not decisive in their assessment about which of these two factors should be dominating at present. The atmospheric inversion method, once it passes the test of independent replication, would trump model predictions of what ought to be happening, in my book.

A decrease in ocean uptake is more clearly documented in the North Atlantic by Schuster and Watson [2007]. They show surface ocean CO2 measurements from ships of opportunity from the period 1994-1995, and from 2002-2005. Their surface ocean chemistry data is expressed in terms of partial pressure of CO2 that would be in equilibrium with the water. If the pCO2 of the air is higher than the calculated pCO2 of the water for example, then CO2 will be dissolving into the water.

The pCO2 of the air rose by about 15 microatmospheres in that decade. The strongest Henry’s Law scenario would be for the ocean pCO2 to remain constant through that time, so that the air/sea difference would increase by the 15 microatmospheres of the atmospheric rise. Instead what happened is that the pCO2 of the water rose twice as fast as the atmosphere did, by about 30 microatmospheres. The air-sea difference in pCO2 collapsed to zero in the high latitudes, meaning no CO2 uptake at all in a place where the CO2 uptake might be expected to be strongest.

One factor that might be changing the pressure of CO2 coming from the sea surface might be the warming surface waters, because CO2 becomes less soluble as the temperature rises. But that ain’t it, as it turns out. The surface ocean is warming in their data, except for the two most tropical regions, but the amount of warming can only explain a small fraction of the CO2 pressure change. The culprit is not in hand exactly, but is described as some change in ocean circulation, caused maybe by stratification or by the North Atlantic Oscillation, bringing a different crop of water to the surface. At any event, the decrease in ocean uptake in the North Atlantic is convincing. It’s real, all right.

Canadell et al [2007] claim to see the recent sluggishness of natural CO2 uptake in the rate of atmospheric CO2 rise relative to the total rate of CO2 release (from fossil fuels plus land use changes). They construct records of the atmospheric fraction of the total carbon release, and find that it has increased from 0.4 back in about 1960, to 0.45 today. Carbon cycle models (13 of them, from the SRES A2 scenario) also predict that the atmospheric fraction should increase, but not yet. For the time period from 1960 to 2000, the models predict that we would find the opposite of what is observed: a slight decrease in the atmospheric fraction, driven by increasing carbon uptake into the natural world. Positive feedbacks in the real-world carbon cycle seem to be kicking in faster than anticipated, Canadell et al conclude.

There is no real new information in the Canadell et al [2007] analysis on whether the sinking sink is in the ocean or on land. They use an ocean model to do this bookkeeping, but we have just seen how hard it is to model or even understand some of the observed changes in ocean uptake. In addition to the changing ocean sink, drought and heat wave conditions may change the uptake of carbon on land. The infamously hot summer of 2003 in Europe for example cut the rate of photosynthesis by 50%, dumping as much carbon into the air as had been taken up by that same area for the four previous years [Ciais et al., 2005].

The warming at the end of the last ice age was prompted by changes in Earth’s orbit around the sun, but it was greatly amplified by the rising CO2 concentration in the atmosphere. The orbits pushed on ice sheets, which pushed on climate. The climate changes triggered a strong positive carbon cycle feedback which is, yes, still poorly understood.

Now industrial activity is pushing on atmospheric CO2 directly. The question is when and how strongly the carbon cycle will push back.
 
—–

Canadell, J.G., C.L. Quere, M.R. Raupach, C.B. Field, E.T. Buitehuis, P. Ciais, T.J. Conway, N.P. Gillett, R.A. Houghton, and G. Marland, Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks, Proc. Natl. Acad. Sci. USA, doi 10.1073, 2007.

Ciais, P., M. Reichstein, N. Viovy, A. Granier, J. Ogee, V. Allard, M. Aubinet, N. Buchmann, C. Bernhofer, A. Carrara, F. Chevallier, N. De Noblet, A.D. Friend, P. Friedlingstein, T. Grunwald, B. Heinesch, P. Keronen, A. Knohl, G. Krinner, D. Loustau, G. Manca, G. Matteucci, F. Miglietta, J.M. Ourcival, D. Papale, K. Pilegaard, S. Rambal, G. Seufert, J.F. Soussana, M.J. Sanz, E.D. Schulze, T. Vesala, and R. Valentini, Europe-wide reduction in primary productivity caused by the heat and drought in 2003, Nature, 437 (7058), 529-533, 2005.

Le Quere, C., C. Rodenbeck, E.T. Buitenhuis, T.J. Conway, R. Langenfelds, A. Gomez, C. Labuschagne, M. Ramonet, T. Nakazawa, N. Metzl, N. Gillett, and M. Heimann, Saturation of the Southern Ocean CO2 sink due to recent climate change, Science, 316 (5832), 1735-1738, 2007.

Schuster, U., and A.J. Watson, A variable and decreasing sink for atmospheric CO2 in the North Atlantic, J. Geophysical Res., in press, 2007.


680 Responses to “Is the ocean carbon sink sinking?”

  1. 201
    Jim Eager says:

    Re 180 Matt: “The IPCC isn’t even really all that scary on water level rises.”

    Despite it being pointed out to you repeatedly that the IPCC explicitly assumed no change in the rate of Greenland and West Antarctic ice sheet melting in its projection of sea level rise, you still cling to the conservative IPCC projections as comforting and more reliable than what has actually been observed and measured since the release of the last report. That simply is not rational.

  2. 202
    Matt says:

    #190 Ray Ladbury: Gore got most of the science right. Lomborg got almost none of it right–and what is more, he’s proud of that.

    A 20 foot sea rise without a time scale given? You think that is fair? You are aware that Harry Smith asserted to Michael Bloomberg on Monday that “Manhattan will be underwater by 2050″. Where did Harry Smith get that?

    [edit - keep the rhetoric in check please, and who is Harry Smith?]

    what do you consider Lomborg’s biggest error?

    BTW, you are underestimating Lomborg. Michael Crichton was extremely effective in the debate against pro-AGW scientists earlier this year–turning the crowd from believers to skeptics while pro-AGW scientists stood by and watched, mouths agape. And he’s merely a wordsmith. Lomborg is quite a bit more effective than Crichton. And if the leading pro-AGW voices won’t debate him, and if he can turn a NYT writer into a mass of admiring jelly, the problem (or solution, depending on viewpoint) is only going to get worse.

    You claim that Lomborg “embraces uncritically all the positions of the right”. You are aware that he used to be a member of Greenpeace, and actually grew tired of dealing with all the made-up numbers Greenpeace was using to forward their cause. Hardly uncritical.

  3. 203
    Matt says:

    #194 Jim Eager: Despite it being pointed out to you repeatedly that the IPCC explicitly assumed no change in the rate of Greenland and West Antarctic ice sheet melting in its projection of sea level rise, you still cling to the conservative IPCC projections as comforting and more reliable than what has actually been observed and measured since the release of the last report. That simply is not rational.

    Let’s see. So if I reject the IPCC documents outright, then I’m castigated for rejecting “the largest body of scientific consensus ever assembled.” But if I embrace the IPCC, then I’m castigated for ignoring the fact that they “assumed no change in the rate of ice sheet melt”

    So, which is it? Are all the scientists wrong? Why did the IPCC assume there was no change in the rate of melting if in fact a year after publication all the ice sheets are melting? Or is there a small group of scientists that think this is a big problem, but a larger group aren’t as worried? Presumably if most IPCC scientists were worried about this, it would have been in the IPCC.

    [Response: It is in the IPCC. And if you are castigated, it's probably because you aren't actually reading the IPCC report. Quote (from SPM): "Dynamical processes related to ice flow not included in current models but suggested by recent observations could increase the vulnerability of the ice sheets to warming, increasing future sea level rise. Understanding of these processes is limited and there is no consensus on their magnitude." (see also http://www.realclimate.org/index.php/archives/2007/03/the-ipcc-sea-level-numbers/ ). I'm pretty sure everyone will agree that IPCC could have been clearer about what their numbers meant and how important this uncertainty is, but your characterisation of the IPCC statements are simply erroneous. - gavin]

  4. 204
    Lynn Vincentnathan says:

    RE #193, my impression is that maybe millions have already died from GW, its effects, and its repercussions.

    I understand the WHO estimates that 160,000 die each year from disease spread (like malaria…someone tell that to Lomborg) due to GW. They attribute half the heat deaths in the 2003 European heat wave to GW, so I imagine a portion of heat deaths around the world might be attributed to GW; it’s not only the daytime heat, but the nighttime increases in temp(largely due to GW) not allowing people to recouperate from that day’s heat, that contributes heavily to the death toll.

    Then there is the reduced agri output you mention; and I would add in farmer suicides as at least in part caused by GW and GW-induced droughts, floods, fires, and other crop-harming events. Even if one were to claim that GW’s contribution to these is minor, it could in many cases be seen as the straw that breaks the camel’s back.

    RE wildfires enhanced by GW, we would also have to add in deaths or shortened lives due to the smoke pollution, such as deaths due to asthma, on top of deaths directly from the fire (or that portion…the top portion…of the fire intensity and spread due to GW).

    The list goes on.

    I think a way to think about it is how many deaths there would have been from these types of causes (whose increasing effects can be linked to GW) in a non-AGW world, subtracted from deaths from these causes today (then, of course, subtact out from that difference the lives saved due to GW….like not slipping on that ice that is no longer there bec of GW). [It is interesting that someone has actually calculated the deaths due to going from daylight savings time to regular time, so these types of calcs can be done to some extent.]

    However, just as with our inability to know the exact number of species that have gone extinct in recent times, we would never be able to get an exact figure on how many have died or are projected to die from AGW, its effects, and its repercussions. But I’m thinking it will be quite large. When you consider that even one person’s life is invaluable to a moral person (a person who detests killing innocent people), this is a very urgent, high-priority issue that requires all moral persons to deal with, and mitigate GW.

  5. 205
    SecularAnimist says:

    Joe Duck wrote: “The type of climate impacts that would be required to kill millions are very unlikely”

    You are just plain wrong. The type of climate impacts that would be required to kill millions are in fact very likely, if not already inevitable, and are indeed already underway — principally, the complete loss of glacier-fed fresh water supplies for hundreds of millions of people in south Asia, and prolonged severe drought afflicting the world’s most productive agricultural regions.

  6. 206
    Jim Galasyn says:

    Re Matt in 197, can you explain why habitat loss due to land development and biomass loss due to ocean overexploitation would not cause widespread species extinctions far in excess of the background rate?

  7. 207
    Nick Gotts says:

    Re #202 (Matt) “You are aware that he used to be a member of Greenpeace, and actually grew tired of dealing with all the made-up numbers Greenpeace was using to forward their cause.”

    From Wikepedia article on Lomborg:
    “He has claimed to have been a supporter of Greenpeace. When challenged that Greenpeace had no record of his ever being a member or supporter, he stated that he had given money to Greenpeace collectors.”

    From Sourcewatch on Lomborg “When challenged on this point on ABC Radio National’s Earthbeat Lomborg said “I’m a suburban kind of Greenpeace member, your stereotypical person who contributes and nothing else.”

    In other words, his claim is dubious at best, an outright lie at worst, like so many others he has made.

  8. 208
    SecularAnimist says:

    Matt wrote: “[Lomborg] used to be a member of Greenpeace”

    As far as I know, Lomborg has never been able to provide any evidence to support his claim that he was a “member” of Greenpeace, and Greenpeace has stated that they have no record of Lomborg having any active role in the organization. Of course many nonprofit organizations refer to any donor, even of five or ten dollars, as a “member”, so if Greenpeace uses this terminology, and if Lomborg sent them a few bucks once, then he can legitimately claim to have been a “member” of Greenpeace. But I fail to see how that gives him any credibility, especially given his well-documented, monumental dishonesty, inaccuracies and nonsensical rationalizations when it comes to the substance of his “arguments”. Lomborg is a darling of the corporate-funded so-called “right wing” because he tells them what they want to hear.

  9. 209
    Joe Duck says:

    And if you are castigated, it’s probably because you aren’t actually reading the IPCC report

    Gavin – Matt’s comments seem compatible with *your take* on the likelihood of various sea level rise scenarios. In a different comment you estimated extra rise from Greenland would add something like 25cm over the next century. [pls correct if I missed your point before] This departure from IPCC’s range of 18-59cm seems reasonable to me, but would change the range from 33-84cm over the next 100 years. This seems a far cry from the catastrophic implications of many comments throughout RC. How can we rationally consider the subject if we do not assign any probabilities to sea level rises?

    Jim: You seem to imply it’s irrational to take IPCC, published months ago, at face value because new studies (like Hansen’s?) indicate the possibility of much greater sea level rises. Rational analysis of mathematical phenomenon *require* that we use numbers, not hyperbole. So what numbers do you suggest Matt use if not IPCC and not Gavin’s adjusted IPCC ranges? Uncertainties should lead to assignment of value ranges that are within very high probability. IPCC does a standup job with this, RC comments fall very short in this regard. Rational people accept IPCC as a good measure of what to expect in our climate future.

    [Response: I don't recall ever making a quantitative prediction - what would I base it on? The only point I make is that the upper bound is unconstrained, and paleo evidence for SLR greater than meters/century exists, and we know that the last time the planet was as warm for a substantial period as we project for 2100, SL was 20ft higher. Probabilities would be great, but they don't exist and I can't make them up. Clinging to the thermal expansion numbers (the bulk of the oft-quoted 'IPCC' range) in the hope that this means there is nothing to worry about is foolish. More research is definitely required, but I wouldn't bet the beach house on it showing there's no risk. - gavin]

  10. 210
    Jim Eager says:

    Re: 203 Matt: “Why did the IPCC assume there was no change in the rate of melting if in fact a year after publication all the ice sheets are melting?”

    The key words being “a year after publication.”

    New observational data on the state of the Greenland ice sheet have become available AFTER the report was debated, written and published.

    The unprecedented Arctic sea ice melt took place AFTER the report was debated, written and published.

    Are you simply temporally challenged or are you being deliberately obtuse?

  11. 211
    Majorajam says:

    Joe,

    I guess we’re off Mendelsohn now- or at least the part where his analysis depicts the least developed countries getting pummeled by global warming damages- sucks to be from Mozambique. We’re moved onto ‘most economic analysis’…

    No, I don’t think most economic analyses ignore uncertainties.

    i.e. Mendelsohn’s work. I thought of a solution though. You’ve got his email at the ready, why don’t you just ask him to confirm your assertion? Ask him what probability of the scenario with large scale damages from ice sheet melt gets assigned? (What’s that? Ice sheet melt doesn’t occur in any scenario? Well, I guess it can’t happen then. Whew! That was a worry.) Ask him to confirm that his analysis is ignoring climate sensitivities that mainstream science is telling us are possible.

    And speaking of possibilities Joe, you should consider the distinct possibility that you’re not familiar with the state of the literature on the economics of climate change, nor informed enough to be the first to claim a consensus and certainly not one that disavows Kyoto, (nor would it appear that you or Lomborg are truly interested in determining any optimal capital allocation that finds room for mitigation).

  12. 212
    Majorajam says:

    “Dass ich schon beim Schreiben des Buches die Schlussfolgerung kannte, mag manche der Dinge beeinflusst haben, die ich schrieb” [The fact that I knew the conclusion already when I started to write the book may have influenced many of the things that I wrote]. – Bjørn Lomborg, Interview in NZZFolio, monthly magazine of Neue Zürcher Zeitung, Januar 2006, p. 42

    He neglected to give wanton opportunism and a complete absence of expertise and integrity their proper due. Perhaps that bit was off the record. In any case, RC has attracted itself some committed trolls now. I’m beginning to consider the virtue of not feeding them.

  13. 213
    tom says:

    #203 – And How many lives have been saved by AGW?

    How much INCREASEs in crop yield are attributable to AGW?

    How likely is it that LACK of tropical cyclones in the Pacific contributed to the condition that led to the fires in Calif.?

    Are we to assume that the optimal earth temperature existed somehere around 1980 and that every increase above that leads to dysfunction?

  14. 214
    George says:

    Please, could we have a new post? Comments here are beginning to resemble the classic Monty Python “Argument” skit, only not funny.

  15. 215
    dhogaza says:

    You are aware that he used to be a member of Greenpeace…

    This is a classic science-denialist rhetorical trick.

    “I USED to believe in evolution until I studied the science myself”

    “I USED to believe in AGW until I studied the science myself”

    “I USED to believe HIV causes AIDS until I studied the evidence myself”

    “I USED to belong to Greenpeace until …”

    Lomborg also follows the denialist handbook by cherry-picking data or ignoring science, for instance insisting that the documented number of species extinctions is an accurate indicator of how many species have actually gone extinct despite the scientific consensus that takes the opposite view.

    He also employs the standard denialist trick of insisting that he, despite having no training in the relevant scientific fields, knows more about science than scientists themselves.

    He knows more about population ecology than population ecologists, just as Bill Dembski knows more about evolutionary biology than evolutionary biologists, or Steve McIntyre knows more about climate science than climate scientist, or Stephen Milloy knows more about the effects of tobacco smoke on the human body than medical experts.

    His approach is inherently dishonest. Matt needs a better bullshit-detector. If I were wealthy I’d buy him one :)

  16. 216

    Joe Duck writes:

    [[This departure from IPCC’s range of 18-59cm seems reasonable to me, but would change the range from 33-84cm over the next 100 years. This seems a far cry from the catastrophic implications of many comments throughout RC.]]

    33-84 cm of sea level rise is catastrophic. You don’t have to drown a coastal city to make it uninhabitable, all you have to do is flood it enough for seawater to seep into the aquifers and back up sewers. Miami and cities like it will be uninhabitable long before they are under water. Note, also, that the figure under discussion is a global average — the figure will be higher in some places and lower in others, since sea level is not uniform around the world.

  17. 217
    Joe Duck says:

    Joe, you should consider the distinct possibility that you’re not familiar with the state of the literature on the economics of climate change, nor informed enough to be the first to claim a consensus and certainly not one that disavows Kyoto

    I will, and try to consider my deficiencies on an hourly basis.

    Majorajam aside from your Nobel prize for annoying, what are your qualifications in this area?

    Surely you do not see Kyoto as a high quality, viable approach to mitigation?

    I’m still waiting for permission to post Mendelshon’s succinct reply but his ideas are online. You should like him – he’s critical of Copenhagen’s treatment of his climate mitigation proposal.

  18. 218
    Jim Galasyn says:

    Re the claim that Lomborg was a “Greenpeace member,” here’s what he told journalist Alanna Mitchell:

    Lomborg wasn’t an environmentalist, at all, as it turned out. He told me as much when I interviewed him in Toronto that year, confessing that the extent of his involvement had been to carry around a Greenpeace card for a while many years earlier when it had been the vogue for Europeans of a certain age.

    Ah, the folly of youth.

  19. 219
    Jim Galasyn says:

    tom looks for the silver lining of climate change: “Are we to assume that the optimal earth temperature existed somehere around 1980 and that every increase above that leads to dysfunction?”

    I think it’s fair to assume that the relatively stable climate we’ve enjoyed for the past 10k years or so is optimal for the purposes of agricultural civilization. We have no evidence that agricultural civilization can survive in other climate regimes.

  20. 220
    Andrew Sipocz says:

    Here’s some real bad news. The Washington Post’s head environmental writer, in an article for Outside Magazine, believes Richard Lindzen’s goop.

    http://outside.away.com/outside/culture/200710/richard-lindzen-1.html

    Lindzen’s new line is this: So what if the world is heating up to levels not seen in millions of years, it’s done it before, it’s natural and what’s the big deal?

    Increasingly I’ve been reading this “plot theme” in news stories: “Okay, global warming is real, so what?”. Well, we need to do a better job of explaining how devastating a warmer world can be.

    I keep thinking back to Jared’s Diamond’s description of Easter Island’s surviving population, descended from the ruling class, who felt their obvious decent into resource poverty and hardship, and the loss of most the island’s population, was no big deal (I’m obviously paraphrasing here, but read his book, Collapse, for his descriptions). People can suffer a lot before admitting their current societal direction is heading the wrong way, especially if they are in the ruling class and are buffered from early catastrophes. I guess to the wealthy, mobile, “elite”, such as Outside’s target audience, the changes predicted to occur because of a warming world are no big deal. I suppose they’ll turn to indoor ice walls once all the glaciers melt, etc. At any rate, if the call to reduce CO2 here in the U.S. is going to be effective we’ll have to reach over the head of these folks and somehow appeal to the middle class.

  21. 221
    Ray Ladbury says:

    Matt said, “BTW, you are underestimating Lomborg. Michael Crichton was extremely effective in the debate against pro-AGW scientists earlier this year–turning the crowd from believers to skeptics while pro-AGW scientists stood by and watched, mouths agape. And he’s merely a wordsmith. Lomborg is quite a bit more effective than Crichton. And if the leading pro-AGW voices won’t debate him, and if he can turn a NYT writer into a mass of admiring jelly, the problem (or solution, depending on viewpoint) is only going to get worse.”

    That is precisely why scientific consensus isn’t determined by debating skill or by charisms, but by the weight of evidence. Lomborg has none. A glib liar may be able to convince an audience in a 2 hour debate. Sorry, Matt, but science moves more slowly. It involves checking the facts–and lo and behold, the reason we’re seeing warming on Neptune is because it’s summer there.

    People like Crichton and Lomborg…and you…are frightened by the scientific method because it subverts their ability to bullshit your way through life. Crichton writes science fiction, but didn’t even know enough about evolution to realize that the depiction of evolution in The Andromeda strain is a joke. Lomborg glibly spins a story about being a former Greenpeace member until his conversion on the road to Damascus–and then lo and behold, somebody looks it up. He is at least as glib with his use of scientific factoids. Like it or not, Matt, there is an objective reality, and it has consequences. It behooves us to try to understand those consequences, and the way to do that is science.

    Now, I’m going to tell you something about scientific consensus: The product of scientific consensus is almost always conservative rather than alarmist. The reason why the IPCC numbers underestimate sea level rise is because that is what the scientists could agree upon. Some, probably most, would have been happier with higher estimates, particularly given recent developments. However, the IPCC represented the consensus–what the experts could all agree upon–at the time. And that is why, the consequences considered so far have concentrated on sea level rise. It is a virtual certainty. Other consequences–widespread drought, increased storm intensity, increased incidence of impulsive rainfall, increased disease, crop failures, etc.–do not have the level of consensus needed to come out with a strong statement. Their consequences may dwarf those of sea-level rise, but they are not certain.
    Now I’m going to tell you something about risk management. An uncertain, unbounded risk is a greater concern than a high risk. You may want to study it to quantify it better, but if your study will be completed too late to complete mitigation, you had better either start mitigation in parallel with your study or try to buy time (e.g. slow down carbon emissions). You cannot ignore an unbounded risk.

  22. 222
    Joe Duck says:

    Gavin – I apologize for suggesting you had assigned some specific extra CMs to the IPCC – I just looked back and I think I had misread the gist of your March post about IPCC Sea Level rises. I would be very interested in how people feel we should do risk and cost benefit analysis without assigning a range of probabilities to the various scenarios. As you get to “highly unlikely” events it’s very important to assign a very low probability – otherwise you wind up spending a trillion on asteroid defense shields which would in fact lower the chance of planetary destruction, but would be an unwise use of money given the probability of an asteroid collision.

  23. 223
    Jim Eager says:

    Re 209 HJoe Duck: “Jim: You seem to imply it’s irrational to take IPCC, published months ago, at face value because new studies (like Hansen’s?) indicate the possibility of much greater sea level rises.”

    No, I implied, and hereby explicitly state, that it is irrational to continue to take comfort in the IPPC’s projected numbers in the face of new data and observation of what is happening real time in the real world.

    The IPCC knew their projected numbers were subject to change, which is exactly why they explicitly included a caveat about those numbers in their report. The wisdom of this has been justified by the extent of this summer’s Arctic sea ice melt and observed changes in Greenland since the report was released. Basically, all projected numbers quantifying how much and how fast the cryosphere will change are now suspect. To pretend otherwise is foolish.

  24. 224
    J.S. McIntyre says:

    Vanishing Point
    On Bjorn Lomborg and extinction
    By E. O. Wilson

    http://www.grist.org/advice/books/2001/12/12/point/

  25. 225
    Jim Galasyn says:

    Re the citation on Lomborg’s Greenpeace cred, I completely munged the URL. Here’s the corrected link:

    The Pollyanna of global warming
    http://honolulu.craigslist.org/kau/pol/435448272.html

  26. 226
    J.S. McIntyre says:

    re 213.

    Tom, can you provide supported answers for any of those questions?

  27. 227
    David B. Benson says:

    I preferred 1950 myself. :-)

    There are now several studies regarding the high likelihood of climate wars over diminishing resources. Risky business changing the climate.

    Matt might care to read Jared Diamond’s Collapse with regard to known effects of climate change on civilizations.

  28. 228
    Jim Galasyn says:

    Taking George’s comment to heart, let me ask an on-topic question:

    Can we estimate the degree to which the large-scale destruction of ocean ecosystems affects the ocean CO2 sink? A lot of carbon gets sequestered in living creatures, but we’re rapidly strip-mining the oceans of all but the most ancient organisms.

  29. 229
    John Mashey says:

    re: optimal climate
    Humans can certainly survive a range of climate conditions, and one has somje hope of adapting some crops, maybe.

    On the other hand, not only is agriculture adapted to a specific climate, but a huge amount of expensive coastal infrastructure has been built in the last 150 years, with relatively stable sea levels. Back to economics:

    I’d claim that one needs to seriously consider the possibility, not of just of a low discount rate, but of a negative one. The planet had a one-time pot of really cheap energy called fossil fuels. We either hit Peak Oil (50% used) in the next decade, or we already did in 2006 (if you believe T. Boone Pickens).

    Put that together with the strong positive influence of exergy (energy used x effiency) on wealth: see Ayres & Warr:
    http://www.iea.org/Textbase/work/2004/eewp/Ayres-paper1.pdf
    Especially, read the conclusion.

    Now, consider the belief that the population will rise to 9B over the next 50 years, with less oil (and peak natural gas about 20 years after oil. We’d have to improve efficiency by 50% just to stay even in exergy/person, ASSUMING we can replace the oil&gas with solar/wind/geothermal/biofuel/(nuclear) even-up, which seems unlikely in the short-term, for all that we’re trying hard.

    US East Coast (and some Gulf Coast) cities have infrastructure accumulated over 300 years, most of which was built with *REALLY CHEAP ENERGY*. Under BusinessAsUsual, especially with terrific pressure to burn coal, it’s hard for me to see how sea-level isn’t up at least 20 feet 300 years from now, which seems a reasonable planning horizon. [I don't know why 2100 is magic: the world doesn't stop then, I hope.]

    These days, people build dikes with bulldozers, steel & concrete, and rebuilding a city somewhere else will take a lot of the latter two.

    Here’s a “fun” exercise: you’re mayor of New York City, and it’s time to rebuild somewhere else. How much will that cost? and by the way, there is no cheap petroleum…. well, I guess the Egyptians built the pyramids without.

  30. 230
    Hank Roberts says:

    > ocean CO2 sink

    Yep.
    Just posted a link and excerpts at Tamino’s site, here:
    http://tamino.wordpress.com/2007/10/29/new-policy/#comment-8316

  31. 231
    Majorajam says:

    My qualifications? I’ve got a degree in social science from the Copenhagen business school… Joe, if you find me annoying I can only point out that the feeling is mutual, if not personal- it is more that I’m not partial to people who make patently erroneous statements with high-handed confidence, and more so when the person in question dutifully ignores the argued and sourced disagreement. Speaking of which, my statement that you should consider your own qualifications was intended to highlight that you’ve pulled this consensus from thin air and tried to assert its meaningful existence on numerous occasions (which I’d be happy to cite if thou protesteth… at all). If you have a source for this claim, do tell. If not, please avail us of the expertise of yours that qualifies you to make such a statement. And if you’re unclear what I mean still, you don’t have to go far up the thread to find a quintessential case in point:

    Surely you do not see Kyoto as a high quality, viable approach to mitigation?

    There in one line and, what, fifteen words, have you expressed a sentiment that you are unable to remotely back-up- that the mainstream rejects Kyoto and that it is not serious to advocate it or something similar. And you would be unable to support such innuendo because it is simply not the case. This is true both on the basis of ‘purely economic’ evaluation and more so for any more comprehensive review that examines the relevant agency issues. On the latter point, as people have been at pains to point out to you on this subject in the past, Kyoto is a framework- it is a way of establishing the ground rules and infrastructure to make mitigation workable in the future. Conceiving of the best academic scenario for an emissions treaty is pointless if it ignores the political realities, i.e. where the Kyoto protocol actually lives. Any criticism of Kyoto that doesn’t take those into account and is not properly qualified is therefore deeply flawed.

    So, in light of those realities, do I think the Kyoto protocol is a good treaty? If I take your question to mean, should all nations have signed on, that to me is an unequivocal yes (well, as a global citizen, yes- it changes a bit as an economic actor amongst asymmetries, but I digress). This doesn’t make it perfect (e.g. a global carbon tax is preferable to emissions targets but it’s not clear that can be helped. some of the carbon sink fudges are clearly side payments, but those are to be expected, etc.). The point is that dismissing (or supporting) the treaty by slight of hand is lazy, disingenuous and/or ignorant, and that apply the ‘mainstream’ sticker to your side of the argument for the same purpose is worse.

    P.S. While I acknowledge Mendelshon as an expert who knows a lot more about building integrated assessment models (amongst other things) than I do, I find his methodology lacking (not accounting for uncertainty in the economics of climate change is like not accounting for the point spread when betting on a game) and his claims dubious (middle of the distribution warming to have a net zero effect on welfare… ??). More generally I have huge issues with economists who have the temerity to push their extremely flawed models on the public as the best means of making policy decisions, (and huge respect for those who highlight the reasonable and unreasonable inferences that can be made from economic analysis, e.g. Weitzman). There are many of these, including one prominent one who assured me that heat stress has no effect on drinking water, in about so many words. Meanwhile, I can get no such pat answer from any climate scientist, so the only place we can be assured that such conditions exist is in this academic’s model.
    P.P.S. Speaking of the utility of integrated assessment models, a case can be made that climate change had a role in the Darfur crisis. It’s not open and shut, but it isn’t totally baseless. Something in me doubts such a scenario is conceivable in an integrated assessment model.

  32. 232
    Aaron Lewis says:

    RE 219;
    The warmth and sea level of 1980 may not have been “optimum,” but it is what our infrastructure was engineered for; and our crops were bred to expect. Any other climate and sea level will require significant capital investment.

    Change is not the problem, it is the rapidity of the change that is the real problem. Moreover, it is not so much rapid change per se that is the problem, it is unpredictable change that is the problem. If we are sure of a 0.10 meter of sea level change between 1/1/ 2031 and 1/1/2041, then we can plan for it and we can survive it at a minimum cost. However, if we are not certain, then some people will not prepare, and then even a few cm of sea level rise in that decade will cause damage, resulting in costs that will propagate through the global economy affecting all. If we all plan for a 0.10 m sea level rise, and we get a 0.20 m sea level rise, again there are damages and costs that propagate through the economy. As we plan for the changing environment, we need to incorporate safety factors.

    Unpredictable change makes resource allocation decisions more difficult. Decisions are delayed until we are “sure,” and the delay results in wasted resources.

  33. 233
    Joe Duck says:

    Majorajam – thank for that thoughtful reply to my note above. Mitigation economics is the key point of contention in the AGW debate and I’m hoping to learn more. So far, for me, Mendelsohn’s thinking has the most intuitive appeal. I simply do not understand discounting well enough to know if he’s reasonable in this matter or not, so I’m letting his credentials speak for him in that matter. I’m still trying to understand why Stern (and many here) have such pessimism about the future.

  34. 234
    Andrew Sipocz says:

    Re: #220 I should have read the story twice through before commenting on its author’s intent. Sorry about that. It’s a well written article that gets to the heart of Lindzen’s and Lomborg’s popularity.

  35. 235
    GoRight says:

    I have a general question regarding the primary contributors to this site and don’t know where to post it. If there is a more appropriate place please direct me accordingly. I believe that the answer to my question is self-evident but the point has been called into question.

    Is it fair to say that all of the primary contributors on this site agree with the consensus that the current global warming trend is predominantly anthropogenic in origin?

    Worded in a slightly different way, could any of the primary contributors to this site be legitimately characterized as an AGW contrarian or a skeptic, and if so would they admit to being such?

    [Response: We're all practicing, publishing climate scientists, and I think we all buy the argument that the warming of the past decades was caused rising CO2 concentrations, and expect that if more CO2 is released, the temperature will rise further. We're skeptical about new results all the time, as witness perhaps the post before this one. Contrarian means to me disregarding evidence that doesn't support one's desired conclusion, not a good strategy for a scientist. David]

  36. 236
    Hank Roberts says:

    Joe, imagine someone able, in 1776, to show Jefferson and Washington that within 200 years all the great North American forests would have been cut and not regrown, the buffalo herds gone, the passenger pigeons gone, the salmon and codfish and whales all but gone, the chestnut trees gone, most of the elms gone, the small towns and farms and farmers gone, and fifteen feet of topsoil washed off of the middle of the continent down the Mississippi. They would have been as pessimistic about their country’s future as Stern is now about his.

    Most of that damage could have been avoided at low cost — but nobody was able to foresee it when it was happening.

    We can see what’s at risk now, and the debate is whether it’s worth even the “no regrets” effort with provable payback, compared to the current-quarter bottom-line profit margin costs.

  37. 237
    David B. Benson says:

    Joe Duck (233) — Did you follow the link in comment #133? Did you follow the link in comment #230? Have you read Jared Diamond’s Collapse? Do you understand the import for the future of the main post on this thread?

  38. 238
    Aaron Lewis says:

    Integrated assessment models assume that everything can be priced in dollars. While it may be possible to price one human life, is the value of the human species, no more than the population times the value of one life?

    Assume that human extinction will not occur for a few years, use discounting and the current cost of an act that will result in the extinction of the human species is ~$0.00. With this view, there is no responsibility for one’s actions because you can show that no action has any cost associated with it.

    Of course, I have made a “Slicing the Salami “argument which is absurd. But, it is no more absurd than a too high discount rate for goods and services provided by Mother Nature, or a too long a discount period for the onset of costs associated with climate change.

    AGW will have real costs, and they will be unpleasant. They cannot be “discounted” away. There will be real suffering. By acting now, we can reduce that suffering. By acting, we can minimize the intensity of the global warming, and by acting now, the effects of the global warming that does occur can be reduced.

  39. 239
    David B. Benson says:

    Here is a small bit of slightly encouraging news regarding cirrus clouds, should it be verified:

    http://www.sciencedaily.com/releases/2007/11/071102152636.htm

  40. 240
    Rod B says:

    dhogaza (176), I can accept that. The rules of accounting do say that you can only count things that are countable. While this leads to occasional goofy accounting results, neither should economists be held to General Accounting Standards.

  41. 241
    Hank Roberts says:

    Is that Sciencedaily release a reference to some new Spencer-Christie paper? Can’t tell from the story; link’s just to their school PR office. Sounds to me like it’s this one:
    http://www.agu.org/pubs/crossref/2007/2007GL029698.shtml
    Full text here (secondary source, looks like a photocopy)
    http://scholar.google.com/scholar?num=100&hl=en&lr=&newwindow=1&safe=off&scoring=r&q=Spencer+Christy+Lindzen+iris&as_ylo=2007&btnG=Search

  42. 242
    David B. Benson says:

    Hank Roberts (241) — The Science Daily article states the paper is in the GPL on-line edition, co-authored by John R. Christy, W. Danny Braswell and Justin Hnilo, but since Roy Spencer is extensively quoted, I believe it refers to the paper in GSL that you provided a link to, with exactly those four co-authors.

    Why do you ask?

  43. 243
    Ray Ladbury says:

    Joe Duck, the knock on Kyoto is that it was too little to be effective. Likewise, the knock on Mendelsohn’s approach is that we don’t know whether “low-cost” measures will have sufficient effect to keep us out of the positive feedback regime. Kyoto had more symbolic value than real value. Likewise, Mendelsohn’s approach if viewed as a “starting point” has some merit, just as Kyoto did.

    People do not realize just how conservative the IPCC consensus analyses are. Things could get much worse, but they are unlikely to be better.
    My own view is that the low hanging fruit–conservation, energy resource diversification away from carbon-intensive sources, etc.–is the obvious place to start. Aid for energy and transport infrastructures of developing countries is another area that will pay serious dividends well into the future. Is that enough? We don’t know. A lot depends on the pace of development for technical solutions. The most important thing is to buy time so those solutions have a chance of being realized.

  44. 244
    Hank Roberts says:

    > Why do you ask?
    Just odd to see a Sciencedirect article dated this week, long after the article it appears to be based on came out. I recall it got a lot of discussion at the time it was published — it’s more tentative than the current flurry of mentions on the denial sites make it seem though. That’s where you’ll find current discussion.

    Ah, but Christy was just in the WSJ recently, perhaps his school sent out a fresh press release without the cite.

    Spencer discussed the paper a while back at Prometheus:

    “… In our resulting August 9 GRL paper … the tropospheric temperature variations were very large.

    In something of a “fishing expedition” we examined a variety of satellite observations that could be related to the tropical tropospheric heat budget. For the 15 largest intraseasonal oscillations between 2000 and 2005, we averaged TRMM TMI rainfall and SST, Terra MODIS cloud fractions, CERES reflected SW and emitted LW fields, and AMSU-A tropospheric temperature data to daily time scales, over tropical average space scales. The result was clear evidence in support of Lindzen’s “Infrared Iris” hypothesis, at least on the intraseasonal time scales we examined. (Unpublished was an analysis of the 15 next-largest ISOs, which revealed very similar signatures.)…”

    I haven’t found cites to it, but it’s early yet I guess.

  45. 245
  46. 246
    Rod B says:

    Oh! Hank, your 236 hyperbole and histronics make good literature (it is well written) but not very helpful…

  47. 247
    Matt says:

    #206 Jim Galasyn: Re Matt in 197, can you explain why habitat loss due to land development and biomass loss due to ocean overexploitation would not cause widespread species extinctions far in excess of the background rate?

    Eastern US has seen forests fall to 2% of what it was 200 years ago. How many extinctions did we see?

    Brazil’s Atlantic rainforest has been 88% cleared since the 1800′s. How many extinctions did we see?

    According to Lomborg, 1 and 0.

    According to EO Wilson’s model, the number of species would have been halved.

    Now Lomborg only addresses animals for the US forests, and animals and plants for the Brazilian rainforest. So I guess a lot of insects could have been lost and Wilson would have been right.

    It’d be interesting to hear if what Lomborg wrote is true. If it is true, can you explain the reason why EO Wilson’s predictions failed to materialize?

  48. 248
    Matt says:

    #207 Nick Gotts: From Wikepedia article on Lomborg:
    “He has claimed to have been a supporter of Greenpeace. When challenged that Greenpeace had no record of his ever being a member or supporter, he stated that he had given money to Greenpeace collectors.”

    That’s funny. I just checked Wikipedia and he said he was the regional director and shows a picture of him and Jacques Cousteau smiling together. Oh, wait, it just reverted. Never mind.

    Seriously, if you won’t even believe a statement he makes about something in his own life, then there’s not much hope for anything else he does. Speaks volumes about your mindset though…

  49. 249
    Matt says:

    #208 SecularAnimist: But I fail to see how that gives him any credibility, especially given his well-documented, monumental dishonesty, inaccuracies and nonsensical rationalizations when it comes to the substance of his “arguments”.

    Ray passed on the chance to point out Lomborg’s biggest mistake, so I’ll pass the torch to you. I hold the guy in pretty high regard, and would seriously like to know where he’s screwed up. I looked at a anti-Bjorn websites and found everything pretty petty.

    Perhaps if you produced something you had studied in detail, I could study it too and come to some common understanding?

  50. 250
    S. Molnar says:

    Re #214: No, they’re not.


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