Geoengineering, Science, Consequentialism and Humility

The Uehiro Centre has recently hosted Clive Hamilton who was visiting from the Centre for Applied Philosophy and Public Ethics at Charles Sturt University. Hamilton is well known for his work on the politics of climate change. While here he presented a paper on the ‘Ethical Foundations of Climate Engineering’, which he has now been revised and is available at his website: http://www.clivehamilton.net.au/cms/media/ethical_foundations_of_climate_engineering.pdf.

Climate engineering is also known as ‘geoenginering’ and the ethics of geoengineering has recently been discussed in a joint paper by several members of the Uehiro Centre who take a view that Hamilton strongly disagrees with: http://www.practicalethics.ox.ac.uk/__data/assets/pdf_file/0013/21325/Ethics_of_Geoengineering_Working_Draft.pdf

 Hamilton’s paper is an attack on consequentialist justifications for geoengineering – attempts to use technology to try to manipulate the Earth’s climate in order to ameliorate the effects of climate change. He sees such attempts as part and parcel of a world view which springs from the Scientific Revolution. He tells us that: ‘The consequentialism of climate ethics is built on an unstated (and mostly unrecognized) understanding of the natural world, one that grew out of the Scientific Revolution in the 17th Century and the European Enlightenment philosophy that went with it.’ According to Hamilton, people who are in the grip of this scientific world view, including consequentialist philosophers, lack ‘humility in the face of nature’. The ground for this humility is, ‘… acceptance of our limitations in the face of the superior power, complexity and enigmatic character of the earth’. Hamilton sees the presumption that we might be able to ‘master’ nature as fundamentally misguided: ‘Climate engineering represents a conscious attempt to overcome resistance of the natural world to human domination …’, however, ‘… the sheer complexity and unpredictability of the natural world resists attempts at total mastery’.

 While scientists and consequentialist philosophers clearly do lack ‘humility in the face of nature’, as they do not generally accept the ‘enigmatic character of the Earth’, there is a sense in which both scientists and consequentialist philosophers are humble. Both science and consequentialist philosophy have epistemic humility built into their very methods. Scientists aim to ensure that their views do not reach beyond available evidence and acknowledge that their findings are always revisable in the face of new evidence. Consequentialists display a similar humility in the face of evidence. If new evidence regarding the consequences of a possible consequentialist policy prescription comes in, then good consequentialists will be willing to revise that prescription.

 Hamilton suggests that ‘the results of Earth system science’ can be used to ‘critique the worldview given to us by the Scientific Revolution.’ Apparently these ‘… expose the limits and contradictions of the mechanical and systems understanding of the world and the technological thinking that goes along with it.’ Should scientists and consequentialist philosophers humbly accept that the evidence he points to is sufficient grounds to abandon the project of attempting to understand and then control the climate? On the basis of the evidence presented, I think the answer to this question must be a firm no. Hamilton points out that the climate system is very complex and beset by ‘non-linearities’ and ‘tipping points’ that are not well understood. But all this show is that scientists need to do more to attempt to understand the climate before attempting to apply geoengineering solutions to climate change – hardly news, and hardly evidence of either limits or contradictions.

 Those who accuse others of lacking humility invite questions about their own humility. Clearly Hamilton’s views are indicative of ‘humility in the face of nature’ and are consistent with having a humble character, but they are very hard to square with an attitude of epistemic humility. If Hamilton was making the claim that the project of geoengineering might not succeed because the sheer complexity of the climate might defeat us then he would be making a point that was warranted by available evidence and which would be accepted by any serious scientist. But Hamilton goes way beyond this attitude of healthy skepticism. His position seems to be that the superior, complex, enigmatic Earth will defeat our attempts to master it. But how does he know this? The comments he makes about the current state of Earth systems science do not do nearly enough to warrant the claim and, in any case, Earth systems science may well develop in ways that he does not anticipate. The history of science is littered with the debris of hubristic claims about the limits of science: humans will never fly, humans will never walk on the moon, the atom can never be split, and so on. Those who presume to have identified the limits to science would do well to temper their views in light of lessons from the history of science.

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53 Responses to Geoengineering, Science, Consequentialism and Humility

  • Peter Wicks says:

    "Consequentialists display a similar humility in the face of evidence. If new evidence regarding the consequences of a possible consequentialist policy prescription comes in, then good consequentialists will be willing to revise that prescription."

    Indeed, and this is in my experience the point that supposed refutations of consequentialist philosophies, including utilitarianism, always seem to miss. They always seem to be attacking a particular, flawed version of consequentialism/utilitarianism, and mistakenly leaping to the conclusion that they have found a reductio against consequentialism/utilitarianism itself.

    In that context I would also dispute that consequentialism is incompatible with an essentially "humble" (read: pessimistic) view of our ability to reliably master nature. On the contrary: such a view is basically saying that the "enigmatic nature of the Earth" is likely to derail such attempts and lead to bad consequences. So consequentialism says we shouldn't attempt them, it doesn't mean we should give up on the while idea of taking responsibility for the consequences of our actions.

    • Anthony Drinkwater says:

      Hi Peter,
      Sorry to mix theads and all ….
      When you state that “I see no fundamentally obvious reason to object to anything on non-consequentialist grounds”, I fear that you are putting the barrier very high.
      For a start, few (if any) philosophers change their minds about anything. If, on top of this, the reason for the mind-change has to be “fundamentally obvious”….
      For seconds, a blog is hardly the place to convince those who don’t want to be convinced (and I put myself in that category too) …. I quickly read through Clive Hamilton’s paper, but know that for a bear of little brain such as myself it would take at least half a week full-time to digest and redigest and analyse and, possibly, critique. (But certainly there are bears with much bigger brains than mine.)
      For thirds, let me just state (but it may seem to be just an ad-hominem argument) that I am simply DISSATISFIED with utilitarianism; and this for three principal reasons :
      1. it reduces moral discourse to being merely a series of particular choices between alternative actions. I cling to a belief that moral discourse does, and should, cover issues beyond this sort of choice
      2. it justifies, on occasions, the unjustifiable – torture, to take a simple example
      3. it is based on the premise of maximum utility (or happiness, or whatever). This premise has no more self-evidence than any other virtue …. Indeed, I would argue that it has less obvious reason to exist than certain human rights principles.
      You can (and probably will) disagree !

      • Peter Wicks says:

        Thanks Anthony. I take your point about a blog not being the place to "convince those who don't want to be convinced", although I don't entirely agree with it: I think that over the course of many threads regular commenters such as ourselves can gradually become aware of each others' thinking on the fundamental issues, and this does help to refine our thinking. Provided of course that we generally keep our contributions relevant (to the posts to which we are responding), constructive and not too repetitive. (This last sentence is a note to myself as much as anyone else!)

        On your three points, my three quick replies would be:
        1. What other issues do you have in mind? My guess is that, if they are at all relevant for moral discourse, they will also be relevant in terms of consequences and utility.
        2. Yes, I guess I can imagine circumstances where I might consider torture justified.
        3. As you know I don't hold consequentialism to be "self-evident" any more than (but also any less than) other systems such as rights-based ones. It is just what makes sense to me. Ultimately we have different intuitions (i.e. aesthetic reactions) with regard to morality, and this is fine…provided we recognise that this is the case rather than trying to claim an objective basis for our respective preferences. Once again, it's a matter of choice, not a matter of truth.

  • Dave Frame says:

    Nice post, Steve. I must admit I read the abstract for that talk and decided to skip it. There's something a bit too new-agey about some of the claims made in the name of Earth System Science. Basically, it's just the same enviromental science we've been doing for ever, with a fancy new handle. There is renewed emphasis on non-linearity, complexity and so on, and the multi-scale thing is as hard as ever. But it's still the same thing it ever was: scientists expect their colleagues to set out hypotheses and test them against data, falsifying them where possible and tinkering with them where necessary. It's not remotely a fundamental challenge to our ways of doing science, it's just kinda hard.

    I don't remotely buy the idea that environmental science ‘… expose[s] the limits and contradictions of the mechanical and systems understanding of the world and the technological thinking that goes along with it.’ I just don't see environmental science as being any different from regular science. It'd argue it's true that the development of nonlinear physics (and allied disciplines) is a profound development in the history of physics, but that's because of the vast array of new systems we might expect to be able to analyse** rather than because it alters anything about the scientific method itself.

    **IIRC a mathematician made the observation that speaking of "nonlinear systems" was on a par with speaking of "nonelephant mammals": there are far more in the nonX set than in the X set.

  • Brad Arnold says:

    "The alternative (to geoengineering) is the acceptance of a massive natural cull of humanity and a return to an Earth that freely regulates itself but in the hot state." –Dr James Lovelock, August 2008

    "The Greens' resistance to geo-engineering sits very uncomfortably with its message that the planet is screwed and we're all going to die. It suggests that Environmentalism has less to do with saving the planet than it does with reining in human aspirations. It suggests that they don't actually believe their own press releases, and that they know the situation is not as dire as they would like the rest of us to think it is. And that Environmentalists are cutting off their noses to spite their faces – "we'll save the planet our way or not at all." It suggests that Environmentalists regard science and engineering as the cause of problems, and not the solution." –Climate Resistance, 24 March 2008

  • Clive Hamilton says:

    Steve. Thanks for your comments on my paper; you have gone to the essence of the argument. But in focussing on Earth system science I was attempting to draw attention to a larger question. What type of human lies behind the consequentialist understanding of the world? This is not a question about personality types or culture but about ontology. It asks what lies behind the idea that ethical judgments can be made by weighing up consequences. I'm suggesting that it reflects a particular image of humanity, one that has emerged since the Scientific Revolution. Consequentialism rarely accepts that this is a particular image of humanity but maintains that this is just "reality", that is what humans are. This reflects the dominance of the analytical approach to philosophy which pretends there is not a long and fundamentally important debate within philosophy over the question "what is a human being?" or that the debate has been decisively resolved in favour of some kind of rationalistic post-Kantianism.
    The argument implied in your post, and expressed explicitly in a couple of the comments, that I have to decide whether it is better to support or oppose geoengineering (and I am not really an environmentalist unless I do) is really an attempt to impose on me that same consequentialist framework, to argue that I can have standing in the debate only if I give the same answer to the question of what it is to be human, whereas in fact the whole point of my essay is to challenge it. My essay asks "What can geoengineering tell us about ethics?' but it has been turned into the standard question of "What can ethics tell us about geoengineering?", where the "ethics" in question is simply assumed.
    I invoke the climate crisis and Earth system science as an invitation to reflect once again on the question "What is it to be human?' It seems to me that we have crossed a threshold in which the identification of humans as the rational animal, one with the capacity to take control of the planet as a whole, exposes, for those willing to step outside of the dominant view for a moment, the essential danger of understanding humans that way.

    • Peter Wicks says:

      So presumably the alternative understanding of humanity that we are supposed to embrace is something along the lines of John Gray's "Straw Dogs", just one species among many, currently undergoing a Malthusian explosion, enjoying (some of us anyway) our time in the sun, and heading directly to a bonfire of the vanities.

      By the way, "consequentialism rarely accepts…" is a horribly logically flawed phrase. You mean "consequentialists rarely accept…". This consequentialist certainly does accept that the idea that ethical judgements can be made by weighing actions reflects (among other things) a particular image of humanity, although I would suggest that it emerged explicitly (thought probably not for the first time) in parallel with the Scientific Revolution, rather than subsequently. And it is implicit in human thought pretty much ever since we learned to think at all.

      I would also agree that regarding humans as "the rational animal" has its dangers (the ongoing financial/economic crisis is partly a result of this). But recognising our partly irrational nature, favouring ecosystem approaches, and nurturing virtue rather than assuming that we will always do what is right if we can only figure out analytically what that means can all be done without throwing out the (surely rather essential) idea that ethical judgements can be made by weighing actions.

      Furthermore, assuming we're not satisfied with the "Malthusian collapse" scenario, we urgently need to find new ways to understand the relationship between actions and consequences. On my blog (http://peterwicks.wordpress.com) I've sketched out the beginnings of an argument that suggests that this might even mean questioning the inviolability of the second law of thermodynamics. By contrast, de-emphasising the relationship between actions and consequences seems to be going in exactly the wrong direction.

    • Dave Frame says:

      Hi Clive, thanks for joining the thread.
      One feature that jars for me is how emphatically you seem to believe that climate change=catastrophe. I think you're overemphasising a few results at the expense of the bulk of the literature. It's true that a few papers show evidence for "tipping points", but a large number do not, and many scientists are pretty sceptical about tipping point arguments either in principle (because they don't believe in the possibility of specific alleged tipping points (eg the AMOC's ability to "shut off" is contested)) or in practice (because constraining weakly nonlinear systems is often pretty hard, especially with the levels of uncertainty we face in climate modelling). I'd find your arguments more compelling if they better reflected the speculative nature of catastrophic climate change – as you must be aware, most the evidence (AR4, for instance – it's striking how little you cite this) suggests a serious but not catastrophic problem. What would be the harm in expressing your argument more contingently in this area? Weitzman, for instance, is careful to couch his position in terms of low probability, high consequence conditions, rather than best guess conditions. You seem often to reply on similar bad luck, rather than best guess**, so why not add that into your analysis? [I'd also disagree with your assertion that Earth system science has "destabilised the idea of the earth as a knowable" system.]

      That said I appreciate that your primary aim isn't to discuss science but rather to explore what it is to be human in a world of anthropogenic distortion of the biogeophysical world. I agree with you that some aspects of climate change throw up challenges to instrumentalist reasoning and to traditional ways of calculating consequences, partly because of the long-standing problem of valuing non-market goods. [I also think it invites deep challenges to standard ways of thinking about welfare economics.] But I don't see why these problems invite a wholesale rejection of consequentialism or instrumentalism. I really like your analogy on p17:
      "For instrumentalism it is always ethically justified to engineer a different climate, even though the process of calculation may show that it is imprudent. The procedure is analogous to resolving the ethics of destroying a sacred site by asking how much money the traditional owners would be willing to accept as 'compensation'. Simply posing the question this way puts the issue outside genuine ethical judgment. The question itself is morally offensive and, when posed, elicits not a calculative reflex but a sense of outrage."

      But what if the sacred site is the only place I can build a much-needed hospital in our community, and what if the site is sacred only to you? I imagine most people would intuitively think these two features – the reason for the destruction and the number of people adversely affected; ie the consequences – matter. They may not be the only thing in play, but to argue that the mere consideration of these contextualising features is "morally offensive" seems peremptory.

      In my bottom drawer I have a thermostat that sets the temperature (and climate) of the world. Where should I set it? My guess is if we asked everyone, they would not opt for pre-industrial (my guess is just about everyone would say "the optimal climate is the one I remember as a kid on holiday"). But to ask everyone would surely be to fall into some trap regarding expected utility (or welfare). It sounds as though you would argue for a pre-industrial climate, even though this would probably be unsatisfactory to more people than (say) a 1960-1990 climate. Deliberately to ignore any aggregation of the wishes of other folks, preferring instead to cleave to a somewhat arcadian notion of "stability", strikes me as the antithesis of "humility".

      **Best guess conditions imply warming of ~2.5C above pre-industrial in response to a (non-policy!) B1 scenario (IPCC AR4 SPM), which contrasts with your claim "that, even with optimistic assumption about how quickly emissions can be cut, the world is expected to warm by 4°C this century."

  • Steve Clarke says:

    Hi Clive,

    Thanks for your response to my post. As you can guess I'm pretty much in sympathy with many of the comments that Dave Frame and some of the other commentators have made. My main concern in the original post was to put pressure on your views about the nature of the Earth and what we can or cannot know about it. These seem to me to go well beyond what the relevant evidence allows us to infer. I don't accept that the Scientific Revolution has tied contemporary consequentialist philosophers and scientists to a rationalistic image of humanity. Science has intellectual roots in the Enlightenment and key Enlightenment figures such as Descartes really did hold a rationalistic view of humanity. However, the intellectual descendants of the Enlightenment threw off this view of humanity some time ago. These days, I think, it is standard for scientists as well as consequentialist philosophers to assume that humans are highly irrational and that our thinking is beset by a range of cognitive biases, framing effects and the influence of emotion.

  • Clive Hamilton says:

    There's quite a bit to respond to, so let me do it in two or three posts over the next day or two, starting with Dave's claim that I emphasise the bad end of the science.
    If you are relying on AR4 then it does seem soothing. But AR4 was recognised as being out of date even before it was published, for good reasons of scientific caution, but also because the process meant that research done in the 3-4 years before publication was not included. And the science became much scarier in those years, and since–see the updated "Reasons for Concern" diagram and the report by IPCC scientists just before Copenhagen.
    But the most misleading part of AR4 lies in the scenarios, ones developed in the 1990s. As has been shown several times, actual global emissions have been tracking above the "worst-case scenario", defined as A1FI (largelyt driven by China). So the world is now on a path that is worse than the worst-case scenario, one that in the early 2000s most people thought simply could not happen.
    I explain all of this in Chapter 1 of my book, Requiem for A Species. I had the science in it checked by a number of top climate scientists. Perhaps a better sense of what the climate scientists are saying can be found in Chapter 7 where I recount the "World at 4 Degrees" conference held in Oxford in late 2009. Scientists who model future concentrations believe that we will be lucky if we can limit warming to four degrees, and that will be catastrophic. For the latest in expected warming based on current policies see, for example, the MIT "scorecard", which estimates we are heading for 4.1 if current promises are implemented.
    http://climateinteractive.org/scoreboard
    I think AR5 will reflect all of this much more clearly. Weitzman's fat tails are not outliers

    I speak to climate scientists quite a bit and I have not heard any challenge the tipping point analysis in any substantive way (other than the AMOC shut off which has always been speculative). Can you point me to any papers challenging the tipping point argument of, say, Lenton et al.? From what I have read, recent paleoclimate studies only seem to reinforce it.

    • Dave Frame says:

      Hi Clive,

      While I'm sure some climate people agreed with the headline messages from the Copenhagen meeting, many climate scientists thought the "AR4 is out of date" line pushed at the Copenhagen science meeting was poor form, for two reasons: (1) "no, it isn't out of date"; (2) "who says?" I was there, and I was very uncomfortable both with the level of politicisation of the science messages and with the conduct of the meetings organisers. The key messages were agreed before the meeting occurred, and as far as I can tell they were agreed by a small group, but sold as if they were representative of the meeting's attendees.

      Some aspects of the science of climate change probably have moved on since 2007 but the core doesn't seem to have changed all that much, at least as far as I can tell from the literature. As for AR5; we'll just have to wait and see. As for Marty Weitzman, he thinks he's talking about low probability worlds, but I'm not sure what you mean by "fat tails are not outliers" – do you mean that fat tails have become a mainstream framing device or that the probability of catastrophic damages is high? I'd buy the former, even though I think there are issues with it, but not the latter. Not at all.

      On recent emissions being higher than we expected in 1990. Absolutely. Does it decrease our chances of staying under 2C. Probably a bit. Does it justify thinking we're heading for catastrophe? No, because that claim rests on additional premises regarding either the response or damages.

      Re: tipping points. A couple of models show this sort of behaviour but most don't.** The ones that do are (as far as I'm aware) highly simplified EMICs, such as GENIE and CLIMBER. Many climate scientists are skeptical about EMICs in general (much to the chagrin of various folks who work on them) and even those who work in the general area of EMICs can often be quite sceptical about each others' models. The fact that our most comprehensive models don't show much of this behaviour makes me downweight the simpler models that do, but I (personally) don't think that means we can rule them out. But it does seem justifiable to assign them low probability. The question is how to interpret the diversity of models and their results. Obvious ways of trying to combine models can lead into cul-de-sacs: the excellent Lenny Smith rightly cautions us not to "confuse the diversity seen in our models for uncertainty in the real world." But that doesn't necessarily help me actually interpret the diversity… but one move I think is very hard to defend is to pick on a model (or two, or three) that give a desired result and then claim that these have the answer. That's what I think you're doing.

      But I think all this (and more to and fro that could go on for ages) can be bundled up as follows: even within the science core of climate change there is considerable legitimate scientific disagreement about the magnitude and pattern of climate change. My problem with your position (and that of Mark Lynas, though Mark has toned it down a bit since he's decided to become an international statesman) is that you don't reflect this disagreement, and to me it feels as though you're cherry-picking the literature for conveniently alarming results. The sceptics do the same thing from the other side of the distribution, of course. The thing for me is that I don't see why you need to do it. What if the problem were merely "serious". Wouldn't most of your criticisms of predominant ways of thinking still hold?

      **Fairly broad generalisation, but it'll do for now. Here's just recent one GCM-based paper that doesn't find tipping points in sea-ice http://www.agu.org/pubs/crossref/2011/2011GL048739.shtml. I have it lying around because a mate who is very much in the world of earth system modelling sent me the link with the droll remark "won't someone think of the children?"

    • Dave Frame says:

      Oh yeah..as for the bit about heading towards 4C: the claim was "even with optimistic assumption about how quickly emissions can be cut, the world is expected to warm by 4°C this century." But I don't see the tabled (near-term, mostly) proposals inherent in the MIT scoreboard as being "optimistic assumptions about how quickly emissions can be cut". Do you really believe current announced policy represents such optimism?

  • Clive Hamilton says:

    "But what if the sacred site is the only place I can build a much-needed hospital in our community, and what if the site is sacred only to you?"
    The point about my example was to highlight that there are two kinds of value that are, for non-utilitarians, incommensurable. Forcing us to choose between them does not make them commensurable, which is the trick economists try on all the time when they say things like "When we decide to spend on road improvements rather than X then we are IN EFFECT valuing a life at $3 million".
    Utilitarians must insist that all of the positive and negative effects are commensurable, so that one can be traded off against another—or, rather, so that they can be traded off without feelings of guilt, regret or anguish. So when you say "what if we need the site to build a much-needed hospital" (as opposed to the miners who would claim they want to dig it up for "much-needed profits") what you are doing is what the utilitarians do, but the other way around. Instead of turning the ethical value (sacred site) into an economic value (willingness to pay) you are turning the economic value into another ethical value.
    In other words, you are loading up the other side with guilt, regret and anguish. So whichever is chosen becomes "a necessary evil" instead of a guilt0free trade-off. Sure, you can force a choice, but the real ethical question becomes how to account for the guilt or regret from choosing the hospital over the scared site or the sacred site over the hospital. It's just displacing the problem.
    On the "sacred only to you" question, of course the claim to sacredness must be recognised by society or through some legitmate appeal to rights, and cannot be arbitrary. How that occurs is another question.

    • Dave Frame says:

      Clive wrote:
      "The point about my example was to highlight that there are two kinds of value that are, for non-utilitarians, incommensurable. Forcing us to choose between them does not make them commensurable, which is the trick economists try on all the time when [etc]"

      Agreed. But I didn't say that consequentialism should be the only way of reasoning, just that consequences are a factor. I think my position is that consequentialism, deontological and virtue ethics all shed different sorts of light on problems, and the real action is often in the shakedown that occurs as these ways of reasoning collide and negotiate over the actualities of problems. I've never been able to back any particular conception of ethics (even at the broad consequentialist etc level) because there are times/situations when one or other seems more appropriate.** One move that does make me uncomfortable is when someone argues that we should turn off one of those lights completely, usually because the person making the case invokes "outrage" or some other synonym for moral offensiveness. I have a strong prior that more light is better than less light, so calls for less light make me wonder what people are trying to hide.

      **This may be the result of my own cognitive predispositions. I've been in Britain 12 years and I like football, but I've never managed to quite form an attachment to a particular team. Except maybe Oxford United, which is kind of pointless, buried as they are in the noise.

  • Clive Hamilton says:

    While I am on a roll, let me respind to Steve's comments on rationality. In a way, the exceptions you give prove the rule, because the swathe of irrational behaviours are regarded as imperfections to the true model, and consequentialist philosophy, whose conclusions should govern our behaviour, is seen as the paragon of rationality, purged of the imperfections.
    I have found helpful the chapter by Erik Parens in "Human Enhancement", edited by Julian Savulescu and Nick Bostrom. In the bioethics debate he finds two distinct "orientations towards life" at the root of differences, ones that he labels "creativity" and "gratitude". Supporters of human enhancement understand humans as “self-making”, with an obligation to transform the world and fulfil our potential. Opponents see life as a gift for which we should be grateful and not attempt to tinker with.
    There is a danger in each: gratitude can become mere passivity and fatalism, which seems to run counter to something that is essentially human; creativity can turn into unwarranted faith in one’s own capacities for understanding and control.
    It can hardly be denied that humans are creative; they have transformed the Earth in ways barely imaginable and in the process created many marvellous things. Yet with the climate crisis upon us creativity has got way out of hand.
    I think we can read swings between creativity and gratitude into historical epochs driven by social forces. The rise of the environment movement from the 1960s, and the challenge to “production science” presented by “environmental impact science” (which developed into ecology), can be understood as attempts to restrain rampant creativity with a strong dose of gratitude.
    While successful in some domains, they have not overturned the powerful forces pushing relentlessly for “creativity”; the climate crisis and dreams of geoengineering the planet indicate that creativity has turned into a monster we can no longer control. So one of my essential claims is that in our campaign to master the world we have forgotten how to master ourselves. Thus when confronted by the evidence of our own failure (climate science) we engage in more of the same (geoengineering).
    I'll leave it at that and hope later to return to the most important and most vulnerable part of my argument, what the climate crisis and Earth system science are telling us (and what it means to say that they can tell us anything).

    • Dave Frame says:

      For me, this is the really interesting bit. I agree that improvements in our understanding of complexity and the contemporaneous rise of environmental research have been a big deal. I think, for many scientists, the improved understanding of how nature works leads to a deepening sense of awe – not sure about "gratitude"; it seems rather too anthropomorphising a term for me to relate to. But this new knowledge has been arrived at through the old modes of enquiry (albeit somewhat silicon-enhanced).

      But I still don't see why you need a climate *crisis* to motivate the observation that unreflective emphasis on creativity is likely to lead you into trouble, since you're not taking environmental constraints (broadly conceived) at all into account. That point can be made as long as (1) the costs of a fossil fuel economy outweigh the benefits or; (2) the damages from emissions of fossil fuel contravene duties we have to others (or their human rights or however you want to put it) or; (3) the values we express when we emit loads of CO2 are out of whack with the virtues we aspire to instantiate (or however you want to put it). You could justify any of these without reference to catastrophism.

    • Peter Wicks says:

      "I’ll leave it at that and hope later to return to the most important and most vulnerable part of my argument, what the climate crisis and Earth system science are telling us (and what it means to say that they can tell us anything)"

      Maybe that we urgently need to step up our efforts at geoengineering? (In a suitably humble, circumspect and equitable way, of course.)

  • Steve Clarke says:

    Hi again Clive,

    Thanks for your response. An important part of the disagreement between us concerns the way in which intellectual traditions we have inherited continue to constrain or frame our thought. It seems that I view the intellectual tradition emerging from the scientific revolution as a much looser set of commitments than you do. Despite what you say, I don't regard the ideal of full rationality as something that scientists or consequentialist philosophers are necessarily committed to trying to reach. Recently, a lot of people working in both science and philosophy have become heavily influenced by Damasio's work which shows up various judgmental and behavioral problems that beset pure rational minds devoid of emotion; and as a consequence they do not regard themselves as committed to an ideal of full rationality. I don't see this development as a radical departure from the intellectual traditions of the scientific revolution. Rather, I see it as a matter of an already diverse tradition naturally evolving.

  • Andrew Glikson says:

    David Frame's comments include little or no reference to the measured levels of greenhouse gas forcing, atmosphere energy/forcing rise levels and rates, temperatures, ocean pH, trends in perspective of natural boundaries, and the rising spate of extreme weather events. To bring examples:

    1. David refers to the upper 2 degrees C limit, which in view of the evidence presented by the IPCC-2007 forcing diagrams and more recently by Hansen et al. 2011 exceeds 3 Watt/m2. The equivalent temperature level of +2.3C , which is transiently masked by the short-lived sulphur aerosols. The 2C limit has thus been superseded even though it continues to be referred to in political and economic debates, inconsistent with the science.

    2. David must be aware of the non-linear nature of climate change and that the CO2 growth rate of +2 ppm per year is the fastest recorded in geologic history (excepting global CO2 release due to volcanic and extraterrestrial impact factors). At this rate, feedbacks due to reduced capacity of CO2 sequestration by ocean and vegetation, forest fires, methane release from permafrost, and the ice albedo flip (including the opening of the Arctic Ocean) have come into play.

    3. The IPCC AR4 stated they were not in the position to assess upper limits of sea level rise as they had little information regarding ice break dynamics. Since 2005 new information has come into light, as in papers by Rignot and Velicogna 2010 and Hansen and Sato 2011, Hansen et al. 2011, indicating a doubling of ice breakdown rates every 5 to 10 years, a process which has become the major contributor to sea level rise.

    4. At 393 ppm CO2 and a growth rate of >2 ppm/year, by mid-century GHG levels will reach the upper stability limit of the Antarctic ice sheet as defined by numerous paleo-climate studies. Last time the Earth experienced such levels is 34 million years ago, which means that over a short 2.2 centuries humans have returned the atmospheric energy forcing level to that which existed that far back in time!

    5. While we cannot predict the precise point in time when future tipping points will occur, these take place differentially in time and place as suggested by Lenton and Schellnhuber (2009). The spate of extreme weather events around the globe, where the frequency has near-trippled over the last 20 years or so (as monitored by Munich Re-Insurance), tells us something we may not wish to know, i.e. that what is happening since the 1980s may constitute a protracted tipping stage expressed through these events … I wish I am wrong!

    Andrew Glikson
    Earth and Paleo-climate science
    Australian National University

    3 September, 2011

  • Dave Frame says:

    This is the sort of point by point stuff I was hoping to avoid, since I think it's pointless. But since silence might be mistaken for consent let me make just a couple of comments: 2C isn't a "limit" it's a goal. There's no evidence that anything special happens at 2.000C, but I dare say someone will soon tune an EMIC to change that. Your point (2) is interesting – 21st century at the global level looks remarkably smooth at the global level in GCMs. At those scales (time & space) it doesn't seem particularly nonlinear in the most comprehensive models. It may be if forcings are sustained longer or if you look instead at regional change.

  • Dave Frame says:

    …sorry I hit reply unintentionally. I'd have probably edited it a bit more. Basically, I think you're mistaking me for another animal. As a mainstream climate scientist ofcourse I accept all the obvious bits about the relationship between GHG, forcing, temperature and so on (and the point that extremes are likely to drive damages in the next few decades). I just don't believe the evidence points to a looming catastrophe, but rather a serious problem driven by a century or two of significant change. This is in keeping with the buld of the evidence, in my view.

    [As for sea-level rise: who knows. It's a very contested area.]

  • Andrew Glikson says:

    David.

    I am not sure why you state "This is the sort of point by point stuff I was hoping to avoid since it is pointless", since anything civilization attempts to do (nothing so far) needs to be tied-in with developments in the atmosphere/ocean system.

    There is nothing "smooth" in climate change since early in the 20th century, including (1) a sharp GHG and temperature rise between WWI and WWII (related to both high C emission and a minor increase in solar forcing); temperature decline between WWII and the mid 1980s (attributed to heavy aerosol release and a minor lull in solar sunspot activity); (3) a sharp upward turn in all aprameters in the mid-1980s (1975-1976) showing on most plots; (4) huge El Nino peak in 1998, followed by a gradual rise between 2000 and the present including the 2005 and 2010 peaks – the latter exceeding 1998 despite the La Nina stage.

    This is clear from the trends, best shown on a dynamic display of climate evolution by the Global Carbon Project download at http://www.globalcarbonproject.org/misc/misc.htm

    The "goal" of 2C is now exceeded since in reality civilization is already exercising geo-engineering to the extent of -1.2C (see Hansen et al. 2011 – The global energy balance, Figure 1 http://www.columbia.edu/~jeh1/mailings/2011/20110415_EnergyImbalancePaper.pdf ). Methane, likely the most powerful feedback process to current events, is already streaming out of Arctic lakes.

    From a geological perspective, current trajectories are unique. The upper stability limit of the Antarctic ice sheet being at ~500 ppm CO2 (Zachos et al. 2001), human emissions and land clearing have triggered energy forcings now just under 50 percent of forcings triggered y solar pulse and related glacial albedo flip feedbacks at the last glacial termination ~14,000 years ago.

    Regarding sea level rise, I suggest you look at Rignot and Velicogna 2011 (http://www.agu.org/news/press/pr_archives/2011/2011-09.shtml) and references therein regarding the breakdown dynamics of the large ice sheets.

  • Dave Frame says:

    I think it's a bit silly to have in depth conversations about details of the climate system on a blog called "practical ethics" because (1) they rather miss the point of the blog. (2) They're also potentially vast conversations, since respondents can cite numerous papers to argue for their positions and that can take a very long time, for very little benefit. (3) It's not obvious to me that they're remotely significant or important conversations, since blogs are – (sharp intake of breath!) – not actually important venues in the world of real world policy formation.

    My main point, which I absolutely stand behind, is this one: "even within the science core of climate change there is considerable legitimate scientific disagreement about the magnitude and pattern of climate change." Do you dispute this? It has been obvious at every scientific meeting on climate change I've ever been to and it is, essentially, why we bother researching things. If we really thought GENIE was the world, or that Jim Hansen had all the answers, the rest of us could go home and get on with our lives. [Personally, I'd get a job analysing sports stats/performance. That would be way more fun.]

    Andrew wrote:
    "There is nothing "smooth" in climate change since early in the 20th century, including (1) a sharp GHG and temperature rise between WWI and WWII (related to both high C emission and a minor increase in solar forcing); temperature decline between WWII and the mid 1980s (attributed to heavy aerosol release and a minor lull in solar sunspot activity); (3) a sharp upward turn in all aprameters in the mid-1980s (1975-1976) showing on most plots; (4) huge El Nino peak in 1998, followed by a gradual rise between 2000 and the present including the 2005 and 2010 peaks – the latter exceeding 1998 despite the La Nina stage."

    This is getting silly. Energy balance models – which are dynamically linear (and fairly smooth – ie a long way (at global, centennial scales) from the discontinuous picture often implied by "tipping points") – do a reasonable job at simulating the response both to (1) observed 20th century forcings** and (2) the sorts of responses GCMs predict in the 21st century. Of course they cannot simulate internal variability (such as ENSO etc). [This limitation is not unique to ebms, either.]

    Rather than cite particular papers – which may mislead innocent bystanders into thinking that a single paper is the full story – I think we, as a community of scientists, ought to search for better ways of expressing the range of views in the literature. Expert elicitation offers one way of doing this, even though it's far too social sciency for many scientists' tastes. One recent example of this on aggregate climate system parameters is ZIckfeld et al., 2010***. On climate sensitivity**** – often taken as a key climate system parameter – we show a range of expert opinions. There is obviously a spread of opinions. My main point is that – when we communicate to the public – we should try to give a flavour of that sort of diversity (which would be wide in lots of important climate system parameters (eg SLR, carbon cycle-temperature feedbacks, etc)). I think Clive does a poor job of this, because he effectively assigns very high weights to a small portion of the literature, and effectively ignores the bulk of the literature. That's all I'm really trying to argue.

    **Which are, of course, combinations of natural and anthropogenic forcings. [Including sharp forcings such as those from volcanoes - it's true that models (incl ebms) often struggle to deal with those forcings very well.]
    ***Zickfeld, K., M.G. Morgan, D.J. Frame, and D.W. Keith, 2010, Expert judgments about transient climate response to alternative future trajectories of radiative forcing, Proceedings of the National Academy of Science, 107 (28): 12451-12456.
    ****Another paper which I recommend is Knutti & Hegerl, 2008 http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf

    By the way, it's "Dave" not "David".

  • Andrew Glikson says:

    Dave

    It is not possible to discuss the climate in terms divorced from the physics and chemistry of the atmosphere-ocean-cryosphere system.

    The view I express does not only reflect that of Hansen and his group – one of the most advanced anywhere – but that of the bulk of the peer revewed liteature, major research institutes (NASA, NSIDC, Hadley-Met, Tyndale, Potsdam, CSIRO, BOM and so on) which are looking at the same trends.

    The variations in interpretations are marginal rather than regarding the principal trajectories – the only people who question the latter are the so-called sceptics who used recycled long-refuted arguments.

    Authorities in the field are now talking about a 4 degrees C world and people who study paleo-climate, like me, understand the implications, in particular when such conditions are projected over a time scale of a century or two.

    When Joachim Schellnhuber, climate advisor to the German government, states: " We are simply talking about the very life support system of this planet.” he knows what he is taling about.

    As elaborated by Hansen et al. 2008:

    "Target Atmospheric CO2: Where Should Humanity Aim?
    James Hansen,1,2* Makiko Sato,1,2 Pushker Kharecha,1,2 David Beerling,3 Valerie Masson-Delmotte,4 Mark Pagani,5 Maureen Raymo,6 Dana L. Royer,7 James C. Zachos8

    Paleoclimate data show that climate sensitivity is ~3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6°C for doubled CO2 for the range of climate states between glacial conditions and icefree Antarctica. Decreasing CO2 was the main cause of a cooling trend that began 50 million years ago, large scale glaciation occurring when CO2 fell to 425±75 ppm, a level that will be exceeded within decades, barring prompt policy changes. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm. The largest uncertainty in the target arises from possible changes of non-CO2 forcings. An initial 350 ppm CO2 target may be achievable by phasing out coal use except where CO2 is captured and adopting agricultural and forestry practices that sequester carbon. If the present overshoot of this target CO2 is not brief, there is a possibility of seeding irreversible catastrophic effects.

    • Dave Frame says:

      And my point is merely that lots of people who know a lot about the climate system *disagree* with Hansen (and Schellnhuber). That Hansen paper did not appear in the places he expected it to, because reviewers didn't agree with it. Whatever any particular author thinks, their word is not the final word on a subject as complex as this.

      "It is not possible to discuss the climate in terms divorced from the physics and chemistry of the atmosphere-ocean-cryosphere system."

      It is possible to discuss responsible treatment of disagreement or uncertainty without needing to cite every instance of both from within a large and rapidly growing literature. Let's show some mercy to readers, eh?

      "The view I express does not only reflect that of Hansen and his group but that of the bulk of the peer revewed liteature, major research institutes (NASA, NSIDC, Hadley-Met, Tyndale, Potsdam, CSIRO, BOM and so on) which are looking at the same trends. "

      That's not really true. One example: I worked at DECC for 8 months and am pretty aware of the information the Hadley Centre provides to the UK Govt. This information is (essentially) in sync with the distributions in Knutti & Hegerl or those in Zickfeld rather than the distribution implied by the Hansen et al abstract you cite. I mention Knutti & Hegerl because it was a review article – hence it was reviewing the available distributions in the *peer-reviewed* literature. Another example: I mention the Zickfeld article because we inteviewed researchers who write on climate sensitivity at a couple of the insitutes you cite (Hadley, Potsdam) as well as various other centres of expertise (Stanford, NCAR, MIT, Oxford). No one gave us a Hansen-shaped distribution, and we did ask about long-term feedbacks. Have a look at the paper – do you really think the folks we talked to aren't experts, or that Knutti & Hegerl really failed to review the literature adequately?

      etc. But as I've tried repeatedly to say, my point is not that the S=3 crowd are right and that Jim Hansen is wrong. My point is the much less controversial contention that we should try to reflect the existing level of disagreement and/or uncertainty when we communicate about climate science. [A reasonably gentle introduction for anyone who has waded through the obcurity of this thread can be found in Mason Inman's artcile from ayear or two ago – http://www.nature.com/climate/2009/0905/full/climate.2009.41.html.

    • Dave Frame says:

      "The variations in interpretations are marginal rather than regarding the principal trajectories – the only people who question the latter are the so-called sceptics who used recycled long-refuted arguments. "

      Difficult to let that slide – do you think I'm a climate sceptic, then? Or do you think this conversation is merely quibbling at the margin? Assuming it's the latter, why not agree with me that citing a wider (albeit less alarming literature) such as that in AR4 etc would be an improvement, since it would be more representative than a biased subsample?

      [Or do you *really* think I'm a skeptic, just because I have the impudence to suggest that there may still be value in AR4 and in non-Hansen experts? Seriously?]

  • Anthony Drinkwater says:

    I may be the only reader to be getting a little lost in this highly technical debate about current climate changes, but I’d like to propose a simple « thought experiment » :
    Let us zoom out by a few factors and ask whether it’s generally accepted, or not, that we are actually in an ice age which started some 40 million years ago and during which we have had dozens of wide fluctuations between glacial and re-warming epochs ?
    If so, then whatever the responsibility of humanity for current warming might be, and whatever geo-engineering scemes might counter average temperature shifts of a few degrees, in the very long term it will probably make no difference to the sustainability of current life forms. Whatever unknown factors caused the shifts since the origin of the earth are more than likely to impose new ones, equally dramatic.
    Which suggest to me that Clive is right to pose with humility the question of what a human being is in the place of things…. which is not out of place in a Practical Ethics blog.

    • Dave Frame says:

      Hi Anthony.

      I agree. I don't see why the basic points Clive makes depend on climate change being catastrophic rather serious. For me, much of the substance holds even if you think climate change is a bummer rather than the end of the world. I think environmental science has deepened our awareness of the fragility and contingency of our lives (history and astronomy have always done this for me, too). Those flavours of experience tend to lead in the direction he wants, from my experience, since they enhance the feeling of cherishing what we have.

    • Peter Wicks says:

      No Anthony, you're not the only reader getting a little lost. It seems to me that at least three separate questions are getting confused here:

      1. Just how serious is climate change?
      2. What does this tell us about the place of humanity in the universe?
      3. What implication does all this have with regard to consequentialism as a foundation for our ethical choices?

      Earlier in this thread you pointed out why you are "dissatisfied" with utilitarianiam (and, presumably, consequentialism more generally). Dave has indicated that he has "never been able to back any particular conception of ethics (even at the broad consequentialist etc level) because there are times/situations when one or other seems more appropriate". I think my position on this would be to agree at a tactical level (sometimes for example it's better to emphasise the need to nurture virtue rather than the need to calculate consequences) but still to insist on consequentialism as the overall raison-d'être (we want to nurture virtue because overall it leads to better consequences).

      So what light could 1. and 2. possibly shed on 3.? Suppose Clive and Andrew are right and the catastrophic scenarios have a significant chance of happening? Why is that an argument AGAINST geoengineering? Or suppose we conclude that the earth system is so vastly complicated that anything we try to do will be counter-productive. What conclusion do we draw from that? Eat, drink and be merry, for tomorrow we die?

      It is easy to make arguments to the effect that the road to hell is paved with good intentions. But life also teaches us that we are more likely to succeed when we actually try. If the lesson is supposed to be that we need to be circumspect and humble in our ambitions, then that's fine with me (provided we don't overdo it). But that's not an argument against consequentialism. That's a consequentialist argument in favour of prudence.

  • Andrew Glikson says:

    Anthony.

    The survival or extinction of species depends on the RATE at which environmental changes occur.

    Paleo-climate science, based on multiple proxies (isotopes, trace elements, fossils) reported in thousands of peer review papers, identifiy many of the factors underlying these changes, including the ability of species to adapt to the variations in temperatures, solar radiation, ice extent, vegetation cover, ocean pH and abrupt events such as methane-release, volcanic eruptions and asteroid impacts.

    As long as environmental changes occur at a slow to modertate rate most species adapt. It is when environmental variations occur at high to extreme rate, such as in the examples above, that flora and fauna may be extinguished – a situation culminating in mass extinction of species seveal of which are recorded in Earth history.

    The concern is that current climate change takes place at an extreme rate of 2 ppm CO2/year – unprecedented over the last 34 million years, disrupting the otherwise regular cycle of glacial/intergalcial eras through which our ancestors lived, and that the level of atmospheric energy is close to the upper stability limit of the Antarctic ice sheet, which threatens conditions mammals can hardly sustain on the continents.

    For a perspective of current climate variations you may like to refer to my 2008 paper "Milestones in the evolution of the atmosphere with reference to climate change" (enter the title on GOOGLE and you will be able to download the pdf file of this paper)

  • Andrew Glikson says:

    Dave

    You write:

    "And my point is merely that lots of people who know a lot about the climate system *disagree* with Hansen (and Schellnhuber). That Hansen paper did not appear in the places he expected it to, because reviewers didn’t agree with it. Whatever any particular author thinks, their word is not the final word on a subject as complex as this."

    In your message you come across as dismissive of the critical observations made by leading authorities in climate scientists (not only Hansen and Schellnhuber but many many other, including statements by major science organizations).

    Given that there is no such thing as an average or even consensus of scientific opinions, for a meaningful debate one needs to look closely at the data and the trends, rather than adhere to the views of one scientist or the other.

    Therefore there is no substitute to a meaningful technical/scientific discussion of bona-fide observations based on the most reliable data at hand.

    In my previous contributions I listed a number of CRITICAL EMPIRICAL OBSERVATIONS regarding the state of the climate, consistent with the basic laws of atmospheric physics and chemistry.

    In so far as you wish to discuss these points I will be interested in your alternative inerpretations of current climate trajectories.

    • Dave Frame says:

      Apologies in advance.
      This one is a little technical. I think Andrew has misunderstood the basic thrust of my criticism of Clive's position. I'd like to use a specific example from the climate literature to show why "trends" alone do not always constrain what we might want to know. It's usually supposed that climate sensitivity is an important thing to know, since specifies the relationship between equilibrium forcing and equilibrium response [See any IPCC report, or Hansen et al., Science ,1985 which is a seminal paper on energy balance.] The problem with current "trends" is that they might be consistent with a variety of equilibrium conditions. There's been a lot of literature to the effect that "climate sensitivity is not well constrained by the observed temperature record"*, a result also obtained by others**, and not only in simple models: "This problem of a non-linear relationship between observable quantities and S was noted long ago in the context of simple models [Hansen et al., 1985] and more recent studies have demonstrated it also applies in GCMs [Murphy et al., 2004; Piani et al., 2005; Knutti et al., 2006]."***
      The basic problem is that the things we can observe tend to scale with feedbacks, and since climate sensitivity, S, is related to feedbacks, L, by the relationship S=F/L (where F=forcing), a roughly gaussian set of observations tend to lead to an inverse gaussian (with a fat tail) in S.## Now this isn't the whole story, because – as lots of people have enthusiastically pointed out – S cannot be completely unbounded at the top end. It's just that recent observations alone (20th century, say) cannot bound those upper reaches. Previous climates offer a way of giving us something of the upper bound, and there have been attempts to use the last thousand years### and the last glacial maximum$$ as potential constraints. There is ongoing debate about exactly how to combine estimates based on previous climates.$$$

      *Stott, P & J Kettleborough, Origins and estimates of uncertainty in predictions of twenty-first century temperature rise, Nature, 416, pp.719-723, 18 April 2002. http://climateprediction.net/science/pubs/nature_stott_180402.pdf
      **eg Forest, C. E., Allen, M. R., Stone, P. H. & Sokolov, A. P. Constraining uncertainties in climate models using climate change detection techniques. Geophys. Res. Lett. 27, 569–572 (2000).
      ***D. J. Frame, D. A. Stone, P. A. Stott & M. R. Allen, Alternatives to stabilization scenarios, Geophysical Research Letters, 33, L14707, doi:10.1029/2006GL025801, 2006 http://www.atm.ox.ac.uk/user/dframe/papers/2006GL025801.pdf
      ## Roe, G.H., and M.B. Baker, 2007: Why is climate sensitivity so unpredictable? Science, 318, 629-632 http://earthweb.ess.washington.edu/roe/GerardWeb/Publications_files/RoeBaker_Science07.pdf, though we also made the point in our 2006 paper.
      ### G. C. Hegerl, T. J. Crowley, W. T. Hyde & D. J. Frame Estimating climate sensitivity from paleoclimatic records of the last millennium, Nature, 440, p1029-1032, 2006. See also the correspondence arising: Schneider, T. Climate modelling: Uncertainty in climate-sensitivity estimates, Nature 446, doi: 10.1038/nature05707 (2007) and; Hegerl, G.C., Crowley, T.J., Hyde, W.T., and Frame, D.J. (2007) Climate modelling: Uncertainty in climate-sensitivity estimates (Reply). Nature, 446(7131): E2.
      $$ see for instance section 9.6.3.2 of AR4 WG1: Hegerl, G.C., F. W. Zwiers, P. Braconnot, N.P. Gillett, Y. Luo, J.A. Marengo Orsini, N. Nicholls, J.E. Penner and P.A. Stott, 2007: Understanding and Attributing Climate Change. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-6-3-2.html
      $$$ http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf

      • Dave Frame says:

        D'oh! Again I hit post when I was still editing. $$$=Knutti, R. and G. C. Hegerl, 2008, The equilibrium sensitivity of the Earth’s temperature to radiation changes, Nature Geoscience, 1, 735-743, doi:10.1038/ngeo337.

        Anyway… all this matters, because what it implies is that you can't simply read off key climate change parameters from recent observations. Other things – specifically the heat capacity of the climate system and the details of the forcing profile matter, too. And of course the model, too. My point is just this: there are lots of estimates of these sorts of things, and estimates of future change often cannot be easily inferred from changes until now. Different groups, reasonably enough, take different approaches, and these can wind up giving different results because of the choice of model, or how strong a constraint they think previous climate provide, etc, even though both studies are similarly consistent with current trends. This is the sort of legitimate scientific disagreement I was referring to, and it's also why "trends" are not always unambiguous indicators. [Just how (un)ambiguous they are depends on the data and the forecast quantity. [I'm pretty sure that current measurements of g, the acceleration due to gravity, are good forecast estimates, too.]

  • Dave Frame says:

    "In your message you come across as dismissive of the critical observations made by leading authorities in climate scientists (not only Hansen and Schellnhuber but many many other, including statements by major science organizations)."

    But I haven't been offering my opinions. I've been citing the opinions of others: two leading experts writing in Nature (Reto Knutti and Gabi Hegerl) and a bunch of experts (Steve Schneider, Tom Wigley, etc) grilled in the Zickfeld study. All I'm pointing out is that various experts have gone on record offering views that are different from those of your favoured experts. I'm surprised you think this is out of order. I don't believe I've been dismissive at all of Hansen or others. I keep saying that we should be clear that some scientists think X and that some (similarly expert) scientists think Y. Let me repeat my basic point for the nth time: my point is not that one group is right and that another group is wrong. "My point is the much less controversial contention that we should try to reflect the existing level of disagreement and/or uncertainty when we communicate about climate science." Do you disagree? Do you really believe I should cease citing recent peer-reviewed studies in top ranking journals?

  • Clive Hamilton says:

    Dave
    I don't want to get bogged down in a debate over climate science either–both because I am not a climate scientists and because this is not the place to do it. But you challenged my reading of the science and suggested that I am guilty of cherry-picking, which is not the sort of accusation that can go unchallenged. Rather than cherry picking my understanding of the severity of the problem was completely transformed by reading the 2008 paper by Anderson and Bows. I set it out in Chapter 1 of my book, but the basic argument can be stated very simply.
    Future temperatures depend above all on two factors–the date at which global emissions peak and the rate of decline thereafter. They define the curve from preindustrial times to, say, 2050 and the integral gives total increases in concentrations (give or take).
    Let's assume global emissions peak in 2020 and decline at 3% annually thereafter. These are very optimistic assumptions indeed. Who really thinks the peak could occur by 2020, so that all increases in developing country emissions must be more than offset by declines in developed countries after that date? And a 3% annual global decline would mean 5-6% for developed countries (and 6-7% in industrial emissions). The only time rates like that have occured historically were in Russia in the 1990s, and that went with a halving of Russian GDP.
    But let's be optimistic and ask where that would leave us. It would see ghg concentrations rise to 650 ppm. That's huge. It would see temperatures rise to 4C plus (on best estimates of climate sensitivity), making the planet hotter than it's been for 15 million years. It would change everything. 4C is an average and would mean 5-6C on land and 7-8C near the poles.
    No-one has challenged the Anderson and Bows amalysis; indeed, it has been replicated by other groups.
    And that is the best estimate of climate change this century using *optimistic* assumptions about how the world is likely to respond to the threat. If I am being catastrophist (along with virtually all the other climate scientists that I have spoken to or heard speaking about these types of projections) then you need to say what is wrong with these projections.
    Andrew's main point, I think, is that there is uncertainty about expected trends, but the uncertainty does not destabilise what we know in any fundamental way; if anything is mostly works to make us more alarmed.
    So while Andrew and I are focused on the trends, which are reasonably robust, and give rise to extreme levels of concern, you keep coming back over and over to the uncertainties, as if these are enough to cause us to be only mildly concerned about the implication of global warming. I read Andrew's reference to "sceptics" as arising from the fact that their strategy is to emphasise the doubts (as in "Merchants of Doubt").
    Having set out, very briefly, the scientific basis for my approach, I hope we can return to the topics that are more philosophical (even though I suspect that the difference between us in our orientations toward the science has roots in diverging philosophical understandings of the world).
    Clive

    • Dave Frame says:

      "you keep coming back over and over to the uncertainties, as if these are enough to cause us to be only mildly concerned about the implication of global warming. I read Andrew’s reference to "sceptics" as arising from the fact that their strategy is to emphasise the doubts (as in "Merchants of Doubt")."

      I said it was a "serious" problem, not a "mild" problem. And I'm intrigued that you seem to interpret my main claim (which I've been very clear about…) as an instance of the sort of dirty tricks discussed in Merchants of Doubt. All I'm asking, remember, is that you cite the range of views on climate change that appear in the literature, citing (just as quick examples) papers in Nature and PNAS, and AR4. When I heard Erik Conway speak earlier in the year, he was referring to spurious or manufactured doubt from marginal or even dubious sources. Do you really think the papers and researchers I mentioned fall into those categories? If so, on what basis? If not, why not concede the point that there is a range of expert views, and cite appropriately?

      In an effort to move things forward, how about I just boil it down to this:
      It's extremely likely that climate change is among the top dozen or so global problems confronting current generations.** You believe your analysis holds if it's#1, obviously. But what about if climate change is #2? #3? … #12? I kind of see your points as holding as long as serious problems can be couched in the appropriate moral language (depending on your conception of ethics… see above). Do you think your argument fails or weakens unacceptably if climate change slips down the list? What about if another environmental problem took its place? I'm just not quite sure why you feel your argument is so contingent on the details of climate change.

      **The idea of a single "greatest problem facing humankind" strikes me as kind of problematic; when I think back to 1900 I can imagine various people arguing for the primacy of quite different problems, all deploying quite reasonable arguments.

  • Clive Hamilton says:

    Peter
    Thanks for your comments. You asked what influence Earth system science and global warming can have on a consequentialist understanding, which is at the centre of the debate we are having here. You frame it in terms the difference the facts could make on how we should act. But this framing is itself consequentialist. I am suggesting we need to step back and ask what sort of being makes these sorts of decisions. Who is it that acts?
    So my paper does not ask "What can ethics tell us about geoengineering?" but "What does the proposed recourse to geoengineering tell us about ethics?"
    Historically, certain big events are associated with revolutions in philosophical thinking. 19th century humanism could not survive the barbarism of World War I. Utilitarianism could not emerge without the invention of the self-legislating subject. I am suggesting that the fearsome threat to settled patterns of living arising from 300 years of industrialism is destabilising the way we approach the world. I don't think we can consider the "ethics of geoengineering" without first coming to grips with our failure take measures to head-off climate change.
    Clive

    • Peter Wicks says:

      Thanks Clive. I see your point, but I'd like to make a further distinction between (i) the predictive exercise of considering how the "big event" of climate disruption might effect our ideas about ethics and geoengineering, and (ii) the normative question about whether should allow the threat of such an event should make us think differently about these issues now. In the end, my question to anyone advocating a non-consequentialist approach to ethics is: what does it mean to say that we should or shouldn't act, speak or think in certain ways if it's not that to do so will lead to good or bad consequences? Why should I take seriously anyone's ideas about what I (or anyone else) should do or say, or how I (or anyone else) should think, if it's not because they shed light on the likely consequences of such action or thought?

      By the way I'm not sure that I believe that WWI would on its own have killed off 19th century humanism (if that's what it did). For a "big event" to trigger such a paradigm shift, there needs to be a pre-existing weakness in the prevailing theory, and at least the germs of a new (competing) theory that can better account for the event. Natural selection could certainly better account for the barbarism of WWI than a naïve belief in humanity's inherent goodness. Behavioural economics can better account for the financial crisis than neoclassical economics (although the latter refuses to die quietly). Earth system science doesn't compete with consequentialism (science and ethics are two different playing fields); on the contrary the two are perfectly compatible.

      The reason why all of this matters, in my view, is that I think we are in a race against time. Climate disruption is only one of the increasing systemic vulnerabilities that threaten the sustainability of our emerging global civilisation. Technology has given rise to the problem, but it also seems to be the only plausible way of dealing with it. Now hardly seems the best time to be scratching our heads wondering whether it's all worthwhile.

      • Dave Frame says:

        "The reason why all of this matters, in my view, is that I think we are in a race against time. Climate disruption is only one of the increasing systemic vulnerabilities that threaten the sustainability of our emerging global civilisation. Technology has given rise to the problem, but it also seems to be the only plausible way of dealing with it."

        I think there's a lot of interesting bits in this, which kind of cuts to the core of the problem. I agree there are a number of systemic risks, but we're a long way from having a systemic approach to managing these. Part of this is agency: there are situations in which people can act together a bit like a single agent (threats from influenza etc – it's pretty obvious we're all united against the pathogen) but there are others – and climate change is a real poster child here – where the incentives to collaborate are so weak it's not obviously meaningful to expect much in the way of collaborative action [See Scott Barrett's Environment and Statecraft or David Victor's Global Warming Gridlock, for instance], hence the idea of a single global agent looks pretty unconvincing. And stongly held, fairly ubiquitous intutions in some areas – regarding family size, public health, famine relief – exacerbate problems in other directions (eg environmental stress). As John Broome has pointed out, we don't have an adequate theory for valuing population, and population is clearly a very significant driver of at least some of the enhanced risks you're referring to. I agree that technology has been a principal driver in the development of these risks. But I also agree it's the only sane, moral game in town for managing many of them. [But not all technologies are created equal, of course - since this thread started out with geo-engineering, let me say that SRM flavours of geo-engineering don't look like good ideas to me.]

        Dave

        • Peter Wicks says:

          Thanks Dave. A related point is the well-known frog-in-a-saucepan phenomenon: we react relatively effectively to acute and obvious threats such as influenza pandemic, whereas we tend to be hopelessly bad at dealing with less obvious, less immediate threats such as climate change, however catastrophic they may eventually become and however close to the point of no return we may actually be. (One can also cross the event horizon of a black hole without noticing anything, if it's big enough.)

          I personally believe that we are at a moment in history where defeatism presents a far more serious threat to humanity than hubris. I don't fear "SRM flavours of geo-engineering", not least because I suspect that by the time we are close to implementing any of them we will have had plenty of time to consider the possible downsides. And at this stage, I think we need all the ideas we can muster.

  • Andrew Glikson says:

    When it comes to matters on which lifves depend great caution needs to be exercised, examples being:

    1. Interference with procedures relating to brain surgery.
    2. Interference with the navigation of a jet plane
    3. Interferecnce with engineering calculations of a suspension bridge

    Unless exercised by people thoroughly versed with the inner workings of these systems, expressing cogent technical/scientific advice.

    Sadly the issue of climate science and climate change, considered by the bulk of climate scientists as dangerous, falls into this catgegory. The issue should not become the subject for a "plebiscite", "consensus" or polemics and participants in the discourse need to be able to provide evidence-based technical arguments.

    In my debates with those who do not accept the basic observations of climate science and ignore the laws of physics I repeatedly encountered the following pattern:

    A. The sceptics attempted to raise a range of long-refuted spurious arguments, contradicted by datasets and trends.
    B. The sceptics then resorted to "playing the man instead of playing the ball" tactics, denouncing scientists on a variety of pretexts.
    C. Essential analogies emerged between these debates and earlier debates realting to tobacco smoking

    The matter would have been of purely academic inerest had it not been concerned with the future of the atmosphere/ocean system and thereby of the biosphere and human civlization.

    As a practicing Earth and paleo-climate scientist I do not accept the views of leading scientists on face value, nor the views of sceptics as necessarily incorrect, but examine each claim with reference to:

    1. Measurements by NASA, NSIDC, Hadley-Met, Potsdam, CSIRO BOM and other technical bodies.
    2. Direct observations reported from around the globe
    3. The laws of physics and chemistry.

    Arguments regarding consensus or the relative nature of truth do not come into these REALITY TESTS.

    The question of ethics arises once a process and a theory are shown to progress beyond reasonable doubt, which is where the precautionary principle and th concept of insuance come in – nations investing $trillions in insuring themselves from alleged military threats.

    I regret my readings of the literature and observations of nature lead me, among many other, to perceive an extreme danger to nature and to human civilization from ongoing carbon emissions. I am willing to provide relevant scientific papers, including my own, which elucidate this point.

    • Peter Wicks says:

      "The question of ethics arises once a process and a theory are shown to progress beyond reasonable doubt, which is where the precautionary principle and th concept of insuance come in – nations investing $trillions in insuring themselves from alleged military threats."

      I would actually go further. The question of ethics arises whenever we are wondering whether or not to do something that will have non-trivial consequences. (Once again, I challenge those who favour non-consequentialist approaches to ethics to reformulate the preceding sentence in a way that de-emphasises the relevance of consequences in determining whether an action, including speech, has ethical implications.)

      But the really interesting point here is your description of "debates with those who do not accept the basic observations of climate science and ignore the laws of physics". What you describe is essentially what happens whenever someone has a non-evidenced based reason for wanting to believe, or wanting others to believe, something. The real tell-tale is stage B. Stage A would be OK: you might just be talking to someone who's relatively ignorant, and once you've refuted their arguments they reconsider their position. When they start getting personal, you know there's something else going on. It might be a hidden (or not-so-hidden) agenda, or it might be simply an emotional attachment to a set of beliefs they've gotten comfortable with. Viz the "stongly held, fairly ubiquitous intutions" referred to by Dave.

      So how do we break down such cognitive inertia and thus save humanity from disaster? There are many ways, of course, but I actually think that the positions that those of us who like discussing such things take on ethics and meta-ethics do themselves have consequences in the real world. A consequentialist, indeed utilitarian approach to ethics, provided it is adequately informed by the various critiques, alternative frameworks, and contemporary knowledge about human psychology, provides the best conceptual framework within which to define solutions and manage risks. A moral subjectivist approach to meta-ethics strikes the right balance between a non-evidence based and (therefore) neurotic attachment to "moral truth" – which creates its own cognitive distortions – and the nihilism of non-cognitivism that states that normative statements are completely meaningless.

      Essentially, a moral subjectivist commitment to utilitarianism says: "There is no moral truth, but there are choices, and those choices have consequences. The kind of future I want to aim for is one in which humans, or post-humans sufficiently similar to humans for us to care about them, flourish. What about you?"

      • Anthony Drinkwater says:

        Hi Peter,
        Re your challenge, herewith a (short and incomplete) answer :

        When you state that « The question of ethics arises whenever we are wondering whether or not to do something that will have non-trivial consequences » you are implying not only that consequences matter (and I don't disagree for one moment that consequences matter) but also that intention matters. Otherwise why include « wondering whether or not to do …. » ?

        To make the same point from another angle : what would the above phrase mean after excluding the part « are wondering whether or not to »:
        « The question of ethics arises whenever we do something that will have non-trivial consequences » ?

        To give two simple illustrations :
        « The question of ethics arises whenever we do something that will have non-trivial consequences, such as falling off a ladder and breaking our back »
        or
        « The question of ethics arises whenever we do something that will have non-trivial consequences, such as buying a lottery ticket that turns out to be a winner »

        I conclude that consequences are not the only drivers of ethics.

        • Peter Wicks says:

          Thanks Anthony. I agree that intention is also fundamental. What I'm wondering though is to what extent (you think) this is not already taken care of within consequentialism. What consquentialism is basically saying is that we should endeavour (intention again!) to act in ways that, to the best of our knowledge, are likely to lead to the best outcomes. When we act, we are responsible for those consequences that could reasonably be predicted, including possible ones that didn't actual occur. (To add a third example: if you overtake someone round a bend, and get away with it, that still doesn't make it right because you had no good reason to assume nothing was coming the other way.)

          So my contention would be that intention is already taken care of in any half-sensible version of consequentialism. If torture is wrong (as opposed to some tragic accident where someone gets hurt), surely it's because of the severe psychological consequences for the person being tortured, and perhaps also because of its effect on the "moral fibre" of the torturer, and the society that tolerates it. And by "moral fibre", I basically mean a set of mental and behavioural habits that are likely to lead to good outcomes for that society. But suppose the very survival of that society is at stake?

    • Regina says:

      I don't know who you wrote this for but you helped a brtoher out.

  • Andrew Glikson says:

    correction:

    The first line should read "on which lives depend".

  • Andrew Glikson says:

    The dictum 'The road to nowhere is strewn with good intentions" holds for where good people "intend" to act but in reality do not take a stand to protect the basic institutions of life.

    It is when they take a stand that, even if inconsequential, at least they can answer to their own conscience.

    Which raises the question of "conscience".

    It appears some have it more than others, which can only be measured by action, not by intent.

    • Peter Wicks says:

      Intention is also important, though: on that I agree with Anthony. Doing good by accident clearly doesn't have the same moral value as doing so by design.

  • Thank you for the interesting post and even more interesting comments and discussion. I enjoyed reading it.

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