Martin Bunzl on “the definitive killer objection to geoengineering as even a temporary fix”

Illustration showing multiple geoengineering approaches

Solar radiation management (SRM) —  aka ‘hard’ geo-engineering — is, literally, a smoke and mirrors solution to the dangers posed by unrestricted emissions of greenhouse gases,.

As science advisor John Holdren resasserted in 2009 of strategies such as space mirrors or aerosol injection, “The ‘geo-engineering’ approaches considered so far appear to be afflicted with some combination of high costs, low leverage, and a high likelihood of serious side effects.

And, of course, those ‘solutions’ do nothing to stop the consequences of ocean acidification, which recent studies suggest will be devastating all by itself (see Geological Society: Acidifying oceans spell marine biological meltdown “by end of century”).

I appreciate that since a serious mitigation effort appears to be non-imminent, people are casting about for other ways to avoid multiple catastrophes (see “Real adaptation is as politically tough as real mitigation, but much more expensive and not as effective in reducing future misery“).  But geo-engineering without aggressive mitigation makes even less sense than adaptation without aggressive mitigation (see The vision of Lomborg’s Climate Consensus is “a dystopic world out of a science fiction story”).

I tend to agree with climatologist and geo-engineering research advocate Ken Caldeira:

Thinking of geoengineering as a substitute for emissions reduction is analogous to saying, ‘Now that I’ve got the seatbelts on, I can just take my hands off the wheel and turn around and talk to people in the back seat.’ It’s crazy”¦. If I had to wager, I would wager that we would never deploy any geoengineering system.

Aerosol injection is, in many respects, the most plausible SRM geo-engineering strategy, since at least some sort of analog to it — large volcanic eruptions — has been observed, at least on a relatively small scale.  But in fact a major analysis in Science this year by leading experts on volcanoes and/or climate — Alan Robock, Martin Bunzl, Ben Kravitz, and Georgiy L. Stenchikov — “A Test for Geoengineering?” (online here), concluded:

Stratospheric geoengineering cannot be tested in the atmosphere without full-scale implementation.

Indeed, they found “weather and climate variability preclude observation of the climate response without a large, decade-long forcing. Such full-scale implementation could disrupt food production on a large scale” — for two billion people!

Prof. Bunzl, who is Director of the Rutgers Initiative on Climate and Social Policy, gave a presentation at the February American Association for the advancement of science meeting, on what he calls “the definitive killer objection to geoengineering as even a temporary fix,” which I reprint below:

My interest in these remarks is how to assess the risks inherent in geoengineering.

My argument is that geoengineering is deviant when it comes to the normal process by which science proceeds – perhaps deviant enough to undermine the whole enterprise.

Some proponents of geoengineering advocate limited experimentation to better the technology by which full scale geoengineering might be effectively implemented. But if there is no basis for full scale implementation whether or not the technology is available, the value of researching the technology is thrown into question.

In these remarks, my talk of  geoengineering is restricted to solar radiation management and does not include carbon capture. Moreover the kind of solar radiation management I have in mind is planetary wide and (for the purposes of discussion) sulfur insertion into the stratosphere. (This is not an arbitrary focus in that, with others, I take this to be the only currently plausible candidate to achieve a 2 degree centigrade cooling should there be a need to do so.)

Some people have worried that such insertion on a planetary wide  basis might produce unforeseen global consequences due to unexpected atmospheric non-linearities. I think these worries are over blown based our general knowledge of atmospheric systems and the record of volcanic eruptions which insert concentrations of SO2 many times greater than the concentration that would be needed to produce a 2 degree cooling.

The locus of my worry is quite different: our current climate models become progressively weaker in their accuracy the more fine grained you go. At the local level, they are of limited value. As such, assessing the risk of sulfur insertion when it comes to local weather disruption (and attendant agricultural output) is very hard to do. And of these the most notable area of concern is  monsoon disruption. Indeed, both theory and modeling raise concerns about sulfur’s role in affecting precipitation as opposed to temperature. (See G. C. Hegerl, S. Solomon, Science 325, 955 (2009); published online 6 August 2009 (10.1126/science.1178530), and A. Robock, L. Oman, G. L. Stenchikov, J. Geophys. Res.113, D16101 (2008).) But even bracketing these considerations, my argument is more abstract: in its applications, most science proceeds from a model, to the laboratory, to field tests, and only finally to wide implementation. Nowhere is that more true than in medicine. At each stage, there is trade off between verisimilitude to the final implementation and the limitation of risk. (Think of the use of animals in experimentation.)   What makes that possible is that most of science deals with modular phenomena. You can test a vaccine on one person, putting that person at risk, without putting everyone else at risk. So, even though we have lot of planetary wide goals – like eradicating smallpox – we can test them for untoward effects before full scale implementation. Not so for geoengineering. You can’t build a scale model of the atmosphere or tent off part of the atmosphere. As such you are stuck going directly from a model to full scale planetary wide implementation.

It has been argued that sulfur insertion could be usefully implemented in polar regions without effects on the rest of the planet. But modeling to date as well as the volcanic record would seem to undermine this idea by demonstrating that polar insertion does not in fact remain restricted to those latitudes.

The idea that one could study the risk of planetary wide insertion with low concentrations might seem plausible. But it has been shown that doing so would require at least a decade to derive enough data to differentiate a signal from noise. (See Robock, Alan , Martin Bunzl, Ben Kravitz, and Georgiy Stenchikov, 2010:  A test for geoengineering?  Science, 327, 530-531, doi:10.1126/science.1186237.)

Geoengineering is not unique in forcing us to go  directly from a model to full scale planetary wide implementation  – but it is rare. The only other example I can think of is genetically altered crops. But a difference between the two is that in the case of genetically altered crops, we have rich theoretical knowledge of natural selection as well as  a long history of selective breeding.

One response to these concerns is to argue that risk is risk and all risk can always be assimilated into a standard cost-benefit (or expected utility maximization) analysis. On that basis, the risks of climate change may be greater than the risks of geoengineering, especially when understood as a temporary stop gap measure.

But such analyses become less and less coherent as our ignorance of both the likelihood and the magnitude of worst case scenarios goes up. That is as true of our understanding of potential untoward effects of  geoengineering interventions as it is for the effects climate change itself.

Now one response to such ignorance is to defend a variety of precautionary principles which come down (in philosophical terms) to adopting what is known as a maximin principle. That is, choose between alternative  courses of action so that the worst case outcome is the best of alternative worst case outcomes.

But to even apply such a maximin approach assumes we have some knowledge to characterize these alternatives. My claim is that we do not have such knowledge in hand for geoengineering and I don’t see how we can gain it to have a basis on which to make a prudent choice until and unless our climate models undergo considerable improvement. Nor do I think is it plausible to think that international agreement to implement geoengineeering would be likely without such improvement in our models.

As such, a focus on more benign forms of intervention that don’t need to be implemented on a planetary wide basis has much to recommend itself,  including, especially, ambient carbon capture.

This research was sponsored by  NSF grant ATM-0730452.

The only SRM geoengineering strategy that is worth pursuing a large-scale at this point — and aggressively so — is cool roofs, the trillion-dollar solution.

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42 Responses to Martin Bunzl on “the definitive killer objection to geoengineering as even a temporary fix”

  1. Colorado Bob says:

    Above is a satellite image of part of Lake Mead, taken in August of 1985. You can see the Colorado River flowing in on the right.

    This was the same part of Lake Mead in August of 2010:

  2. MapleLeaf says:

    Geo-engineering is not the solution. Have we still not learned our lesson? We have been tampering with the biosphere and look where it has landed us. It is illogical and irresponsible to think that further tampering with the biosphere by us will solve the problems that we have created.

    The only viable solution is to reduce our consumption of FFs. That and to adopt more subtle measures, such as painting roofs white or planting green roofs to mitigate the UHI.

  3. Mitch Golden says:

    This argument appears incoherent to me. To apply the maximin principle, we have to be in a position to assess the risks and their likelihoods. As Prof. Bunzl says, our climate models are not adequate to this task. Therefore, are in a situation not of risks but of uncertainty – namely, we just don’t really know what is going to happen if we take either choice.

    So the question persists, unresolved. Assuming we have two choices (and this we hope is a faulty assumption) (1) continue to raise GHG concentrations (at least temporarily) and do nothing, or (2) continue to raise GHG concentrations and try some form of geoengineering.

    I don’t see anything here that militates for (1) rather than (2). Yet we will have to choose something. In fact, if you think that you have *some* knowledge of what the climate system will do when forcings are applied, it seems that a rational person would still reasonably pursue some form of (2).

    So we’re back where we started. If geoengineering becomes a rationale for limiting the choices to (1) and (2), then it is a very bad idea. But if we are limited to (1) and (2) anyway, then I don’t think this is an argument against it.

    Of course we’d rather research CO2 capture rather than stratospheric sulfates. But what if in the end we have no other choices?

    [JR: If you don’t do aggressive mitigation, you basically take most geo-engineering strategies, including sulfates, off the table. BUT the point is, if the world seriously believe the climate models enough to do geo-engineering, they would do aggressive mitigation. If you don’t believe climate models, you’d never do either — since you wouldn’t believe the things we’re going to get even worse and you would have no idea whether the geo-engineering would make things better or worse. AND the other point is that suppose you do the geo-engineering, and then you get a summer like we just had with Russia and Pakistan — how would they know that the geo-engineering hadn’t made it worse?]

  4. Ominous Clouds Overhead says:

    Geoengineering – like throwing good money after bad, it will just use more precious energy resources and cause more problems.

  5. Michael Tucker says:

    Don’t worry. If our government is unwilling to implement ANY law that might increase the cost of energy even by a relatively small amount, they certainly will not spend public money for any kind of climate engineering project. This idea is not popular with anyone on either side of the policy debate.

  6. Prokaryotes says:

    Please take a few moments to fill out a quick one-page survey on government support for biochar development. IBI is working to educate policy makers at all levels of government on the benefits of biochar. This information will help us in our efforts to convince governments to provide more support for biochar.

  7. Prokaryotes says:

    Related (note the article was heavily edited, it does not contain any longer the fact that major oil companies assess geoengineering.)

    Geoengineering fix won’t suit everyone

    First of the precipitation outcomes from sulphuric acid are not controllable and the major side effect, acid rain causes a lot of harm to the flora environment. And yet another implication for the ocean environment. Sulphur injection should only be used to give us time, in certain scenarios – as Prof. Lovelock pointed out.

  8. Turboblocke says:

    Right, so first we pay to burn FFs and then we pay to clean them up? Not burning them in the first place seems like a better idea.

  9. Prokaryotes says:

    Or maybe you have to login now to read the full article at NS, not sure.

  10. bill green says:

    1. JR correctly notes that there is a spectrum of geoengineering options, ranging from “no brainer” white roofs and other light colored treatment of anthropogenic surfaces to others that are much more problematical. It is too simplistic to label all geoeinginnering as “good” or “bad.”

    2. Ken Caldiera is right that we should continue to research geoengineering options. For reasons JR has pointed out, mitigation and geoengineering are potentially complementary.

    3. How much geoengineering future generations are actually willing to risk will depend on how bad things get, which depends both the extent and success of mitigation efforts and uncertainties related to the climate sensitivty and climate feedback parameters. If mitigation lags and/or climate sensitivity and feedbacks are high, geoengineering that seems unthinkable today may look more attractive in the future, notwithstanding its risk. We should make best efforts to keep such a situation from coming to pass, but not all factors are under our control — if sensitivity and feedback parameters are very high, future generations may judge that we may have already crossed that bridge.

  11. These schemes invariably remind me of the “old lady who swallowed a fly”.

  12. Prokaryotes says:

    SRM = Solar Radiation Measure?

  13. Deborah Stark says:

    SRM = Solar Radiation Management

  14. Deborah Stark says:

    Alan Robock, Allison Marquardt, Ben Kravitz, and Georgiy Stenchikov
    Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey
    Submitted for publication in Geophysical Research Letters
    May, 2009

  15. Rabid Doomsayer says:

    Eli Rabett and Slate have taken a different slant on the same question.
    How would the US press react if it was the Chinese preparing geoengineering plans?

    Geoenginering will create winners and losers, the benefits and costs will not be evenly distributed. Any country that geoengineered alone would quickly become a pariah, blamed for all the bad climate whatever the science. Consequently any geoengineering is more likely to be under the auspices of the United Nations.

    Now I see why some say it will never happen.

    I think we will panic and do it, despite knowing the horrendous consequences. And I do agree with those who say it will achieve little if we do not reign in emissions.

    We need to know what the horrors are and critical levels. A mix of techniques might (not will) have a less horrific result.

  16. Bill Waterhouse says:

    All time high temp downtown Los Angeles for any day – 113°

  17. Michael Y says:

    Dear Friends,

    There appears to be a breakdown in communication. There is not a single person in here (at least in the postings above) who would not whole-heartedly push first and foremost for a reduction in CO2 emissions. Let’s take that as a given.

    Then, on the assumption that climate change is real, serious, and impacting us now and is going to generate even more severe impacts in the fuure–again, I think we all agree to this–then the question becomes: Would it EVER be preferable to move to geoengineering (even if at full-scale for the first try, with all its attendant risks, and even with known downsides (e.g., acidification).

    I think so–and I think the answer to when is “now”–BEFORE additional feedback loops and before greater ecosystem collapses and species losses.

    I think this is open to debate.

    However, I think it is incumbent upon all of us who do debate this to be able to answer, at least roughly, if (1) they would support geo-engineering under ANY circumstances and (2) if so, which circumstances. Agreed?

    All the best,

    Michael Yaziji

  18. paulm says:

    “The ‘geo-engineering’ approaches considered so far appear to be afflicted with some combination of high costs, low leverage, and a high likelihood of serious side effects.“

    and failure!

  19. GFW says:

    Bill, “it’s the La Nina … oh wait”.

  20. Michael Y says:

    Here’s a weird scenario….Warren Buffet gets concerned about climate change, talks to too many freaked out people like me, and decides to spend a 10% of his money to set up a sulfer-aerosol contraption out in the open seas, beyond the legal reach of anyone….

  21. Tom Bennion says:

    Apart from passive measures (trees, white roofs) I dont support geoengineering. For the reason that we dont have the right or the ability to institute it without destroying everything we have built in terms of civil society, science and knowledge. Even if everyone was at equal CO2 emissions – an absolute precondition to its use – the remaining inequities would be extreme and more than humanity could or should deal with. We would create such inhumanity that the enterprise would be pointless beyond the bare survival of the species. We are better than that.

  22. Bill Waterhouse says:

    re #15 – Exactly right. Any nation that unilaterally does geoengineering will get blamed for all real or imagined bad consequences. Wars could result.

    re #20 – not so far-fetched. I attended a lecture by a tenured physicist who wanted to start geoengineering in the atmosphere and wondered aloud if he might find a rich angel to help him do it.

  23. Prokaryotes says:

    Is it correct that there is currently no international treaty which organizes geoengineering?

    So many things to read

  24. Raul M. says:

    Returning to committing the errors of the past
    ways doesn’t change the errors to the better
    ways. Just a thought.

  25. Prokaryotes says:

    From the wiki

    In a 2009 review study, Lenton and Vaughan evaluated a range of geoengineering schemes from those that sequester CO2 from the atmosphere and decrease longwave radiation trapping, to those that decrease the Earth’s receipt of shortwave radiation. In order to permit a comparison of disparate techniques, they used a common evaluation for each scheme based on its effect on net radiative forcing. As such, the review examined the scientific plausibility of schemes rather than the practical considerations such as engineering feasibility or economic cost. Lenton and Vaughan found that “[air] capture and storage shows the greatest potential, combined with afforestation, reforestation and bio-char production”, and noted that “other suggestions that have received considerable media attention, in particular “ocean pipes” appear to be ineffective”. They concluded that “[climate] geoengineering is best considered as a potential complement to the mitigation of CO2 emissions, rather than as an alternative to it”.

  26. Lewis C says:

    Prof Bunzl has not actually described the killer objection to geo-engineering – he has written a cogent critique of one technique (sulphate aerosols) being of one of the two forms (carbon recovery and albido restoration) of geo-engineering.
    While I entirely agree with his critique of that option, tarring all forms of albido enhancement with that single brush would not only be mistaken, it would also highlight the absence of arguments against better options.

    Regarding those better options, the professor stated:
    “As such, a focus on more benign forms of intervention that don’t need to be implemented on a planetary wide basis has much to recommend itself, including, especially, ambient carbon capture.”

    Michael Y is right to observe that all here seem to start from the recognition that emissions termination is pre-requisite, for several imperative reasons. That said, my own support in addition of both carbon recovery
    (in the form of a gigahectare of native afforestation optimised for the decentralized production of biochar and fuels, cleansing the atmosphere before century’s end)

    and of albido restoration
    (both via ‘cool roofs’ and in the form of ‘cloud brightening’ over carefully selected key areas of ocean by using wind-powered vessels to loft very fine sea-spray, thereby controlling the heat driving the feedbacks’ acceleration during carbon recovery’s development and operation)

    rests on my understanding that even ending global GHG emissions at a radical rate (say 98% off 1990 by 2040) will be nowhere near sufficient to control the interactive feedbacks. These are already accelerating and are fully capable, given many decades of additional warming under the GHG-cuts-only scenario, of first replacing our entire current GHG outputs, and then of dwarfing them.

    From this perspective the feedbacks have to be controlled asap if we wish to resolve global warming, and I’ve yet to see any coherent description of how that could be done by emissions termination alone. Thus it appears that there is no more point in attempting emissions termination without appropriate geo-engineering options, than there is in attempting geo-engineering options without emissions termination.

    Quite why geo-engineering attracts such opprobrium is interesting – it seems possible, if not probable, that an understated fear of sulphate aerosols being incompetently applied as a status quo maintenance ploy to avoid emissions termination appears so serious a risk that it is tempting to slam all ‘active’ albido restoration options.

    We need a more serious discussion of the issue than that. None here have yet objected specifically to carbon recovery, nor to whitening roofs, both of which are evidently geo-engineering techniques. Nor have I yet found (despite much reading) any convincing objection to sea trials of the cloud brightening option, given that this is essentially localised in effect and rains out within a few days (as opposed to ~two years for stratospheric sulphates’ release).

    From this I suggest that there is the beginnings of a possible consensus here, that some geo-engineering techniques are, potentially, benign and highly relevant, depending of the motivation, the governance, and the scientific prudence with which they are selected and applied.

    Further information on the dire shortcomings of the ’emissions-cuts-only’ strategy would help to clarify the urgent need for that consensus being affirmed, being detailed with specific well-considered recommendations, and being concisely codified for the lay reader.



  27. Omega Centauri says:

    I heartily agree with bill @11 and lewis @27. We can’t tar all these methods as unacceptable. We will almost certainly become desperate enough to need some of them.
    We also need to distinguish between transitory effects and longer term effects. If I were to turn some global SRM knob down quickly, I would expect weaker monsoons for the first few years, as the land responds (cools) quicker than the sea, and the monsoon is driven by the land/air temperature difference( land hot during summer). My expectation is that the monsoon effect would be temporary. Therefore a slow rampup of the SRM knob could avoid the effect. Being afraid of the transitory -as opposed to the long term effect is analogous to not going to the gym, because it will make you tired and weak in the nearterm (day or two).

    I think we all are in agreement that the biggest danger of geoengineering, is the potential for complacency on the emissions front. We have to do the research, but we also have to avoid creating false complacency. Some methods are obviously less odious than others. I strongly dislike sulphate injection, because it decreases sunlight, and makes our skies less clear. (I think the acid rain objections are bunk, the volumes/fluxes aren’t that large) Land based albedo management, combined with ocean cloud seeding (I think Bill Gates gave money to this), seems much more benign, although probably a lot more costly.

    And of course free air capture, perhaps by enhancing natural weathering practices, as well as biochar type solutions could be useful as silver CO2 BBs. The lack of the existence of a silver bullet, shouldn’t preclude the search for as many silver BBs as we can find.

  28. Deborah Stark says:

    Geo-Engineering and Climate Change Investments

    Now that we are in an ever-warming world, is it time for us humans to use our powers for good? The idea of geo-engineering is seriously being considered today at a conference in Washington…..

    I think it’s a tragedy that we’ve come to this point.

  29. Tom Bennion says:

    How glibly it is said that we all agree on emissions reduction, so that that is a given in any discussion of geoengineering.

    All evidence points to the contrary. I would rather any debate proceed from a basis in reality. That is, geo-engineering will inevitably provide an argument for a significant part of the population and industry that they do not need to take obvious steps to reduce emissions, or significantly weaken their resolve to do so. Any proposal has to deal with that fact. Any other approach seems hopelessly naive.

    This creates a dilemma. Geo-engineering will be invoked on the basis of urgency, but one of its side effects will be to weaken the will to reduce emissions. That suggests small localised efforts only, or larger scale efforts proceeding only after nations have agreed on binding reduction targets and monitoring between them.

    Re Lewis C at #15 – and your comment: “a gigahectare of native afforestation optimised for the decentralized production of biochar and fuels, cleansing the atmosphere before century’s end.”

    For me, this is a further illustration how quickly geoengineering discussions lose touch with reality. George Monbiot fairly comprehensively sets out the problems of biochar on a significant scale here:

    Could the debate not begin another way? Assuming large scale fixes might be possible at a technical level (and we will not go further than that theoretical proposition for now), what are the environmental, social, cultural and economic pre-conditions for their use? Then you look to see what technologies might fit those pre-conditions.

    Beginning with a discussion of the technologies themselves leads to efforts to fit the world around those technologies, with the inevitable naive results above.

  30. John McCormick says:

    RE # 28

    Omega, your comments are most helpful for those of us who question the naivete and near-carelessness of those who throw out geo-engineering ideas as if they are flash cards.

    You concluded with the following:

    “And of course free air capture, perhaps by enhancing natural weathering practices, as well as biochar type solutions could be useful as silver CO2 BBs. The lack of the existence of a silver bullet, shouldn’t preclude the search for as many silver BBs as we can find.”

    I would be pleased to know you are not in charge of the global geo-engineering investment industry. Lots of money to throw at BBs. Venture capitalists do that for a living.

    Our planet’s atmosphere and eco-system are not yet elements in a video game. Oh, what did I just say! Will the Sim City guys pick up that idea and create a geo-engineering video game for the couch potato wizards.


    John McCormick

  31. John E Johnson says:

    NO, no, no, no, no, no. Michael Y, Omega, Bill and Lewis you have to change the views you currently hold. Gaia is pissed off and you are making her even angrier. The Earth will right itself without us needing to geo-engineer a thing. How can you in all good conscience think that we can fix AGW through more meddling with the balance nature controls? Is this egomaniacal thinking at its worst? The only thing we need to plan for is life outside of Earth’s gravitational pull if they have their way.

    We have the roadmap to mitigation and there will be some rough spots ahead, but we can’t start trying to find shortcuts that will blow the engine and the tires.

  32. Lewis C says:

    Tom Bennion –

    Your need to resort to distorting what has been written and denigrating those who don’t share your prescriptions seem pretty clear evididence of the weakness of your case. You wrote:

    “How glibly it is said that we all agree on emissions reduction, so that that is a given in any discussion of geoengineering.”

    Nothing at all was said of “any discussion of geo-engineering” – the observation of agreement was specifically about the posts in this thread, nothing more.

    Your claim that it is inevitable that applying geoengineering will weaken the resolve for emissions reduction is your speculation, not reality; you need to learn to distinguish between the two. While your post wholly ignores the necessity of geo-engineering to decelerate the feedbacks, you assume that we could not win the argument on geo-engineering’s proper application – so how exactly do you expect to win the argument on emissions termination ?

    Your ignorance of the deficiency of emissions termination is perhaps at the core of your complacency.

    As for recommending George Monbiot as an authority on biochar, perhaps you’re unaware that within a couple of weeks he had to row back wholesale on that singularly stupid article, when it was pointed out that the most eminent of scientists, such as Hansen and Lovelock, are on record as stuanch supporters of biochar ? It was from George’s self righteous cant in that article that the concept of the “Monbiot Fallacy” emerged – that “If something could be done really badly, then regardless of its exceptional utility if done well, those promoting it should be shouted down and slandered.”

    This is not George’s only cock-up by a long chalk – perhaps you didn’t know that he wrote an article calling for Mike Hulme of UAE to resign after the fossil lobby agents hacked the e-mail archive ? His recent offhand apology for that did not explian why he thought it was a good idea to appease the fossil lobby by giving it the resignation of a senior scientist . . .

    Personally I’m very interested indeed in “the environmental, social, cultural and economic pre-conditions” for the use of geo-engineering techniques. Had you actually bothered to study the issue, you’d be well aware of the relevance to these concerns of the very specific format that I recommended for carbon recovery by means of biochar sequestration.

    After reading this, perhaps you’d better explain to Joe Romm why you think he’s so naive to be promoting the development of ‘cool roofs’ on his excellent site ?



  33. Lewis C says:

    John McCormick at 31 –

    of the many subjects that you don’t mention in your post, the Peat>DOC feedback loop is outstanding:
    as having been first observed globally when CO2 was at ~315ppmv;
    as being driven directly by elevated CO2 concentration, not heat;
    as having raised its output exponentially at ~6%/yr for almost 50 years;
    and, if the rising trend of all-sources CO2 outputs continues, as emitting around 30GT CO2 per year by 2065, thereby replacing current global anthro outputs.

    With respect, I’m loth to take your failure to mention this catastrophic threat in your post as evidence that you haven’t a clue what you’re talking about when discussing geo-engineering. Maybe you could affirm that while you knew of it, you chose not to mention it ?



  34. Lewis C says:

    John E Johnson

    your invective seems pretty pathetic, and seriously ill informed.
    The road map to effective mitigation includes geo-engineering, which is why Joe Romm is promoting ‘cool roofs’ (one form of albido restoration) and Jim Hansen is promoting biochar (arguably the best form of carbon recovery).

    Your assumption that just ending our emissions will resolve the problems of atmospheric stocks of GHGs and of the accelerating interactive feedbacks, is sadly just wishful thinking. –

    Supposing we ended our global GHG emissions by 2040, and that we then had only 440ppmv of CO2 – with the sinks declining for several reasons from their intake of ~1.7ppmv/yr of CO2, and with the interactive feedbacks emitting an unkown volume towards swamping those sinks, there can be little confidence that airborne CO2 would decline after 2040. It could well just continue rising.

    OTOH, if the sinks did somehow maintain a net removal of 1.0 ppmv/yr, it would take them until 2090 to return airborne CO2 to the present 390ppmv. (440 – 50 = 390).

    By my calculation that very lucky outcome of continuing net sinks, would mean the feedbacks have over 80 years of planetary temperatures significantly hotter than at present in which to take off and swamp the sinks, then replace our present total emissions, and then dwarf them.

    The above notes are a brief outline of why some very serious people now recognize that appropriate geo-engineering techniques are an essential component of an effective mitigation strategy that has to be led by binding commitments to emissions termination.

    Further studies are warmly recommended.



  35. Prokaryotes says:

    In this NPR radio show Jeff Goodell gives a great introduction to geoengineering(just misses out on biochar) Though i think Joe missed this one, when mentioning his book on march 15.

    Can We ‘Cool The Planet’ Through Geoengineering?

  36. Prokaryotes says:

    Geoengineering: Global Salvation or Ruin?
    Commonwealth Club

  37. Michael Tucker says:

    Climate disruption will lead to sever and prolonged droughts for the southwest and southeast US.

    Climate engineering schemes that have been modeled show drought for the southwest US is a very likely outcome.

    I think we can do without any further experiments with the climate thank you.

  38. Prokaryotes says:

    Michael Tucker there are many forms of GE, like 2 basic groups SRM & GGR and some of these make sense beside direct GE approaches. See ways of biodiversity increase from reforestation and anti desertification measures, which helps to counter species extinction and makes ecological rich environments.

  39. Michael Tucker says:

    I don’t think that re-planting trees is an experiment. I don’t need any expert or study to tell me it is a good idea. I find it amazing that anyone would think that destroying a forest is a good idea and would somehow benefit the environment.

  40. Prokaryotes says:

    The point is, that not all GE techniques are bad. Such as a worldwide biochar operation. To seal and help the soil keep carbon. At the same time these soils will have better properties to withstand high precipitation events.

  41. Lewis C says:

    Michael at 40 –

    maybe you would enjoy studying forestry a little.
    If you did, you’d find that foresters have been felling trees for millennia and either replanting or, if they’re felled young enough, watching them regrow vigorously from the stump to be ready for the next harvest.

    The latter sylviculture is known as coppice, and has been practiced here in the UK since before the bronze age. Our oldest surviving coppice tree is a hazel near Ashford in Kent, that was planted during the Roman occupation.

    Those who cause deforestation are not foresters. The usual culprit in preventing deciduous forest regeneration is a land-owner/seizer letting livestock graze off the regrowth and the young saplings.

    The assumption that biochar development means deforestation is a pernicious nonsense. It is the original ‘Monbiot Fallacy’, that “If something of potentially exceptional beneficial utility could be done badly, it should be vilified and its proponents ruthlessly denigrated.”

    In reality the decentralized production of biochar offers the best set of incentives on the planet for widespread native reforestation on non-farmland. Notably, one of the exceptional characteristics of coppice, which is the most appropriate sylviculture for biochar production, is that in Europe it accommodates the best biodiversity of any ecosystem.

    In addition to which, with America having liability for by far the largest share of the problematic stocks of airborne carbon, whose impacts are destabilizing food production globally and causing grievous harm to millions already, it would seem somewhat shameful for any American to oppose productive forestry for biochar on grounds that “it might be done badly.”

    Surely the ethical response is to actively help ensure it is done soon and done well ?