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[Episode #26] – Geoengineering


As the world continues to struggle with the effects of climate change, energy transition is more important than ever as a key pathway to stopping global warming. But will it be enough? Many serious climate researchers think it won’t be, and urge deliberate attempts to directly alter the Earth’s climate by using a number of technologies, loosely grouped under the heading of geoengineering. But geoengineering has not won much support from the climate and environmental communities, and still struggles to gain enough legitimacy to attract sufficient research funding to attempt serious pilot projects that might tell us whether geoengineering holds real promise as a safe, cost-effective, and powerful tool in a portfolio of climate change mitigation strategies.

So what is the real potential of geoengineering to address climate change? How much would it cost? How risky is it, and what justification might there be for taking that risk? And what sorts of attitudinal shifts might be needed within the climate and environmental communities to embrace geoengineering as one of a portfolio of strategies? We attempt to answer all of those questions and more in this interview with a veteran science journalist and author of a recent book on geoengineering.

Guest: Oliver Morton is a senior editor for Essays and Briefings at The Economist. He was previously the Chief News and Features Editor at Nature and editor of Wired UK. He is the author of The Planet Remade: How Geoengineering Could Change The World (2015), Mapping Mars: Science, Imagination and the Birth of a World (2002), which was shortlisted for the Guardian First Book Award; and Eating the Sun: How Plants Power the Planet (2007). His work has been published in New Yorker, National Geographic, Discover, Time, American Scholar, New Scientist, New York Times, Financial Times, Guardian and Wall Street Journal. He has a degree in the history and philosophy of science from Cambridge University and lives with his wife in Greenwich, England. Asteroid 10716 Olivermorton is named in his honour.

On the Web: Oliver Morton’s blog, Heliophage

Recording date: September 9, 2016

Air date: September 21, 2016

Geek rating: 5

Chris Nelder: Welcome, Oliver to the Energy Transition Show.

Oliver Morton: Glad to be with you Chris.

Chris Nelder: In your book you cover a number of potential geoengineering strategies and explain in some detail what the scientific basis for each one is, how it might work, and what the uncertainty around it is. In the interest of time I don't want to get into too much detail on the various technologies but I would like to give our listeners just a very brief kind of overview of some of these ideas just to have the context, OK?

Oliver Morton: Sure.

Chris Nelder: So the first major approach that I read about, it imagines a veil of sulphuric acid essentially being created across the stratosphere which is the big layer between our atmosphere and space which would create a reflective layer that essentially would mimic the effect of a large volcanic eruption. What are the mechanics of that approach?

Oliver Morton: Well I just like to pick up on one thing you said there. It wouldn't necessarily mimic the effects of a large volcanic eruption. The amount of cooling that you get depends on the amount of stuff that you do and you do not necessarily want to do the amount of cooling that you get from a large volcanic eruption because that's really quite a spectacular effect. So it wouldn't necessarily be that large an effect but it does work in a similar sort of way. And the way that you do something like this is that you take either sulphur dioxide or more likely sulphuric acid up in a plane or possibly pumped up to a tethered balloon in the stratosphere somewhere about 22 kilometres. You'd want to do a number of different places around the planet and you let out a fine spray of - well if it's the gas you just let out the gas - if it's droplets of sulphuric acid, you let out of a very fine spray. And those will form into aerosol particles which will then spread themselves laterally. The stratosphere is really counterintuitive for those of us who grew up a long way below it because air in the stratosphere moves side to side much more than it moves up and down and so you can actually spread things out really all the way around the planet without that much difficulty. So you don't have to have pumping stations or planes all around the planet a lot of the spraeding comes for free from the stratosphere. The important thing is that you put very small particles up there that reflect sunlight away and what those particles are... The reason that the emphasis has been on sulphur so far has been that that's what volcanoes do. But that's not necessarily what people might choose to do.

Chris Nelder: But isn't sulphuric acid what we're trying to stop when we implemented emissions controls on power plants in the 70s because it was causing acid rain and destroying forests? I mean wouldn't this maybe cause the same problem?

Oliver Morton: It would if you did it at a very high scale. But this is one of the papers that re-ignited discussion of geoengineering exactly 10 years ago in 2006. Paul Krutzen, a great atmospheric chemist made this argument, the argument you're making, sort of in reverse. At the moment we pump sulphur dioxide into the lower atmosphere into the troposphere through power stations and although we in Europe and America do it much less than we used to in China and other parts of the developing country there's still an awful lot of sulphur emission from this. There's also a lot of sulphur emission from marine diesel and things like that. Those are things you want to control but the lifetime of sulphur in the troposphere is very low. It's days to weeks. The lifetime of sulphur in the stratosphere is very high. So you can get a lot of cooling in the stratosphere with a very small amount of sulphur because the sulphur stays up there a long time. So in round terms the amount of sulphur that you might be thinking of putting into the stratosphere would be a couple of percent of what is currently being put into the troposphere and Krutzen's argument was actually very subtle. He was saying that we want to diminish the amount of sulphur in the troposphere because it kills people and damages ecosystems. And those are very good things to stop. When we decrease the amount of sulphur in the troposphere we also effectively warm the planet because we were moving the cooling effect of the sulphur particles in the lower atmosphere. If you could replace that with the cooling effect of much longer lived sulphur particles in the stratosphere you would basically be able to cash in the gains of not polluting the lower atmosphere without having the cost of warming the planet while you do so.

Chris Nelder: Interesting. Okay. So there is a there's a big difference as to where the sulphuric acid particles are located.

Oliver Morton: It's really a matter of lifetime. If you put them up into the high atmosphere they last for a year or so, maybe a couple of years and that gives them a lot of cooling potential. If you put them in the lower atmosphere, they last a few days or weeks. Much lower. And so you can do much more cooling with much less sulphur if you do it in the stratosphere.

Chris Nelder: So this approach to geo engineering for climate purposes is not really considered the same sort of a risk to our forests as acid rain was.

Oliver Morton: No. I mean there would be some deposition but it would be considerably less. The other thing to remember about acid rain is that most of the deposition is pretty close to the source, although not that close, but close in terms of hundreds to a few thousand kilometres. They're transboundary effects, but they're not global effects. Most, in fact the vast majority of the sulphur that you put in the stratosphere you'd expect to be deposited harmlessly in the ocean because it's not being produced by power stations near where people live.

Chris Nelder: Okay that's an important point. OK. The other major direction in geoengineering that you discuss apart from reflecting more sunlight back into space is in capturing and sequestering carbon. And you acknowledge that so far CCS has been a commercial failure and that the technical challenges of it, particularly were concerns capturing very diffuse CO2 out of the air are pretty daunting. And as listeners to this show are well aware, I've dismissed CCS because it's far from achieving any economic viability and no world governments are stepping up with the hundreds of billions of dollars that are thought to be needed to get CCS over the hump with R&D and turn it into a technology that can survive in the market. But you actually seem to see it as more of a policy issue. Do you think governments should be offering direct massive subsidies to make CCS viable?

Oliver Morton: Not necessarily because I think there are other ways to get quite a lot of your low to zero carbon fuel but I think that the problem with CCS is certainly that it is a pre-market technology at the moment and it illustrates one of the things that people who discuss geoengineering worry about a lot which is moral hazard, the idea that the possibility of doing something in the future decreases the likelihood of doing something else today. And so with CCS, one's not being terribly cynical if one says that basically CCS has been treated by the fossil fuel industry in rather the same way that St. Augustine used to pray for chastity. You know, " Make me chaste, Lord, but not yet." And similarly CCS gives you a licence to go on being a fossil fuel economy saying well eventually we will do CCS. But that's only true if eventually you do CCS and as you say both for economic and for policy reasons, that's actually not happened. I remember actually talking back when he was the climate minister talking to Ed Miliband in Britain about this. And here's he was talking about all these wonderful market solutions they were going to do through CCS. I said if you really want to see what a CCS power station looks like an operation, buy one. Don't try and rig the market to give you one, just buy one. Just go out there and buy one. Does your brother - his brother was the foreign secretary at the time - when they want an aircraft carrier, you know, they go and buy an aircraft carrier and no one has really done this. No one has just gone out and said okay I'm going to build one of these suckers at a fairly large scale and we'll see what we can do to make it work better. And the other thing is I remember talking to an energy analyst who was a recovering engineer. He was recovering very comfortably in an investment bank at the time. And he was saying that you know it's just really hard to get engineers very excited about making a coal fired power station rather less efficient. You know its not the sort of thing that you get up in the morning and say oh I'm going to go and sort of like put all these McGuffins on the end of the system at the coal fired power station. They'll do it if you pay them but it doesn't get anyones juices pumping. So the thing about geoengineering with carbon capture is that carbon capture and storage as traditionally proposed doesn't actually offer you anything that you can't get otherwise. There are other ways of getting clean base low power. You may not like it though. I was listening to a conversation you were having about nuclear the other week and we don't need to go into all that now. The thing about carbon capture and storage for geoengineering is that if you burn not fossil fuels but biomass then the argument is you can actually transfer carbon directly out of the atmosphere into geological storage while taking energy at the time and that is a unique capability that nothing other than biomass with CCS really offers you, the idea that you can take used plants as the front end as it were to take the carbon out of the atmosphere and then get energy out of the process that then puts that carbon away. So that's I think why bio energy with carbon capture and storage or BECCS as it's known is one of the technologies that's talked about most in this field. Now I think there are also really severe drawbacks to BECCS. But I think that's what distinguishes BECCS from as it were, classic carbon capture and storage.

Chris Nelder: And that's an important point. I will note however that in most of the big energy agency reports and forecasts and so on they all see CCS playing a huge role in the future and they don't really talk about BECCS. So it's constantly been a matter of puzzlement or even outrage for me to read these reports from IEA and agencies like it that are constantly forecasting this giant future for CCS and I'm looking around going, "Guys this doesn't exist. What are you talking about?"

Oliver Morton: Yeah well as we go on in this conversation about geoengineering we're going to come up with a lot of technologies that don't exist,. but I agree there's something kind of egregious about the way that the policy community - or chunks of the policy community - seem to have agreed to talk about CCS as though it's real whereas people actually making real policies have done very little to actually make it real.

Chris Nelder: OK good.

Oliver Morton: It brings to mind one of my favourite lines from from Bruce Springsteen. "Is a dream a lie if it don't come true or is it something worse?" And that's kind of where we are with CCS.

Chris Nelder: I think that's the first Bruce Springsteen reference on the show. Well done.

Oliver Morton: Well let's make sure it's not the last.

Chris Nelder: So another direction of carbon removal that you discussed was the concept of fertilizing the ocean with iron filings which would essentially stimulate the growth of plankton which would then sink to the ocean floor. So effectively, the plankton would be capturing the carbon and then it would be sequestered down in the ocean floor that way. But you also note that the prospects for this approach are currently pretty slim. Can you think about that a bit?

Oliver Morton: Absolutely. I mean it comes to one of the actual key concepts I think in talking about geoengineering which is leverage you know like Archimedes said, "Give me a lever long enough and a place to stand and I will move the earth." You need to move the climate system. You need a lever. And one of the things I think that people under appreciated is quite what a spectacular lever carbon dioxide is. There's a calculation made by Ken Caldera and one of his grad students... I'm sorry I'm forgetting the student's name. We can put it in the program notes. But they calculated the ratio of the amount of energy that a mole of carbon dioxide captures in the atmosphere to the amount of energy you get by burning a mole of carbon in fossil fuels and the ratio is significantly above 100 thousand to one. So the amount of energy that the Earth's system stores away as a result of the burning of a mole of carbon is 100 thousand times more than the energy humans get. I find that fact under appreciated and staggering. And so for geoengineering you need something which has got similar sorts of leverage and at one point it looked as though fertilizing the oceans with iron might offer something like that because there are these interesting areas - this was discovered when people started looking at the oceans from space basically in the 70s and 80s - where there seemed to be lots of nutrients but not much life. And by nutrients we mean here basically nitrogen phosphorus. And so there were these high nutrient low chlorophyll regions that were a bit of a puzzle. And one of the people who came up with the answer was an American oceanographer called Jones Martin who pointed out that what was missing in these regions was iron. And though you don't need much iron to do photosynthesis, you do need some. And so the photosynthesizers out in the ocean were being limited by lack of iron and theoretical calculation suggested that by adding a mole of iron to one of these regions you might be able to pull down a hundred thousand moles of carbon by the amount of increased photosynthesis you'd get. And this was very exciting. It was also exciting from a pure science point of view because one thing that Martin suggested was that it was possible that during the Ice Ages the oceans were better supplied with iron because there would been more dust blowing off drier continents than the continents today and those oceans with more iron would be more fertile and would have a faster more vigorous photosynthetic pump pumping carbon down into the deep ocean. And so that would be one of the reasons, maybe the main reason, why the carbon dioxide levels were lower in the Ice Ages than they are today. And modern thought suggests that this is a role in the low carbon dioxide conditions and the ice age but not necessarily the determining one. But it was an interesting enough idea both in the geoengineering point of view and from the Ice Age point of view and from the general ecosystem physiology point of view for people to go out and try it. So there have been a number of experiments, in the southern oceans mainly, scientific experiments put on by the research councils of America and Britain and Germany and a few other places where they've put iron in and seen what happens and you do get a plankton bloom but you don't necessarily get very efficient transport of the carbon that's sucked up in the atmosphere in that plankton bloom down into the deep oceans. And this only works as a form of geoengineering if you're genuinely taking the carbon away from the atmosphere and putting it somewhere where it won't trouble you or your descendants for a thousand years or so. And that transport doesn't seem to happen as effectively as people had hoped. There was also a problem that in some cases you were getting nitrous oxide produced by the blooms which of course is much more powerful greenhouse gas than carbon dioxide and that effectively undid any good you might be doing. So at the moment the possibility of doing this on a large scale doesn't look very plausible. You might be able to engineer better systems than the ones they used. You might be able to find cleverer ways to do it but there are also two other overriding problems. One is that the absolute scale of this effect is relatively constrained. Some modelling suggest that even if you were able to make up for all the iron deficiency in the Southern Ocean which is where this really matters you would still only increase the amount of carbon taken down by a billion tons a year. And you know a billion tons of carbon is a lot and that would be a great thing to do, but that's still 10 percent of annual emissions at the moment give or take. And so it could be a contribution to something but it's not as it were the answer in and of itself. The other thing is that with most discussions of geoengineering people worry about the effects that the geoengineering might have - the unintended consequences it might have - for ecosystems. And with ocean iron fertilization... You're actually.... It's not an unintended consequence on the ecosystem. Completely messing up the ecosystem is how you actually do this. You know you completely change the balance of primary production and you would completely change the way that the ecosystem worked over a large part of the southern ocean. And though you might be willing to say that that's a price you'd want to pay. That's the sort of thing that people get I think understandably extremely antsy about. And so I wouldn't say you can completely write it off but both the fact that it's inherently limited turns out to be difficult to do, very difficult to monitor how well you're doing it, and you have to revamp a large part of the ocean ecosystem. Those are fairly big hurdles for that technology to get past.

Chris Nelder: So are there any other major during geoengineering techniques we should discuss before we move on?

Oliver Morton: There were a couple that we glided over. One is... We talked about BECS. There is also the possibility that you mentioned of rather than using plants as a front end of using effectively chemical engineering to take carbon dioxide out of the atmosphere and at the moment there are a couple of small companies that are looking at this. It's possible that in some ways that might be a way of making carbon fuels without fossil fuels. So you could take the carbon dioxide out, you could react it with hydrogen to form either long chain hydrocarbons or methane and you would then have a non fossil fuel source of carbon rich fuels which would then be effectively carbon neutral. You'll have noticed that the problem with this is that it would require a great deal of energy because you both have an energy overhead in taking the carbon dioxide out of the atmosphere because although we're used to worrying about how much carbon dioxide there is and the atmosphere if you're trying to filter the stuff out 400 parts per million it's pretty hard you know. If the atmosphere was a box full of marble, one in 2,500 marbles would be carbon dioxide. That's quite a hard sorting problem taking that carbon dioxide out. Then you have to produce the hydrogen to react it with to make the fuels. So that's... You know, this would be an energy intensive process. At the same time, we know that it's possible now to do some energy intense processes relatively cheaply if you're willing to put them in deserts with lots of photovoltaics around them.

Chris Nelder: But then you still have to address the question of what is the full cycle EROI of this thing? It seems kind of problematic right off the bat right there.

Oliver Morton: Sure! But I'm saying for me it's kind of ludicrous to think that you're going to be making a big difference of things by taking carbon dioxide out of the atmosphere while you're still putting it in. To me taking carbon dioxide out of the atmosphere is an end game thing. And that's an important end game thing but it's an end game thing.

Chris Nelder: Yeah it's a bit like walking the wrong way on an escalator.

Oliver Morton: Yes to do it at the moment... It's kind of problematic. But the other side of that is that we have to remember this is something that I think is important about geoengineering in general is that it widens your perspectives beyond sort of like the next three COPs or the next cycle of the IPCC or even the lifecycle of the generating kit that you're investing in right now. It urges you to see climate in its true centennial to millennial time frame and if that's the case then if you believe as I think I do as I think you do as the whole idea of an energy transition does that at the other side of the energy transition there's quite copious quite clean energy.

Chris Nelder: Well let's hope so.

Oliver Morton: Yeah exactly. If that's not the case then we've got other problems but if that is the case if that is the case that clean energy can be made cheap and copious enough to replace fossil fuel energy, you can go on making it to do other things. So it's not clear... And I think this is an interesting issue we might want to discuss bit... There's a perception that a planet in the 22nd century that's gone clean might a sort of like as it were a low energy planet. But I think if renewables and possibly in the future advanced nuclear provide cheap energy then you can use that cheap clean energy to do a lot of stuff and one of the things you might be willing to do would be to take carbon dioxide out of the atmosphere. But that's a sort of like 2080 to 2150 sort of question not a 2020 to 2030 question.

Chris Nelder: Right. Okay. And I do want to talk a little bit about that kind of low energy future scenario. But first I just want to kind of wrap this point up. So you don't seem to have much doubt that some sort of geoengineering is at least technically possible and capable of restricting global warming to the agreed target of two degrees celsius. And you present some evidence that shows that at least some of the possible solutions would be very affordable, certainly compared to the likely cost of the damage from climate change. Your concerns seem to be more about the political pragmatism of actually making geoengineering happen than its technical feasibility or its economics and you're quite evidently frustrated with people particularly environmentists who dismiss geoengineering on principle, although you do acknowledge their are concerns. So is that a fair assessment of your view?

Oliver Morton: That's pretty fair yeah. I mean I think that doing something that you would call geoengineering, just in terms of terminology... When I talk about climate geoengineering I try to be quite narrow in this and say that I am talking about systems which decouple the climate future from cumulative carbon emissions. And so that's either by reducing sunlight or by taking some of those cumulative carbon emissions out. That sort of decoupling I think is technically feasible but we don't fully understand what all the geophysical and geochemical and biogeophysical feedbacks would be as a result. The challenge is doing this in a way that is safe, just, and governable. And getting to that position where people want to have the discussion... Not that geoengineering sort of like, exists and there's a question of whether to implement it or not... But how do you design a system and a mode of governance that people could have at least a sufficiently large number of people could have a sufficient amount of trust in that it didn't just look like a harebrained waste of time? That's to me the key question. How do you find a way to do climate politics that includes the discussion of these things which, and as you say it's quite conceivable that some of these technologies might allow you to hit a two degree target that you would not otherwise hit. But we have to remember the real aim here is not to hit targets. The real aim here is to reduce the harm done by climate change. And I think it's quite possible there are technologies out there which if properly implemented in a safe, just, and governable way could reduce that harm. And I want to help the world have a conversation which tries to find that out.

Chris Nelder: OK well then I think we do need to move on from the technical stuff and really kind of dive into some of the political dimensions of this. So toward the end of the book you discusse how some kind of cooperative international governance would almost certainly be needed to execute and monitor and maintain a geoengineering program and I admit I don't really share your optimism about the likelihood of that. I mean particularly after what has been I mean I don't think it would be too controversial to say... a really abysmal year for political cooperation globally.

Oliver Morton: In climate or just generally?

Chris Nelder: In general. I mean look around. You know? I mean I wonder if you really believe in your heart of hearts that such political cooperation is really possible or if you're just allowing the possibility mainly because most of these geoengineering streams are likely to be non-starters without it.

Oliver Morton: You do me a great compliment by imagining that I have a heart of hearts. I tend to take the view that that comes from the prison diaries of the Italian Communist and Antonio Gramsci where he said we must strive to have pessimism of the intellect but optimism of the will. If you don't think these things are likely to be possible you won't do them. You won't get anywhere close to doing them. If you think that there are possibilities, if you allow yourself, to borrow a phrase, the audacity of hope, then you will at least have increased the options for your own action. And so that's part of my answer to you. The other thing is that intractable international problems do change over time and I think there are diplomatic problems that get solved. And I don't think geoengineering is as simple as any of the ones that I can think of - or rather climate change is as simple as any of those, but there is focus on that. But also if for instance if you look at the literature about nuclear war and nuclear proliferation from the 1940s and 1950s, it's clear that people have a large expectation - an overwhelming expectation - that proliferation will go quite a long way and that nuclear wars will be fought. Remember that in Hermann Karl's book on thermonuclear war he talks about successive nuclear wars. In fact, by a number of reasons that have to do with chance and have to do with policy and have to do with politics, so far we have avoided that. Do I think that the international governance of nuclear weapons is a huge resounding success? No I think it's a horrible debacle in many ways. But do I think that it has gone better than it might otherwise have gone? Yes I do. And so I think the fact that you can't imagine going forward that things are going to work out all right isn't an excuse for not trying at all.

Chris Nelder: Well alright. Fair Enough. And you know I do applaud your optimism for global international cooperation particularly, you know, considering that we are just a few months down the line here from Brexit, which seems to be going the opposite direction.

Oliver Morton: Yeah. No I quite I quite see that. There is though... And partly we do have the rudiments of a global climate policy although it's easy to overstate the success of Paris, it's absolutely wrong to claim that Paris was not to some extent a success. And there is also the fact that sometimes problems get easier when they get bigger because you get more ways to look at it. There's a quotation which I'm not going to be able to call to mind from Eisenhauer about this. And it is possible. And I talk about this a little bit in the book that you might find ways to use negotiations about geoengineering to encourage people into mitigation and that's a very important thing to do because as I think should be clear from this conversation so far, but I want to make absolutely explicit: geoengineering is not in any way a solution to climate change. It's a response to climate change with more climate change but just of a different sign. And it is in no way an alternative to the goal of large scale mitigation and moving to a zero fossil fuel economy. It's not alternative. It's not oh we can go on business as usual as long as we do some geoengineering. That doesn't work at all because the geoengineering techniques that one might use to enable that, they don't provide you with a perfect counter to the warming that you get through greenhouse gases and the more warming there is and the more you seek to offset it with geoengineering the more difficulty you'll have with that mismatch which will for instance drive changes in the way the water cycle works. So the best sort of geoengineering is the least that you can get away with but it's in no way should it be seen as an alternative to mitigation and it might seem an odd way to look at it but it's really a complementary therapy.

Chris Nelder: Or it almost sounds like you're suggesting it could be a bit of a Trojan horse, which I never really thought about.

Oliver Morton: In what way?

Chris Nelder: Well in the sense that I'm getting people to talk about engineering really think about it opens the conversation to mitigation strategies that might not otherwise happen.

Oliver Morton: That's true and it's I mean so we talked a little bit earlier about this idea of moral hazard about the idea that because you think that you have some degree of safety down the line you will behave more dangerously now. And that has been a big part of people's thinking about geoengineering. They've been afraid that talking about geoengineering now will make make mitigation action less likely. But there's been some work done with sort of like facilitated discussions by social scientists which suggest that the reverse is true, that when people listen to discussions about geoengineering they take climate issues in general more seriously and they say... I mean one way to caricature it is people say "Well if they're serious enough about this to be thinking of that sort of response then I should take it seriously too."

Chris Nelder: Right. Well you know I give you a great deal of credit for being very transparent in this book about your own biases for acknowledging that your views are inescapably personal and for trying to give people on the opposite ends of your argument a fair shake... I think that kind of transparency is really very lacking in most discussions about climate and energy which too often just pretend to be some kind of scientific neutrality when in fact there's a boiling emotional underpinning to their arguments. So you know to quote you in a condensed fashion, in the book you mentioned that your hopes for a geoengineering reflect a feeling that things press in, that history and the world embroil the present in a way that confines choice ever tighter, that you wish for a bit more room, a bit less pressure, time and space to breathe in your confined asphyxiated perception, which I thought was really quite a powerful passage there. That sense of confinement and a desire to break free of it is really a palpable undercurrent throughout your book. Do you worry at all that your bias prevents you from taking seriously other pathways that might ultimately be better for humanity?

Oliver Morton: It doesn't blind me to them I think. I think as I try to be fairly upfront about biases and I am very happy to hear you think that I succeed in that at least better than maybe the not particularly good average in the field. To slightly push back against the grounds of your question, I want a world where humanity can make its own choices about what's good for it and has the maturity, the options to do that. And I think it's in that process. I mean I think that in some ways while I think that would be great about geoengineering that worked, would be that if it worked in the way that I talk about it working - in a safe just and governable way - it would suggest that the world had come up with much better ways of dealing with problems in general. And to some extent that is part of my hope, that geoengineering proves tractable in a way that might be transferred. I've got this nagging feeling that in 100 200 300 years people from a better world - and God I hope it's a better world - will look back and say it's so sad that the way that they were arranged the way that they were tied in to the practices of their time didn't allow them to see that there were better things that they could have done. So this worry that in the end this will be an opportunity cost.

Chris Nelder: Well in a similar spirit I mean I have to admit what is probably my principal bias here which is that you know it's essentially a Pascal's Wager for me. I simply don't trust the same humanity that's been creating large volumes of nuclear waste for 50 years and still has no idea what to do with it or that can't effectively maintain its own infrastructure or halt the enormous damage that it's done to the biosphere and you know I'm talking about things like species extinction vast dead zones in the Gulf of Mexico the Pacific garbage gyre the crashing populations of ocean life and the whole litany of horrible things to engineer a solution that would actually change the entire climate. I mean our species has in my view essentially no credibility to make the claim that it can pull something like geoengineering off successfully. None.

Oliver Morton: But on that basis our species has no claim that it can solve any... I mean putting the environmental litany in those terms, why would you think there would be any good environmental action?

Chris Nelder: Well I mean...

Oliver Morton: I don't think geoengineering is... I mean I can see when you list things like that I can see the cause for your pessimism but it seems to me that that pessimism should then extend to pretty much everything about the environmental future rather than just geoengineering.

Chris Nelder: Well I think that's a fair point. I'm just basically loath to give humanity the licence to take this risk. I don't think it has shown that it can handle itself well enough to be granted that licence. And so you probably won't be surprised that I actually found your treatment of the potential risks of geoengineering pretty light throughout the book. I mean you acknowledge that they exist. In fact I'd like to quote one of your passages here. You say: "I understand why people are afraid of climate geoengineering. Its various techniques pose risks that are not as well understood as they need to be and pursuing some of them with any seriousness may weaken other efforts to limit the risks to which the build-up of carbon dioxide exposes the world. It tampers with what people understand to be natural which arouses feelings from uneasiness to disgust." Okay that's pretty much a good summary of where I'm coming from, but you don't really detail those risks and the book certainly not compared to the detail with which you describe the solutions. So I just wonder if you have given them adequate though.

Oliver Morton: Oh no I mean well mean the risks. I mean there are two classes of risk right? There are the biogeophysical risks, the risks of changing the way the Earth system works. And those are among other things probably very large scale almost certainly highly nonlinear. But in the near field probably to some extent linear and so small amounts of geoengineering - and I think I stress quite a lot in the book that certainly for the sunlight methods for changing the albedo of the planet - I think small is definitely the way to go. The evidence for strong risks strong feedbacks that would be largely harmful is simply not there. There is definitely an effect on the hydrological cycle if you have large amounts of geoengineering. But the idea that geoengineering at the one to two watts per square meter is shown to have big risks to the environment... I simply dont see that evidence and in fact I've been quite struck by the fact that most of the research, most of the modelling research - there are questions in that modelling research we could come back to - has always looked at large amounts of geoengineering, of geoengineering that's equivalent in size but not sign to a doubling or even a quadrupling of carbon dioxide. I don't think that that's something that one... That's something that's useful to look at from a scientific point of view but it seems to me that that's slightly poisoned the policy discussion because it assumed that geoengineering is always very very big and as I say the least you can do is probably the best. There are other potential risks and I think those are why you need to actually do research rather than just say I'm sure there are risks and then we shouldn't do anything towards that because the worst thing about this moral hazard point that we talked about earlier is that the very talking about geoengineering, if there is a moral hazard, raises that moral hazard. The worst thing to do it seems to me is to talk about geoengineering and have some sort of thought that if things got quote really bad if there was an emergency then you might do something. But for the time being not to actually think about how you might practically do it. And I think what you should do is actually think about how you might practically do it because that's how you will actually discover the risks. If you think that it's something that your children's children may have as an option in 80 years time then you're not going to bother to find out about the risks. So at the moment I think we haven't found anything like a showstopping risk but it would be really really good to do the research that found out quite that was able to quantify those risks a lot more rigorously.

Chris Nelder: Alright Well that's fair enough. I'm absolutely a fan of doing research and trying to evaluate the costs and benefits before you get too far down a path. That's fair enough.

Oliver Morton: And also it's not just a matter of costs and benefits. It's about doing research would allow you to find what sort of program you might want and what its goals might be. So for instance David Keith is one of the people I talk about in the book who's done a lot of work on this. He's looked at scenarios where you use geoengineering merely to affect the rate of climate change. So you do enough sunshine diminution to slow the rate of warming as least according to the models. That's a really different goal from the goal of using geoengineering to for instance return the climate to its pre-industrial or to limit a climate change to one level or another. And those sort of discussions about which geoengineering goals fit with which geoengineering technologies and with which risk profiles, those are crucial questions about designing something. Geoengineering's not something out there to be discovered. If it's anything at all it's a human endeavour to be designed.

Chris Nelder: Alright. And you know I certainly wouldn't be opposed to more pilot projects that would actually have a good chance of unearthing what the real risks are and what the real potential benefits are, take a more of a incremental approach. You know I think that's certainly within the realm of good scientific practice. But from a kind of a different perspective I have to wonder what's so interests you about geoengineering when many others similarly inform scientists and pundits think humanity really should be reaching for a solar powered civilisation ultimately. I mean if we're going to talk about goals...

Oliver Morton: I have no problem with that. I quite like the idea of a solar powered civilisation. I don't have any problem with that. I'm interested in reducing the harm done by climate change while we're on the road there. And I think given that we don't know anything like well enough either the time that it takes to reach a solar powered civilisation or the climate sensitivity I think you need to have a broader portfolio. I've got no problem with the idea that in the long run humanity lives with a solar powered civilisation. But again I'm also kind of okay with humanity living with whatever solutions it can come up with that don't harm it and the rest of the planet so I'm not evangelical about solar. I've been really impressed as so many people have that you know the progress in PV has moved at a pace that I hadn't expected from someone who first started looking at this sort of like you know 10-20 years ago. I'm very impressed by that. But the goal of geoengineering is not to produce a geo engineered planet as a goal in itself in the same way that you might talk about a solar powered planet. It's to reduce harm to people that comes from climate change.

Chris Nelder: Okay. Was There any other approach to addressing climate change other than geoengineering though you would actually endorse?

Oliver Morton: Well geoengineering is one of the various things that you would do about climate change. I'm very sceptical about nuclear in most of its formulations but I'm not existentially opposed to it. I'm very keen on renewables in many of their formulations but I don't think there's anything that I particularly like about renewable energy other than its low carbon footprint. That's what I like about renewable energy. So for me if I'm talking about the climate I like to have as much as I can have and I think that geoengineering should be part of a portfolio of responses or at least its consideration should be. Don't think that it's an end in itself and I don't think there's in any way an opposition between a geoengineered world and a solar powered world. And as we were talking about a little bit earlier I could imagine a use for a large amount of solar power in the next century, in the 22nd century. I can imagine a lot of solar power being used to pull carbon dioxide out of the atmosphere. I think that would be something that people might well think was worth their while sometime in the 2150s.

Chris Nelder: You know I want to probe again a little bit about sort of a fundamental worldview here that you're coming from. You seemed to take as a given that the global human population is certainly on its way to 10 billion people, that our objective should be to seek even more complex human societies and a higher standard of living for all, higher level of wealth for all, and then anything short of that doesn't really seem to be worth serious consideration. But I want to take the other side of that view, because I think the default, maybe even the easier path toward addressing climate change is to shrink. Shrink our populations shrink our economies, live lower energy lifestyles and consume less and set as our long term objective a global economy that actually lives on solar income in a managed and deliberate way. And I think that if we take that path seriously we might find that it's not so bad at all. It might even make us happier. And I wonder if you've really given the idea that say human population might peak around 7.5 billion and then decline through the forces of demographic change adequate consideration.

Oliver Morton: There's there's definitely a possibility that but this is not something which I it's not something I wish to see under sort of like active policy control. I mean we had a large amount of history in the 20th century with trying to direct population growth or curtail population growth directly and it was ghastly. You know there were real crimes against humanity done in the name of population growth. I'm very keen on the benefits of meeting currently unmet contraceptive need. It's definitely true that there are people who are getting pregnant who dont wish to be pregnant and having children when they didn't wish to have children I think that's bad and I think that shouldn't happen. But I think that more generally if you say to people that the population should be smaller you are effectively saying to people either you must change your views about procreation or you're saying people have to die more. I mean if you read for instance Erlich's The Population Bomb when you read the passages where says the real problem with Costa Rica is that the death rate isn't high enough and it's just an extraordinary thing to have this world view where you go to a thriving interesting country like Costa Rica and say you know the real problem here is that your not dying fast enough. So I find population... Population dynamics are interesting. Demographics matter. But I dont think beyond meeting peoples individual desires for control over their fertility I dont think they should be an explicit matter for policy. Going to the other part of your question, the solar income as various people have been pointing out since the beginning of the 20th century the solar income is potentially enormous if you can make solar power cheap, why can't you make it extremely plentiful? Particularly in a world where a large number of people live at the moment without any access to modern energy services so I've got no problem with the idea that the world might be a better place if American per capita energy use was the same as Japan's. You know it would be a better place if American per capita energy use was the same as the UK's or France's and it would be a fine place if the UK and France use as much energy as Japan. But I kind of also want Chad to be able to use the sort of energy that Japan does. I want to get away from a world where you know my fridge uses more energy than the average person and Ghana and I don't think the way to do that is just to get me a more efficient fridge, though I did actually get a more efficient fridge last year, it's to increase the availability of energy to people in Ghana. There's an example that I use in the book: we've moved from a position at the beginning of the 20th century where no one had modern energy services to a position at the beginning of the 21st where about two billion people did because about a billion people with modern energy services in the developing world and about a billion of us in the developed world. I really don't think it's reasonable to suggest that the other six to eight billion people don't get that and I think that's to some extent morally objectionable but I also think it's very very bad basis of policy to tell people, "You know what we have? Well we're going to give it up a bit in the way that suits us. And you're never going to have it at all."

Chris Nelder: Well okay. That's certainly a fair point of view. And actually you had some really useful statistics in the book about the amount of solar income that we get, that the sun drops about 170 thousand terawatts of energy around the Earth. About 30 percent of that as reflected back into space leaving more than 20 thousand terawatts of solar income, which is like 10 thousand times the mere 15 terawatts that humanity uses. So it's certainly ought to be possible, if we can continue to develop devices to capture the stuff, that everyone could have a fairly high standard of living in terms of their energy income all from solar.

Oliver Morton: Yeah and I think that as long as you can intercept it and store it, I mean if that's where the energy end game plays out that's fine by me. As long as we stop changing the radiative forcing properties of the atmosphere with carbon dioxide without really thinking about the consequences of that. That's to me the problem. And so I find it slightly implausible from a look at history that you will get to a system where there is really only one primary energy system. I think that you know by and large we've seen that during energy transitions as I'm sure you know better than I do, they rarely go to 100 percent and by and large previous fuels still stick around and alternative fuels stick around for various purposes. So I'd be surprised if we went to 100 percent solar world. But I wouldn't be at all surprised in the long run by an 80 percent solar world. If you took me down to the south of France and gave me lots of nice wine and darkened things and showed me around ITER And told me all about fusion then I might say that sometime in the 21st century maybe we'd do the fusion locally. Though I do tend to agree with you that when there's a very very large fusion reactor just nine minutes away it's probably better to use that than try to build your own. But as I say I'm not really hugely concerned about how people end up doing clean energy. I am concerned about clean energy pathways that I don't think will lead to 80 to 100 per cent decarbonization because I think that's where you need to get. But I like solar fine as a tool to that end. I'm not concerned about given technologies just in and of themselves.

Chris Nelder: No but you clearly also have a strong distaste for anything that smacks of limits. I mean this is something that really jumped out from your book. You seem confident that our remaining fossil fuel resources are sufficiently abundant and affordable for the foreseeable future. You don't see any important limits there. You call the proponents of limits based approaches like Paul Ehrlich, or at least other people who were worried about overshoot, you call them gloomy and lacking imagination and insufficiently concerned with the human condition. You bash Malthusianism at some length. I mean... (laughs)

Oliver Morton: Yes! And if we have more room on the podcast I'll go on with that. I think there's a part of the discussion there that... That's true. I do think that people that if you look at the Neo Malthusian literature of the mid 20th century which still has a presence in the thinking of environmentalists to this day I think there's some very very distressing stuff there and I think you need to realize that. And I think people in general are saying you in particular people in general need to realize that the amount of people and the amount that they do on the face of the earth is not subject to an a priori ecophysiological limit because how people do agriculture and how they do industry changes the amount of agriculture and industry that they can do. And so the idea that there are overall global limits is one that is questionable because the limits depend on the technology. The idea that there are limits to what you can do now is absolutely obvious and plain and part of the lived experience and we need to obviously realize that there are practical limits but I don't think there's much to be gained by thinking that it's necessarily useful to think small about these things.

Chris Nelder: Yes in fact I was quite struck with the way that you dismissed the metaphor of Spaceship Earth as promoted by Bucky Fuller and others as being sort of weak and unpleasant and in fact claimed that it's really an inapplicable idea to climate change because purpose in your view is a fundamentally human judgment. And you have a passage in the book here I'll read: "The question is not how to save the planet as it was but how the planet can be remade in a way that works while respecting the rights of the people living on it and the value that they place on it. It's a task that calls for imagination and compromise much more than naval discipline. It's a task of homemaking, not shiphandling." So you clearly don't like the suggestion that there are fixed limits to Earth's carrying capacity and you sort of rule out solutions that are about living within limits but in the end I guess... I guess I find this view to be sort of profoundly anthropocentric or at least essentially humanist. I mean call me a tree hugger if you must but I actually think that other species have as much right to live on this planet as we do, that we have a fundamental duty to respect and protect our home beyond what humans want or value or what we pronounce to be purposeful. And I do in fact as you say in the book worry about unintended consequences about the side effects on ecosystems and about diversity and about the risks of irretrievably altering the natural world and I don't actually think that humanity's history of altering the world is any sort of a justification for continuing to do it let alone at a vastly grander scale. And so I just wonder if we don't need to start backing these technical discussions here and now interrogate our respective spiritual beliefs.

Oliver Morton: Well yes to some extent, but my problem is that I'm less interested in the rights of natural objects. I'm very interested and very open to arguments about the duties that people have to the world in which they live. But I also think that we need to have solutions that work for people who dont share our values because if our solutions have to involve everyone sharing the same values to begin with, I'm slightly worried about that from an ethical point of view but I'm massively worried about that from a practical point of view. I dont think that changing peoples deep beliefs so that they all deeply believe the same thing and want the same thing is the way to produce a rich vibrant world. I don't think its a practical way to do anything at all. I think you know... I don't remotely think that people shouldn't have values. I try to live up to some fairly high values myself and I fail as I'm sure we all fail. There's something very fundamental about the way that environmentalism has a very strong link to this idea of values and people actually and wanting everyone to see the earth in the same way. I don't mind how people see the earth. I want them to stop harming both each other and the other inhabitants of the earth. And I should also say that various conversations that I've had with various people informally... If what you really want to avoid is ecosystem damage you'd probably do quite a lot of geoengineering. You know? The thing that's going to damage ecosystems most in the near future is extreme temperature variations and I think the evidence is quite good that through geoengineering you might be able to do something about that but I don't think that's the right justification for doing it. I think that things are much more complicated than that. But the idea that geoengineering necessarily means environmental harm, when the alternative is remember not the world as it is or the world as it was, but the world as it is becoming through the processes of climate change then you end up with lesser harms in some routes than others. That's all I'm saying.

Chris Nelder: Well okay you know I think that's a fair enough point of view. Well listen I want to thank you very much for taking the time.

Oliver Morton: I really want to thank you Chris because among other things I mean it's a great opportunity to talk to people. But also it's really nice talking to someone who's read and thought about the book and challenges it and comes back to it and still wants to talk more. I mean I think that's just great. So thank you very much. It's been one of the nicest things I've done for while.

Chris Nelder: Well that's that's what the show's supposed to be all about. So, super.

Oliver Morton: OK. Great. Thanks very much Chris.