How has the governance of solar radiation modification progressed in recent years?

Below are edited highlights from the full C2GTalk interview shown in the video above. Some answers have been edited for brevity and clarity.

The Planet Remade — the first book I read and I think quite a few people read when learning about this field, so thank you — came out in 2015.  At the time, the idea of intentional large-scale intervention in the climate system was still considered rather niche although subject to vigorous academic debate.  Since its publication there has been a greater sense of urgency around climate change in general and interest in new approaches to tackle it.  How do you see the context has changed since you wrote the book, and in what ways might that change some of the things you said in the book? 

Changing the things I said in the book, I would have to think quite deeply about that. The thing I’m surprised by, actually, is the degree to which the debate hasn’t progressed.  People say that there is ever more discussion of climate geoengineering, and I am not entirely sure that’s true, certainly not as a proportion of total climate discussion.  Total discussion of the climate has undoubtedly gone up, largely thanks to impressive youth movements, which don’t have much interest in or much to say about climate geoengineering. 

In terms of the actual practicalities of the field, when I wrote that book the Harvard team was talking about doing a small experiment called the Stratospheric Controlled Perturbation Experiment (SCoPEx).  They built it, but they’re still only talking about doing it.  There has been no real testing of the technologies that might be used for marine cloud brightening.  That still hasn’t happened.  I think that the assessment of solar geoengineering in the Intergovernmental Panel on Climate Change’s (IPCC’s) Sixth Assessment Report (AR6) was actually pretty desultory compared to what they said in AR5. 

So although the issue of solar geoengineering chugs along and people talk about it in some areas quite a lot, I must say I think I have been slightly surprised that it hasn’t taken off.  I just thought, One good book and this field will just explode, and that didn’t turn out to be the way it went. 

 If I could just jump in quickly, I think it might be helpful because there is such a maze of terms and terminology around all of this.  Geoengineering has been used to cover this vast range of ideas from different forms of large-scale carbon dioxide removal, both nature-based and technological, and also various ideas to reflect back sunlight to lower the temperature.  When you talk about climate geoengineering, which bits are you talking about? 

For myself, except when I forget, when I say “climate geoengineering” I mean both carbon geoengineering, which you could call “negative emissions” or “carbon dioxide removal” and solar geoengineering, which might also be called “brightening the Earth.”  Although some people would like to separate these things out — and I come across that mostly from people who want to do carbon dioxide removal and don’t want to be tarred with the brush of geoengineering — I think it’s useful to keep them conceptually linked because what they have in common is that they both decouple the climate you get from the cumulative emissions to date and I think that’s a really important commonality between them. 

I understand that various people are scared of the word “geoengineering,” and so around 2007–2008 people started using this horrible circumlocution “solar radiation management” (SRM), which was actually invented as a joke to make the idea of brightening the Earth sound sort of bureaucratic and as uninteresting as possible.  That term has stuck, so people talk about SRM.  Some people don’t like using the term “geoengineering” and like to talk about “climate intervention.”  I think that is, in some ways, an interesting and useful thing; but when you ask, “What intervention are you thinking of?” then you say, “Well, the thing that is really solar geoengineering.” 

At my base level, I think if people who want to encourage a debate about solar geoengineering try not to use the word “geoengineering,” then people who want to take the other side on this will say, “Oh, well, what they’re talking about is really geoengineering,” so, in fact, you’ll get the term turned back on itself. 

For me, it’s stick with what you came with; and since I wrote a book about geoengineering that dealt with both carbon and solar geoengineering, that is still how I think.  It is probably off-putting or confusing to the newcomer, but it’s not that hard a lexical thing to get through. 

To add one more, we in the Carnegie Climate Governance initiative use the phrase “solar radiation modification.”  We get guided by what the IPCC used in its report. 

I have always wondered why.  I suppose it’s because “management” sounds like you can actually do it; but, in fact, “modification” sounds like you will just have an effect, maybe not the one you are trying to manage.  It’s interesting, that. 

There is also the vexed question of cirrus cloud thinning, which looks very like solar geoengineering but is a bit different because it’s about letting long-wave radiation out.  These are all slightly in the weeds; but yes, solar radiation modification, that’s what the IPCC and the Carnegie say, and that’s very grown up of you all. 

Let’s take one of these approaches to solar geoengineering — solar radiation modification and the stratospheric aerosol injection, or stratospheric geoengineering I think you describe it as in the book. There are potential benefits, costs, and tradeoffs to this.  It could potentially reduce temperatures quickly and relatively affordably; but deployment could also have uncertain, uneven, and potentially dangerous environmental and social consequences.  You have already said you haven’t seen that much more debate on these core ideas since you wrote the book; but do you see at least the level of understanding of some of these challenges as you frame them increase in the years since?  Do we see a broader range of people beginning to engage in these ideas and discuss them? 

I think there is a broader range, but the broadening is reasonably slow.  When we recently saw a volcanic eruption in Tonga, people fairly quickly started saying, “Is there enough sulfur coming out here to actually have an effect on the stratosphere, and can we study it?” 

The answer is, “Well, we may be able to study it; but it won’t be a very big effect, if really any.” 

There has been a lot of modeling work.  There has been a lot of work in the climate-modeling community around a project called GeoMIP (Geoengineering Model Intercomparison Project).  There has been work on, as it were, optimizing or ways of putting sulfur — if it’s sulfur you choose — into the stratosphere, but I don’t think there has been anything that anyone would point to as a striking breakthrough.  By and large, the results still look as though, net, a well-designed solar geoengineering program could significantly reduce harm to quite a lot of people while increasing harm to relatively or possibly absolutely few.  I think that is still more of less where that part of the science sits; but there are both known unknowns, such as: what does this warming in the lower stratosphere do to the upper troposphere and what does it do to stratospheric chemistry?  There are also, one assumes, unknown unknowns, and that certainly needs more and deeper research. 

I think there is also — this is something that Donald Rumsfeld never concerned himself with — an unknown known, which is that the evidence from work so far is that solar geoengineering could have quite significant benefits with relatively low costs in terms of direct geophysically mediated human suffering. 

That’s on the physical side of it.  How about on the governance side of it?  Do you think there have been advances in understanding how humanity, in all its complexity and diversity, might go about reaching agreements to deploy or not to deploy or to research or not to research?  Do you think there is an understanding of the metrics by which different risks can be assessed against each other and the places those discussions might be had? 

Well, there is this organization you may have heard of called C2G which has been carrying these things forward very nicely. 

There hasn’t as yet been anything like, say, the Pew Commission on the oceans, which was very agenda setting and mind clearing when that happened.  There haven’t been very big discussions in international fora.  There was a move to have an assessment program put forward under UNEP (United Nations Environment Programme), which, as you know, did not get approved.  There is still what some people would like to see as a moratorium under the Convention on Biological Diversity, although I and most of the lawyers I talk to think that is not a moratorium in any real sense of the world. 

I don’t think there have been many new steps.  I think more people have become part of the discussion, and in some places the discussion has, I think, probably deepened more than broadened.  I think it is very hard to understand these issues.  One can scope them, and I think that C2G has done very well on that, but to actually understand them, I think at some level you have to start working through them. 

It was striking.  I was at a slightly fringe-y meeting a couple of years ago, in the great “before times,” about space-based geoengineering, so big mirrors in space, which people talk about now and then — and it’s good to talk about things now and then — but at the moment they really do not to me look like a practical alternative. 

But one of the things that was interesting was that if solar geoengineering was done that way, then at least the Outer Space Treaty would provide a really quite firm basis for governing it because it says what humans are allowed to do in space and what reasons they should do it for, that is to say basically the common good of humankind.  It is funny that a technical no-go would at least have the benefit of providing a forum for discussion, and at the moment there is really not that forum. 

Do you think it could be governed internationally in a way that is fair and inclusive? 

I’m not sure I think anything is governed internationally in a way that is fair and inclusive, and I am torn on this because I think to some extent what I just said is what people deplore as “whataboutery.” Obviously, one would want it to be governed in a fair and inclusive way; but if you think about an end-member case of solar geoengineering, which is where one country decides to do it for what it perceives of as its own reasons, it is not clear to me how there could be a fair and inclusive way of stopping that country because, as we are seeing in all sorts of situations around the world, you can’t stop sovereign nations from doing things they really want to do.  You can increase the costs for them; but, again, I think actually setting up a sanctions regime in such a situation might be quite hard. 

I think the moves toward a fair and equitable governance regime would be a very good idea, but I think it’s that process rather than the idea that you will end up with an ironclad regime that would be more interesting than the end result. 

To put it another way — I don’t think I put that as clear as I could have done — if you are faced with what people might call a “rogue” geoengineer, it’s much better to have had the discussion about what a fair and equitable approach to geoengineering is when you are faced with something that isn’t one of those than it is to just start from scratch. 

There have been recently some calls by a group of 60 or so academics and scientists for an international nonuse agreement for solar engineering.  Ungovernability was one of the issues.  There are a couple of other issues that they raised.  Do you think that represents an opening up of this debate in a useful direction? 

I think it definitely represents the views of the people who have signed onto it. 

It’s slightly hard for me to see something which calls for, for instance, international organizations not to give house room to solar engineering as a way of opening up the debate, but I do think it may be an interesting way to clarify some of the tensions and contradictions.  There are people who signed that open letter who I have known for years and like, trust, and admire.  I know that we have differences, and I would like to see the discussion go on further as to what they think about other ways of dealing with overshoots.  If they don’t have any very strong sense of how to fairly and justly deal with overshoots, it’s not clear to me quite on what moral ground they say that although we don’t know anything else for this, we ought to not discuss at an international level this possibility. 

One of the general critiques around the discussion is that geoengineering or solar radiation modification and the ideas around it have been dominated by a fairly limited group of people from the North and certain types of people.  I think you once characterized this group as the “geo-clique.” 

That’s actually Eli Kintisch’s phrase.  I have happily embraced it, yes.  I think my definition of it is anyone I have had breakfast with more than twice at a geoengineering conference is a member of the geo-clique. 

Does that still exist in the same way that it did maybe five years ago?  To what extent does this relatively small group of people still dominate and frame the debate, and how might one go about expanding that to different types of people? 

It has broadened out.  One of the things I would say is something really good that has happened since I wrote a book in this field is that you have, as it were, geoengineering native researchers both in the physical and the social sciences.  You can count them on one hand, I think.  But there are now people who did a PhD on a geoengineering topic who are now tenured professors.  That is something that there never used to be.  There basically wasn’t anyone — there are still very few people — who work full-time on solar geoengineering, very few indeed. 

Given that, it’s a hard thing to broaden out.  I think probably — I haven’t looked at numbers — the gender balance in the field has improved somewhat, but it is still dominated by men.  I think somewhere where there has been progress, but this is slightly an advertorial I am a trustee of a charity called The Degrees Initiative, which funds solar geoengineering research in developing countries in the Global South.  That is not in order to promulgate the idea that solar engineering is a good thing because that is not the charity’s position; it is to say that the Global South, which must be at the table in this — some would say must own the table in this — needs to have resident aligned scientists who know what they’re talking about.  We have funded quite a lot of work and are funding more work now.  I think that is a genuine broadening of the area. 

Do you think basically helping, supporting, and promoting science from the Global South has been the primary initial obstacle to getting a wider array of voices; or are there other fundamental obstacles in terms of how people from other parts of the world can get into this debate, the willingness to get into this debate, and actually to be heard? 

I think that creating a community of scholars in the Global South who are taking this seriously is the thing that I am in a position to help with to some extent.  Obviously, the work is actually done by the brilliant Andy Parker and the other people.  I give some of my time to this because I think it’s a really good cause.  Does it make everybody heard?  No.  I don’t know fully how to address that problem.  I think it is a problem that we have in a lot of different areas, and I understand why friends and colleagues who have signed on to the no-use agreement talk about ungovernability.  This is one of their reasons for doing so. 

To say from the outset as a governance scholar that something is necessarily ungovernable is either to have a really high normative value of what sort of governability counts as being governable or a council of despair.  It’s not as though there is a wide, deep level of discussion of geoengineering anywhere.  There is not one in the Global North either.  It will always be a problem with deep technical projects. 

The science is obviously one crucial part of it; but also clearly this is an area which leans heavily or is viewed very much through the lens of different ethical and religious beliefs.  I know this is an area you have had an interest in.  To what extent do you see different religious and ethical frameworks influencing and changing how people engage with solar geoengineering, maybe ideas also around the Anthropocene — is humanity getting good at being a god? — ideas around the difference between technology and nature.  How do you see all of these other ideas feeding into the discussion, such as it exists, around solar geoengineering right now? 

It seems to me that climate geoengineering, in general, is sort of like the poster boy for the Anthropocene.  One thing I didn’t mention when we were talking about what had happened since I wrote the book is that I did subconsciously focus quite heavily on solar geoengineering.  Climate geoengineering has changed hugely, of course, since that book because the idea that part of the end state of climate action is a net-zero world in which carbon dioxide is being taken out deliberately at the same rate as it is being introduced deliberately, that is a huge change. 

People can see that within a certain sort of stewardship model of the human relationship to the Earth, that you take out and you put back, whereas there is something quite alienating and Promethean about solar geoengineering which goes against many people’s, I would say, religious intuitions.  I am not a scholar of Laudato Si, but I am pretty sure that if one were to go through it, you would not find much. It is pretty down, as the Catholic Church has every right to be, on sins of pride; and I am pretty sure that I know which way it would come down on solar geoengineering.I think that is really problematic.   

My friend Matt Watson ran a blog, maybe still does, called The Reluctant Geoengineer.  I think an interesting question for me in my own thinking and writing is: How do you talk about these things in a spirit of humility without just throwing up your hands?  Because if you think that these are things that need to be talked about, you absolutely have to try to do it in a spirit of humility, but the enterprise seems so profoundly hubristic that that is very hard to do. 

I can’t claim that I am even a lived example of working this through myself, but humility seems to me the key thing one can take from greater faith traditions here more than notions of the correct human relationship to nature because I think it’s clear that ideas about the correct human relationship to nature are always already extremely complex.  There is a reason why in the great sociologist Raymond Williams’ book Keywords: A Vocabulary of Culture and Society “nature” has, I think, the longest entry — how to define what is natural and what is human and what is human nature.  These are endless areas of tussling. 

So nature is something that will actually be up for grabs; but I think humility is something that you can take from faith traditions and really try to inject into this discussion while also remembering what I think of — but I don’t know if this is correct — as a more Christian conception of loving kindness, that there must be some level of cherishing involved in this too, that there is a worthy urge to protect at play.  

There are also of course art, culture, film, books, novels some of which may be influenced by religion and some of which may not; but we have seen almost the emergence, I guess, of a subgenre of “Cli-fi,” a subgenre of Sci-fi, talking about geoengineering issues.  The Ministry for the Future by Kim Stanley Robinson, Termination Shock by Neal Stephenson, and so forth.  To what extent do they reflect a sense that society is coming closer to this?  How important are these books and other movies with geoengineering plots in them in influencing how humanity thinks about these ideas? 

I think that’s actually going to be a question you will have to ask historically to some extent.  But, yes, there are now — way back in the distant past when I first started thinking about geoengineering, I was actually thinking of writing a novel, and then I decided that my skills lay elsewhere.  My novel might have been not un-akin to the third of the recent climate geoengineering novels, Veil by Eliot Peper.  Stan Robinson is a friend of mine.  I have known Neal Stephenson for a long time, and I have now met Eliot; so what they have to say has not come as a complete surprise to me because we have talked it through. 

I don’t know to what extent this will really come home through novels.  I don’t think that Michael Crichton’s god-awful climate-skeptic book, the name of which I forget — State of Fear, maybe? — it reflected the fact that there was climate skepticism in the world; but it didn’t, I think, really move it forward particularly, I think at the margin. 

It’s very interesting the degree to which the climate action community has really taken Stan’s book, in particular, to its heart.  But then again, it’s interesting that solar geoengineering happens in Stan’s book.  His love is much more for getting humans involved in the carbon cycle, and it’s that bringing together with the economic cycles and the carbon cycle that is the heart of where his utopian nature is. 

There are other books.  Just as a plug, I would greatly recommend Austral by Paul McAuley in which geoengineering has happened and it has changed some things but not other things.  I think to some extent that is a much more realistic way of thinking about the future of geoengineering as being not the center of anything but something that, if it were to happen at all, would happen as an annoyance, a threat, or a good thing.  To me that feels a more natural way of dealing with it, but I have enjoyed the novels.  I don’t know if it’s really hitting. 

When I think about geoengineering in the broader world of arts.  I think about it in terms of that ever-changing dialectic of human nature and nature and humanity.  My talks on geoengineering tend to have pictures from the Hudson River School of American landscape painting, where they are also dealing with this question of the savage landscape versus the tamed human world or some more apocalyptic images from Anselm Kiefer. 

The work of art that, to me, speaks most directly to concerns about geoengineering was a wonderful installation at Tate Modern in Britain by Olafur Eliasson called “The Weather Project,” which was a huge artificial, in many ways, sun filling up the Turbine Hall of what used to be a fossil fuel power station.  People’s reactions to it, both in terms of its uncanny-ness and in terms of its beauty were really fascinating to me.  That’s where geoengineering art for me comes to a pinnacle.  I think Olafur did not in any way intentionally mean to be making a commentary on geoengineering. 

From your experience interviewing policymakers, legislators, and international negotiators — obviously, as you do this work, you will have a bunch of texts, briefing notes, and positions — do you think, in the back of the mind, there is also a sense of where would I be in this novel, where would I be in this piece of art, what piece of art am I creating here?  Do you think there is a sense in which people are also driven by those considerations when working out how you might go about governance or taking decisions about deployment, research, and so forth? 

Wow.  That’s a wonderful question.  I have no idea. 

I would suspect that self-image through novels isn’t as domain-specific as that, and I could imagine dealing with someone who has in the back of their mind the idea that they are part of War and Peace or someone who thinks in the back of their mind that they are part of a novel by Disraeli or a novel by Michel Houellebecq.  I am not sure that I would expect people to take their cues from fiction in quite that way. 

Maybe from a more low-brow way.  I am thinking of Star Wars — Darth Vader, Luke Skywalker, or Han Solo. 

Yes.  I am very interested in the way that science fiction tends to deal with climate as a fixed thing and, in fact, an incredibly monotonous thing.  In Star Wars you have a desert planet, you have an ice planet, you have a swamp planet, you have a planet without a surface at all with Lando Calrissian tooling around.  Maybe he’s doing something in that stratosphere that we should be told about, up there in Cloud City. 

But, in fact, I suppose the novel that people point to as a novel of ecological science fiction that is interesting here is Dune and the film of Dune, which are very powerful meditations on power and the environment, even though, in an environmental science sense, Dune makes no sense whatsoever.  It’s very powerful.  Ecological scientists I deeply admire reread Dune on a regular basis.  And in later Dune books — spoiler — Arrakis does get terraformed, so it does get geoengineered.  Maybe Mr. Villeneuve’s second or third Dune films will bring this out a little further, the question of whether one should change the world or not. 

One journey that I know people who tackle this subject have gone on is the changing sense of the likelihood that we will see some form of attempted deployment of geoengineering in our lifetimes and in what timeframe that might happen.  Do you have at the back of your mind — obviously, no one has a crystal ball — a sense that we might see significant advances in this field in the next 10, 20, 50, 100 years, and what the sort of precipitating events might be that actually move this from still a somewhat theoretical discussion to a very real and practical decision to be made? 

I think, given the current state of debate, we have to start thinking about large-scale carbon dioxide removal as happening — let me be generous to myself — within my lifetime, which I will take out to 2040.  You have to think that, unless everyone who says net zero is just full of it, there has got to be something happening, at which point the dye will be cast and you are setting out towards a world where eventually — it may be not for centuries — the climate, as in the level of carbon dioxide, is under human control.  There will be a choice in such a world as to whether you go for 400 parts per million or 350 parts per million, to take a number that is close to many hearts. 

There are already very small direct-air-capture organizations.  There is already various sorts of sustainable and regenerative agriculture, looking at soil.  There are lots of often not very good afforestation projects.  That side of doing stuff primarily to change the climate in the way you want — yes, that’s going to happen, and that’s going to happen within my lifetime. 

Solar geoengineering — I genuinely don’t know — is one of the reasons why the topic is interesting.  My default position is that it won’t happen on a very large scale and that in 2100 or 2120 people will look back and say, “You know, we might have saved ourselves quite a lot of hassle if we had looked at that harder.”  I suppose that’s the world that I’d like to see my work as trying to avert.  I don’t want a world with solar geoengineering come what may, but I also don’t want future generations to look back and say, “I wish they’d thought about this just a bit more thoroughly.”  

I just want to end on a note of how you tackle or thinking about how society tackles anxiety and climate grief.  Professionals working in climate dealing with these issues, you obviously talk about these issues and engage with them in a rational sense, but every so often there’s a, “Wow, this is really something dramatic going on,” and this has an emotional impact.  Different people have different ways of dealing with that emotional impact in terms of hanging onto hope or staving off despair.  How do you think about those issues?  How important is the question of tackling anxiety and grief over the next decade going to be, and how do you actually deal with that working in your work for influential media outlets? 

Mark, that’s a good question.  I found it harder when I was doing some work in the early 2000s on global public health, and I really admired the public health officials I came across in that work; but when I just thought about the real ongoing situation of millions of unnecessary deaths every year, that did actually have a genuinely bad effect on how I was thinking about other stuff. 

In general, I tend to think that, certainly in my lived experience, strong emotional reactions and issues probably have, if not deeper causes closer to home, certainly causes which are more amenable to change closer to home because if you build your notion of what your good life is on the basis of things over which you do not have any control, I think you are taking a bad bet on the universe. 

There is a sense also that one can be, in one’s work today, part of a generation or a set of generations now that is for the first time taking a different attitude towards the Earth and the human role in it and an attitude that, with some optimistic assumptions, not about basic human nature but about what the nature of some human society is, might work out okay.  That can be uplifting. 

The ur-memory of all this for me is being in Washington D.C., in a bar on top of the Hotel Washington with my friend Andy Lawler — Andrew Lawler; if he ever heard me call him Andy, he would kill me — and we were looking out basically at the White House and at a spectacular sunset.  I remember saying to Andrew: “You know, that’s Mt. Pinatubo.  That’s the stratosphere.”  

I hadn’t thought about solar geoengineering at all, I think, at that point; but knowing that geophysical events around the world could lend a particular atmosphere to a particular consideration of politics in what is probably still the most important square kilometer of the Earth politically, that has always stayed with me, and the idea that there are ways that this could come out a bit better, that, in the words of my friend Francis Spufford in his wonderful book Unapologetic: Why, Despite Everything, Christianity Can Still Make Surprising Emotional Sense, “There’s more can be mended than you would think.”  That is not a bad thing to take into your emotional life.