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Ethics Forum: Should We Use Technology To Fight Global Warming?


As evidence of climate change increases, scientists are beginning to focus on "geo-engineering" technologies to mitigate potential climate catastrophes. As part of our monthly series on Ethics in Science and Technology, we'll explore how researchers think they may be able to manipulate the climate and whether they should.

Maureen Cavanaugh (Host): I'm Maureen Cavanaugh. You're listening to These Days on KPBS. Each month we focus on a subject in the science and technology field and discuss its ethical implications. We take our cue from the Center for Ethics in Science and Technology which hosts public forums on those subjects. This month the Center is launching a three-part discussion about a topic that researchers are starting to explore very seriously. They're looking at ways to use technology to manipulate climate in an effort to avert some of the potentially disastrous consequences of global warming. In addition to examining the question of is that even possible, is the added question of should we even do it? Here to give us just a taste of the complexities involved in those two issues are my guests. Lynn Russell is professor of Atmospheric Chemistry at Scripps Institution of Oceanography. And, Lynn, welcome to These Days.

LYNN RUSSELL (Professor, Atmospheric Chemistry, Scripps Institution of Oceanography): Thanks, Maureen.

CAVANAUGH: And Darrel Moellendof (sic) is professor of Philosophy at SDSU and director of the Institute for Ethics and Public Affairs at SDSU. And, Darrel, welcome to These Days.

DARREL MOELLENDORF (Director, Institute for Ethics and Public Affairs, San Diego State University): Oh, thanks very much, Maureen.

CAVANAUGH: Now, Professor Russell, Lynn, why are researchers now thinking about ways to actually intervene with technology against climate change? Is the consensus that it’s too late, you know, to change light bulbs, to buy an electric car, those solutions that we’ve been hearing so much about for such a long time? It’s really just too late for that?

RUSSELL: It’s certainly true that global warming is a scientific consequence of the CO2 increases and it’s certainly not just a belief, it’s a scientific consequence. So reducing CO2 emissions to combat that is sort of – I think of it like saving for retirement. We need to do it soon and we need to do it seriously with CleanTECH and recycling and lifestyle changes and all these things but I think there is an aspect to global warming that while the basic science is understood and well known, there are many quantitative details that cannot be predicted. Just like wildfires, you can’t foresee when or where each will happen, you know, they usually happen in the dry months of summer but in order to – in addition to being able to save for retirement, we also want to be prepared for specific events that can’t be predicted or foreseen where the impacts on specific locations may be quite drastic. And so I think of geoengineering as sort of like buying insurance. We all buy fire insurance to think about what we can do if there is one of these unpredictable events that occurs sooner than sort of the average changes of climate.

CAVANAUGH: I see, so, in other words, if, indeed, there is a situation that develops be – no matter what we do now, it’s basically irreversible and in the cards. We have to be prepared for it, in your opinion. Your expertise is in the proposals that involve aerosol particles. First of all, what are aerosol particles?

RUSSELL: Aerosol particles are the little bits of smog and smaller particles, some of which are natural and some of which are manmade, that are emitted all over the planet and some of which we breathe each day in urban areas. And those particles, in addition to having effects on visibility and health, they also increase the amount of sunlight reflected back to space. And so by doing that, they have a cooling effect on the planet and their net effect over the last 50 years has certainly helped to reduce the impacts of global warming on climate change and to slow the rate at which the planet has been warming. Recently, in addition to increasing particles by increased urbanization and power usage, we’ve also been doing quite well in reducing particle emissions and so because of that there’s potentially a thought that we can replace some of those particles in ways that don’t impact health and don’t impact visibility.

CAVANAUGH: What kind of particles are we talking about? I’ve heard sulfate particles. Is that part of the idea?

RUSSELL: So sulfate particles have been proposed for injection into the stratosphere because there they would have a long lifetime and would be reflecting the light. They’re very efficient at reflecting light, and in small quantities, they’re relatively harmless. And because they’re in the stratosphere rather than where we breathe them, they have very few impacts on human health.

CAVANAUGH: Is that sort of along the line of what a volcanic eruption does?

RUSSELL: Yes, it’s similar to what volcanoes do. Volcanoes put both ash and sulfate particles into the upper atmosphere, sometimes in the stratosphere, as in the case of Mt. Pinatubo.

CAVANAUGH: And so we – Do we have – Let me ask you this, then. Do we have the technology that could actually do that at this point? Where are we in the exploration of the idea of seeding the stratosphere with sulfate particles in order to reduce the level of heat, I guess, that we get from the sun, is that right? Where are we on that?

RUSSELL: We’re sort of at the drawing board stage.


RUSSELL: It hasn’t yet been done intentionally. There are unintentional things, like volcanoes and to some extent contrails where we can draw from the types of things that happen to particles there. But we aren’t yet at the point of being able to design and engineer a fleet of planes that could produce those particles on a regular basis or to know how much that would cost.

CAVANAUGH: Now from what I understand, that’s just one of the possible ways that we could intervene. Another one has to do with trying to create more of a cloud cover for the globe. Tell us about that.

RUSSELL: The other idea is to use a natural phenomenon, the formation of clouds in humid areas and to add additional particles as seeds to those clouds, which won’t create new clouds but will brighten the clouds that are there such that they reflect more light into space by making – you actually make the cloud droplets, on average, slightly smaller and more numerous and that makes them more efficient at reflecting light. It makes them actually appear whiter. And so that kind of idea, especially if we did that over the ocean with particles made of sodium chloride or seawater components, would be expected to be fairly harmless.

CAVANAUGH: But that would have to be done very often. It would have to be sort of a continual process of trying to continue to get these clouds made and make them as white as possible.

RUSSELL: Yeah, that would be envisioned as fleets of ships in various parts of the ocean continually emitting particles to continually seed the clouds because the particles in this lowest kilometer of the atmosphere last 5 to 7 days. In the stratosphere, we expect they would last on the order of a year, and so you wouldn’t need to put as many up there. You could do it less frequently.

CAVANAUGH: Now, as I say, your expertise is in the idea of aerosol particles being used to try to mitigate against catastrophic climate change but there are also other technologies that are being explored in trying to find a way to reduce the effects of climate change. What are some of the other ways scientists are thinking of doing that?

RUSSELL: Yeah, and just to clarify, my expertise is in understanding how aerosols affect the atmosphere and how they naturally, as a result of pollution, have had these effects. And so thinking about how we might do those things intentionally is sort of a new thing that I’m looking into.

CAVANAUGH: I gotcha. I understand.

RUSSELL: And then – But you’re right. There are a number of other ways people have proposed to counteract the effects of global warming. One is to launch a mirror into space.

CAVANAUGH: A mirror.

RUSSELL: A mirror, a very large mirror, very smooth, very efficient, very reflective mirror, and to have it reflecting, again reflecting back part of the sun’s energy so that the amount of heating the earth receives is less so that even though when you add in the extra greenhouse warming, you kind of come back to where you were supposed to be in the first place or where we used to be. So that’s one idea. Another idea is to enhance the rates of natural CO2 uptake, either by fertilizing the ocean with iron or by actually creating factories that can take CO2 up and then artificially sequester it somewhere.

CAVANAUGH: And that’s called carbon capture, right?

RUSSELL: Carbon capture and sequestration. And it’s – it has been technically demonstrated. The limitation there is that the cost is still prohibitive so a number of people are working on how to do that more efficiently. And the second aspect is where to put the CO2 so that it’ll stay and not create unintended consequences.

CAVANAUGH: Now is it fair to say that we’re a number of years away to seeing any of these ideas put into action?

RUSSELL: At this stage, there are some preliminary experiments going on on some of these fronts. But they’re – In order to actually implement any of them, I would be, I think, we’re very uncertain in terms of the science that is required in order to implement them. And so at this stage, most of what’s going on is research into those uncertainties and I think that’s where we should be for a few years in order to have a better idea of what the consequences might be before we do them.

CAVANAUGH: I’m speaking with Lynn Russell. She’s professor of Atmospheric Chemistry at Scripps Institution of Oceanography. I’m about to introduce, again, Darrel Moellendorf, who is professor of Philosophy at SDSU, Director of the Institute for Ethics and Public Affairs at SDSU. We’re talking about the ethics of cooling the planet through geoengineering. It’s a forum, a three-part forum, that’s about to start at the Center for Ethics in Science and Technology. And as I go to the ethical questions involved in all of the good information that Lynn Russell just gave us, let’s go to the phones because I think we have a caller who might set us up on some of the ethical questions involved in all of this science. Peter is calling us from Encinitas. And good morning, Peter. Welcome to These Days.

PETER (Caller, Encinitas): Thanks for taking my call. So my – I guess it’s a little hard to know exactly how to formulate this question but it has to do with pride and hubris if we want to put it in a philosophical realm. It’s just astonishing to me to think that anyone imagines that at this point we’d begin to have enough knowledge of the atmosphere to think that we can cure our problem of polluting it by polluting it more. It seems to me we have a system that has worked in the past and it worked for many millennia, which was to not pollute it. Things worked great as long as we didn’t pump as much CO2 as possible into it and fill our waters with toxins and so on and so forth. I think…


PETER: Personally, I think the best thing we need to do is to quit polluting it, let it recover, and if that takes a little longer than we would like, then that’s the price we pay. We’ve extracted a lot of wealth from the atmosphere by burning gasoline, for example, and throwing the trash in the air. I think it’s time – I guess our bills are coming due and that’s what we have to deal with.

CAVANAUGH: Peter, thank you for your comment. I appreciate it. Darrel Moellendorf, I’d like to get your reaction to Peter’s comment.

MOELLENDORF: Well, I think Peter makes a very good point. I think there are surely limits to our scientific knowledge and I think Lynn has expressed some of those concerns already. And there’s a more general concern about whether or not we, as a species, should be in the business of trying to alter, intentionally alter, the planet and I think that that speaks a bit to Peter’s concern about pride and hubris. And I think that many of us have these feelings and that they’re appropriate feelings. The alternative, of course, is to begin to get serious about mitigating climate change through lowering CO2 emissions and the problem there is that, on the international scale at least, we don’t have a consensus about what to do and we don’t have a treaty forthcoming. The United States doesn’t have a climate change policy and that’s – this is holding up international negotiations right now. The – there will be a meeting in Cancun in December, and this is a meeting at which there’s a possibility of an international treaty to actually get serious about mitigation but it doesn’t look like it’s going to happen this year. Perhaps it’ll happen next year. In the meantime, I think people begin to wonder whether or not there should be an alternative approach.

CAVANAUGH: And in fairness, what researchers are looking at here is not to stop perhaps an iceberg from melting but to stop what could be catastrophic climate change. And if you could talk to us a little bit about that, Darrel, about what the kinds of scenarios we might be looking at in the not-too-distant future that scientists might want to step in and mitigate.

MOELLENDORF: Well, I need to preface this by saying that I’m not a scientist.


MOELLENDORF: And I don’t have, you know, I don’t have detailed knowledge on the basis of studies that I’ve actually performed myself but if you look at the documents in the scientific community, if you look at the documents of the intergovernmental panel on climate change, which is an international body that correlates the best climate science and looks at the peer-reviewed work in climate science over the last several years, and they produce these every four or five years, one of the things that you’ll see is that there’s a tremendous lack of knowledge right now about the dynamics of ice sheet collapse. And this is a concern because that ice that’s on the land, if it collapse (sic) and melts, it falls into the ocean and it produces sea level rise. And at the high end of current thinking with respect to how high the seas might rise if there’s a sort of linear progression of ice sheet melting, it’s about four meters. But nobody really expects there to be a linear progression. Nobody knows what the progression might be and that means that there could be significant sea level rises. Four meters might not sound so significant but consider that 10% of the world’s population lives at ten meters or below. Large metropolitan areas like New York City, like Miami, Shanghai, Dhaka, Bangkok, Mumbai, all of these are within that range. And then you have millions, millions of people living in low – lowland delta regions in the Ganges Delta and Bangladesh, 125 million people. The Nile Delta region, 80 million people. The Mekong Delta region, 15 million people. So these are the sort of scenarios that alarm people with respect to sea level rise, and there are other concerns with respect to sea level rise but we could be talking about massive human suffering.

CAVANAUGH: Massive human suffering that these technologies have the possibility of, as you’ve been saying, mitigating but there are potential side effects as well, aren’t there, Lynn Russell?

RUSSELL: Yes, and so it is only in the case, in my view, of such potential catastrophic events that we would try and implement these things. I want to reiterate that I do believe in saving for retirement. I think reducing CO2 is, first and foremost, what we should be doing but there are consequences that may happen before that approach can bring us back to where we were 100 years ago. And one of those potential consequences, in addition to what Darrel mentioned, is loss of the Arctic Sea ice, which is something that’s been in the news recently and that is an event that if the sea ice is lost, there’s a huge amount of concern in the scientific community that it’s irreversible, that we could never bring that back and that has a huge impact on – that would accelerate the warming by reducing the amount of white coverage of the planet and the reflectance of that. So those are the types of things that make us try and think about whether it is always okay just – I mean, normally doing no harm, right, is a good precautionary principle but in this case doing nothing already may mean harm.

CAVANAUGH: And Darrel.

MOELLENDORF: Maureen, if I could, just there are a couple of ethical considerations that I think are relevant to the discussion that we’re having. And these – Obviously, this is an issue that raises a number of them but if I could just briefly mention three that I think are significant. One is whether or not, and I think Lynn has touched upon this, is whether or not we have sufficient scientific knowledge to act responsibly in this area. Do we know enough about the intended consequences and then about the side effects? And that seems very important if we want to proceed responsibly in a project like this. But another one that I think is equally important is suppose that we have the technology to do that. Who would have the right to deploy this technology? I mean, we might be sitting here thinking that obviously this is something that the United States is going to do and we feel comfortable about that perhaps but would we feel equally comfortable if China decided to do this unilaterally? Or if Russia decided to do this unilaterally? Or if Iran decided to do this unilaterally? Which body or which group of people have the right to intentionally alter the climate that affects the entire planet? This is a, seems to me, a terribly important question. And then the third that I’ll mention because Lynn brought up the insurance analogy early on and I think it’s a nice analogy in one way but it also points out, I think, a problem that’s referred to in the insurance industry as the moral hazard problem. That is, suppose that we have this insurance policy of a climate change, might this cause us to be less enthusiastic about pursuing serious mitigation of the climate because we know we have the Plan B that we can always pull out at some point in the future.

CAVANAUGH: That is – that’s fascinating. So given – do you think that we have actually any time left to actually even really do these things, to develop these technologies? There is some controversy as to whether or not things are proceeding so quickly that there’s – this is just really a moot point.

RUSSELL: So the beauty is we don’t know, so we might as well – we might as well try and do what we can. And that’s – But we don’t know how long it’s going to take. There’s a, you know, if there’s a 2% probability that it’ll happen tomorrow, you know, you maybe wouldn’t – Well, it’s how seriously do you take that 2% probability. I mean, I think that people are starting – a number of people are starting to think seriously about CO2 reduction and I think that’s really good even though it may take the globe awhile to get its act together. But I think we also need to simultaneously think about other things.

CAVANAUGH: That insurance policy that you’re talking about.

RUSSELL: And you’re right, there is a moral hazard to, as Darrel brought up, but – and that’s certainly not what we’re pushing here. You still need to save for retirement even if you buy fire insurance.

CAVANAUGH: There is so much more to talk about in this huge and crucial subject. I want to let everyone know the first part of the Ethics of Cooling the Planet Through Geoengineering Forum, focusing on “Will Aerosol Particles Prevent Global Warming?” takes place next Wednesday, October 6th at 5:30 at the Reuben H. Fleet Science Center in Balboa Park. Lynn Russell and Darren (sic) Moellendorf, thank you so much for speaking with us today.

MOELLENDORF: My pleasure. Thanks very much.

RUSSELL: Thanks, Maureen.

CAVANAUGH:, go online if you’d like to post a comment. And stay with us for hour two of These Days, coming up in just a few minutes here on KPBS.

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