John Donvan:
Some of our best debates ever are those where we stretched hard to look over the horizon at coming technologies that have potential to change how we live, and each time asking a key question, "Just because this technology perhaps can work, does that mean that it should be put to work?" We have asked that in relation to artificial intelligence, and genetic engineering, and a number of other similar technological developments, similar in the sense that, what once seemed far fetched has become at least plausible, and therefore we think debatable.

And now, over that same horizon, we see an idea taking shape that requires a mouthful of syllables to give its name, "solar geoengineering," also known as solar radiation management or modification. And that is a proposed set of technologies that aim to reflect some sunlight and reduce the inflow into the atmosphere of solar energy, thereby partially reducing global temperatures. That's the idea.

Or, put another way, it's the idea that the amount of heat that we get from the sun can be controlled, and in an era of concern about climate change, partially reflected away from the earth by a number of different means, by putting reflective materials on rooftops, or putting mirrors into orbit, or injecting aerosols into the stratosphere that would effectively act like a kind of sunblock.

You get the idea. The question is, "Are these ideas feasible, and if they are feasible, are they desirable?" Well, we think in all of these questions, we have the makings of a debate, so let's have it. "Yes," or, "No," to this statement, "Engineering Solar Radiation Is a Crazy Idea." I'm John Donvan, and I stand between two teams of two who are experts on this topic and passionate about it, who will argue for and against this resolution.

As always, our debate will go in three rounds, and we are here at the Kaye Playhouse at Hunter College in New York City. That -- this audience will choose our winner, and also, if all goes well, civil discourse will also win.

A reminder to our audience one last time to cast your pre-debate vote, the vote before you hear the arguments. Visit iq2us.org/vote. You will be prompted to cast the vote for or against the resolution, or to declare yourself undecided. And I want to explain now you'll be voting again after you've heard the arguments.

And it's the team whose numbers have changed the most in the upward direction between the first and the second vote that we will declare our winner.

Our resolution, "Engineering Social --" our -- I'm going to just pick up, because I get to edit, and when I make mistakes, they didn't actually really happen. They just get lost.

[laughter]

So our resolution, "Engineering Solar Radiation Is a Crazy Idea." Let's meet our debaters, starting first with the team arguing for that resolution. Ladies and gentlemen, welcome Clive Hamilton.

[applause]

John Donvan:
Clive, you've come a long, long way to be part of this debate. You're a professor at Charles Sturt University in [unintelligible], Australia. You are a climate advocate, a best-selling author. Some of your books include, "Earthmasters: The Dawn of the Age of Climate Engineering." Most recently, your book, "Silent Invasion: China's Influence in Australia," was published finally after three other publishers pulled out, signing fear of punishment from Beijing, and that book then became an immediate bestseller. So congratulations to that, and thanks for being here, Clive.

[applause]

John Donvan:
And now let's meet your partner. Please, ladies and gentlemen, welcome Anjali Viswamohanan.

[applause]

John Donvan:
Anjali, welcome to Intelligence Squared U.S. You're a scholar at the Blavatnik School of Government at Oxford. You're a lawyer. You're an energy policy enthusiast. Previously, you've worked with the Council on Energy, Environment, and Water in New Delhi on renewable energy policy finance in governance. You've worked at some of India's top law firms on energy projects. Welcome. It's great to have you, Anjali, on Intelligence Squared.

Anjali Viswamohanan:
Thank you. I'm very happy to be here.

John Donvan:
Thanks very much.

[applause]

John Donvan:
So two of our debaters came a very long way, and the others also traveled, just not quite as far. Let's welcome the team arguing against the resolution, starting first with David Keith.

[applause]

John Donvan:
Hi, David. You worked at the meeting point at Climate Science and Energy Technology and Public Policy for 25 years. You're a professor at Harvard, where you led the development of a solar geoengineering research program. You're the founder of carbon engineering. That's a company developing technology to capture CO2 from ambient air. Time Magazine named you one of its heroes of the environment. That must be a burden to carry, but I want to thank you very much for joining us at Intelligence Squared. Welcome, David.

David Keith:
Thank you. Happy, tonight, to be here.

[applause]

John Donvan:
And your partner, also arguing against the resolution, please welcome, ladies and gentlemen, Ted Parson.

[applause]

John Donvan:
Hi, Ted. You study international environmental law and policy, and the role of science and technology in policymaking. You're a professor of environmental law at UCLA, codirector of the Eminence to climate change and environment there. You've worked and consulted for the White House Office of Science and Technology Policy, and the U.N.'s environment program. Ted, it is great to have you here at Intelligence Squared.

Ted Parson:
Thank you, it's great to be here.

[applause]

John Donvan:
So here they are, four debaters welcome to get started. And let's move on to round one. Round one will be opening statements by each debater in turn. They will be six minutes each. Speaking first for the resolution, "Engineering Solar Radiation Is a Crazy Idea," Oxford scholar, Anjali Viswamohanan.

[applause]

Anjali Viswamohanan:
A very good evening to everyone present in this room today, and everyone joining this discussion virtually. This debate on solar geoengineering has been rife within the scientific, the academic, and the policy focus, but this is one of the first few instances of an open and hopefully engaging public conversation on this topic. As in the fight for regaining climate change justice, the voice of the people will be of critical value in setting the tone of the discourse on climate geoengineering, and therefore, what you take from this room tonight is of -- it's very important.

In this part of the evening, I'd like to take a shot at answering the question of whether we really need solar geoengineering, because I think that would give us half the context we need to really start thinking about the proposition tonight.

When Clive takes over, he will start -- he will talk about the issues associated with deployment of the technology, specifically those around control of the technology and its implications for global security. One of the first things that came to my mind when I thought about what I'd like to speak tonight -- speak on tonight is this episode from this American sci-fi sitcom called, "Rick and Morty." The sitcom revolves around two main characters, which is this nutty scientist grandfather, Rick, and his naïve teenage grandson, Morty.

So in this particular episode, Morty had some trouble speaking to a girl that he fancies at his school.

And Rick helps him through this process by developing a love potion of sorts. And, as is the case with most of Rick's inventions and solutions, things go horribly wrong, and the entire world is destroyed, but Rick and Morty travel to a parallel universe, and pick up their lives like nothing has changed at all. Now, the reason that I brought up this episode is not to imply, by any means, that any of the scientists involved behind climate geoengineering are crazy, not at all. The only reason that most of us are in this room, here, tonight is because we are very concerned about the implications of climate change.

The only reason that we are sitting on the opposite sides of the stage tonight is because we differ in the way we are approaching this problem. Now, getting back to the episode, the whole disaster could have been avoided if Rick, being the grandfather, and the wiser, and more competent person had pointed out that, instead of looking for a quick fix in the form of a love potion, Morty should have just taken time to muster courage on his own, and go speak to the girl in a while.

Now, on similar lines, the problem we are discussing tonight is global warming, and solar geoengineering is perhaps an answer to the question of, "How can we most effectively cool the world fast?" But I think that your question is, "How can we most effectively cool the earth fast and keep it that way in the long run?" We already know that we need to maintain the global warming from reaching -- from going beyond 1.5 degrees Celsius to prevent disastrous consequences for the planet. IDCC, which is a U.N. expert panel of climate scientists, have already out pathways we could follow to stay below this 1.5-degree target. It requires immediate drastic action to shift to carbon neutral technologies.

The report categorically excludes solar geoengineering from any of these pathways due to what it calls large uncertainties and knowledge gaps, as well as substantial risks, and institutional, and social constraints, and that's putting it mildly. Solar geoengineering does not affect the processes that are making the world warm.

It merely attempts to stop or slow the process and getting -- and making the effects from getting worse, buying us more time to do what we should already be doing, which is changing our energy sources and cutting our profligate consumption. Any such effort to buy us more time is only likely to enable more opportunists to step in and benefit in wily ways from the shifting landscape.

There are wide differences of opinions, even amongst the scientists working on this technology, regarding the effectiveness of this technology, the -- what does -- what the real-world risks of this technology are, and to what extent these risks can be contained.

The lists of negative impacts on deployment is quite long, but one of the most immediate impacts that will be felt will be to the change in the precipitation cycles. It will also affect tropical forests, the ozone layer, and the oceans. It will also reduce the amount of solar radiation leaving the earth's surface. This will affect both crop use and also diminishing the potential of solar energy, which is one of the biggest alternators that has been contemplated to foster fuel energy generation. The [unintelligible] pathways see to new ways contributing towards 70 to 80 percent of the energy supply by 2015, of which solar energy will constitute a sizable chunk of.

Throwing solar geoengineering into the mix will result in the lack of a coherent strategy on damaging climate change.

I am also certain that, at some point during the discussion today, we are likely to hear that solar geoengineering is intended to benefit the most vulnerable populations, protecting them from the harms of climate change. But what may not be explained as clearly is that there are going to be winners and losers in this victory [unintelligible] called, "climate." And, right now, the discourse on solar geoengineering and -- on both research and deployment is in the hands of the global not [spelled phonetically]. Let me rephrase. It is controlled by nations that have yet to take full responsibility for their disproportional historical contributions to GEG emissions, which is why they're forced to have this conversation today, in the first place. To conclude, there's no sugarcoating it. Keeping warming to below 1.5 degrees would be very hard, but let's also be very clear that the world has a scientific understanding, the technology, the capacity, and the financial means to tackle climate change at its source without considering solar geoengineering. Thank you.

[applause]

John Donvan:
Thank you, Anjali Viswamohanan. The resolution again, "Engineering Solar Radiation Is a Crazy Idea," and here to make his opening statement against this resolution, which means he is in favor of the idea, UCLA professor, Ted Parson. Welcome.

[applause]

Ted Parson:
Thank you. Geoengineering does sound crazy when you first hear about it. That response is completely understandable, and it's also politically potent. That's why, for the past 10 years or so, our opponents have won. Talking about geoengineering is pretty much taboo in polite scientific and environmental company.

It's been starved of research support, and marginalized in climate change assessments, but this is dangerous. It's dangerous for the environment, and it's dangerous for preserving opportunities for human development.

It is essential to take geoengineering seriously, to research how it might work, and what risks it holds, and to confer on how to safely control it. Now, to talk sensibly about geoengineering, you have to consider the climate change risks that it's intended to combat, how bad they are, and what other preferred ways there are to reduce them. The answer is sobering. The risks are grave, the opportunities to limit them adequately through other means are weak, and the news gets worse with each passing year. You know the headlines. We've already heated the earth about two degrees Fahrenheit and are seeing pretty serious impacts. And we're on track to continue heating another two to nine degrees Fahrenheit within the lifetimes of today's children. Stopping climate change requires reducing human greenhouse emissions to zero.

This means cutting fossil fuels from the present 80 percent of world energy to about zero. There is no serious disagreement on this need, but such a vast economic and technological transformation is a project of decades, not years. And despite positive recent signs, like the Paris Accords and the rapid recent gains in solar and wind energy, we've barely started.

World emissions are still growing. And even with a crash program, it's probably too late to limit climate change to safe levels by cutting emissions alone. Now, cutting emissions isn't our only tool. We can also remove carbon dioxide from the atmosphere. This can help maybe a lot, but we're relying on it now to a dangerous degree. The most optimistic climate projections all assume that we'll scale this up rapidly from zero to billions of tons a year.

This reliance on technologies which are not fully developed or tested is a huge gamble. And even if this does work, it's probably too slow. Removing CO2 from the atmosphere is like draining a lake through a straw. It will work, but it'll take a long time. So deep emission cuts and carbon removal are both essential, but they may not be enough soon enough, even with extreme efforts. We need something else, and geoengineering might be that something else. Now, I'll address the two biggest policy concerns that have been raised about geoengineering. First, "Can it be governed at all?" Geoengineering presently looks like it might be cheap and easy, at least cheap and easy to do it crudely. This is actually a problem for governance, because it may put the capability within the reach of more than a dozen nations.

As a result, if we should ever face decisions about using it, we would want them to be under effective international control.

Even if someone tried to do it unilaterally, that would still require an effective international response. Building this international control won't be easy, but nations have come together many times to address global challenges adequately, even if not perfectly.

Think about the post-war creation of the United Nations, or the Global International Economic Order, or more recently the successful global phase out of ozone-depleting chemicals. You can imagine the required body being a U.N.-style global institution, a concert of great world powers, a set of soft law norms, or something in between these. But there are simply no grounds to claim that building the needed governance capacity is impossible. And this is a way that calling geoengineering crazy is doing real harm. In addition to blocking needed research, this stance is also obstructing the policy discussions that are needed to help develop governance.

Last month, a swiss proposal in the U.N. environment program to start research and consultation on geoengineering was blocked by the United States, Brazil, and Saudi Arabia.

This enforced silence is making risks worse, risks of climate change and also risks of reckless, badly governed geoengineering. The second big objection to studying or normalizing geoengineering is that it will tempt us away from the essential work of cutting emissions. Now, we agree with our opponents that anything that hinders deep emissions cuts is dangerous.

But will studying geoengineering have this effect? Research suggests the opposite. When people learn about geoengineering, their support for emission cuts gets stronger, not weaker. They don't see it as a get out of jail free card, they see it as a signal of alarm. If you're thinking about doing something this radical and scary, then climate change must be really bad. Even the fossil fuel denial group -- fossil-fuel funded denial groups seem to get this.

They've recently started attacking geoengineering as crazy. This seems strange, given their prior behavior and the interest they represent. So a likely explanation is that they think attention to geoengineering will raise alarm about climate change, and so galvanize action on all fronts, including emission cuts. In conclusion, the gravity of climate risks demands looking at all responses, even those that may at first seem frightening. There are plenty of grounds for concern about geoengineering, but there is no basis for calling these insurmountable, without serious examination, nor is there any basis to decide in advance that the risks of a world aware of geoengineering are worse than those of a world with severe climate change, and no means available to limit it in time.

Just as other technologies that carry risks as well as benefits are not crazy, chemotherapy for cancer treatments, vaccines for infectious disease, geoengineering is not crazy. Treating it as crazy is blocking needed research and blocking policy dialogue on how to use it safely. The resolution is dangerous. Please vote, "No."

[applause]

John Donvan:
Thank you, Ted Parson. And a reminder of what's going on, we are halfway through the opening round of this Intelligence Squared U.S. Debate. I'm John Donvan. We have four debaters, two teams of two, arguing out this resolution, "Engineering Solar Radiation Is a Crazy Idea." You heard the first two opening statements, and now onto the third, debating for the resolution, that, "Engineering Solar Radiation Is a Crazy Idea," Clive Hamilton, author of, "Earthmaster: The Dawn of the Age of Climate Engineering." Ladies and gentlemen, Clive Hamilton.

[applause]

Clive Hamilton:
Solar geoengineering of the kind that our opponents are advocating means handing to someone the power to regulate the amount of sunlight reaching the earth, and so the climate system of the planet.

On our side, we want to know, "What level of political maturity and ethical sophistication is necessary to use -- or anyone who has that power to use it safely?" And since solar geoengineering will affect people around the world in different ways, we want to know whether it can be used in a way that's fair. So we're here tonight debating geoengineering because the big carbon polluting nations of the world are so befit by political, social, and ethical failings that they have shifted the earth's climate system through rapid increases in greenhouse gas emissions to a point where we're on track to see an unfolding catastrophe.

And these nations have done it in full knowledge of the consequences. Yes, solar geoengineering may well be able to reduce -- for a time, to suppress, I should say, the rate of warming of the planet, but it sidesteps the political, social, and ethical problems.

It's the mother of all technofixes. The same political institutions and the same people running those institutions, who have so mismanaged the emissions of greenhouse gas emissions around the world, will be responsible for deploying the solar shield between the earth and the sun. Who would you trust to have their hand on the global thermostat, that is the power to turn the earth's temperature up a bit, down a bit, up a bit more, down a bit more, to change the weather in ways that may benefit Chinese people at the expense of Indian people, Americans at the expense of Africans. Who should make the decision? Should the Kremlin make the decision?

Should the polit bureau of the Chinese communist hierarchy make the decision? Should Donald trump make the decision? Could we expect to see a Tweet one morning, "Hey, this heat wave here, down at Mar-a-lago, is getting out of control, so I've instructed the U.S. climate regulatory authority to turn it down, turn it down."

[laughter]

Clive Hamilton:
Our opponents have put a great deal of thought into countering those who argue that solar geoengineering would unintentionally harm some nations while benefiting others. It's been suggested by some climate models that it could disrupt the Indian monsoon. David has said previously that, if geoengineering is done carefully enough, these unintentional harms can be avoided. But we -- on our side, we're concerned about the intentional harms, that is when those who had their hand on the global thermostat use it to deliberately damage their adversaries.

After all, the generals have always dreamed of controlling the weather. It gives a decisive military advantage. It's what's known as a force multiplier. Any program of solar geoengineering will inevitably involve the military. It's a strategic issue, and so the landmark 2014 report on solar geoengineering by the U.S. National Research Council was partly funded by the CIA. The CIA wanted to know if America's adversaries could use solar geoengineering to damage the interests of the United States.

The militaries around the world, as well as the intelligence agencies, are watching this debate because they're anxious about the strategic implications of putting a shield between the sun and the earth.

And those in charge of climate regulations through sulfate aerosol spraying, for example, will be twiddling with the knobs on a weekly or monthly basis. How much should be sprayed? How frequently should it be done? Where on earth should the planes be sent to spray the sulfates into the upper atmosphere? What kind of particles should we use? Each decision will change the weather conditions of some people more than others in different ways. Who would you trust to have such power? Our opponents believe that it will be done on the advice of a cohort of clever, rational scientists. But that's not how the world works. And, even if it did, we may not get a Professor Keith in charge. We may get a Dr. Strangelove.

After all, one of the earliest and strongest advocates of sulfate aerosol spraying was Edward Teller, the father of the hydrogen bomb, and the real-earth model, incidentally, for Dr. Strangelove.

He wanted to use nukes to flatten mountains and carve out new harbors. Teller celebrated man's mastery over nature. His protégé and coauthor of his paper advocating solar geoengineering, Pentagon weapon [unintelligible] Elo Wood, he said, "We've engineered every other environment we live in, why not the planet." Some advocates say there's nothing wrong within -- nothing inherently desirable about the climate that nature gave us, and we've now got these exciting new tools to set the climate of the earth wherever we choose. So the great promethean dream of human domination over nature could be realized with solar geoengineering until, that is, nature starts to fight back.

So, tonight, to finish the decision is yours. All things considered, if you trust humans to use the technology responsibly and fairly, then vote, "No," solar geoengineering is not a crazy idea.

If you believe, as we do, that our leaders cannot be trusted to have such power over nature, over their own people, over other nations, then vote, "Yes," geoengineering is a crazy idea.

[applause]

John Donvan:
Thank you, Clive Hamilton. And that is our resolution, "Engineering Solar Radiation Is a Crazy Idea." And here to make his opening statement against this resolution, David Keith, Harvard professor and founder of carbon engineering. Ladies and gentlemen, David Keith.

[applause]

David Keith:
Thank you. If you want a stable climate, you must stop putting CO2 in the atmosphere. Nothing about solar geoengineering changes that essential fact in any way at all, but cutting and -- fossil fuels are the core of those emissions, and it's tempting to think, "Because we have to end fossil fuels, that anything that distracts us from that is crazy."

That's not quite right. The fact is that emissions cuts are absolutely necessary, but that's not the whole story, and the reason is the following. Emissions cuts are absolutely possible, very doable. We can get emissions to zero with confidence. The increasing low price of solar power is fantastic, and that, combined with the use [unintelligible] that we're seeing gives me some hope of real political change. The challenge is the following. Even on that marvelous day where emissions are finally brought to zero, which is absolutely doable, the climate problem is not solved. This is not a choice between doing things slowly or quickly.

It's a choice about what we do. The reason for that is that climate risk is proportional to cumulative emissions of carbon dioxide.

The more we emit, the higher the risk gets, whatever we do about solar geoengineering. When we bring emissions to zero, we have simply stopped building up that interlaying risk. We have not eliminated it. So cutting emissions to zero is necessary, but it is not a sufficient and complete solution. We will also need to adapt. We can adapt to reduce climate risks by measures such as air conditioners or dikes, but that also cannot be a complete solution. Polar bears cannot take advantage of air conditioners, and dikes can only hold back water in some places, particularly rich ones. The CO2 we put in the atmosphere has an environment footprint that lasts for thousands of years. Even once emissions are brought to zero, if we want to reduce the underlying long-run risk of climate change, solar geoengineering doesn't help.

We need to do it by removing CO2 from the atmosphere, but that is inherently a slow process. There is no way in which it, itself, can be a sufficient solution to the climate problem.

The reason is -- the reason is both that it's slow and expensive, and that it makes no sense as is in those IDCC [spelled phonetically] scenarios to use it in the near term while we are also massively pumping CO2 into the atmosphere. The first rule of holes is, when you find yourself in one, stop digging. It doesn't make sense to imagine that this technology of carbon removal is going to get us out of the problem, that we need stop putting CO2 in the atmosphere by political action. So solar geoengineering may allow us to significantly reduce the risks of the CO2 that's in the atmosphere. It is no panacea, but the evidence that it can reduce risks is strong. Essentially every major climate model has been run, looking at how solar geoengineering works. And they find that, if it is done relatively uniformly over the planet, as could be achieved with aerosols in the stratosphere, and if it is done to roughly cut in half or moderate the warming effect of CO2, if it's done therefore as a supplement to emissions cuts, not as a substitute for them, we find that, in essentially every region, climate risks are reduced: not just warming, but extreme precipitation, precipitation, the changes in water availability -- those changes are reduced, not water availability, but the changes in it, tropical cyclones, sea-level rise.

Our opponents have claimed that this is theory, that we shouldn't trust these models, but they're the same models with the same physics, with the same aerosol physics, as are used to understand the risks of building up CO2 in the atmosphere. You cannot easily have it both ways. You cannot say that you believe the models that tell us how risky CO2 in the atmosphere, and which you should, and say that those models have nothing meaningful to say about how aerosols in the stratosphere might reduce risks.

So solar geoengineering really can reduce risks, or at least there is strong evidence for it, but it cannot be a complete solution for climate change, two major reasons. One, it has a whole set of poorly known environmental side effects. You're adding aerosols to the atmosphere, and aerosols are a health hazard. You can damage the ozone layer. The warming -- even if you reduce warming, you can reduce precipitations some places that could harm people. Second, there is no way in which it can ever be a perfect substitute for adding emissions. For example, the atmosphere -- the ocean will still acidify. So if one thought that you could keep emitting carbon dioxide, and turn up the amount of solar geoengineering again and again, you'd walk yourself further and further away from the current climate with more and more danger, of course, that could only end in disaster.

The, best claim that I think one can make about solar geoengineering is that a combination of emission cuts and solar geoengineering might be less dangerous than emission cuts alone. There's lots of evidence to that claim, but that evidence is not decisive.


If the motion tonight was, "Should we do it? Should we start geoengineering?" I would vote, "No." But the motion tonight is solar -- engineering solar radiation is crazy. And what crazy means is that you never want to do it under any circumstances. It means you are so sure you don’t want to do it, that you want to do research [unintelligible] 10 people to do it. It means you don't even want to talk about it because people get dangerous ideas in their head.

Our contention is that solar geoengineering might be part of the way that humans manage environmental risks of climate change this century, that a combination of emissions cuts, adaptation, carbon removal, and solar geoengineering might enable a safer climate.

But only by discussing it openly and researching it, can people make that judgment with information.

[applause]

John Donvan:
Thank you, David Keith. And that concludes round one of this Intelligence Squared U.S. Debate where our resolution is Engineering Solar Radiation is a Crazy Idea. Now, we move on to round two. And, in round two, the debaters address one another directly. And they take questions from me, and from you, our live audience here at the Kaye Playhouse in New York City.

We have two teams arguing this resolution, Engineering Solar Radiation is a Crazy Idea. The team arguing for the resolution -- which means that they are highly skeptical of the idea of solar radiation -- Anjali Viswamohanan and Clive Hamilton, have argued, basically, taking the position: do we really need geoengineering? They say that the real need is getting to the point of total emission cuts; that solar geoengineering represents a quick-fix, a solution that will not work in the long-run; and that it is full of all sorts of hazards; at best, it buys time to do what we should be doing.

They doubt, very much, that in that bought time, the right thing will be done.

They talked about negative impacts on tropical forests; on the ozone layer; on crop fields; on the potential, actually, to use solar energy, since some of the sun's rays will be blocked. They talked about the fact that there will be winners and losers. And they raised the prospect that the Global North will take control of this; if not, the military. And that the losers will be the powerless and, very likely, the weak.

And the large question they raise is the question of, "Who will be in charge? Who will have governance over this?" And they raised very, very serious questions about wanting to trust the hand of whoever controls the thermostat; that this is an ethical challenge, as well as a practical challenge.

The team arguing against the resolution -- which means that they are arguing for -- at a minimum -- further research, study, and exploration of the concept of engineering solar radiation -- Ted Parson and David Keith. They say, "Sure, on first glance, it does sound crazy." But they're arguing that the idea should be taken seriously, that it deserves focus on its merits, study of the possibilities.

They say, "It's long past time that the taboo status of this idea -- it marginalization -- should end." They say that they agree that the end goal should be cuts to zero carbon, but that the clock is ticking, and that we're already past the point where damage has been done, that the idea of geoengineering should be done in concert with cuts because we already need the shield that's in place.

And they, also, address the governance question, with a, kind of, a basic trust in the fact -- looking back at the past -- that difficult transnational ideas have been successfully brought together in the past, and that that could be done again. They do have some trust -- as their opponents said -- in the ability of scientists to figure things out, and of governments to figure things out.

So, there's a lot to get into here. But, before we do, for the -- before we, actually, begin the competitive part of the conversation -- for the sake of the layperson -- I would just like to get a concrete picture of what it is we're talking about when we're talking about putting aerosols into the atmosphere.

I did a radio interview, and somebody's question to me was, "Is it going to smell? Is it -- is the sky going to look different? How will those things get there?" And I thought, you know, these are practical questions for the layperson.

So, I'm not sure who wants to take that on. I think -- I'm tempted to ask David to tell us how does -- if it works, what's being discussed, without -- if you could do it, also, in 45 seconds or less, that would be really appreciated.

[laughter]

David Keith:
Well, there are many ways that it might be done. But if it was aerosols in the stratosphere, it would, likely, be put there by airplanes -- a number of, sort of, 20 or 30 airplanes, by midcentury -- operating from a few airfields. That's one way it could be done.

John Donvan:
And they would go up, every day, and do this?

David Keith:
They'd be flying continuously, putting up aerosols. And the aerosols, naturally, spread evenly in the stratosphere. It's, actually, very hard. So, you can't get them in one place to block. Well, that's, actually, impossible, if you wanted to. So, the stratosphere -- everything's spread pretty evenly. And so, you'd be bringing aerosols up there and they'd be spreading over the stratosphere.

John Donvan:
And what's the chemical being discussed?

David Keith:
For the most -- best understood chemical is sulfates or sulfuric acid. So, it's the same thing that is naturally in the stratosphere, both from volcanos and natural emissions. But there's a bunch of other ideas.

John Donvan:
Okay. And I want to -- let's go to the other side. If you can help us understand what's out, yet, competing, on the concept, just to describe what it is we're talking about. So, not telling us why -- it's a bad idea? But telling us what the idea, actually, is, if there's more to add to that.

Clive Hamilton:
Well, David has described the actual -- most likely, most discussed -- actual vehicle process of solar engineering: sending up a fleet of planes, on a regular basis, to spray sulfate aerosols, which react in the chemicals of the stratosphere -- the upper atmosphere -- in a way that blocks sunlight coming in. And it could be regulated so that you could, basically, adjust the amount of sunlight.

John Donvan:
Okay.

Clive Hamilton:
[unintelligible]

John Donvan:
So, we all agree to that. And, will it smell?

Clive Hamilton:
No.

John Donvan:
And will it -- the sky -- look different? No?

Clive Hamilton:
Yes, it will be --

John Donvan:
Oh.

Clive Hamilton:
It will whiten the sky.

John Donvan:
No, the sky would -- well --

Clive Hamilton:
Oh, now we're off and running.

John Donvan:
[laughs]

Clive Hamilton:
This gets into the question of --

John Donvan:
A little bit.

Clive Hamilton:
-- how much we're doing.

John Donvan:
Okay.

Clive Hamilton:
So, if you did enough solar geoengineering to, say, offset the effects of four times CO2, taking you all the way back to pre-Industrial -- and it you did it in the, sort of, way that makes that makes the biggest particles -- which would be crazy -- then you can see some whitening.

John Donvan:
Okay. So, you want to --

Clive Hamilton:
Well, I mean --

John Donvan:
Go for it.

Clive Hamilton:
-- let me just finish on this. Because, you know, David has been a crucial person, probably the leading scientist pushing for a research program in solar geoengineering. And he's, even -- in some of his writings -- suggested we should be deploying it soon.

One of the problems with it is that how much of it do we do? Initially, people were saying, "We should do so much to reduce the temperature back to pre-Industrial levels, one degrees Celsius, or a bit more." David says, "No, we need to do much less than that."

But I just point out, there's a sulfur industry that would be -- will be drawn -- called upon to provide the sulfur to be put in the planes to send up. Some of that sulfur comes from -- is extracted from the flu gases of coalified power plants.

And that same sulfur -- which we don't allow into the lower atmosphere because it causes sulfur pollution, [unintelligible], bad health, and so on -- is, then, put on planes and put into the upper atmosphere, where is -- blocks some sunlight reaching the planet. I think that -- along with the damage to the ozone layer -- would undue all of the work that we've been doing reducing CFCs to try to reduce the whole in the ozone layer. Really tells us that when you start messing with the chemistry of the upper atmosphere, you're really in very dangerous territory.

John Donvan:
I want to go to the other side. But, first, I just want to ask the audience here in New York, "Have you had enough of the sketch of what it is we're talking about?" Okay. I'm taking your word for it because I get it, also. Who would like to respond -- on the other side -- to what's just been said? Ted, do you want to take a --

John Donvan:
[inaudible] technical points, first, or do you want to --

John Donvan:
Yeah, you can -- technical points, fine, and then I'll pick up a couple of [unintelligible].

Ted Parson:
It's very tough to sort out the technical from the non-technical. But I want to respond to two points Anjali made at the beginning. One is: she said that it would make the precipitation change.

John Donvan:
You mean, Anjali?

Ted Parson:
Pardon?

John Donvan:
You mean, Anjali said it?

Ted Parson:
I said, yeah, that it would make precipitation change. That's absolutely correct. But you didn't say, "Which direction." And, of course, one of the big risks of climate change is that precip [spelled phonetically] -- and, especially, intense precipitation -- goes up. And what solar geoengineering does is it tends to reduce that.

So, you, kind of, hid from the audience the fact that one of the major risks of climate change -- for example, extreme tropical cyclones -- are not increased, but reduced, by solar geoengineering.

John Donvan:
Well, since you put a specific --

Ted Parson:
Yeah.

John Donvan:
-- out there, I want to let Anjali respond to that, if you would like to.

Anjali Viswamohanan:
I agree with what David said, that the precipitation levels has, sort of, gone up with global warming and the, sort of, idea that he's talking about is to, sort of, bring it back to what it was --

John Donvan:
I just want to --

Anjali Viswamohanan:
-- maybe [unintelligible].

John Donvan:
-- encourage the debaters to play to the audience [unintelligible].

Anjali Viswamohanan:
Yeah. So, maybe, as in what David's plan with -- and the general plan that solar geoengineering is, generally, to bring back precipitation to what it was at earlier levels. But I think that your point to really think about here is that a lot of countries have, sort of, adopted the climate change over the years. It's not something that started today or yesterday. So, a lot of, say, crop grow -- and a lot of the agricultural seasons in different countries have, also -- climate change. And the sudden change back to what it was may not, necessarily, be in everybody's best interest.

David Keith:
I need to come in and say that is, absolutely, not my plan. I think that would be nutty. I've never advocated that. I, actually, don't know anybody who is.

Anjali Viswamohanan:
Okay.

David Keith:
What people who seem to be advocating for doing something -- first of all, what we're advocating for is understanding --

John Donvan:
That's -- that's --

David Keith:
-- and what the risks are. And, for precipitation, if I was going to advocate anything, I'd advocate that we regulate it, so it doesn’t keep increasing.

Clive Hamilton:
That's David's plan.

David Keith:
Yeah.

Clive Hamilton:
That's David's plan for solar geoengineering. It's a plan that's evolved over quite a few years. I've been debating David on this question for -- I don't know how long -- eight, seven or eight years. And David, I think, has adjusted the plan to try to deal with as many of the objections have been raised to it, including the ones that Anjali has mentioned.

Now, if the world decides to go with David's plan -- rather than somebody else's more radical plan, perhaps -- then, maybe, that's a good thing.

But what I've noticed with David's plan is that he's been adjusting it, over years, in a way that tries to head-off the principle objections that people in [unintelligible] have been making, in order to make it more palatable to the general public. So --

John Donvan:
Well, let me -- let me --

Clive Hamilton:
-- this is a politicized --

John Donvan:
But what you're doing, there, is you're questioning his motives, as opposed to his science?

Clive Hamilton:
Well, no. I'm saying this is a -- no.

John Donvan:
Okay. Because --

Clive Hamilton:
Well, no, I'm saying the science can't be separated from the way in which --

John Donvan:
Okay. I --

Clive Hamilton:
-- solar geoengineering is presented in a more palatable way --

John Donvan:
Okay.

Clive Hamilton:
-- to the general public.

John Donvan:
I just want to, as a presumption here, like, assume that all of our debaters are arguing in good faith. And if your plan has evolved, in response to criticism, or critiques, or questions, or challenges --

David Keith:
I don't think I --

John Donvan:
-- I'm not sure --

David Keith:
I don't think I have a plan; I, really, don't.

John Donvan:
Okay.

John Donvan:
[unintelligible]

David Keith:
May I comment on this?

John Donvan:
Yeah.

Ted Parson:
So, there, actually, is a lot of confusion between scientific results and things that people propose might be reasonable bases for action. And there's ways that you can get confused, by mixing up the two.

So, it would, probably, be extraordinarily damaging and destructive to let CO2 go to three or four times pre-Industrial levels and, then, hammer the earth with solar geoengineering to bring it back to pre-Industrial. I don't know anybody who's ever proposed that that would be a sensible idea.

What you can find in the literature is scientific studies, using climate models, where they assume that in order to hit the modelled climate really hard and get an informative result. But you don't want to misinterpret those results as saying, "That's how it would be used. And that's how the scientific authors advocate its being used." The broader point, here, is that --

John Donvan:
Is it similar to when -- in biology -- when they dose mice with enormous amounts of something?

David Keith:
That's a very nice analogy.

John Donvan:
Well, I'm not going to be on your side. I'm just trying to understand.

David Keith:
Yeah, yeah. Well, one sort, or the other. But it's something that illustrates the fact. Often, in scientific studies, if you have constraints on what you're able to do, you want to hit a system -- an artificial system or a small system -- really hard to observe how it responds.

But no one in their right mind would propose acting in that way in the real earth that we all have to live in.

The broader point, here, is that we're all arguing about hypotheticals. Because nobody knows what interventions might be feasible; fair, in their effects; desirable. We don't even know --

John Donvan:
Well --

David Keith:
-- that the main form of intervention would remain sulfur.

John Donvan:
Let's let Anjali jump in on this.

Anjali Viswamohanan:
I think it is very reasonable to assume that, once we're talking about research and modeling, that we would always try and see what would happen if we increase sulfate aerosols in the atmosphere, like, 10 times as what we initially planned.

Because we are all, initially, modelling. We are trying to see what the impacts of it would be on the earth. And it's all research. It's nothing that we -- we aren't deploying it. But we're trying to see what the impacts of different circumstances would be on the earth. Is -- am I not right in saying that?

David Keith:
I'm not criticizing these scientific studies. I'm agreeing that these are useful ways to get information.

Anjali Viswamohanan:
Yeah.

David Keith:
But I'm --

Anjali Viswamohanan:
And I agree with that.

David Keith:
-- what I'm criticizing is the misunderstanding that says, "Because we studied a huge hit like that in a model, that's what we're advocating doing."

Anjali Viswamohanan:
I don't -- I completely agree with that. But my point is that once that information is out there -- that in case we increase the amount of aerosols in the atmosphere -- that might reduce the warming photo. That might just instigate a bunch of players in the markets to, sort of, increase their emissions, and not for low government [unintelligible].

John Donvan:
Clive, there's, sort of, a -- both sides have raised something of a -- more of a philosophical issue. You have raised the concern about moral hazard, that if this tool exists –

Clive Hamilton:
Yeah.

John Donvan:
-- that the pressure to cut carbon emissions to zero will be lifted. Your opponents are making a different argument -- more on the philosophical realm -- which is, "Let's just find out." Their argument is: "Let's find some moral answers to the questions you're raising. Let's --" they claim there was a taboo on the topic. And they're fighting back against that. So, take on the -- and I want to take your question to them. But take on their point, that, let's just look into it and find out.

Clive Hamilton:
Well, yes. Thank you. Everyone says -- including our opponents tonight -- that they completely agree that cutting carbon emissions must come first, and that solar geoengineering should never be a substitute for it. We all completely agree on that. But I have to say that it can become a, kind of, incantation. Because we have to consider how -- in practice -- this kind of grand technology is going to play out, politically, in policy.

Incidentally, we are not attempting to close down the debate, at all. I mean, we're here tonight. We jumped at the chance to debate this in public.

What we're worried about is the way in which a research program, without proper governance, will be taken over by particular groups, that a constituency will emerge; so: who will carry out the research; what ethical guidelines they will follow; and, in particular, who will own the results?

Because there's already been a rash of people taking out patents on geoengineering technologies, privatizing, including aspects of solar geoengineering. So, we have to consider the political implications. Research is never pure. It always takes place in a social, and institutional, context.

John Donvan:
David, can you -- those sound like very, very legitimate concerns.

David Keith:
Absolutely, they're legitimate concerns, I think. I was, actually, one of the early people to raise them. And I think that we should not be patenting. And I think this needs to be pretty global.

That's why I'm really happy to see there's an Indian research program. There's a Chinese research program. There's research programs in Europe. In fact, the only one of those countries that does not have a formal research program is the U.S. --

John Donvan:
But once --

David Keith:
-- [unintelligible] a good thing.

John Donvan:
But once we hear the word, patents, I mean, you're getting -- going back to biomedicine and --

David Keith:
Oh, so, Peter [spelled phonetically] --

John Donvan:
-- controlling [inaudible].

David Keith:
-- I, actually, can't think of a single solar geoengineering patent that's remotely relevant. So, I think it's a good concern. And, at Carnegie Mellon, we, actually, ran a meeting, trying to figure out if it was legal to ban --

John Donvan:
What about --

David Keith:
-- patents, which you would like to do.

Clive Hamilton:
-- what about the stratoshield [spelled phonetically]?

David Keith:
But it's important to say that there's, essentially, none of it happened, in practice.

Clive Hamilton:
No convert, no mobile stratoshield?

David Keith:
Correct. That's one of them. It seems completely ridiculous [laughs] and implausible. And I don't think there's much there, but --

John Donvan:
Is there a 10-second explanation you can catch up us with, what you were talking --

Clive Hamilton:
Well, Nathan Myhrvold -- the former Chief Technology Officer at Microsoft -- set up a company called, something ventures -- I forget, exactly --

John Donvan:
Intellectual Ventures.

Clive Hamilton:
-- Intellectual Ventures, which has taken out a series of patents, including one over deVas [spelled phonetically], called the stratoshield, which is, essentially, a balloon tethered to the earth with a tube on it. And it would pump sulfite aerosols into the upper atmosphere [unintelligible].

John Donvan:
That, absolutely --

Clive Hamilton:
[unintelligible] patent over it. So, if that turned out to be the best way to do it, we'd have to go Nathan Myhrvold, and pay them, presumably, large amounts of money in order to buy the rights to save the earth.

John Donvan:
You're saying, David, his idea is not very feasible. But what if there were a feasible idea with a patent owner, and there would be the scenario that Clive is talking about?

David Keith:
[unintelligible] just override. And there's good precedent for that. So, in this workshop that we had at Carnegie Mellon, it's learning how to do that. There are places where states just assert control. So, I think the answer is -- there are many different states in this world. And if there was only a single patent on some piece of technology for solar geoengineering, other states would just override.

And, in practice, the technologies here are, actually, very, sort of, basic.

They're not particularly high technologies. And there's multiple roots. This isn't, like, biotech. So, it's, actually, pretty hard to see that a patent would make much sense. It's important [unintelligible] know, patents are cheap. Nathan's group files a lot of patents. And I don't think they think they're serious. I don't think that one's serious. I don't like it.

I oppose it. But I think, actually, of the things that are wrong with solar geoengineering -- and there's a lot -- this is pretty low on the list.

John Donvan:
I want to go to audience questions in just a moment. But, before we do, I have one question I want to bring to Anjali. Anjali, you, alone, on the panel, raised the issue of potential disparities of control between the -- a small group of powerful nations, who, historically, have put most of the carbon into the air, making decisions for -- in the north versus south. And your opponents expressed a, kind of, optimism that that's a pretty -- but that's a fixable problem -- not, merely, conceivably fixable -- but that, historically, the track record is pretty good, when something big has to be done, that nations can come together -- do it the right way. What is your response to that?

Anjali Viswamohanan:
I think there is, generally, a disconnect between advancement of science in the U.S., as opposed to, perhaps, the rest of the world. Because there is a, sort of, a techno-optimist approach that is in conflict with the values that a lot of the other counties, and regional communities, place as inherent in some technologies that is being developed.

In solar geoengineering, specifically, the [unintelligible] approach is particularly apparent in how some countries -- like the United Kingdom and Germany -- have withdrawn support for geoengineering research in their countries.

In light of these differences in opinions on how we want to duly proceed on the technology -- and without there being a global governance [unintelligible] every country is onboard on how we proceed on the next steps on climate change mitigation, or any step forward on climate change -- there has to be a global governance [inaudible].

John Donvan:
And you think that's unlikely to happen?

Anjali Viswamohanan:
Yeah, I think that's unlikely.

John Donvan:
Let's take it back to Ted. You were more optimistic about that.

Ted Parson:
I am. So, let me stipulate, again, we're all arguing about hypotheticals: what would a world be like in which there had been some decision made to develop, and use, these technologies; and who would be controlling it; what would be the impacts? You're absolutely right that the issue of sectional control by a powerful group is a serious concern.

Clive, I think you're right that the concern about the debate being distorted by people who have, kind of, material interest in intellectual property is a significant concern. And we can see other issues where both of those have been of concern. But we can, also, see issues where there have been effective, adequate, relatively equitable regimes enacted, internationally, to address global problems.

And, moreover, there's a couple of reasons to think that geoengineering is likely to not be a particularly pernicious problem in terms of effective and equitable governance -- relative to all the ones that we face. First of all, there's this worry that the fossil interests will take it -- sort of, capture the debate, and, basically, advocate too much and use that as a justification for continuing to pollute and not cutting emissions.

John Donvan:
You're talking -- coal and petroleum gases?

Ted Parson:
Yeah, yes, yeah, petroleum and gas. We're talking about climate denial organizations will just move from saying, "Climate change is nonsense; it's not real," to saying, "Oh, now we've decided it's real. But here's the solution: we still don't need to cut emissions." That, absolutely, merits concern and attention. But the oddity is that all the evidence that exists goes the other way.

The other concern -- that it would be captured by Nathan Myhrvold, or someone else who holds the crucial patent -- here's one place where the oddity of climate engineering -- that it's so cheap -- I talked about how its being cheap was a problem because it, sort of, it makes the possibility of unregulated or competitive use by multiple actors.

Its being cheap also means that there's no fortunes to be made in it. And so, the configuration of interests of people, kind of, monopolizing it and, then, hijacking the debate -- you might say, the analogy to a military/industrial context -- it isn't really that persuasive.

If this is ever used -- which is not what we're advocating, or arguing, tonight -- my guess is it will look like a dreary public works project.

John Donvan:
Let me --

Ted Parsons:
So --

John Donvan:
Let me -- I still want to go to audience questions. I'm going to cut into a little bit of that time to let Clive respond to [inaudible].

Clive Hamilton:
A dreary public works project? Transforming the atmosphere of planet Earth? I don't think so. And when you think -- as I suggested -- that this would -- is a strategic issue; it has military implications; the military are all, already, watching this very carefully -- I think it's a profound issue of geopolitics.

And when we look at the fact that the coal and oil industries are taking a -- look, I should say -- most of the people who've been at the forefront of the researching, including -- and advocacy -- including David and Ted -- come to it with the best of motives.

They, like us, are deeply concerned about climate change and the failure of the earth to act. Our concern is that once it gets out of the hands of people who are well-motivated and do insist that there should be -- that emission cuts, actually, would come first -- we're in very murky and difficult territory.

I mean, think about it from the point of view of the coal and oil industries. If you have solar geoengineering, there's no need to tax carbon emissions; there's no need to worry about gas-guzzlers; or, deforestation. We'll just ramp up the fleet of [unintelligible]. Sounds crude and irrational? Boy, in Washington today, don't crude and irrational arguments work? I mean, look at the NRA.

So, you know --

[applause]

Clive Hamilton:
-- my worst -- let me tell you about my worst nightmare. It's a very short one. And that is that Rupert Murdoch watches this debate, and says, "This sounds like a great idea." And he sends a tweet out. And his -- I think it's 321 -- editors around the world say, "Rupert has spoken. We now support geoengineering."

And every Murdoch newspaper in the world doesn't take account of the subtleties and environmental emphasis that David and Ted do. They say, "Screw cutting emissions. We're going to put up a solar shield." Then, we're really in trouble.

John Donvan:
Let's go to audience questions, please.

Female Speaker:
Hi. I'm Bonnie [spelled phonetically]. If it is so cheap, is there a risk that all the geopolitical agreements will be put aside by someone -- like, Elon Musk -- just doing it?

John Donvan:
Ted Parson?

Ted Parson:
No, no. Because any megalomaniac individual entrepreneur is a citizen of some country and their enterprises operate under the legal jurisdiction of some country, or countries; and that --however much it is the modern fashion to, kind of, ignore the state, and to disrespect the state, and collective action -- in fact, states have the authority.

And so, if it's ever done, it will, very likely -- in fact, almost certainly -- be under the authority of states. We might mistrust the competency and integrity of state decision-making. And I don't want to be any slouch in believing in political folly [laughs]. But I think we don't need to worry about -- we don't need to worry about Dr. Evil, or Elon Musk, or Bill Gates, doing it on their own.

John Donvan:
Anjali, would you like to take that?

Anjali Viswamohanan:
I think it is unfair to not point out that there have been instances of individuals attempting to test these technologies on their own, in terms of some ocean acidification that has been done off the coast of Canada. And that has been only discovered much later. And it has caused a lot of impact on the sea life in that area.

John Donvan:
This was where a bunch of iron was dumped --

Anjali Viswamohanan:
Yeah.

John Donvan:
-- into the water in order to spur algae growth to get the algae --

Anjali Viswamohanan:
Yeah.

John Donvan:
-- to --

Anjali Viswamohanan:
Yeah.

John Donvan:
Okay. So, I don't think most people know that -- that, actually, some guy did that.

Anjali Viswamohanan:
Yeah.

John Donvan:
-- as a test. And then --

Ted Parson:
Some guy did it. And, then, the government of Canada, forcefully --

David Keith:
I think it's --

Ted Parson:
-- asserted its authority

David Keith:
-- yeah. And they did so little. It, actually, had no impact. It was a completely terrible stunt. But the point is: the state ruled.

Ted Parson:
As it would.

David Keith:
Yeah.

Clive Hamilton:
Well, I'll just come back to Musk and Gates, and so on. I mean, Bill Gates has put a few million dollars into supporting research into geoengineering.

And I think -- and there's -- and there's Nathan Myhrvold, too, who's very interested in it. And what it tells you is that there's -- it's the American technotics [spelled phonetically]. Silicon Valley love these kinds of grand schemes: "We'll just take control of the earth." You know, it's a technological solution that prove, once again, the ingenuity of humankind, you know, intervention over nature.

And for people like us, we find this extremely worrying. You know, we don't trust -- in this context -- where you've got the extraordinary complexity of the earth system, as a whole -- which is still poorly understood -- [unintelligible] with by some human technological program, which we really don't understand.

John Donvan:
Thank you for the question. It was perfect in getting the debate to go to a new place. I really appreciate it. Right there.

Female Speaker:
I might have missed this in the debate. But I'm wondering if you can speak to -- in case I didn't miss it -- what happens to the sulfuric acid after it's been -- daily, hourly -- pumped into the stratosphere? I'm reading through the list of health effects of sulfuric acid, right now. And it doesn't sound great. And, then, my other question is -- as we are talking about reducing emissions to zero -- where are the solar-powered trucks that are going to deliver the sulfuric acid? Where are the solar-powered planes that are going to be delivering it into the atmosphere?

John Donvan:
Okay.

Female Speaker:
Isn't it, somewhat, ironic, at least, to use fossil fuels to put sulfuric acid into the stratosphere?

John Donvan:
David Keith?

David Keith:
Yeah. So, sulfuric acid is dangerous. And sulfate aerosols kill people. The numbers matter. So, right now, in the lower atmosphere, I put about 50 million tons a year of sulfates, and [unintelligible] -- shorten the lives of people in very polluted cities by years.

At the peak, if you were doing solar geoengineering the way I’ve been talking, you’d be putting about one or two million tons into the stratosphere where it would come down evenly.

And we’ve actually worked with people who are leading health experts who have looked at this. And it turns out that the sulfates already in the atmosphere cool the planet a bit today. Sulfates in the stratosphere will cool the planet with a thousand times smaller health impact. So, they do have a health impact but it’s about a thousand times smaller than the aerosols in the lower atmosphere.

And I think the point is we need a low-carbon energy system where we need to figure out how to have planes without energy, I think -- without tech carbon.

John Donvan:
I wanted to ask something -- Anjali, you covered a lot -- a lot of material in your opening, but I think I heard you say that putting this stuff into the atmosphere could compromise the effectiveness of solar-powered devices, you know, be gathering on the ground. Did I hear you correctly?

Anjali Viswamohanan:
Yes.

John Donvan:
In other words, if these solar energy needs the sun and you’re putting something to block the sun, you’re cutting off its power source. Did what -- I understand that was your argument?

Anjali Viswamohanan:
Yes. And so basically to have a coherent strategy on climate change -- and we are all working towards building renewable energy sources into our whole energy generation system, and then we come up with this solution which is only going to reduce the feasibility of this one scenario where we’re using solar energy to power our systems. And that is what --

John Donvan:
So, yeah, it’s something -- kind of a catch 22. I’m wondering how your opponents would respond to that.

David Keith:
Numbers matter. So, the things we’re talking about would reduce sunlight by an order of one percent. But it turns out that solar panels work less well when they’re hot.

So, it doesn’t actually reduce the solar output by one percent; it’s less than one percent because the panels become more efficient when they’re cooler.

And what this effectively does is it raises the cost of solar panels by something under one percent. In the last four years or so, the cost of solar panels fell by a factor of three. So, while there are a lot of things wrong with solar geoengineering, I think that kind of less-than-one-percent change over a century in the cost of solar panels is not credibly one of them.

Anjali Viswamohanan:
I think it’s really important to bring this aspect back that this is an imaginary technology as of now. And once it’s implemented it could -- it could take the fancy of any number of nations that it is impacting the climate for the better, and they may want to increase the amount of solar -- of sulfur aerosols in the atmosphere and this could have a worse impact than what is initially contemplated.

So, again, it is a matter of control and how much and who’s doing what.

John Donvan:
Another question, right on the aisle, please. If you could stand up, please.

Male Speaker:
M name is Ahmad [spelled phonetically].

My question for the team for the motion is: Why not we start now, as David said. David said we should not start now. Why?

John Donvan:
Oh, okay. That’s a great question -- David, yeah.

David Keith:
I think that’s easy. At this point, there’s a pretty small group of people who are working on this. They’re mostly Western; mostly Western white males. They’re actually global. There are people in China and India, as I said, and in South America.

But it’s a small group. And there’s the danger of “group think.” So, the simple answer is we might be wrong. So, we -- these climate models all say this could reduce risk a lot; maybe there’s some big thing we’re missing.

I spend a lot of my time wondering if there’s some systematic way that climate models make this look too good.

So, at least for me, I would not consider implementation until a much larger group has looked at it; until we had groups of people whose specific job was to think technically about all the ways it could go wrong; looking very, very carefully at what we suggested.

John Donvan:
I want to see if that reassures your opponents, that point of view.

Clive Hamilton:
Well, I mean, I’d just tag off the point again of governance before research because research doesn’t take place in a vacuum. And we think the vacuum should be -- explicitly be filled, because we want to know who should carry us out. Should it be David with his plan?

Forgive me, David, if this has changed in recent times, which is to carry out an experiment on -- in -- using a balloon in Arizona to inject sulfate aerosols into the lower atmosphere because we don’t have the technology yet to put balloons in the upper atmosphere.

Who sets the ethical constraints? Who will own the results? Knowledge gives power to those who earn it. And as I said already, people are trying to cash in on this idea of geoengineering by taking up patents -- both solar radiation management and a whole range of carbon dioxide removal technology.

I should actually point out, we on this side aren’t opposed to carbon dioxide-removing technologies as a way of removing CO2 from the atmosphere after we’ve reached net zero, because we will have to take it out of the atmosphere.

So, we worried that a research program will create constituencies; it will give momentum that the idea of deploying it is enhanced by a group and a constituency that backs the research. So, that’s our anxiety.

John Donvan:
Yeah. Ted Parson.

Ted Parson:
So, when you have a -- when you have a controversial set of technologies, it’s always attractive to say, well, we need to go slowly, and we need to develop governance in advance of research. But that’s almost never how the development of governance for anything works. And the reason is that you don’t know what governance you need until you need something about -- until you know something about the thing being governed.

[applause]

So, a crucial question that’s come up several times and, really, on which nobody knows the answer is, if such a technology was ever deployed, would its effect be a roughly global distribution of benefits kind of moving every part of the world back toward a less perturbed climate? Or would it have a real strong possibility for, as Anjali said, winners and losers?

The early results suggest much closer to the former. It’s actually very hard to torque this in a way that would be geopolitically destabilizing or militarily attractive because it’s really hard to do something here and control it different from something here.

But this is early days. You don’t know.

Now, should that research proceed, and should that research proceed even before we’ve developed a system to effectively govern, you know, use and deployment? I think it has to.

John Donvan:
Another question?

Male Speaker:
Thank you very much, my name’s Yuan [spelled phonetically].

So, my question is, what do you see as the urgentness of this issue?

Because I think whether we should call it crazy depends on what actually we see it. Do we see that as our last resort to, like, save the humankind, or do we see it as just one of the 20 options that we can have which we have the time to really study one by one?

John Donvan:
Yeah, that’s a great question. Can I -- can I rephrase it and make sure you agree with this and put it to David Keith?

Are we in trouble if we don’t do this? Are we in more trouble if we don’t do this than if we do, do this?

David Keith:
To me?

John Donvan:
To you, David Keith.

David Keith:
I don’t --

John Donvan:
Are you good with my rephrasing of that question?

[talking simultaneously]

Male Speaker:
I think I speak for everyone here: We are receiving information on both sides. On one hand, I think the debaters have emphasized that actually we have to do something now and hopefully quick because there is an urgency there.

But then, I also heard the debaters say we don’t want to be called crazy because we just need some space to actually carry on -- to carry out very detailed and specific researches, which implies we actually don’t want to start actually doing something in the very, very near future.

John Donvan:
So, I think the question is about the urgency of this -- figuring out that this is the right solution or not.

David Keith:
It certainly isn’t the right solution and it’s not a solution.

But the question is, is it useful to reduce risks this century? And I think there’s a lot of evidence that it could be very useful, enough evidence that it makes sense to understand it much better, including think about how it would be governed.

But I think your answer -- you had a great question about whether there were 20 different things. I think there really are kind of about four or five big buckets.

The most important is cutting emissions. There’s this thing carbon removal you’ve been hearing about. There’s adaptation, reducing local risks. And there’s solar geoengineering. There are not a whole bunch more, I would say.

John Donvan:
Anjali would you like to try to?

Anjali Viswamohanan:
I think the way to really think about this is that the political way to addressing climate change has never been stronger, and perhaps we as the world got started on this very late, but I feel that we finally have seen some place to start work on fixing this problem that we have.

And by talking about any other technology that would distract our efforts at the moment would just -- would just fizzle our efforts towards working on mitigation and adaptation and all the technologies that we know will work.

And the -- and the thing that I want to highlight here is that the technologies that we are advocating, we know it will work. And all of -- and all of -- all of the risks associated with solar geoengineering keeps it from being a technology that we know will work.

John Donvan:
Clive, do you want to add to that?

Clive Hamilton:
Well, I just wanted to add this: that we interpret the question -- solar – deploying solar geoengineering is a crazy idea. And one of the reasons is I think the pure objection to it which hasn’t been mentioned yet is that it’s been estimated that if we did send the planes out, it would take at least 10 years of gathering data before we even – knew whether it worked, before we could sperate out the effects of sulfate aerosols spraying from natural climate variability and the effects of global warming itself. And so, think about that.

Let’s say 10 or so years, the world’s climate is changing, but we don’t know whether it’s due to the sulfate aerosol spraying.

So, if a monsoon fell in Pakistan or a -- or there was a long drought in the Sahel, would those people start blaming the scientists at the climate regulation authority in Arizona or Tashkent or wherever it might be? You bet they would.

Of course, they’d look to the scientists, and the scientists would only say, well, we don’t really know whether that drought or that monsoon is due to what we’re doing.

John Donvan:
Let me take that to David or Ted. Are we talking about actually needing something like a decade-long experiment to figure out if it’s working or not? Ten years is reasonable?

David Keith:
There’s no simple answer.

I want to push back on the idea that we know that emissions cuts will work.

We know emissions cuts will work to cut emissions. But that doesn’t deal with the climate risk of the CO2 that’s in the atmosphere.

Clive Hamilton:
I’ll ask, David, you’ll give a complicated answer if there’s no simple answer to the question of 10 years, because I think it’s a crucial question.

David Keith:
So, I think -- I don’t think it’s a crucial question, I guess.

So, the obvious question is, why don’t we know now what the climate impact of CO2 is? And we don’t because there’s all this internal variability in the system. And precisely because solar geoengineering is in fact -- although it seems like a huge thing to Clive -- and it is in some ways emotionally -- it’s a small change to the earth’s system.

So, what we’re talking about is instead of having your system pushed by, you know, five units, we’d be pushing it by three units, and that’s spread out over a century. So, in fact the answer is, it takes a long time to see that effect. You can see the bad effects of sulfates in the stratosphere quickly; you can see those in a small experiment quickly.

But to see the long-term climate effects is inherently slow, just as it’s inherently slow to see the long-term [inaudible].

John Donvan:
So, Clive’s point that it could be 10 years is not -- is -- that’s not [inaudible].

David Keith:
I’m not sure what the “it” is.

John Donvan:
To see -- well, I understood it to mean if you put planes in the sky to see what the impact would be of doing this kind of aerosol injection, it would take 10 years to find out if it was having the kind of impact you want it to have.

Clive Hamilton:
I mean, you -- it’s an engineering question. In engineering, you make a change to a system. You collect data on what’s happened. You adjust your change. And you get a -- you optimize it. But if you have to wait 10 years before you have enough data before you know whether it’s working.
And the thing is, the difference with CO2 emissions is no one’s putting CO2 emissions into the atmosphere in order to change the climate. It’s a tragic side effect.

If you’re putting SO2 into the upper atmosphere, you are deliberately trying to regulate or have an impact on the climate. And that changes the dynamics, the politics, the blame. The whole ethical question of blame is a very profound one that I’m suggesting would create all kinds of geopolitical problems.

John Donvan:
So, I just want to come back to -- would either of you like to respond to where we are? I think that question of 10 years is still [inaudible].

Ted Parson:
Yeah, there’s still two things that -- on the 10-year question, I think you can’t have it both ways. The fact that it takes -- would, we think now -- take a long time to observe the climate effects of an intervention, is a manifestation of the intervention being small and incremental.

You could see effects faster if you hammered with a huge intervention. But that would be a dangerous thing to do. It would be a dangerous thing to do whether it was for the purpose of pushing the climate that far or for the purpose of understanding the effect.

So, hard signal to noise is actually a manifestation of prudent, incremental interventions within the limits of what we now know.

Can I also comment on intentionality versus inadvertent?

John Donvan:
Yes, yes, yeah.

Clive Hamilton:
No, you may not.

Ted Parson:
[laughs] It’s an -- it’s an important distinction philosophically, but I’m not convinced that it’s an important, top-level issue in practical terms.

I mean, we already are making an enormous and clearly destructive perturbation to the atmosphere. And the fact that is the inadvertent side effect of things that people have done for 150 years for good reasons of advancing prosperity and getting energy and so on, doesn’t let us off the hook. The blameworthiness is present and large.

And the differences with an intervention being intentional, I think, lie in the domain of practical political calculations.

Those that are raised by Clive’s arguments earlier, you really do want to worry very much about who’s in charge. And that depends on how unequal the effects will be. But you do want to worry very much. And so, you need governance [inaudible].

John Donvan:
Clive, I can give you 25 seconds.

Clive Hamilton:
[unintelligible] yeah, think about it from the point of view of the peasant farmer in Pakistan and the rains have failed, there’s -- people are starting to go hungry. You know that someone somewhere in the world is messing with the climate system.

It’s not -- it’s not an act of God. And a political stirrer comes along and tells you America, the great Satan, is messing with your climate. You’ve got a massive political problem.

John Donvan:
And that concludes round two of this Intelligence Squared U.S. --

[laughter]

John Donvan:
-- where our resolution is “Engineering Solar Radiation Is a Crazy Idea.”

[applause]

John Donvan:
Now we move onto round three. Round three are closing statements by each debater in turn. These will be two minutes each.

Making her closing statement in support of the motion that “Engineering Solar Radiation Is a Crazy Idea,” please welcome again Oxford scholar Anjali Viswamohanan.

[applause]

Anjali Viswamohanan:
To wind up discussions today, let us go back to the proposition, which is that solar geoengineering is a crazy idea.

It is important to recognize that, at this point, solar geoengineering is filled with uncertainty.

Former U.N. Secretary General Ban Ki-moon once said, “Engineering solar radiation could risk exacerbating wider threats to international peace and security.”

Without complete global scientific and political cooperation, there are high chances of misuse of solar geoengineering, the impact of which will burden predominantly on the global south than it will in the rest of the world.

The first attempt at establishing a global governance regime was initiated at the U.N. environment assembly held in Nairobi last month.

The resolution on geoengineering failed for some reasons, which included the forum of where it was raised, but, more interestingly, regarding the continuation of research using a precautionary approach.

The precautionary approach is a notion that an action must first and foremost avoid doing any harm. And the proponents of an action must demonstrate this avoidance before any action can be taken.

And, for me, here is where the road forks tonight.

Today, each component that determines the fate of this planet and its people are precariously poised. Upsetting one piece will have disastrous consequences -- maybe more for one segment of the population more than the other, but disastrous, nonetheless.

In these times of uncertainties, where global leaders can’t agree to proceed with precaution on a technology that we already know will have negative consequences, that’s where I say that any efforts to propagate this technology is crazy. Thank you.

[applause]

John Donvan:
Thank you, Anjali Viswamohanan. And that is the resolution “Engineering Solar Radiation Is a Crazy Idea.”

And here to make his opening statement against -- I mean, here to make his closing statement against this resolution, from UCLA, Ted Parson.

[applause]

Ted Parson:
Time is everything in dealing with climate change because it moves so slowly relative to human perceptions and plans.

Climate change is a train wreck happening in slow motion. Visualize that. Be cinematic.

If we were having this debate in 1990, I’d be on the other side. We knew enough by then to warrant strong action to cut emissions. And if wed started then ,we would have had time to stop the train.

We could have managed a transition to a post-fossil climate-safe world economy, and confidently held climate change and its impacts to within manageable limits.

But it’s 2019. And the 30 years of delay has let that opportunity slip out of reach. It is still possible to hold climate change to manageable limits. But it’s no longer possible to do this confidently relying only on technologies and policies that are familiar, comfortable, uncontroversial.

Our opponents have highlighted the fact that climate engineering is a technical fix, and they’ve highlighted the importance of political folly and short-sightedness. The category of technology is too broad to form a meaningful opinion.

Everything we do as a human society has technology and it has behavior, and every environmental problem that has been adequately managed so far has been managed to a substantia degree by the deployment of changed and new technology.

Why is the air in my home city of Los Angeles so clean now, when in the 1970s it was so dirty? Technological changes driven by rational public policy.

As for political folly, it’s like I don’t want to yield anything to our opponents in my recognition of political folly, but you have to make the case that it -- political decision-making would be either more vicious or its consequences more severe in a word that has knowledge about climate-engineering or geoengineering than in one that doesn’t.

And I don’t think that’s an easy case to make, and I don’t think they’ve made it.

[applause]

Ted Parson:
We’re in a really troubled situation. We need -- we need to consider research and study every plausible approach to emissions-cutting -- even though we’re late; to adaptation; to carbon removal; and also, to geoengineering.

Geoengineering needs scientific research to inform its capabilities and risks, and it needs serious critical investigation of how to govern it competently, prudently, legitimately, and fairly, and how to integrate it into a coherent, effective climate-change response. To call it crazy is to block this needed investigation, and to court severe and unnecessary risks. I ask you to vote “no.”

[applause]

John Donvan:
Thank you, Ted Parson.

The resolution, again, “Engineering Solar Radiation Is a Crazy Idea,” and here making his closing statement in support of the resolution: Clive Hamilton, author of “Earthmasters: The Dawn of the Age of Climate Engineering.”

Clive Hamilton.

Clive Hamilton:
I think this debate really comes down to how you understand how power and the way that societies work.

Technologies aren’t neutral. With solar geoengineering, it’s highly likely that the climactic preferences of rich, white people will prevail. Incidentally, the same people who are likely responsible for bringing on the climate crisis.

Take this story which I tore out of “USA Today” just today. The headline is, “Facial ID Tools Show Bias.”

And the story is, “A growing body of research shows that artificial technology capabilities are rife with biases and discrimination.”

It shows, for example, lending tools charge higher interest rates to Hispanics. Job-hunting tools favor men. Negative emotions are more likely to be assigned to black men’s faces. And the people who did this study at New York University identified the key reason why: The people building these technologies are overwhelmingly white and male.

Those who control powerful technologies use it to accumulate more power. That’s how the world works, even if we’d love that it were otherwise.

And so, we would endorse the powerful words of one of the United States’ most eminent climate scientists, Ray Pierrehumbert, formerly of the University of Chicago, and now at the University of Oxford. For him, “crazy” is too mild a word. “Solar geoengineering,” he said, “is wildly, utterly, howlingly barking mad.”

Vote yes.

[applause]

John Donvan:
Thank you, Clive Hamilton.

[applause]

John Donvan:
And the resolution is, “Engineering Solar Radiation Is a Crazy Idea,” and here making his closing statement against the resolution: David Keith, professor at Harvard and founder of carbon engineering.

David Keith.

[applause]

David Keith:
Some of you may think that this technology should never be used under any circumstances.
Some may think we should have a serious research effort. Some of you might think we should do it relatively soon in order to keep temperatures under 1.5 degrees.

None of us is making the decision. This decision will get made decades from now by the next generation. It will be considered. Some government -- maybe China after a monsoon causes the crops to fail, because geoengineering actually can help with that; maybe Indonesia after a heat wave kills 100,000 people; maybe the United States, after a category 5 hurricane hits this place, this city, head-on. It will be considered.

Suppose our opponents keep winning. Suppose solar geoengineering stays in its crazy corner. We can’t bind our children’s hands. The decisions about deployment will still be made, but they will be made without adequate understanding of what the risks are, without exploration of technologies that could substantially reduce those risks, without knowledge about how to monitor it adequately, and without enough time for nations to discuss how they might govern this technology.

Our choice tonight is not about deployment. It’s about doing as Ban Ki-moon advocated, not as that little quote said, which was to take this seriously and study it and have open debate.

A vote for the resolution is a vote that says you are confident that this should never be used. That’s what crazy means.

But I don’t know where that confidence could come from. I think that is overconfidence -- overconfidence to the point of hubris. I urge you to vote “no.”

[applause]

John Donvan:
Thank you, David Keith.

And that concludes round three of this Intelligence Squared U.S. debate where the resolution is “Engineering Solar Radiation Is a Crazy Idea.”

I just want to say something about your closing statements.

When we -- when we ask debaters to come onto the program, particularly debaters who do not know the program, they ask how it unfolds and what you should -- you know, what works, and what are the closing statements like.

And there have been a couple of debates over the years that I refer new debaters to. I say, why don’t you watch this debate, they have really great closing statements.

Tonight’s debate became the one I’m going to start using, because all four closing statements were -- just knocked it out of the ballpark. It’s very, very hard in two minutes to make your point, and you all did it really, really greatly.

[applause]

John Donvan:
And another thing I want to say, it’s clear that there was passion and, you know, deeply held feelings among four people who are all similarly concerned about the climate. There was almost a sort of Rocky and Apollo Creed relationship here --

[laughter]

John Donvan:
-- where you’ve been fighting each other so you kind of learn to respect each other. And I felt that respect on the stage. I think it typifies the thing that we want to do in Intelligence Squared, which is to have a good, tough conversation but be able to shake hands afterwards. So, I congratulate all four of you for what you did today.

[applause]

John Donvan:
And Ted Parson, maybe it’s the fact that you’re Canadian, but I loved your use of the English language, and I’m going to come -- I loved your description of all of this work is to create a, quote, “less perturbed” climate.

Ted Parson:
[laughs]

John Donvan:
I’m going to start using that from now on.

While we’re waiting for the vote, I just have a question -- something that’s relatively out of the news to the topic we’re on tonight, just to get your take on it. This is not part of the competition.

But geoengineering came up at a U.N. environment -- United Nations assembly discussing the environment. And when the topic came up about whether to continue a conversation on the issue of researching and regulation and oversight of -- you know, really to put geoengineering on the table, the two strongest leading votes against doing that -- kind of the votes for “crazy,” I guess, were the United States and Saudi Arabia.

And, I’m -- you know, Saudi Arabia, that -- they’re big-fossil. So, I’m -- your point would be big-fossil would want to keep this going.

So, I’d like to get the take from all four of you: What do you think is going on there politically?

David Keith:
I’ve been trying to get the inside scoop on this ever since it happened, and I’ve heard a few contradictory stories.

So, we’re not doing the debate anymore --

John Donvan:
No, no.

David Keith:
-- but if we were still doing the debate, I’d say, C. It’s the three countries that are most vigorously opposed to aggressive emission cuts that are trying to shut down debate on geoengineering.

Someone who was there suggested to me that the United States’ story was simpler than that. That it -- it’s just the United States hates the U.N. environment program and doesn’t ever want it to do anything because it’s U.N. environment.

And I don’t know if you all know: the U.N. environment program has an explicit mandate of, kind of, more equal representation and participation from the global south relative to other international organizations, so.

John Donvan:
Yeah, Clive.

Clive Hamilton:
Well, I been to quite a number of these massive U.N. climate conferences, and, you know, the reasons that certain nations take certain positions can be Byzantine.

And you really have to -- you know, there’s no obvious answer to the question. You really have to go into it; people will give you different kinds of answers. It could’ve been -- I wasn’t there; I’m just purely speculating -- but they -- what you said is quite plausible; hate U.N., we don’t want to give them power to do anything.

And, I don’t think this is true, but one argument might have been, well, you know, when it comes to it, we’re not going to give this kind of pissy U.N. organization having any say.

And we’re the united states; when it comes to it -- if it comes to it -- we’re going to want to --

John Donvan:
“We’ll take charge.”

Clive Hamilton:
-- have a say in it.

John Donvan:
Anjali, your expression seems to think -- says, yes, you think there’s more to it than that.

Anjali Viswamohanan:
So, that’s what I was talking about in my closing remarks.

So, the only thing I know about what happened at the UNE from different perspectives that people have written on from it. And I think the two points of contention was whether the forum was the right forum to bring up geoengineering at; and the second one was about the precautionary principle.

So, the U.K. and a lot of the European countries were unwilling to pass the resolution unless the term “precautionary approach” was included in the resolution, which the U.S. and Saudi Arabia did not back. And that was one of the reasons that the U.K. and the E.U. also pulled back their support from passing the resolution.

John Donvan:
Finally, David [inaudible].

David Keith:
Yeah, I agree with that story precisely. And part of it evolved -- is the preamble language of it evolved, and so those things came into the countries that originally pushed it, and the countries that opposed it changed.

I think the other part is a straight jurisdictional fight, that some set of countries think this should be resolved in the U.N. Framework Convention on Climate Change, not in UNE. They’re both kind of U.N. umbrella agencies, but they’re different agencies, and so there’s a battle about that.

John Donvan:
All right, interesting.

Thanks for sharing all of that.

All right. I have the final results now. Again, we give victory to the team whose numbers have changed the most between the first and the second vote.

The resolution is this: “Engineering Solar Radiation Is a Crazy Idea.”

On the first vote, 24 percent of you agreed with the resolution. That means they think that solar engineering is a crazy idea. Thirty-seven percent voted against the resolution. That’s the side that David and Ted were arguing here tonight. Thirty-nine percent were undecided.

Again, it’s the difference between that vote and the one I’m about to announce that determines our winner.

In the second vote, the team arguing for the resolution -- their first vote was 24 percent; their second vote was 19 percent. They lost five percentage points.

The team voting against the resolution, David and Ted, their first vote was thirty-seven percent; their second vote was 75 percent. They pulled up 38 percentage points.

[applause]

That makes them the winner. The team arguing against the resolution that engineering social radiation is a crazy idea, our winner, our congratulations to them, but our congratulations to all four of these debaters. Thank you very much from me, John Donvan, and intelligence Squared U.S.

We’ll see you next time.
[applause]
This is a rough transcript. Please excuse any errors.