[Scott] Next on "Energy Switch," we'll explore the controversial subject of geoengineering.

- The technology exists, if you will.

It is, relatively speaking, so cheap and it has almost immediate effects.

But if you were to stop overnight, temperatures would increase dramatically.

And that alone might cause dramatic problems.

- This is an enormous amount of power on the global stage.

You're handing over control of the basic climate system.

You know, how warm it is, where it rains, all these kinds of things.

And I think that that will have major geopolitical consequences ultimately for the future of humanity.

[Scott] Coming up... Should we even begin to research a technology that could control our climate?

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[upbeat music] - I'm Scott Tinker, and I'm an energy scientist.

I work in the field, lead research, speak around the world, write articles, and make films about energy.

This show brings together leading experts on vital topics in energy and climate.

They may have different perspectives, but my goal is to learn, and illuminate, and bring diverging views together towards solutions.

Welcome to the "Energy Switch."

Geoengineering is the idea of engineering Earth to remove CO2 from the atmosphere or to reflect the sun's heat.

The ideas range from well understood, like planting forests, or capturing CO2 from the air, to highly controversial, such as injecting huge volumes of aerosols into the stratosphere to cool the temperature of the entire globe.

The technologies could be straightforward, but the politics and ethics are not.

We'll discuss with Gernot Wagner.

He's a climate economist at Columbia Business School and author of six books, including Climate Shock and most recently, Geoengineering: The Gamble.

Stephen Gardiner is a professor of philosophy and director of the program on ethics at Williams University, where he has written extensively on the ethics of geoengineering.

Coming up on "Energy Switch," get ready for a remarkable discussion on geoengineering.

So let's dive in.

What do we actually mean by geoengineering?

- We mean intentional technological interventions, typically a planetary scale.

- Okay.

- So they're aimed at combating climate change.

[Scott] So what are the benefits?

- Yeah, well, the hope is first to just reduce the magnitude of climate impacts.

And especially moving forward as warming is expected to increase or accelerate.

One of the other benefits is supposed to be that it would potentially buy time for decarbonization.

- Okay.

Anything to add on the benefit side?

- Benefit of solar geoengineering is that it would limit climate risk and do so relatively quickly.

- Piece of the puzzle.

- It is one piece of the puzzle.

- Okay.

What are the downsides?

Just high level.

- Well, it might actually increase risk.

It's not as if we have the technology readily to hand and it's been well tested and we have a lot of experience of it, of using it in the real world.

And solar geoengineering in particular seems to involve a real concentration of control over something basic that governs the basic facts of people's lives.

That's an enormous amount of power to put somewhere.

- That's a downside.

Okay.

Downside?

- China last year increased solar power production by 40 plus percent while we are here debating a climate technology that isn't.

- Okay.

Let's dive in.

Let's dive into some of these topics.

Carbon dioxide removal.

What does that mean?

I mean, what should I picture when I think of that technology?

- CDR is about taking CO2 out of the atmosphere and then ideally puts it all the way underground where it can no longer escape.

- Okay, so you're moving lots of volumes of air through big filters, if you will.

- Industrial fans, lots of energy which by the way is one of the problems.

So what you don't want to do is cause more pollution while pretending to be taking out CO2.

- Robbing from Peter to pay Paul - Yes.

- So anything to add to that?

- We tend to focus initially on the how we can get it out of the air.

And not spend so much time thinking about what are we going to do with it?

So some serious questions that come up are whether we're going to have enough storage space and whether that storage space is gonna be secure over the long term.

- Okay.

I think most of our viewers would probably have heard of de-sal or taking salts out of water.

And that works, but you end up with a bunch of salt.

So what do you do with it?

The volumes here are much larger of carbon dioxide.

Could we absorb enough through natural means like planting forests?

Why not just plant trees?

- Well, it helps and trees are good, but they are trade offs.

Trees keep the CO2 in the biosphere.

Trees die.

Trees decompose.

CO2 gets released almost immediately.

- You know, it used to be the case that there was more enthusiasm for planting more trees than there currently is.

And part of the reason for that is because of people have tried to calculate how much land it would need.

And how many people and their ways of life need to be displaced to make that happen.

And there are also concerns about, you know, which kinds of species are best.

And they might not be the same ones as the native species, you know, local ecosystems.

- So what we're describing here is you're saying plants are great, but they won't address the issue.

- Oceans might.

They are the biggest geological carbon sink.

So one CDR method is, let's speed up that process.

- Yeah.

- Let's figure out how to get the CO2 into oceans faster.

Addressing a couple other problems in the meantime, like ocean acidification.

Speeding up that process may be a different story.

- And the main way that people have talked about doing that is putting things like iron on the surface of the ocean to stimulate plankton growth, which will then suck carbon dioxide out of the air and then hopefully in the longer term, make it sink to the bottom where it will be stored.

- Interesting.

- At least that's the thought.

- Are you convinced?

You don't look too convinced?

- Well, I think there's always a question about what we count as natural and what we don't count as natural.

Because clearly we're doing something very artificial and intentional.

- Right.

- It would presumably have effects on ocean life and on other dynamics in the ocean.

- Enhanced weathering is another process we've heard about and talked about.

Thoughts on that.

- So that's on land.

Right?

So this is, you know, rocks, weather.

Buying CO2.

- Yeah.

- Speeding that up by, for example, crushing the rock.

- Okay.

- Distributing it over larger surfaces and doing in decades what would otherwise happen over centuries or millennia is yet another human intervention-- - Right.

- into the natural world in an attempt to take more CO2 out of thin air faster.

- Have any experiments or pilots or demos been run on things like this that we can think about?

How are they working?

- We know enough to know that yes, it is technically possible.

Early techno economic analyses seem to suggest that it would actually be relatively cheap.

- Yeah, that one sounds not too techy.

- It's, yeah, you know, you crush a bunch of rock, right?

And what could go wrong?

You need power to do this.

So once again, you need to decarbonize the power system first in order to ensure that this method in fact is-- - Right.

- net win for the planet.

- Yeah.

Good intentions and unintended consequences.

Let's talk about solar radiation management different from CDR.

What is it?

What are the types that are being proposed here?

- The fundamental principle is why winter jackets are black and summer dresses are white.

Mediterranean villages painted white.

Yeah, there is a historic reason for that.

It works.

[Scott] Sure.

- Solar radiation management is that principle-- - Right.

- at a planetary scale.

- Okay.

And how do you do it at a planetary scale?

- Well, the most popular proposals in the sense of being the most widely discussed are spraying sulfate particles or things like sulfate particles into the stratosphere to reflect a tiny fraction of the incoming sunlight back into space.

- Okay.

What's that?

How does that work and cost for something like that?

- So volcanoes have been doing it forever.

Mount Pinatubo erupts in the Philippines.

- Yep.

- '91.

1992, global average temperatures, half a degree centigrade, almost a degree Fahrenheit.

- Lower.

- Lower.

- Yeah.

- What happened?

20 million tons of gunk, you know, some SO2 thrown into the stratosphere where they stay for 12, 18 months or so.

And while they're up there, they are tiny reflective particles reflecting sunlight back, cooling the planet.

So SAI is newly designed, high flying planes, massive wing spans, 8, 12, 18 engines or whatever to get it up into the stratosphere, dump the stuff and come back down.

- Interesting.

- And that is 100-ish planes, twenty four seven, right?

So this is thousands, tens of thousands of flights.

But it could solar geoengineer the planet with noticeable global effects.

- Yeah.

What gunk are coming out of the airport?

What's the stuff?

- It's SO2.

- Okay.

- So sulphuric acid, in fact, is what it forms then.

If that doesn't sound scary, then I'm doing my job wrong here.

- Does it settle out then down through onto the earth's surface and the oceans?

- It does eventually.

A year and a half later, almost everything will have fallen out.

But it comes down again.

You need to keep doing it.

It has almost immediate effect.

And the technology exists, if you will.

[Scott] Right.

- I would hesitate to say that the technology exists right now to actually deploy and maintain over decades or centuries.

- Yeah.

- Sulfate injection is the main technology that people talk about.

But there has been some move in part of the literature to talk about not just other particles, but specially engineered nanoparticles.

And I think that's worth mentioning because it is then talking about inserting into the system these novel particles in a highly sensitive part of the system, mainly the stratospheres.

And I suppose the last thing I would add is that I think sometimes scientists decry the lack of knowledge and the lack of monitoring we're doing of volcanoes.

- Right.

- And what the effects really are.

Especially since we're contemplating not just injecting and then letting it fall away over a year and a half, but continuing for decades or centuries.

- Right.

Right.

- So there is a lot of empirical work to be done there.

- Yeah, I mean, I'm envisioning a billionaire or a autocrat or a mad scientist saying, "Oh, I'm just gonna go do this."

[chuckles] Could that happen?

Some ambitious startup.

Somebody just going out and doing something on their own.

- It is, relatively speaking, so cheap, right?

Single digit billions of dollars per year that, yeah, you can imagine quite a few governments, the odd billionaire, and emphasis on odd in this case, actually willing and/or possibly even able to say, "You know what?

Let's try."

- I don't think as it were that a random billionaire could do this, namely solar radiation management in this way.

Because that would involve managing the system for decades or centuries.

- Right.

- And I think that could only-- - A hundred billionaire.

- I think that can only be achieved with at least the implicit tolerance or toleration on the part of major powers.

- Or governments.

Big governments.

- Now, I do think-- - I agree.

- there are superpower questions here.

- Oh, sure.

- Right?

I mean, could a superpower do it?

That's a more serious question.

I mean, yes, the U.S.

is one candidate.

Europe might be a candidate.

China might be a strong candidate.

- Yeah.

- India and so on.

- Middle East.

Aerosols are short-lived though, so if we start doing this, let's just roll the tape and pretend like we do, can we just stop if it's not working?

- So the yes part is yes, you can.

The no part, if you were to stop overnight, temperatures would increase dramatically overnight or, you know, within weeks, months.

And that alone might cause dramatic problems, possibly worse problems than- - Right.

- the climate change in the first place.

- Interesting.

- I would also say there's a problem of sociopolitical barriers.

I mean, once you've started doing something like this on a major scale and it's having some kinds of impacts, there are people invested in it.

Literally and metaphorically invested.

- Yeah.

- But nonetheless, we shouldn't be naive about just because it's possible to turn a technology off - that means it's going to be-- - Yeah, it's not a sure shot.

- easy to do it.

- This seems of all the things we've discussed though, feasible, and I guess it begs the question, is this the most likely one to get started with in your opinions or not?

- Technologically feasible, possible.

Economically, feasible in the narrow economic sense of, right, the costs of developing the plane.

And the decade or so it would take.

Yes.

Now, okay.

Politically, ethically challenging?

Of course.

But there's a good reason we are talking about it.

- Right.

And that kind of comes to more to the, should we do it?

Should we get started?

You know, at least in the research and the pilot testing and the demos or not?

- One sort of normal scientific paradigm here would be, you know, we do some theoretical work, we do some modeling work.

We get some of the technology ready to switch on as it were in the real world, But then we do field trials.

- Right.

- We do some testing and at various scales to build up to a full deployment, if you like, of the technology.

- Yeah.

- We're in a very early stage in that process, right?

Which is partly why no one's saying we should do this tomorrow.

A longstanding concern is, well, it's not really clear there's much of a difference there between testing and deployment.

So that's one issue.

But there's another issue, which is, suppose we could figure out, you know, ways of testing that don't amount to full deployment and don't take global level risks, it might take us quite a long time to do those, you know, kind of to our satisfaction.

- Yeah.

- Are we just going to jump that stage and start doing it and then get data on what it's doing?

Are we willing to as, if you like, experiment on ourselves in real time to see if this high leverage intervention technology works in the way we expect.

- So you're pretty cautious.

- I do think that it is worth doing some more research on many of these things.

- Okay.

- If we can do it in an ethically responsible manner.

- Okay.

- And that might be a contentious issue.

And then the other big if is if there's some reasonable likelihood that it will actually be used in an ethically defensible manner.

- Right.

- Right.

So those are two big ifs.

- Got it.

Yeah.

Let's argue for and then against.

What are the couple solid arguments for geoengineering?

- Unmitigated climate risk is really, really costly.

Trillions of dollars.

The potential, potential, net benefits, and I would immediately say that's not the right decision criteria, but the potential net benefits are large.

The reason why we are talking about it, the reason why we haven't killed it already long time ago is because there are benefits that outweigh the costs by one, two, three orders of magnitude.

- Right.

- It is about risks.

It's about risk-risk trade-offs.

Risks of unmitigated climate change or the world we're heading toward.

And the risks and uncertainties, and they are real, of solar geoengineering.

- Right.

- I do think that the best argument for these kinds of intervention does involve them contributing to pulling climate risk down.

I think there's many really serious issues though.

We're dealing with technological imaginaries more than we're dealing with real things.

Yet, hopefully that will change as more research is done.

It's easy to subconsciously assume that the implications will be taken care of.

- Yeah.

- But sometimes you worry that that could be magical thinking.

- Right.

- Years ago, it was said by James Lovelock that these initial geoengineering schemes for climate would be just the tip of a geoengineering iceberg.

We will do more and more large scale interventions.

And then we probably have to do extra interventions to fix the problems created by the interventions.

And so it goes on.

And before you know where you are, you're on a radically different kind of planet.

It might just be that we do geoengineering, including research, and then ultimately deployment in a way which doesn't make things better, but could make things worse, maybe even dramatically worse.

Mainstream climate policy, I would argue, has been failing for decades now.

Many of those same drivers of bad behavior could just manifest themselves again-- - Interesting.

- with inside geoengineering policy.

- Right.

- We might do geoengineering policy in a way that imposes extra burdens on future generations.

- Right.

- And spares ourselves.

So we might make it worse for them in physical terms or maybe say in geopolitical terms.

And that might be more destabilizing even than some of the climate risks-- - Yeah.

- that might occur.

- What gives you hope?

When you think about geoengineering as a topic, what gives you hope as you look out in the future?

- Up to a point, it might be the thing that might finally jolt us into wanting to do more to address the problem in the first place, right?

If pointing to volcanoes isn't scary enough, then we did not do a good job describing the technology, right?

If the fact that we are talking about it, serious people, serious scientists are talking about a potential intervention of adding more pollution to the atmosphere.

And we have a serious conversation about the risks and rewards and benefits and costs of potentially doing this research, right?

Well, if that does not mean we finally, hopefully do more to address the root cause, then what else can?

- Yeah.

- What gives me hope?

Not much around, around this debate, because I really am concerned that many of the same problems that are so awful about contemporary and preceding climate failure will just reappear within the geoengineering space.

Sometimes I say the question of innovation in governance and ethics is as urgent as the technological question.

But all our emphasis seems to be on the technological question.

- Right.

- And that seems to be a serious mistake.

So I'll get to a little bit of hope is I hope that when people hear that this sort of thing is being taken seriously, they will be moved to take the governance questions really seriously and the social political questions really seriously.

- Yeah.

Interesting.

Same kind of a concern.

- Same sentiment.

- Yeah, same sentiment here.

You got a big audience.

Kind of one or two things would you like to leave them with to make sure they take away from our conversation?

- I would like them to take away that this is an enormous amount of power to bestow on whether it's some country or a small group of individuals within the country, say, on the global stage.

You're handing over control of the basic climate system.

Potentially how warm it is, where it rains, all these kinds of things.

And I think we should suspect that that will have major geopolitical consequences.

And consequences ultimately for the future of humanity, right?

So we are not just talking about some very isolated technological issue that only, you know, geeks like us should be talking or thinking about.

- Interesting.

Yeah.

Couple of good thoughts.

- Solar geoengineering is different from lots of other potential interventions.

It also shares some characteristics.

And the things like fusion technology or green hydrogen or whatever else we might want to dream up where it's often the case that we then use talking about fusion as an excuse not to do the boring stuff that's already cheap, scalable.

We know we should do it.

Solar geoengineering does that on overdrive.

And at the end of the day even if solar geoengineering is something we will never touch, the thought experiment, the research going into it, the social science research, the ethical research, the techno-economic research going into solar geoengineering might actually teach us something about how to deploy the boring, scalable, already cheap climate technologies.

- Interesting.

Yeah.

Yeah, it's a good thing to leave with folks.

Well, look, I appreciate the dialogue and it's technology and ethics and spans the gamut there, which is really important to think about.

Stuff we don't always cover on this show actually.

So I appreciate your both being here and sharing your thoughts and expertise with us.

Scott Tinker, "Energy Switch."

Gernot, Thanks.

- Thank you.

- Appreciate your time today very much.

- Thank you.

[Scott] Geoengineering includes carbon dioxide removal from the atmosphere.

That could be planting forests, increasing rock weathering, or using direct air capture machines to filter CO2 out of the air.

But given the grand scale of atmospheric CO2, their impacts on warming would be minor.

So some have proposed solar radiation management.

It doesn't address CO2, but the warming it causes by injecting reflective aerosols into the upper atmosphere.

Volcanoes do it naturally, so we know it could work to cool the globe.

But to keep it cool, we'd have to do it continuously.

The technology, large high-flying airplanes, would be relatively easy to develop and deploy, but many worry it would have ecological and geopolitical consequences and give a small group of people control of global temperature and rainfall.

Our experts hope the controversy could encourage us to better address international climate policy so we can avoid geoengineering.

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