Is Geoengineering A Good Idea?

Summary

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Podcast Summary: Are We Doomed?

Episode: "Is Geoengineering A Good Idea?"
Host: Ben Bradford (NPR Network)
Date: June 30, 2026

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Overview

This episode tackles the controversial and rapidly developing field of geoengineering—the deliberate large-scale intervention in Earth’s climate system, usually proposed as a solution to counteract global warming. Host Ben Bradford explores both the potential scientific feasibility ("Can we?") and the profound risks and ethical dilemmas ("Should we?") associated with geoengineering, particularly the idea of spraying particles into the stratosphere to reflect sunlight. Guests include pioneering climate scientists Kate Ricke and Alan Robock, whose expertise and skepticism animate a conversation ranging from madcap scientific proposals to genuine existential risk.

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Key Discussion Points & Insights

1. Origins & Definitions of Geoengineering [00:26–04:21]

• The episode opens with an anecdote about Nobel-winning scientist Paul Crutzen’s 2005 essay suggesting deliberate atmospheric interventions could offset global warming.
  • The idea: re-introduce some forms of pollution (previously removed due to health risks) to reflect sunlight and cool the planet.
• Geoengineering emerges from fringe speculation to a serious field, with two camps:
  • "We have to—it might be our only option to survive."
  • "We can’t—it’s too dangerous and could spell doom."

2. Science and Feasibility: Can We Geoengineer the Climate? [04:21–16:34]

a. Early Skepticism and Research Beginnings

• Kate Ricke explains her initial reluctance:
  • "No, I didn’t want to do it because it sounded like a really terrible idea." [05:31]
• The field started small—only about 25 researchers—dubbed "the wall kids of climate science." [05:52–06:09]

b. Proposed Methods (Both Real and "Bonkers") [07:24–10:10]

• Ideas range from giant sky vacuums to suck out carbon, ocean fertilization to encourage phytoplankton growth, and marine cloud brightening to reflect sunlight.
  • "How about dumping a massive amount of fertilizer in the ocean, which could grow a bunch of phytoplankton?" (Kate Ricke, [07:48])
  • "What if we just paved a whole continent and painted it white?" (Kate Ricke, [09:52])
• All are unproven at scale, and some are dismissed as "mad science."

c. Most Promising—But Still Alarming: Stratospheric Aerosol Injection [10:15–16:34]

• The most credible proposal: spraying reflective particles (e.g., sulfate aerosols) into the stratosphere to mimic volcanic cooling effects.
  • "We would put these reflective particles up into the stratosphere, have airplanes fly high..." (Kate Ricke, [11:13])
• This idea draws from volcano-induced "volcanic winters" that cool the earth after large eruptions.
• Kate Ricke notes:
  • "We have observations of it working, namely volcanoes." [14:28]
• Within a decade, engineers could feasibly build a fleet capable of this deployment.
  • "We could probably have capacity to do this at a large scale within 10 years." (Kate Ricke, [15:35])
• Potential side-effects: skies could change in appearance (higher contrast), but would mostly go unnoticed without close study.

3. Risks, Ethics, and the Should-We? Debate [16:34–29:53]

a. The Skeptic’s List: Alan Robock’s 20 Reasons Against Geoengineering [17:56–22:39]

• Alan Robock, a leading expert in atmospheric science, recounts his horror at early geoengineering proposals:
  • "We're going to fly an airplane over your daughter's school and we're going to spray sulfuric acid in the air, and that's going to solve global warming." (Alan Robock, [18:31])
• His evolving list of objections—most still valid—includes:
  • Potential for ozone depletion
  • Disrupted weather patterns (rainfall, monsoons)
  • Reduced food production and quality [21:00]
  • Unknown impacts on air travelers and atmospheric chemistry
  • Governance: Who operates the planetary thermostat? What if it breaks or is misused?
    • “Would you trust the entire planet that we live on for this very complicated technical solution?” (Alan Robock, [21:58])

b. Termination Shock & The "Snowpiercer" Hypothesis [22:39–26:58]

• Inspired by the movie "Snowpiercer," Ben and Kate discuss how abrupt halting of geoengineering would trigger termination shock—a sudden, catastrophic warming as reflective particles dissipate.
  • "If we did geoengineering for a really long time and then stopped, the planet’s gonna warm up to where it would have been if we’d never done geoengineering at all. And it’s going to do it really quickly." (Kate Ricke, [26:32])

c. Moral Hazard & The Geoengineering Trap [24:59–26:10]

• Kate worries:
  • "If geoengineering becomes an acceptable solution to climate change, it will reduce the amount of mitigation we would have otherwise done." [25:20]
• Cheap, quick solutions risk political and behavioral backsliding—governments and individuals may abandon emission cuts, leading to dependency on perpetual (and escalating) intervention.

d. The "Lesser Evil" Argument [27:10–29:53]

• Kate frames geoengineering as perhaps the "lesser evil" in a world where climate change is spiraling out of control.
  • "We're facing a really uncertain future...some manifestations look pretty bleak for us in terms of what the impacts of climate change are going to be." [27:10]
  • "There’s nothing else we can do to cool the planet that quickly. This might be the only option for taking some of that pressure off.” (Kate Ricke, [29:12])
• The fundamental comparison: a risky, artificial planet or a catastrophically hotter, “natural” one.

4. The Politics and Power Vacuum: Who Decides? [29:58–36:46]

• No global agreement exists for geoengineering governance.
  • "There’s no, you know, international law that directly constrains these activities in any way. So that is kind of a problem.” (Kate Ricke, [33:44])
• Localized interventions could create losers as well as winners. For example, US efforts to cool its own territory could trigger deadly heat elsewhere.
  • “At a certain point it actually starts to cause risk of extreme heat in other parts of the world.” (Kate Ricke, [34:47])
  • "Could that produce conflict between countries?" (Alan Robock, [35:00])
• Potential for geoengineering to become a cause of geopolitical conflict or even war.

5. Private Sector Acceleration: Money and Risks [36:09–37:26]

• Startups have begun testing small-scale geoengineering, selling carbon credits, and raising millions to build operational fleets for atmospheric interventions.
  • "Once you have people who've invested tens of millions of dollars…those people are going to expect a return on their investment, whether it’s a good idea or not." (Kate Ricke, [36:46])
  • The threat: hasty or profit-driven actions, not grounded in democratic or global consensus, could drastically and recklessly alter the climate for everyone.

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Notable Quotes & Moments

• On the Dystopian Flavor of Geoengineering:
  "I totally agree that it sounds sci fi and dystopian. And that's how I felt as well." — Kate Ricke [04:51]
• On Reluctance to Enter the Field:
  "No, I didn’t want to do it because it sounded like a really terrible idea." — Kate Ricke [05:31]
• On the Scale of Intervention:
  "We're not talking about changing a cloud anymore, but the entire planet." — Kate Ricke [07:24]
• On the Premise of Stratospheric Aerosol Injection:
  "We would put these reflective particles up into the stratosphere, have airplanes fly high..." — Kate Ricke [11:13]
• On Volcanos as Guidance:
  "We have observations of it working, namely volcanoes." — Kate Ricke [14:28]
• On Speed and Risks of the Solution:
  "The thing that makes geoengineering attractive, which is that it works quickly, is also the thing that makes it dangerous." — Kate Ricke [24:51]
• On Termination Shock:
  "If we did geoengineering for a really long time and then stopped, the planet’s gonna warm up to where it would have been if we’d never done geoengineering at all. And it’s going to do it really quickly." — Kate Ricke [26:32]
• On the Lack of Global Governance:
  "There's no...international law that directly constrains these activities in any way. So that is kind of a problem." — Kate Ricke [33:44]
• On Private Enterprise Leading the Way:
  "This has probably been the most demoralizing event in my time working on this." — Kate Ricke [36:04]
• The Existential Risk Summed Up:
  "If global warming's impacts are so bad, we might just have to do it and live with that risk anyway because we can't live with the warm world we've created." — Kate Ricke [39:14]

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Important Timestamps

• 00:26–04:21 — Introduction to the history and concept of geoengineering
• 04:21–10:10 — Kate Ricke on the field’s origins, skepticism, and early ideas
• 10:15–16:34 — Discussion of stratospheric aerosol injection and volcanic analogies
• 17:56–22:39 — Alan Robock’s critique and detailed risk list
• 22:39–26:58 — The risks of termination shock and the Snowpiercer scenario
• 29:58–36:46 — Governance, potential for conflict, and decentralization risks
• 36:09–37:26 — Private startups moving fast—potentially too fast
• 38:20–39:29 — Reflections on the likelihood of global consensus and the paradox that if geoengineering is needed, we’re already in trouble

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Concluding Thoughts

Bradford and his guests offer no easy answers, but the message is clear: the science of geoengineering is advancing rapidly, the risks are profound, and the governance vacuum—whether at the national or global level—represents a major, perhaps existential, dilemma. With private companies racing ahead and nations failing to agree even on emissions cuts, the planet may soon face decisions about technological fixes before society has reckoned with their implications or resolved their dangers.

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Next Time

Ben Bradford teases the next episode: exploring survivalist myths versus the likely real scenarios of post-apocalyptic life.

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Transcript

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[Ben Bradford]

San Francisco 2005 Earth and Space scientists from around the world are gathering to present, argue, drink cheap conference wine and gossip today. Not a dui, not an affair. Clutch your pearls. It was an essay.

[Alan Robock]

Did you hear about the paper that Paul published?

[Ben Bradford]

The prestigious Paul Crutzen conference heavyweight Nobel Prize winner in chemistry, was circulating an electric controversial new idea. Not how to reduce pollution, but to add it back. At the time, the US and other countries had massively cut back harmful emissions from refrigerators, shaving cream bottles, car tailpipes. A win for air quality, the ozone layer, lungs and cancer rates. The cons sunsets were less spectacular and one much bigger problem. Climate scientist Kate Rickey recalls, we're cleaning

[Kate Ricke]

up pollution near the ground that makes people sick. But that pollution also reflects sunlight, creating a cooling effect.

[Ben Bradford]

In other words, these emissions had actually been combating global warming. But now, as they vanished, greenhouse gases could run even more unchecked, speeding climate change. So our heavyweight scientist Crutzen in his essay says maybe we should think about putting some of them back intentionally.

[Alan Robock]

He's saying we should consider doing this to reduce global warming.

[Ben Bradford]

It's not just the adding pollution that had the conference chattering.

[Kate Ricke]

It's the larger concept, us as humans, deliberately intervening in the Earth system that determines what the climate feels like.

[Ben Bradford]

It's called geoengineering. As a species, we're used to messing with the atmosphere accidentally and causing harm. Let's do it on purpose to save ourselves. Geoengineering. It had been a fringe concept, but no longer.

[Kate Ricke]

Because it was Paul Crutzen, people felt enabled to start doing some research.

[Alan Robock]

That sort of opened the floodgates.

[Ben Bradford]

From nuanced tales distributed by the NPR network, this is Are we doomed? I'm Ben Bradford. Since that essay, the field of geoengineering has exploded. You can see the appeal. As climate change spawns more crises, floods, droughts, heat waves, hurricanes, and as nations consistently fail to curb the emissions causing it, here is a new tool. We geoengineer our way out of it. Grab the thermostat and yank it back. I have two questions. Can we do it credible? Scientists have proposed all kinds of methods of manipulating that thermostat one more wacky than the next. From space mirrors to fertilizer in the ocean. Could any of them work? We'll look at that. Second question. If humanity can actually do this, can manipulate our climate back to normal through abnormal means, should we? As far as I can tell, the field splits into two camps. One, we have to. It's the only way to save ourselves from climate change. On the other, we can't. This would lead to its own doom. So that's what I want to figure out today. Geoengineering, Is it an option? Are sky mirrors our salvation or our doom? Okay, so intentionally manipulating the entire atmosphere of the earth to counteract the effects of climate change. Can we do it? Let's find out.

[Kate Ricke]

I'm Kate Rickey. I'm a scientist who studies climate change.

[Ben Bradford]

Kate has researched whether we can do it for decades. As you might imagine, it's not going to be easy.

[Kate Ricke]

There's all these components of a very complicated Earth system that interact with each other to produce the conditions we experience every day. The temperature, the precipitation, the humidity, et cetera.

[Ben Bradford]

There's an instant reaction I get sometimes when I'm talking to people about these things. This sounds sci fi and dystopian.

[Kate Ricke]

I totally agree that it sounds sci fi and dystopian. And that's how I felt as well. When I was first starting studying geoengineering,

[Ben Bradford]

Kate got dragged into this field, which I think makes me trust her more. As she tells it, she was a grad student who wanted to do like normal climate research, but her advisor had just read a certain essay causing quite the stir at a conference, and so he pushed her.

[Kate Ricke]

People are talking about this geoengineering idea. I think there's an interesting project here and I think you should work on it. And I said, I don't think I want to work on that, but I.

[Ben Bradford]

Wait, you said?

[Kate Ricke]

That's how I got into it.

[Ben Bradford]

You didn't want to do it?

[Kate Ricke]

No, I didn't want to do it because it sounded like a really terrible idea. And I didn't want to work on

[Ben Bradford]

that because it seemed dystopian, because it was untried. It wasn't clear if we could do this. It screamed career killer. But she got started and she was asking this question, can we do it? She was one of only a few people trying to figure it out.

[Kate Ricke]

The entire research community could fit in. A large conference room was just the same. 25 of us, a couple dozen people,

[Ben Bradford]

the wall kids of climate science. They kept flying to larger climate events and summits and then all packing into the same one meeting.

[Kate Ricke]

Some of us know each other really

[Ben Bradford]

well because of that, Kate says to the question of can we? When she started, there wasn't a lot of precedent. And what there was wasn't exactly inspiring. The science of the 1940s brought us nuclear weapons, Velcro, Kitty Glitter, and cloud seeding. Airplanes dumped chemicals, dry ice or silver iodide into clouds that had been mining their own business. This, theoretically could induce rain and delight chemtrail conspiracists. In the 1960s, the US government tried it for war in Vietnam. Military aircraft ran cloud seeding missions, strafing the skies over enemy roads in an effort to cause downpours that had bogged down vehicles in thick mud. Kate says the track record of a technology working then or since is pretty meh.

[Kate Ricke]

Mixed or not, very successful effects.

[Ben Bradford]

But that was one of the only real world examples of geoengineering she had to look back on. And what she and her cohort were exploring and what we're discussing went so far beyond this feeble attempt. We're not talking about changing a cloud anymore, but the entire planet.

[Kate Ricke]

The scope of this is much larger.

[Ben Bradford]

Can we do it? In the decades since Kate started with that lonely example of cloud seeding, there have been all kinds of theories studied about how to do this. Let's see what you think. You could pull carbon that's already been emitted back out of the air with giant fans, an enormous sky vacuum cleaner.

[Kate Ricke]

How about dumping a massive amount of fertilizer in the ocean, which could grow a bunch of phytoplankton.

[Ben Bradford]

This microalgae eats carbon from the air. In order to hear me out, get

[Kate Ricke]

the ocean to take up a bunch of CO2 really fast.

[Ben Bradford]

Don't like that idea. What if, instead of using fertilizer, dumping

[Kate Ricke]

a bunch of lime in the ocean?

[Ben Bradford]

The mineral, not the fruit. Best known for its use in steel manufacture and Tums. Lime has only one desire to turn into limestone, and it absorbs carbon to do it.

[Kate Ricke]

So it also gets to the ocean to take up a bunch of CO2 really fast.

[Ben Bradford]

Pour the lime, it sucks carbon from the air, turns to rock, and sinks to the bottom of the ocean. This is not a Lex Luthor plan. It's not a Monty Python sketch. It's a serious proposal for geoengineering against climate change. Moving on.

[Kate Ricke]

Trying to stop the collapse of the

[Ben Bradford]

Antarctic ice sheets so ocean levels don't rise. How?

[Kate Ricke]

Drilling big holes in them and pumping water out from the bottom so that the ice sheets can't slip into the ocean as easily.

[Ben Bradford]

Not totally clear on how that works. What else we got?

[Kate Ricke]

Marine cloud brightening.

[Ben Bradford]

Some of the most prominent concepts involve attacking climate change through the science of colors. Lighter colors absorb less sun, less heat,

[Kate Ricke]

so whiten things make the atmosphere reflect more sunlight.

[Ben Bradford]

In this case, clouds. It's like what they did in Vietnam, except instead of making the cloud rain, you make it change color. All of these ideas, at least theoretically, could cool the earth. All of these ideas, at least large scale, are untried. All of them sound bonkers, right? I mean, sky vacuums and ocean tums. It's mad science. But also any plan on a scale to environmentally tamper with the entire earth kind of has to be. What is just the worst idea that you've come across?

[Kate Ricke]

Oh, gosh, that's a. Well, what if we just paved a hole continent and painted it white? Things like.

[Ben Bradford]

And you don't think that's promising?

[Kate Ricke]

No, no, that's a pretty bad one.

[Ben Bradford]

That's saying something because figuring out the bad ideas is a key part of Kate's job.

[Kate Ricke]

A lot of my research is actually focused on trying desperately to uncover worst case scenarios out of all of these ideas.

[Ben Bradford]

The sky vacuums, the ocean chemistry, the ice drilling one keeps coming up, one that scientists have given the most consideration to. To Kate, it seemed the most promising, least dangerous, most feasible. It's also the oldest. It too involves reflecting sunlight. Around the time President Lyndon Johnson was allowing rain attacks on Vietnam, his science Advisory council inked a massive tome of an environmental report among the 133 pages.

[Kate Ricke]

Oh, hell.

[Ben Bradford]

One section read. The possibilities of offsetting climate change need to be thoroughly explored. Yes, we knew about climate change back then. The report offered a geoengineering solution, A rough proposal of what would become this.

[Kate Ricke]

We would put these reflective particles up into the stratosphere, have airplanes fly high,

[Ben Bradford]

really high above the clouds, above rain, where the air is too thin to breathe. The airplanes are packed with a substance,

[Kate Ricke]

gases, or it could be liquids that then once you spray them or release them into the stratosphere, they turn into

[Ben Bradford]

these little droplets which are reflective, bouncing sunlight away from the earth.

[Kate Ricke]

Really strong winds spread them out all over the planet really quickly.

[Ben Bradford]

The particles fly out around the globe, and then in the thin, dry air, just sit there hanging, meditating.

[Kate Ricke]

They sit in the atmosphere for a long time because they're so small that it takes a long time for them to fall out.

[Ben Bradford]

But eventually they do, and the planes would take off again.

[Kate Ricke]

You would have to have a fleet of airplanes constantly emitting more material so that you have an even distribution of these reflective particles where you want them all the time, reflecting that sunlight.

[Ben Bradford]

This is the idea, possibly our most promising geoengineering idea. It's also the same basic idea that showed up in a certain essay in the mid 2000s and kickstarted this whole industry. To recap it, a fleet of airplanes spray little tiny droplets acting as little mirrors to make the entire sky reflect sunlight. I have so many questions. Does the sky look different? Like, what does this look like?

[Kate Ricke]

Right, so sulfate aerosols, which are the most common thing people have talked about doing this with, are the same thing that is pollution coming from, like, power plants. So it causes, like, acid rain, right?

[Ben Bradford]

Wait, wait, wait, wait, wait, wait, wait. What?

[Kate Ricke]

Well, yeah, this is air pollution, right? We're talking about moving air pollution from down by the ground up to the stratosphere instead.

[Ben Bradford]

This is a real hear me out moment. Kate says, yes, it's the same substance that causes acid rain. But hear her out.

[Kate Ricke]

The health effects from these same particles are very different.

[Ben Bradford]

Have you ever heard the phrase the dose makes the poison? Well, Kate says back when we were burning a hole in the ozone layer and sizzling car paint with acid rain, it was because we were creating a whole lot of it here on the ground. And in this plan, that doesn't need to be the case.

[Kate Ricke]

So we're talking about using orders of magnitude less particles to reflect the same amount of sunlight.

[Ben Bradford]

Because these droplets, once they're sprayed out into the stratosphere, they hang. So fewer droplets can reflect the sun longerno acid rain, no hole in the ozone, cooler atmosphere countering the effects of climate change. Can we do it? Kate says there's a reason this idea, as mad science as it may sound, seems more plausible than others.

[Kate Ricke]

We have observations of it working, namely volcanoes.

[Ben Bradford]

When a volcano erupts, it spits ash into the sky. Powerful eruptions can rifle it into the stratosphere. The ash spreads around the globe and can lead to global cooling. Volcanic winter.

[Kate Ricke]

The science is very well understood.

[Ben Bradford]

That's why this ideait's called stratospheric aerosol injection is the oldest idea. That report on LBJ's desk said, hey, look at volcanoes. That big buzzy essay from Paul Crutzen said, hey, look at volcanoes. We literally know of a way to cool the Earth because the Earth does it itself very rarely. But still, the mad science idea is basically mimic a volcano. Can we really do that? Well, not yet. Kate says we don't actually have the fleet of planes that can fly high enough. We haven't designed them, but in the grand scheme of things, it doesn't seem like a major hurdle. This plan, or some form of it, seems achievable.

[Kate Ricke]

The engineers who have done some of the work on this say that we could probably have capacity to do this at a large scale within 10 years.

[Ben Bradford]

Within a decade, we could spray the sky to fight climate change. And by the way, it would change the color. At least one study found it'd upped the contrast just a little, not enough for most of us to tell. Still, I think that gives a sense of the scope of the idea, the zaniness of these proposals. How much ambition has grown since the US tried to consistently make clouds weep in Vietnam. Maybe this sounds like a terrible idea too. Fleets of planes pollinating our skies with the stuff that causes acid rain changing its very color. Well, research is advancing. Plans to test spraying are already in motion. And as it grows more likely that this idea or other forms of geoengineering get implemented, we have to ask our next question.

[Kate Ricke]

Should we There is a way, technically that you could have a snowpiercer situation.

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[Kate Ricke]

I've been very dissociative, so that's a problem for my future therapist.

[Ben Bradford]

Yeah, I see. Let's talk about the fact you're not in therapy. That's fascinating.

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[Ben Bradford]

The year is 2006. A certain essay has recently published kickstarting interest in geoengineering. And at another conference, Alan Robach is glowering. He's sitting in his first workshop about the topic the room is hot, but no one can seem to figure out the thermostat. Not a good sign. He thanks for human ability to control the temperature of the world. Can't even do it for the room.

[Alan Robock]

And these engineers and physicists were getting up there saying what a cool idea it was, how we can manipulate this, manipulate that, control the climate.

[Ben Bradford]

He couldn't believe what he was hearing.

[Alan Robock]

We're going to fly an airplane over your daughter's school and we're going to spray sulfuric acid in the air, and that's going to solve global warming. And I started writing down reasons why it might not be such a good idea.

[Ben Bradford]

Potentially blow a hole in the ozone, create acid rain, cause countries to fight over the room temp like an old married couple, but without the love and in this case, for the fate of the world.

[Alan Robock]

I came up with 20 reasons and published that in 2008. So 20 reasons why geoengineering may be a bad idea.

[Ben Bradford]

It sounds like the work of a crank. But Alan isn't just any crank. He's one of the world's most distinguished authorities on how blocking the sun can cool the planet. You know how some geoengineering ideas are based on mimicking volcanoes? They're piggybacking on Allen's research.

[Alan Robock]

I discovered that volcanic eruptions are the largest natural cause of climate change.

[Ben Bradford]

You know, the biggest danger posed by nuclear Armageddon. Alan did pioneering research on it.

[Alan Robock]

Smoke from fires after a nuclear war

[Ben Bradford]

and how all that ash rising into the sky causes nuclear winter. His entire career, Alan has studied the damage from these effects. So you can understand his glower in that sweaty conference room as he heard proposals from people who want to cause them and they can't work a thermostat. Did you ever think that people would look at that work and say, we should do that intentionally?

[Alan Robock]

No, I never thought about that.

[Ben Bradford]

He scribbled his initial 20 concerns, but didn't stop there. Allen started investigating the idea himself. And he hasn't stopped scribbling ever since.

[Alan Robock]

We've published 170 papers so far, and

[Ben Bradford]

they've led to very little xing out items on his list. How many of the ones that you wrote down on that list do you feel like checked out as you kind of researched later?

[Alan Robock]

Oh, 18 or 19. And since then, I've added more things to my list.

[Ben Bradford]

Should we geoengineer our way out of climate change? The concept with the most momentum is that fleet of planes spraying meditating aerosols to reflect the sun, creating a mild volcanic Winter, Alan rattles off items from his list opposing the idea it would deplete ozone. Last time humans generated these pollutants, they ripped a hole in the ozone. Even if this doesn't, since it's a lower dose. Alan says the loss of sunlight could affect cloud formation, it could change rainfall patterns, it could kill crops.

[Alan Robock]

What people care about the most important thing is food. And so it might affect the amount of food you can grow, and it also might affect the quality of the

[Ben Bradford]

food, even if it doesn't. And our other scientist, Kate, thinks it won't. Or not worse than climate change already will. What will those gases high up in the air do to people high up in the air?

[Alan Robock]

I'm doing some research right now to calculate what the impact would be on airplane passengers.

[Ben Bradford]

You're on a bumpy flight, a child already screaming two rows behind you, and then you start breathing in banned refrigerator coolants might be a blessing. But most of all, beyond any one specific technical item on Alan's list, he keeps coming back to that thermostat in the hot conference room.

[Alan Robock]

So you want to create this huge technological system and it's not hard to think of complicated technical things that have

[Ben Bradford]

failed the Spanish Armada Quibi, you understand,

[Alan Robock]

anything built by humans, anything operated by humans could fail. And so would you trust the entire plan planet that we live on for this very complicated technical solution?

[Ben Bradford]

That goes for spraying aerosols, but also any of the other possible ways to cool the Earth. From carbon sucking sky vacuums to ocean fertilizer. Intentionally changing the climate of the Earth is a huge endeavor untried with possible catastrophic consequences. All of them face those two questions. Can we? And if so, should we? It would be reasonable to answer at this point with a hard no to say it is an obviously bad idea

[Alan Robock]

to spray sulfuric acid in the air. And that's going to solve global warming.

[Ben Bradford]

Let's hear one more reason this could be a terrible idea. When we started this episode, I had a question. Burning a hole in me the size of the ozone layer finally couldn't help it. Had to ask our other climate scientist, Kate Rickey. Okay, there's a movie called Snowpiercer. Have you ever seen Snowpiercer?

[Kate Ricke]

I have.

[Ben Bradford]

Snowpiercer. The last vestiges of humanity huddle on a train circling a permafrozen Earth.

[Steve Inskeep]

It's one of the most crucial sections in the train.

[Ben Bradford]

If we take it, we have the upper hand.

[Kate Ricke]

We don't even have to go to the very front.

[Ben Bradford]

I mean, the plot of Snowpiercers is like knife fights on a train. But the context is that humans are on that train because they accidentally froze the world by spraying aerosols to fight climate change. It was instantly what I thought of when I heard the idea we're discussing. I just am wondering if you worry about a snowpiercer scenario.

[Kate Ricke]

I don't worry about a snowpiercer scenario. I think I worry about enough that's more realistic.

[Ben Bradford]

So far, so disappointing.

[Kate Ricke]

But then, oh, you know. So there is a way technically that you could have a snowpiercer situation.

[Ben Bradford]

Hell yeah.

[Kate Ricke]

It's just not with particles. So the way that you could get a snowpiercer situation is if we did geoengineering with space mirrors.

[Ben Bradford]

Space mirrors, real idea. Because no particles, no pollution, they still reflect sunlight just from orbit.

[Kate Ricke]

If you put those mirrors in space and they malfunctioned in some way and you couldn't get to them, you could cool down the planet sort of indefinitely. Too much.

[Ben Bradford]

Do not worry. Space mirrors appear prohibitively expensive. According to Kate, our meditating aerosols are much cheaper. Around $18 billion in one estimateto cool the earth by a degree. That's enough to reverse most of the man made climate warming we've experienced so far. All for the price of a couple New York subway extensions. Kate thinks the low price could actually be a problem. She leans a tick toward we should or might have to. But she fears how cheap and easy it may be.

[Kate Ricke]

The thing that makes geoengineering attractive, which is that it works quickly, is also the thing that makes it dangerous.

[Ben Bradford]

She fears her research could help lead to a world where fleets of airplanes coat our skies with particles. And in a couple years it works. The Earth is cooler. So then governments ease emissions regulations, consumers blast air conditioning and buy Hummers because why not we can spray more particles?

[Kate Ricke]

If geoengineering becomes an acceptable solution to climate change, that it will reduce the amount of mitigation we would have otherwise done.

[Ben Bradford]

We're good, we're fine. We covered it. Everything's fine. It's nice out. Exactly. Who cares? Eco friendly Dishwashers are out. 120 octane gasoline is in. Why not? We can spray more particles, the Earth starts getting hotter, faster. That means we need to send more planes up, spray more aerosols. The sky gets high contrast, the sunsets are spectacular Again. All of this geoengineering has not stopped climate change, just covered it up. The greenhouse gases in the atmosphere are thicker than ever. So we spray more particles.

[Kate Ricke]

We're going to have to do geoengineering for a really long time and potentially do more and more of it.

[Ben Bradford]

And then there's a hiccup, a funding issue, a new fad of aerosol denial. A government faction ascends to power that believes we don't need it.

[Kate Ricke]

Things go wrong in the world, Systems

[Ben Bradford]

get disrupted, and one year the planes don't fly.

[Kate Ricke]

The planet's gonna warm up to where it would have been if we'd never done geoengineering at all. And it's going to do it really quickly.

[Ben Bradford]

The worst effects of a much hotter planet hit suddenly as the coolants drift from the air. Hurricanes, wildfires, drought. It's called termination shock.

[Kate Ricke]

The entire planet would be affected.

[Ben Bradford]

Everything you've just heard sounds like a reason not to. There is an argument for the opposite. We have to. It starts by really understanding the situation bearing down on us.

[Kate Ricke]

We're facing a really uncertain future, and some manifestations of that future look pretty bleak for us in terms of what the impacts of climate change are going to be.

[Ben Bradford]

I think climate change is slow. The name is boring. It's easy to be numb to it. So it can be hard to visualize how it makes the doom list with, say, nuclear war. Let's try this. All of the worst extinctions we know about in the history of the world were ultimately from sudden extreme climate change. It wasn't the asteroid that killed the dinosaurs. It was the decades long winter. The dust from it kicked up when a volcanic maw the size of Alaska opened 250 million years ago in Siberia. This is real. It wasn't the lava that killed the vast majority of us, all creatures on Earth. It was the emissions it released. They catastrophically warmed the planet. It's called the Permian extinction, the Great dying. That's the path we're hurling down with the sudden, in geological terms, spike in emissions we've created. And the slow, boring, hard to visualize thing offers the same existential dangers to us as it did to the creatures of the Permian. No plan to cut emissions has kept up with the pace of the change we're creating. Faced with that doom, the argument for geoengineering is we need to do anything we can to pump the brakes, try

[Kate Ricke]

and reduce the damages from climate change.

[Ben Bradford]

And geoengineering, especially reflecting sunlight, also offers a huge advantage over simply cutting emissions.

[Kate Ricke]

Just operates on a different timescale than taking greenhouse gases out of the atmospheric.

[Ben Bradford]

Methane emissions into the atmosphere can linger for decades. Carbon dioxide can last for hundreds of years. We've only started to feel the effects of climate change that we have baked into the future. But geoengineering, we could feel the reversal almost instantly.

[Kate Ricke]

I mean, on the timescale of a year or two, there's nothing else we can do to cool the planet that quickly. This might be the only option for taking some of that pressure off.

[Ben Bradford]

To Kate, if the reward outweighs the risk, it's not because there isn't risk, but because doing nothing isn't exactly safe either.

[Kate Ricke]

Things are already changed. It just becomes a matter of what are you comparing a geoengineered world to? Are you comparing it to a world of the past that we can't necessarily realistically get back to at this point?

[Ben Bradford]

And so Kate thinks if we can safely, then maybe we must.

[Kate Ricke]

We need to understand as well as we can before we get there what the trade offs are.

[Ben Bradford]

That means not just sorting out the technical details. The new fleet of planes. To her, that seems doable. To her, the science so far looks promising. But those are not the biggest hurdles. The real challenge that Kate sees is one, our naysayer, Alan Robach. You have the list fears. Two, who gets to decide whether to change the entire Earth?

[Alan Robock]

You might have a system where you think 90% of the people are better off, 10% won't be. Should the world then do that?

[Ben Bradford]

The question of can we extends beyond the science. It's politics.

[Alan Robock]

How could you agree on what level to do it?

[Ben Bradford]

It's governance.

[Kate Ricke]

We have made no progress, progress whatsoever. And that's really frustrating.

[Ben Bradford]

And most of all, Kate worries before the politics are settled, before anyone decides democratically if we should, someone will. Because of a new development.

[Kate Ricke]

This has probably been the most demoralizing event in my time working on this.

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[Ben Bradford]

December 2025. Kate Rickey walks into the same climate conference she's been attending for almost 20 years. There's still wine, still gossip, but now her research, instead of on the fringe, is center stage. Geoengineering a key part of the agenda.

[Kate Ricke]

The science has exploded on this topic. There's been so many papers published, there are so many more researchers working on it.

[Ben Bradford]

It puts Kate on the forefront of an innovative field. Her risky bet as a grad student paid off. Not only that, the topic has media coverage, public interest, the excitement that creates opportunities for publication and funding, and all of that worries her. Let's talk about the money and politics of this a little bit. What are the politics of this? I mean, who gets to decide? Who do you think should decide?

[Kate Ricke]

I mean, there isn't really a politics around this yet because it's not really on the agenda of anyone with power.

[Ben Bradford]

While the science of geoengineering moved forward over decades from bothering a few clouds to very real proposals to spread reflective particles throughout the skies, Kate says no one has figured out who gets to do this.

[Kate Ricke]

There's no, you know, international law that directly constrains these activities in any way. So that is kind of a problem.

[Ben Bradford]

There is a law against using it for war after the whole Vietnam cloud thing. But while can we is looking a lot like probably no government or international body has taken charge of the should we. And that might be the greatest danger of geoengineering. A power vacuum over the world's thermostat, right? As countries are learning, they might be able to take control of it. And so Kate worries. For instance, she's been studying another form of cloud brightening. A country like the United States could spray its clouds with natural substances that can make them whiter to reflect the sun. It would combat deadly heat waves sweeping across the western United States. It could save lives. And a country like the US could do it on its own. But because weather is complicated, Kate's research shows at a certain point, it actually

[Kate Ricke]

starts to Cause risk of extreme heat in other parts of the world.

[Ben Bradford]

And so now the US is air conditioning itself and cooking someone else. And where does that end? Alan Robach asks.

[Alan Robock]

Could that produce conflict between countries?

[Ben Bradford]

Ever since a glowering Alan made that list, of all the ways geoengineering engineering could go wrong, this has been the one that perhaps concerns him most.

[Alan Robock]

A Princeton professor went around and asked people, what's the worst thing that could happen if we did this? And the answer to his poll was global nuclear war. Because different countries would not want their climate change in order to make another

[Ben Bradford]

country's climate better, the fight over the thermostat becomes existential. Ironically, the nuclear winter that followed would cool the planet. A form of geothermal geoengineering just way, way too much. In addition to, you know, all the other problems of global nuclear war. So should we geoengineer? While countries have not figured that out, private money has begun pouring in. Philanthropic dollars, venture capital dollars. And more than anything, that worries Kate More than governments, companies, this has probably

[Kate Ricke]

been the most demoralizing event in my time working on this.

[Ben Bradford]

Startups are already out there. One company launches weather balloons full of sulfur dioxide into the stratosphere. It's doing sky brightening on a modest scale. It makes money by selling carbon credits to other businesses. And that's small compared to another company that's already raised tens of millions of dollars to do the fleet of planes, the full on spraying the stratosphere with reflective particles. It's getting ready. If it launches, one company could change the entire earth's atmosphere. What do you worry will happen?

[Kate Ricke]

Well, once you have people who've invested tens of millions of dollars, hundreds of millions of dollars, whatever, in developing the technology to do geoengineering, then those people are going to expect a return on their investment, whether it's a good idea or not. And so the concern is that we end up putting a bunch of stuff in the atmosphere to cool down the planet because somebody wants to make money off of it instead of because it's going to save people's lives. And then we're in a really scary world.

[Ben Bradford]

Geoengineering, should we? It sounds like we may need to figure out how to do this right, like the logistics of it before a company or a nation goes rogue. Right now companies in the US do have to report if they're engaging in weather modification. Mostly that's cloud seeding, trying to create rain or snow, but that's it. I don't want to be controversial, but it does seem like there should be some kind of approval process for geoengineering the planet. That may yet happen. There was a congressional hearing last year about the topic. The EPA recently expressed concern about that weather balloon company attention does seem to be ramping up as the possibility of actually doing this ramps up. Still, Alan Robach with his list is skeptical countries can ever come together and agree on rules for this technology to save us from climate change.

[Alan Robock]

It's been 31 years, we're trying to solve the global warming problem and the countries of the world can't even agree on that. And so how could they agree on this very sort of radical kind of so called solution to climate change?

[Ben Bradford]

Because think about what thoughtful, coordinated, safe geoengineering would require. A treaty, a global compromise between nations of different size, power and industry, consensus about who would pay and how much and how that'd be spread out. In other words, exactly the same challenges as a climate accord. And the world has collectively failed at that. Which is the biggest argument for geoengineering. We can't. If we could, we wouldn't need to. We would have already agreed on the simpler, safer thing, cutting emissions. But that answer gets less satisfying as the world gets hotter.

[Kate Ricke]

What's the alternative? If global warming's impacts are so bad, we might just have to do it and live with that risk anyway because we can't live with the warm world we've created.

[Ben Bradford]

Geoengineering might be reckless. It might smack of mad science. So does what we're doing causing climate change? I have less idea now about whether we should, whether we have to, or whether we can't than when I started this story. But I have learned the science is advancing, the companies are forming, the money is arriving. It would be its own kind of recklessness to pretend no nation will get desperate enough or no company hungry enough to grab the thermostat. So we need rules, however elusive that's been so far. And if nations can come to agreement on something as strange and scary as geoengineering the sky, I wonder if that could do more. If we can make rules for how to cool the earth, maybe that could pave the way for the rules on how to stop heating it. What would a post apocalyptic world really be like? What would it take to survive? Do the preppers have it right? Next time on Are we Doomed? We're exploring our myths, our stories, and how we think they compare to reality. It was clear that, you know, this was people's idea. I'm going to go out in the woods and I'm going to survive in all of that that you can help us continue to make this show by going to Dunpod.com support and as a thank you, there are bonus episodes and a lot more. Also, if you haven't, check out our YouTube for fully animated versions of previous episodes. Are We Doomed? Pod at YouTube. Are We Doomed is a production of Nuance Tales. I'm Ben Bradford. Our producer is Lindsay Kilbride. Our sound designer and engineer is Jay Sebal. Our editor is Tracy Samuelson. Theme music is by Dylan dagenet. Animation on YouTube by Alboris Kamalazad. The show is distributed by the NPR Network. Huge thanks as always to Dan McCoy, Kalia Ali and the rest of the team at NPR. And thank you. See you next week. Sam.