We know humans are having an impact on planet Earth, but what if we really put our backs into it, and intentionally tried to change the entire planet? Either to make it better, or to fix some terrible mistake we’ve made. The technique is called geoengineering. Could it work?
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Fraser: Astronomy Cast Episode 438: Geoengineering
Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know but how we know what we know.
My name is Fraser Cain. I’m the publisher of Universe Today. With me is Dr. Pamela Gay, the director of Technology and Citizen Science at the Astronomical Society of the Pacific and the director of CosmoQuest.
Hey, Pamela. How are you doin’?
Pamela: I’m doin’ well. How are doin’, Fraser?
Fraser: Good. How’s that title rollin’ off my tongue?
Pamela: It’s – It deeply amuses me every single time you try and stumble through it.
Pamela: It’s long. It’s long, I’ll give you that.
Fraser: Can I give – Aah. Can we give you a new title? Like, we’re in territory now where we can give you – Like, can you have, like, the Director of Awesomeness or like, how about Administrator of Space Command? How ‘bout –
Pamela: I think that one’s probably not something I want, in case, like, an asteroid decides to attack.
Fraser: The Thrilling Space Agency.
Pamela: I’d go with: And she codes stuff for Cosmo Quest at ASP.
Fraser: Okay. Is there any – Do we have anything we need to organize? Or we’re going to get straight into fixing the planet, after we wrecked it last time?
Pamela: I think – having discussed the ways to ruin the world – rebuilding it is a perfectly good way to start an episode.
So, we know humans are having an impact on planet Earth, but what if we really put our backs into it and intentionally tried to change the entire planet, either to make it better or to fix some terrible mistake we’ve made? Technique is called geoengineering. Could it work?
So, again, this is Episode Two of a ongoing series. Who knows how many episodes we’re gonna get? But we are going to smash up the planet, and perhaps the universe, and then we’re gonna try and fix it; and then we’re gonna smash it again; and then we’re gonna try and fix it again.
I look forward to seeing how we can fix the galaxy. Ooo, we should do, like, building, like, a Type 3 civilization; rearranging the entire galaxy, using – Anyway, don’t worry about it. I’ll pitch that –
Pamela: That’s definitely more than one episode.
Fraser: I’ll pitch the episode at you. But don’t worry, you’ll love it. It’ll be fun. Alright.
So, when we talk – and this is, like, just so in bizzaroland, right? We talk about global warming and how we are increasing the temperature across the planet; we are creating unstable weather patterns. We are doing damage to the planet in ways that are, you know – we’ve not seen in the historical record for tens of millions of years. But don’t worry – science got us into this and science can fix it.
So, what is the idea of geoengineering?
Pamela: So, the basic idea is: You have Earth – that’s the “Geo” part – and you engineer it, which is the “engineering” part.
Put less sarcastically, it’s the concept of applying the skills of civil engineers, of mechanical engineers, of geologists, all working together – hydrologists – all working together to figure out how to do massive restructuring of the Earth’s surface or the Earth’s waterways in order to change large-scale functionality of different ecosystems, or perhaps even the entire world.
Fraser: We’ve demonstrated with our chlorofluorocarbons, with our global warming – the temperature increases that we’ve already seen – we are perfectly capable, unintentionally, of polluting waterways, of creating gigantic gyres of plastic. I mean, there are all kinds of things that we’ve been able to do. So I think – I feel pretty confident that we can impact the planet at a global scale.
Pamela: And the problem comes in – going from unforeseen consequences of things like the Industrial Revolution, which completely changed our atmosphere and our ecology – to, “Well, how do we fix this?”
And one of my favorite first, personal examples of starting to read about geoengineering was the massive work that has been done to try and prevent the loss of Venice. This prior island nation is essentially in a big lagoon that is happily letting its water table go up, up, up and, as that happens, this city that is inches above what used to be the water table, is becoming below the water table – which is a bad place for a civilization to be. And so, they’re working to restructure the lagoons and waterways and drainage systems around Venice; institute locks and dams and work to prevent further erosion of the city.
Fraser: And you’re seeing something similar with Miami now. They’re having to build a giant wall around the – seawall – around the ocean because the flooding in Miami is getting worse and worse every year and this is just going to accelerate. You’re seeing that in Europe as well.
But these are not – I mean, these are like local levels to try to just sort of prevent some of the downsides of the things that we’re doing, in terms of climate change and so on. When you geoengineer, though, like what kinds of projects would you be doing? What’s the scale we’re talking about?
Pamela: So, smallest level geoengineering is what we were talking about with Venice, where you restructure the massive drainage systems for a river network or a lagoon system. So, the Mississippi Delta region, they have major geoengineering projects to try and prevent the loss of the city of New Orleans.
But then you can scale things up and keep scaling things up, where we start looking at things like: How, exactly, do we change the albedo of the planet Earth – where albedo is the amount of energy that the planet is able to reflect from the incoming sunlight. So, if we want to cool the planet off, can we build stuff that will prevent sunlight from getting to the surface of the planet and let us just naturally radiate away some of this excess heat we’ve got?
Fraser: Okay. So we’ll just start there then. I mean, the albedo of planet Earth – how does that impact our temperature?
Pamela: So, the albedo of the planet is a fancy way of saying: The sun is shining light at us and we’re reflecting away a certain amount of it. The more snow we have, the more of that light we reflect away; the more effectively we’re able to keep that ice and snow because things aren’t heating up.
One of the terrible feedback mechanisms we’re dealing with right now is, as the ice and snow melts, dirt doesn’t reflect so well. Dirt, instead, absorbs the heat, heats up, re-radiates it in the infrared, melts more ice and snow – and so we have this feedback loop of planet getting warmer because not enough ice and snow.
Now, we can do crazy things – and people have put forward the notion of doing crazy things – like putting a bazillion dragonfly-sized mirrors in orbit around the planet that will reflect away sunlight, and it’s the light that goes between these dragonfly space satellites. People have supported the notion of – well, in some cases, let’s just spread out highly reflective material. This is probably one of the most environmentally bad ways to try and save the environment. People have put forward the idea.
Fraser: So you just, like, take a spray can and spray the Arctic white?
Pamela: Well, paint doesn’t do it quite so well but things like large swaths of white plastic have annoyingly, and not legitimately, been put forward – much to my amusement and disdain.
But this whole idea that we just need to make things reflect better, it’s the kind of idea where – if we could figure out how to do it effectively and in a way that doesn’t disrupt satellite communications, doesn’t endanger things that we’re trying to take off – it has the interesting possibility of cooling the planet in a way that’s fully reversible.
Fraser: I wonder how you’re going to clean up all those little dragonfly-sized mirrors. But I guess they’ll all re-enter the atmosphere on their own. So –
Pamela: They’re self-cleaning.
Fraser: They are. So you just keep – You have to just keep launching them if you want to keep doing this.
Pamela: And so, here, it starts to become an issue of: Is the amount of greenhouse gasses that you insert into the atmosphere launching all of these things going to be sufficiently devastating that this idea becomes counteracting itself?
There’s lots of caveats on all of these things, with changing the albedo. But this is one of the first places that a lot of folks go, in trying to figure out how to solve problems with our planet.
And it’s not just trying to save our planet. People also look to geoengineering to try and figure out ways to generate energy from new sources.
Fraser: Right, okay. So I’m just sort of imagining these ideas of, like, putting out, like, gigantic white sheets of plastic into the Arctic Ocean. That’s kind of crazy.
But one of the issues is that we have, you know – Carbon dioxide is a greenhouse gas and the more carbon dioxide that gets into the atmosphere, the more you will increase the temperature; the more it absorbs. And we’ve done whole episodes about this.
But the other idea is that you can put other substances into the atmosphere that will do the opposite thing. I mean, we see things like – with big volcanic eruptions – enough dust is put into the atmosphere that it actually cools the whole planet. So, could we go that route instead? Could we create synthetic volcanoes?
Pamela: So that’s another idea that people have thought about. And this is where dragonfly-sized reflectors actually are self-healing a little bit better.
But there are folks that have actually looked to figure out – so, again, in the idea of: These are not things we should actually try but they’re things people have thought about – people have started to look at: Well, what happens if we try and trigger eruptions? What happens if we try and look for artificial ways to sequester the carbon that we hadn’t thought about?
And then we start looking at bio-geoengineering. So, instead of artificially filling the atmosphere with stuff that changes the albedo, what if we just make it so we don’t have to do that by sucking the carbon dioxide out by triggering algae blooms?
Fraser: How would you do that?
Pamela: You can do it by changing the chemical composition of the ocean, ever so slightly; so, basically, scatter the right chemicals that is the algae-bloom-inducing stuff.
Now, one of the problems that we’re realizing is, algae doesn’t always do quite what you want. We’re starting to hit the point where soils are so warm that root systems, which used to sequester carbon – where the thought was: You plant a bunch of stuff, get things growing; the root systems, which get left in the dirt no matter what, sequester it – but we’re actually having a change in the bacterial life forms in the top levels of the soil such that, instead of sequestering the carbon, the bacteria are ingesting it and then just outgassing it straight back to the atmosphere.
Fraser: Right, right.
Pamela: So, all of these things are kind of in the land of where Descartes said that “the ultimate source of sin is acting beyond full understanding.”
Fraser: Right. Well, this is one of those situations where you’ve got, like, Hawaii, where they brought the – they accidentally brought – What was it? They brought the rats to Hawaii and so, they brought mongooses to kill the rats but the problem is that one is, you know, a day creature and one is a night creature, and so they never meet. And so you just get these situations – the unintentional consequences – of your big idea.
And when you are attempting to affect the planet’s climate at a global scale, cane toads are going to look like a walk in the park compared to what kinds of things you might unleash. You know – as I’m shooing European Starlings out of my birdfeeder, you know –
But go back to seeding the ocean with chemicals. I know, sort of one of the ideas is just tanker-fuls of iron. And you just take these tankers out into the middle of the Atlantic Ocean; dump the iron in – like, that’s the rate-limiting chemical in the oceans. And so you just create these enormous algal blooms. And hopefully, it sequesters a bunch of carbon and then it drops to the bottom of the ocean; out of sight, out of mind.
Pamela: And so the question becomes: What else are we taking out of balance when we do that? How much does that change the thermodynamics of the ocean? Which is one of the things that we worry about most with changes in salinity.
One of the most terrifying pairs of articles I read – it was either in a single science or a single nature magazine – back in late 2002/early 2003, I was sitting at my desk; decided to flip through it. And there was one article on models of: If you change the salinity of the ocean, what happens?
And one of the things that happens is the mid-ocean conveyor belts – these great currents that bring the coldest water down from the polar regions and then cycle it up through the tropic regions and then take the warm water up, which keeps England and Vancouver and Seattle and these northern latitude cities nice and happily warm – if you dump a bunch of fresh water into the ocean, you change the salinity which changes the simple thermodynamics; how much things rise and sink – the buoyancy properties.
And the article went on to describe how you could very easily disrupt this system and create a great new glacial period, while the middle parts of the world got nice and overly toasty warm and weren’t exactly fertile anymore. So that was nice and traumatizing.
And, in the exact same issue, was an article about how the melting ice sheets are – in measureable ways – changing the salinity of the oceans.
Fraser: With unknown consequences. We don’t know what changed salinity of the oceans is going to do downstream to the fish populations, to what we depend on to eat.
Pamela: We know what it will do to the weather. We don’t know what it will do to the fish populations. We don’t know – and clearly, fish that live in one part of the world won’t be able to stay put. But we’re already seeing that. We’re already seeing where coral reefs are dying off because the temperatures have gone up in certain ocean regions. We’re already seeing migration patterns that are changing for birds, fish, seagoing mammals.
Fraser: This is the heart of what we’re dealing with here, is that we have modified the planet to some extent. We’re not killing the planet, right? We always we want to “save the planet” but the reality is, if we weren’t here, give the planet a few thousand years and it would reset – no problem – as if we were never here. It will get that carbon dioxide out of the atmosphere. It will get rid of the – you know, the ozone layer will replenish. The – all of the pollutants will be gone and the planet will move on just like it always was.
What we are doing is we are making the planet uninhabitable or – for us, for humans – the way we like it.
Pamela: This is where we have to remember, the way the dinosaurs died was a planet-destroying event. If that event happened right now, civilization – gone. No more civilization.
Pamela: And the planet recovered and we’re here.
Fraser: Yeah, it wasn’t a planet-destroying event; it was a dinosaur happiness-destroying event.
Pamela: Yes, yes.
Pamela: And so, where we’re trying to figure out how to save all of our coastal-dwelling populations, while we’re trying to save our ability to grow and harvest and hunt and gather enough food for the world’s population, we need to keep in mind that’s what we’re trying to do.
And the real risk that we’re looking at right now is, in some of the worst-case models, we’re looking at: If those mid-ocean conveyor belts shut down, we end up with increased overall heating; we end up with increased cooling in otherwise fertile areas – like England. We end up with inability to grow crops in a lot of places – in equatorial outwards, the mid-latitudes – that we previously have been able to, quite happily, grow in. And so, we end up with this narrowing band of: Where do we have a sufficient ability to grow crops?
And we also lose all the cities that are happily sitting on the coasts right now.
Fraser: Right. But this sort of goes back to the geoengineering. I guess the point is, is that there are amazing, mind-bending ideas about the things that you could do to push back against the kinds of changes. If the temperature is rising across the planet, the temperature rise is due to the albedo; it’s due to the amount of energy that is reaching the Earth. Push on one of those levers and you will get the temperature to move in the direction that you want it to move – with unintentional consequences.
Pamela: And so, it becomes a matter of: What are the connected variables? What are the dependent variables – in math terms – and what are the independent variables?
So, if we create an algae bloom, how does that change the salinity? How does it change the acidity? How does it change all those things that cause me to periodically freak out – that I just killed three fish due to not noticing the algae bloom in my own personal fish tank? The ocean’s a whole lot more complicated than my personal fish tank.
But we know that the atmosphere is directly tied to the thermodynamics of the ocean, which is tied to the salinity of the ocean. So now we have a bunch of dependent variables. We also know that the salinity is tied to the melting of the ice because of albedo effects. So, does the albedo become the dominant variable that we need to change? That’s where a lot of people are looking.
How do we fix salinity of the oceans? That one is just sort of, like – Well, there’s some children’s stories out there but that doesn’t help reality.
Fraser: Put salt in it. Right?
I mean, again – I mean, the thing is, is that when you get to this mindset where you’re like, “We can just undertake an enormous project. We are going to fill 10,000 supertankers with iron, we’re going to dump it into the ocean, we’re going to cause algal blooms and that’s going to –”
You know, once you’re at that place, I think you’re way beyond trying to fine-tune things. This is a hammer –
Fraser: – that is trying to buy you time to stop the bigger, larger disasters – the runaway situation.
What kinds of costs are we looking at, to impact – to affect some of these changes? Are any of them reasonably priced?
Pamela: The – Strangely, the most reasonably priced is probably dumping a whole bunch of dragonfly reflectors in space.
Pamela: Which sounds kind of ridiculous but it’s a nice, straight-forward, reversible process where we know all of the variables involved in getting it done.
Other things that I’ve heard, that seem to not necessarily have impossible prices, include things like: Let’s start pulling the water back out of the ocean where the glaciers are going in and freezing it. So, think massive snow-making machines where you’re pulling fresh water out, putting the salt back into the ocean. That starts to look much, much more expensive again but is technology we have.
Pamela: These are things we know how to do.
Fraser: I mean, that’s like – That’s how a salination – desalination plant works, is you’re pulling ocean water out. You’re separating out the salts. You’re using the fresh water and you’re dumping them in a pile. Why not take them and throw them back out into the ocean to try and balance out that salinity level?
Pamela: Now, Lord only knows if we can make new glaciers. I personally find that kind of on the impossible list and am much happier with dragonfly mirrors in space.
I don’t know where to put dumping iron in the oceans on the feasibility scale, simply because that one seems to have so many dependent variables that we don’t fully understand; that you have to wonder: So, is all of that happy, little, metabolizing life going to generate extra heat we haven’t taken into consideration? What is it going to do to all the other populations in there? It’s kind of crazy.
Fraser: What are some of the craziest ideas that you have heard – ideas on modifying our planet at a massive scale? I mean, your dragonfly idea is already bonkers but –
Pamela: It’s bonkers but it’s bonkers within reach.
Pamela: Which I’m fine with.
Fraser: If you think that launching hundreds of millions of tiny, little mirrors into space to float around the planet is within reach, I – our space exploration program is doing great. Elon Musk is going to have so much money.
Pamela: Well, so along that same path, another idea is to put giant solar collectors in space; then tight-beam down the energy to, basically, collection facilities. But you’re reducing the overall amount of light generally hitting the planet and focusing it into a special facility designed to go, “Hi! I’m taking all of your energy and turning it into clean electricity.”
Fraser: Or keep that energy in space. Have space factories –
Pamela: Yeah, just –
Fraser: – that turn that energy into something useful out in space; send the final products back down to Earth. But that, again, is a level of space solar system colonization that we are so –
Fraser: – unequipped for, right?
Pamela: And the problem with trying to use solar panels, solar collectors, giant reflectors – that are large solid objects – is you need to put them in a larger orbit, a more stable orbit. And that also means they have to be proportionally bigger because – any of you who’ve ever made shadows with your hands know – the closer you are to something, the bigger the shadow to a certain degree.
So, I mean, it all depends on the light source. I’m talking about collimated light source; here, we’re talking about the sun. The further away you are, the bigger the shadow you’re going to have but, at the same time, the overall amount of area that you’re going to have to cover – to cover the entire planet – you need bigger things to have the same amount of overall coverage. So, if you’re close-in, you can block 90 percent of the surface with smaller things than if you’re trying to block 90 percent of the stuff from further out.
So this is a very counter-intuitive system that is extremely hard to try and figure out how to sensibly explain without drawing stuff. And getting things into higher orbits is more expensive. Building bigger things is more expensive. Getting a whole bunch of little, tiny dragonflies in a nice, friendly, lower orbit they decay out of – at a reasonable rate – it’s easier.
Fraser: The state that we’re at right now with sort of the political discourse across the planet, we can’t even agree – you know, people in various countries can’t even agree on – that reducing greenhouse emissions are important; that taking these kind – making these kinds of changes matter. I just can’t imagine the political agreements that would be required to, for example, expend $10 trillion – give $10 trillion to Elon Musk – to launch all your little dragonfly mirrors into space. Or to, you know –
And I guess – But obviously, you know, you get to a place where it’s become obvious that we’re past the point of no return; that everything is just going to get worse. Is it then too late? I mean, isn’t that sort of the problem with projects of this scale, is they won’t get approved until it’s too late to do them anyway?
Pamela: This is where – just to be entirely bleak – sometimes you just need a good supervolcano to go off, and the one under Naples is looking pretty friendly right now. Go visit Naples now; it may not be there in the future.
The planet does periodically undergo some nice, friendly catastrophes that help lower temperatures. But, when it comes to trying to fix things on our own, it is the kind of thing where the longer you wait, the worse the problem gets and the harder it is to fix.
Looking at the often-discussed asteroid issue, if you essentially breathe on an asteroid far enough away, you can deviate its orbit enough that you don’t have to worry about it. But if you wait until it’s three months away from the planet Earth, we may not have the capacity to save ourselves. And that difference in moving something just a tenth of degree in orbit, that tenth of a degree compounds and compounds and compounds. So the earlier you can do it, the more it matters.
If anyone’s ever played pool, you know that if the difference between the cue ball and the one you’re trying to get into a pocket is 3 inches, you don’t have to be as careful with your aim as if you’re trying to go across the entire table. We’re looking at the types of problems that slight, not-exactly-on-target mistakes add up the same way. If we can do something now that doesn’t require the same level of accuracy – that doesn’t require the same amount of strength – we can probably turn things around. But it may be too late.
Fraser: Right. And it’s one of those things that the – As you say, the earlier you know that the problem is there, the earlier you know that the solution is there, the longer time you have to put in your changes and see them compound over time. But, at the same time, the more difficult it is to get everyone’s agreement that that’s the direction – that’s the action – that you have to take.
If we find that asteroid on its way to Earth and we know for certain that it’s going to hit us in six months, everybody’s going to go, “What can we do about it?” And you’ll have as much political agreement as you need to go out and try to stop that asteroid from coming but it’s probably too late. If you find out about it a hundred years in the future and it’s very easy to make the change, it’s going to be very difficult to find the political will to reach out to it, until it gets – becomes more and more of an urgent issue. So it’s a funny thing.
This was not the helpful rebuilding happy episode that we, I think, thought we were going to have, going into it.
Pamela: Oh, no. I knew how bleak this one was going to be.
Fraser: Yeah, yeah.
Pamela: I think we need to start – having given up on the possibility of geoengineering solutions –
Pamela: – ahead of time, why don’t we spend our next episode talking about, “Okay, we ruined the planet.”
Pamela: Now –
Fraser: Okay, how do we fix the terrible things that we’ve done?
Pamela: Yeah. How do we fix a world that we’ve given up on?
Fraser: Sounds good. How do we terraform Earth?
Fraser: I love it.
Alright. We’ll talk to you next week.
Pamela: Talk to ya later.
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Duration: 32 minutes