Short Wave - Who Should Control Earth's Thermostat?

Episode Date: May 21, 2021

Solar geoengineering--the human attempt to cool the planet by reflecting sunlight away from Earth--is fraught with technological and ethical challenges. Maddie discusses some of these with contributor Ariela Zebede.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, nerds, Maddie Safai here with former Shortwave team member, now contributor, Ariel Zabidi. Hi, Madi. Hi, Izzy. Today, I want to talk about solar geoengineering. It's this idea that humans can cool down the planet by interfering with how the sun hits the Earth. Let me play you something. Today, 79 countries will begin dispersing CW7 into the upper layers of the atmosphere.

Is this the movie Snowpiercer? According to scientists, the artificial cooling substance, CW7, will succeed in bringing average global temperatures down to manageable levels as a revolutionary solution to mankind's warming of the planet. Is this just because you love the movie Snowpiercer? What are we doing here? It is an amazing movie. And for anyone who hasn't seen it, they shoot these particles into the sky to try to cool the earth. And it's based on solar geoengineering. Okay.

I brought Snow Pearson here today for a real purpose, which is to say that this used to be the stuff of science fiction, but now there are some scientists seriously looking into this type of technology. And the basic concept is actually pretty simple. It's getting too hot on Earth, so let's just turn down the heater. The heater being the sun. Exactly. The sun sends energy to the Earth, which heats it up.

And the idea with solar geoengineering is to make it so that less of the sun's energy ever reaches Earth in the first place. So we kind of like dim the sun. Yes. Okay, okay. Not to immediately derail things, but even if solar geoengineering did cool things down, we've still got a ton of greenhouse gases in the atmosphere, right? Yes, and warming isn't the only problem that comes with emissions.

We've got ocean acidification and local air pollution. Solar geoengineering doesn't adjust those issues at all. And isn't the point of the unbelievable movie Snowpiercer that solar geoengineering is also really risky? Like, in the movie, it leads to an ice age. Yeah, and snowpiercer is obviously dramatized, but there is a lot researchers don't understand about the climate system, and messing with it could have terrible consequences. So today on the show, a look at solar geoengineering.

How this technology works, the risks and benefits, and how its ethical implications might be even more complicated than the scientific ones. This is Shortwave, the Daily Science Podcast from NPR. All right, Aiz, before we dive in, I want to understand why scientists are talking about solar geoengineering if it is like, you know, kind of risky. Well, the world we're living in is already risky. We're already seeing the devastating impacts of climate change now. And the planet is on track to keep on warming, which could lead to huge parts of the planet being uninhabitable. It's going to take a lot of changes big and small to stave off the worst effects of climate change, which is something Juan Mora

General Cruz told me. He served on a National Academy's Committee to examine solar geoengineering research. We are running out of time and options. And the fact that we're thinking about this is the most clear indication that we are in a very difficult time. Because if we had done what we should have been doing back in the 1990s, once we first realized we had to move our away from fossil fuels, we probably wouldn't be thinking about solar geoengineering because solar engineering is risky. I have to start with saying that none of these solar geoengineering technologies really exist yet.

There are a couple of small-scale establishing trials, but this is all mostly theoretical right now. And so there's a few different ways this might look. A lot of this technology is actually inspired by volcanoes. A desolate and eerie landscape in the northwestern Philippines. In 1991, there was this big volcanic eruption in the Philippines from Mount Pinatubo. It looks like the aftermath of a nuclear holocaust. Oh, yeah. I remember hearing about this. It was devastating. Hundreds of people died and thousands lost their homes.

As it settled, the debris blotted out the sun and coated hundreds of kilometers of Philippine countryside. And when it erupted, it also released a lot of sulfur dioxide into the atmosphere, almost 20 million tons. And these particles reacted with elements in the atmosphere. and spread all over the world, eventually covering the globe in this kind of hazy shield. For the next 15 months, the planet was half a degree Celsius colder. Wow. I mean, I didn't realize that. And scientists are hoping to limit warming by like 1.5 degrees. So half a degree at once is a really big deal. Yeah, it is.

I mean, how does that work? Well, these sulfate particles are like tiny mirrors. When sunlight hits them, they reflect almost all of that back into space. So the sunlight never reaches land, and then we have cooling. Yeah, and one version of solar geoengineering involves having special planes release these types of particles into the atmosphere. The idea is that on a large scale, like what happened after Mount Pinatubo, this would have a cooling effect by reflecting sun away. There's another kind that has to do with clouds. Scientists are playing around with adding different particles to clouds to make them whiter, so they reflect.

even more light away. Wild. Okay. So even if these techniques successfully turned some of that sunlight right back around and slowed down warming, it still seems pretty risky. Like, is it at all realistic that this ends up in like way too much cooling, like Ice Age style snow piercer? Unless we did it on purpose, probably not. But there are other potential concerns with implementing something like this. And researchers don't know the full scope of what they could be. That's why people are advocating for studying it. They hope that there's a way to do this with minimal side effects. Theoretically, though, it could harm oceans, it could affect global rain patterns, lead to flooding or severe droughts. It could also affect agricultural production. Okay, and what about health concerns?

I mean, we've spent like years trying to get pollution out of the air, we breathe, and now we're going to intentionally add particles to the atmosphere. Yes, and scientists are exploring different types of particles they could use to have the same cooling effects without being. dangerous to inhale. The bigger health concern, though, is that some of the particles people are thinking about could damage the ozone layer. After the Mount Pinatubo eruption, ozone depletion rates skyrocketed. Right. And that puts us at risk for increased UV exposure, which can lead to cancer, bad stuff. Bad stuff. And maybe the main technological concern is that these particles only stay in the atmosphere for a couple of years. And when they fall down,

temperatures quickly spike back up to what they would have been. That sudden spike, in temperature could be even more disastrous than the gradual one from climate change. So it's not like a one and done thing. No. We'd have to keep spraying these indefinitely if we go this way. Yeah. And Maddie, even with all of the risk we've already talked about, I actually think that the ethical and social implications of using solar geoengineering are even more complicated than the technological ones. Makes sense.

The first thing to realize is that this technology is theoretically pretty cheap. They estimate that a program to release reflective particles would cost about a couple billion dollars a year, which sounds like a lot, but is way less than the trillions of dollars needed to transition to clean energy. And a couple billion dollars a year is something a powerful country could swing easily, or even one billionaire could potentially do on their own. Okay, so even if one country can do it, the technology would affect everyone, right? Like we all share one atmosphere more or less. Exactly. And different people and different countries will disagree on how much cooling we want to have. In some places near the poles, warming may mean more laying can be used for agriculture, but the same temperature change could devastate many island nations. So the question's like, who gets to set the thermostat, essentially? Right. Or say there are a series of terrible climate disasters in a certain country. A leader might decide to implement solar geoengineering in response. And remember, these effects are pretty fast acting. Here's Juan again.

One of the main reasons why this could be an issue is because the political cycles and the geoengineering cycles align in the sense that if you want to run for re-election and you deploy solar engineering, you will see the effects before your next election cycle. Wow. Yeah, and researchers worry that if one country decides to dim the sun, another country might try to undo those effects by putting warming particles into that atmosphere. I have spent the second part of my career researching this trying to look for ways in which this doesn't end up into a stratospheric war in which people just start to throw things in the atmosphere, trying to cool each other or warm each other. And it's hard to think about that. To avoid that kind of scenario, Juan says there would need to be some sort of global coordinated effort, an effort that includes imposterous. from people and governments alike. And most importantly, includes the voices of low-income countries because warming will probably

hit them hardest. And high-income countries are usually the biggest polluters. So, you know, why should they get to decide? Absolutely. All right, Ariel, honestly, this feels impossible. Yes. I don't mean so hard for the world to get on the same page about anything. I can't imagine a world in which we all agree on doing it one way and that way is ethical.

Yeah. And there are also these more fundamental ethical questions. Like, is it moral for humans to intentionally mess with the climate in this way? For many, the Earth and the sky are sacred. I spoke to Tom Goldtooth. He's the executive director of the Indigenous Environmental Network. We cannot treat the living world, our Mother Earth, as an engineering subject, as a laboratory. That's wrong.

Scientists that don't understand that we're not. relationship with that sacredness of Gaia, that sacredness and spiritual relationship with Mother Earth. So we're trying to also wake up Western forms of science to understand that Mother Earth is a living entity, has a spirit, has a personality, has a voice, and she has their own songs. So even if the technology ends up working really well with no side effects, for some, all of these ethical and governmental concerns might be reason enough not to pursue solar geoengineering. All right, Ariel. Well, okay, today I've learned that this whole thing is more complicated than it seems. And honestly, it already seemed really complicated. Like,

I'm having in a hard time understanding how or, you know, why anyone wants to do this. Well, no one I know of is saying, yes, let's do this. Great idea. You know, all in. The big argument happening right now is should we be devoting any resources to researching solo geoengineering? Many scientists who work on this technology say they hope society never has to use these technologies. But they also say that humans have let climate change get out of control. And if we don't get our act together soon, the negative effects of solar geoengineering might be. better than the alternative. And that's why people are advocating for research because, you know, the world as we know it is already changing. Right. But a lot of other people advocate for a global ban on solar geoengineering. Some worry that even talking about geoengineering will distract from

efforts to decarbonize the economy. If people know that there's this emergency break option, maybe they won't be motivated to tackle the root causes of climate change. Here's Tom again. You know, we consume too much. We create too much waste. We are addicted to energy, and we have to make a just transition as soon as we can away from a fossil-frew economy. You know, society, humanity takes shortcuts rather than making those hard decisions that we need to make. Yeah, I mean, the changes businesses, governments would actually need to make, like significant changes to address the root causes, instead of treating the symptoms, are really hard. And he's arguing that geoengineering would allow us to continue to take those shortcuts. Yeah. But for some people, the possibility of a future with geoengineering is just

terrifying. And maybe that fear is enough to motivate people to act on climate change. Here's Lisa Dilling. She worked on the same National Academies Committee as Juan. I'm just going to say that. I have a lot of respect for people who are arguing that we need to understand it more. But I have to say, this is just personal, after going through the two years of the committee, I feel even more committed to working on the root sources of climate change myself. I hope that, and this is my personal view, I hope we never, ever have to deploy a geoengineering technology. All right, Arielzeb. This was super interesting. I had no idea this was going

on. So thank you for bringing it to us. You got it, bud. This episode was produced by Rebecca Ramirez, edited by Giselle Grayson, and fact-checked by Tyler Jones. I'm Maddie Safaya, and you're listening to Shortwave, the Daily Science Podcast from NPR.