Although climate change is at the forefront of discussions throughout the world, geoengineering (climate engineering) is not. Most people have never heard of it, and of the few who have, they don't really understand it. We created a teaching module to educate students about the science and engineering of geoengineering. In doing so, we have an opportunity to be early movers, setting the tone for responsible, informed discussion of climate engineering and establishing a climate literate populace. Through these objectives, students will become part of the solution.
Purpose
In the face of global warming, students are dreaming up a better climate future
Quoting NPR All Things Considered from August 5, 2024 interview:
"This conversation is part of a larger lesson about developing technologies that reduce planet-heating pollution. The lesson was created by Kravitz, an associate professor of earth and atmospheric sciences at Indiana University; his colleague Paul Goddard; and Kirstin Milks, DeWayne Murphy’s science teacher at Bloomington High School South in Bloomington, Ind.
With heat waves and extreme weather becoming more and more common, Milks wants to empower her students with information and the creative freedom to dream up big ideas for a better climate future.
“The fact is that climate change is the story of these young people's lives,” Milks says. “Our students need to know not just the stuff about it that is challenging and difficult, the stuff we hear about in the news, but also they need to see how change can happen. They need to feel like they understand and can actually make a difference in our shared future.”
Kravitz says, “The only permanent solution to stopping that is reducing our greenhouse gas emissions.”
Scientists already know some technologies that could help. Solar and wind energy combined with big batteries are helping the world transition away from oil, coal and gas.
But Kravitz says the world isn’t moving fast enough. So he and other scientists are studying strategies to temporarily alter the Earth’s climate to reduce the effects of climate change. It’s known as climate engineering, or geoengineering."
The Climate Engineering Module is a wonderful experience to inform students about climate engineering, as well as engage them in the real work of building climate solutions.
Catherine Peterson, Bloomington High School South
About the Teaching Module
This module is part of the Educating for Environmental Change (EfEC) project. This teaching module aims at providing opportunities for students to understand the basic concepts of geoengineering, the social influences involved in the geoengineering process, and the emergency and complexity of addressing climate change issues.
Each lesson in this module is inquiry based with hands-on activities (aligned to specific Next Generation Science Standards!). Teachers can either use each lesson and/or activities individually to incorporate into your current curriculums, or use this module as a complete unit on climate engineering. We recommend that these lessons follow a unit on climate change science and its impacts. EfEC hosts many professional development workshops to help teachers prepare to teach climate and environmental science in their classrooms. We also encourage completing the lessons in order as the learning outcomes of each lesson build upon themselves. Materials to run the experiment in Lesson 2 are available for lending, please reach out to Paul (pgoddard@iu.edu).
All lessons are aligned to NGSS and include lesson plans, powerpoint presentations, worksheets, and materials. The lessons also contain tips for scaffolding and suggestions for “gear up and/or gear down.” Feedback is most welcome.
Climate Engineering Introduction
Description of the video:
00:00:00:00 - 00:00:28:35Unknown
Hello everyone. So I want to talk briefly about climate engineering or geoengineering as we call it. So we're going to talk about geoengineering. We have to start with climate change. And this is a piece about climate change in ten words that I really like. It's real. It's us. It's bad. Scientists agree there's hope. And so let's look into this a little bit more.
00:00:28:38 - 00:01:01:16
Unknown
This came out very recently. in UN news there is no credible pathway to keeping global mean temperatures below 1.5°C above pre-industrial. Right. And so, there's a lot of pessimism about the idea of there's hope around climate change. Now let's look at this. This is guess temp. So this is, an index of global mean temperature change over the past 150 years.
00:01:01:20 - 00:01:29:15
Unknown
And we can see it's going up. That's greenhouse gases, but it's not going up uniformly. You can see there are some dips there. There are some greater rises. And in particular I want to point out these two dips right here. Those are due to some of the largest volcanic eruptions in the late 20th century. So in 1963 there was Mount Agung, and in 1991 there was Mount Pinatubo.
00:01:29:18 - 00:01:53:33
Unknown
And Pinatubo cooled the planet by about half a degree Celsius. And the way it did that is volcanoes, when they're really explosive, can take a lot of stuff up into the upper atmosphere. One of those things they can take is sulfur and sulfur. When it gets up into the atmosphere, forms these highly reflective microscopic droplet that we call aerosols.
00:01:53:36 - 00:02:20:32
Unknown
And those aerosols made out of sulfur are really reflective. They're very bright. And so they send off a small fraction of sunlight back to space. And that cools the planet. And so people looked at this and thought, well, if nature can do this, maybe we can do it on purpose and deliberately cool the planet. So that led to a variety of proposals under what we called geoengineering.
00:02:20:35 - 00:02:43:08
Unknown
So the one I just talked about is up in the top, right. Increase reflectivity from aerosols. there's also the one in the top left. Increase reflectivity from low clouds. If under certain circumstances, if we spray sea salt into these low clouds over the ocean, they can get brighter. there are a bunch of other ones as well.
00:02:43:11 - 00:03:15:31
Unknown
encompassing both increasing how reflective the planet is and also figuring out how we can pull CO2 out of the atmosphere. here's a sort of analog for the idea of making low clouds brighter. So ship tracks, ships, put out, a bunch of stuff from their, smokestacks. Those are called aerosols as well. And those aerosols can get into these low clouds and under certain conditions, make them brighter.
00:03:15:34 - 00:03:44:07
Unknown
and we can observe this from satellites. And so that's a way that we know that the so-called marine cloud brightening might work as well. So some of the main messages that I want to convey to you here are we could probably do this and it would be comparatively cheap compared to, say, reducing our greenhouse gas emissions. it could help a lot of people, but it wouldn't be perfect.
00:03:44:10 - 00:04:13:00
Unknown
The effects can be tailored somewhat. And very importantly, geoengineering can't be the only thing we do. So I'll go into some details on all of these. Here are some outputs from climate models. Specifically this is an average of 12 models. So and it's showing what happens if you increase CO2 and you turn down the sun. So this is a really simple way of representing geoengineering in climate models.
00:04:13:03 - 00:04:39:21
Unknown
You increase CO2. So that's the climate change part. You turned on the sun. And that sort of mimics the idea of reflecting more sunlight back to space. And what you can see here is there are some residuals. There are some changes. So in this case geoengineering over cools the tropics and under cools the poles. in order to get no change in global mean temperature.
00:04:39:24 - 00:05:07:08
Unknown
And all of the models show this. And you might look at this and you might think, wow, that's not great. so there are a couple of important messages on here. Number one, geoengineering is not perfect. reducing our greenhouse gas emissions is the way to stop climate change from reducing our greenhouse gas emissions. Geoengineering is not perfect, but this is compared to just the baseline.
00:05:07:11 - 00:05:32:17
Unknown
If you compare this to a high CO2 world, in the high CO2 world, everything would be red. We're talking like five, six, eight degrees of change on here. So geoengineering actually does help quite a lot. Now let me show you precipitation. So here are the sort of same simulations. On the right is if you increase CO2 and you turned on the sun and you can see there's some drying.
00:05:32:17 - 00:05:59:22
Unknown
So if you offset all global mean temperature change with geoengineering, you over dry the planet, especially in the tropics. So that's not good. But compare that to the left which is just the change due to the high CO2 world. And you see a lot of changes, especially really big changes in the tropics. So precipitation does go down under geoengineering, but it would have gone up under global warming.
00:05:59:26 - 00:06:25:03
Unknown
And you can dig into this in some detail and figure out that the areas that are getting wetter under climate change were already wet. So we're talking about more floods. The areas that we're getting drier under climate change get even. the the areas that are dry get even drier under climate change. And so you you're basically making everything worse under climate change.
00:06:25:03 - 00:06:49:09
Unknown
And geoengineering offsets that pattern. So it's not just more rain or less spraying. It's how does that rain fall? Now, this is a figure that's always worth pointing out. We call it sudden termination or geoengineering. So what if you're doing geoengineering and for some reason you have to stop? Well, because you've still got greenhouse gases in the atmosphere.
00:06:49:12 - 00:07:15:21
Unknown
The climate quickly rebounds to where it would have been if you'd never done geoengineering. So that's what that yellow line represents. So the red line is geoengineering. You're kind of going along offsetting a bunch of climate change. Then you stop. And the yellow line represents the rebound which happens over like ten years. So that's really hard to adapt to adapting to sudden climate change is never good.
00:07:15:24 - 00:07:38:36
Unknown
Now what this suggests is we need to figure out a way, if we ever did this, to mitigate that risk. And so the answer is, I mean, if you look at these simulations. So the blue line shows the climate change background. By the end of the 21st century, it's off setting like five degrees of climate change. That's too much.
00:07:39:00 - 00:08:01:07
Unknown
And so we would never want to get into a situation where we're doing that. And so what's the right amount of climate change for geoengineering to offset? We don't know. But five degrees apparently poses way too much risk. Now here's the effectiveness of geoengineering. So this is a really complicated figure. But there are ways to look at different metrics.
00:08:01:08 - 00:08:35:05
Unknown
So on the left precipitation minus evaporation. That tells you something about how much water is available for plants in the soil and on the right. Maximum five day precipitation. That tells you something about really intense precipitation events. So severe storms that might cause flooding. Each dot on here is a grid cell in a climate model. So a particular place and what they did in this study is they looked at okay, climate change does something to these two metrics.
00:08:35:08 - 00:08:57:38
Unknown
it moves it farther away from the baseline. And we're saying that's bad because people are adapted to where they are right now. So climate change move things away. What does geoengineering do? Does it move it back toward the baseline or does it make things worse? So if one of those dots is in the blue areas, that means geoengineering makes things better.
00:08:58:06 - 00:09:24:01
Unknown
Climate change does something in geoengineering moves. It back. If it's in the red, geoengineering makes things worse. On top of climate change. And what you can see from this figure is the vast majority of points are made better under geoengineering. So geoengineering does a really good job of offsetting climate change. Not perfectly, but it moves it in the right direction.
00:09:24:04 - 00:09:40:28
Unknown
Now, that's not, I can't make blanket statements like that. Like if you live in one of those dots that's in the red region, you might care a whole lot about this. But for the vast majority of people, it appears to make things better.
00:09:40:31 - 00:10:08:02
Unknown
Now this one, the effects depend on how you do it. This is a really complicated figure. I do not want you to memorize it, but I want you to look at, So each row is a different location of injection of geoengineering, and each column is a different season of geoengineering. And the the colors show you where the aerosols are and basically how thick the aerosol layer is.
00:10:08:05 - 00:10:29:38
Unknown
So you can see they're all different. if you inject mostly in the northern Hemisphere, the aerosols tend to stay in the northern hemisphere. If you inject in the southern hemisphere, the aerosols tend to stay in the southern hemisphere, and they vary by season. So this really matters because where the aerosols are is where the sunlight's getting reflected, which is where the cooling happens.
00:10:30:02 - 00:10:51:08
Unknown
So you can get different climate effects depending on where and when you do geoengineering. You can't get every climate effect you could ever want. Like you can see, for example, that if you injected a certain latitude, the winds will blow it around the earth so you don't get to pick. You know, I only want to inject over my country.
00:10:51:11 - 00:11:16:03
Unknown
It's a pretty broad coverage, but you can get some degree of control. And so how that matters. looking at these, for example. So there are three simulations represented in here looking at temperature change in the Tibetan Plateau. So it's that red square on the right. And precipitation change in India, which is that black square on the right.
00:11:16:06 - 00:11:41:00
Unknown
So these three simulations look at injecting year round, or only injecting in the autumn, or only injecting in the spring. And what you can see from these is so if everything were on that very thin black line, geoengineering would offset climate change perfectly. So none of these does that, but the red line is closer to that than the other two.
00:11:41:03 - 00:12:12:14
Unknown
So for these particular objectives, injecting sulfur in the autumn does better than injecting it in the spring or year round. Now, what I'm not showing you on here is that's great for India, but for the Amazon it's the opposite. You want to inject in the spring according to these simulations. So there are some trade offs in here. And balancing all of those is going to be a really hard task for the politicians who need to wrestle with this topic.
00:12:12:17 - 00:12:35:26
Unknown
So what's the role of solar geoengineering? What should we do with geoengineering? And so on. The left is, a way a lot of people really talk about it. So on the x axis is time. On the y axis are climate impacts. These are deliberately unlabeled because that's still an open area of research. But if you look at that red line there so that's business as usual.
00:12:35:35 - 00:13:00:09
Unknown
Just keep emitting. Don't worry about climate change. Just emit because that's what we want to do with our energy system. and you can see the impacts keep going up. Now in the black we can cut emissions aggressively. And that's great. We have to if we're going to stop climate change. But that will freeze the impacts where they are because CO2 lasts in the atmosphere for a really long time.
00:13:00:13 - 00:13:24:21
Unknown
It doesn't make things better. It just keeps them from getting worse. So the way we can make things better is to actually pull CO2 out of the atmosphere. And that's the green. So pulling CO2 out of the atmosphere and pumping it underground, for example, will eventually reduce the climate impacts because the climate impacts are caused by the CO2 in the atmosphere.
00:13:24:24 - 00:13:52:19
Unknown
But that is slow. It's going to take a long time. And so what do we do in the meantime if we want to bring climate impacts down? Maybe this is a role for geoengineering. We can temporarily bring the impacts down while these other things, get going. So that's on the left. On the right is if we view geoengineering as a substitute for all of these.
00:13:52:27 - 00:14:16:02
Unknown
So just keep emitting, do whatever we want and only do geoengineering. And what you can see from that graph is we would have to do more and more and more geoengineering forever. So that's not a sustainable solution. And as you saw from the plot I showed earlier, there's a greater and greater risk of termination. The more geoengineering you're doing.
00:14:16:05 - 00:14:40:37
Unknown
So we don't want to do that one. Now is it possible? And if so, how would you do it? So on the right is sort of an artist's rendition of all of the different methods that people have proposed to do this. So pumping sulfur up in a very tall tower or launching it in weather balloons, or shooting it up into the atmosphere with artillery.
00:14:41:01 - 00:15:14:07
Unknown
As it turns out, the best idea, both in terms of cost and just general feasibility, is airplanes. and there are people who are working on what might these airplanes look like? So if we want to cool the whole planet by about a degree Celsius, we would need about 10 million tons of sulfur up in the atmosphere. And we could do that with airplanes on the order of 10 to $100 billion a year.
00:15:14:11 - 00:15:38:14
Unknown
with the number of aircraft you would need or the number of air traffic you or the amount of air traffic you would need is on the order of a large airport. so, you know, this is expensive, but it's also reasonably doable. If we needed to do this. So some conclusions you can pull from this. And I already said what these were.
00:15:38:17 - 00:15:57:20
Unknown
We could probably do this and it would be comparatively cheap. So 10 to $100 billion a year is a lot of money. I don't have that, but it's certainly cheaper than the trillions of dollars we would need to overhaul the energy system. Another catches. We have to do both.
00:15:57:23 - 00:16:17:22
Unknown
This could help a lot of people, but it wouldn't be perfect. And what's really important in here is who would it help? that's a very important question to consider, because if it's just helping the people who are rich and could adapt to climate change anyway, and the people who can't afford to adapt to climate change are the ones who are suffering.
00:16:17:26 - 00:16:45:30
Unknown
That's not good. The effects can be tailored somewhat. So it's not perfect. There's still going to be trade offs. But it's not just the world needs to agree on one global temperature. It's more nuanced than that. And I've said this before and I'll say it again. Geoengineering can't be the only thing we do. It has to be accompanied by mitigation, carbon dioxide removal, adaptation.
00:16:45:34 - 00:16:50:25
Unknown
All of these things that we are talking about a lot.
00:16:50:28 - 00:17:10:01
Unknown
So now I want to talk a little bit about some supplemental material for the teachers. So if you're going to teach this, of course, you know, you want to be familiar with the topics, you're probably going to get a lot of questions. So here are some resources. the first one is a primer written by some colleagues of mine.
00:17:10:05 - 00:17:33:02
Unknown
It's a little advanced, but it's meant to, be for a general audience. I think they did a really good job. The second one is a video called A Horrible Idea we might Have to Do. I think they did a nice job with this. The third one is a video from The Economist. They did some things that I really like, and they did some things that I really don't like.
00:17:33:05 - 00:17:49:28
Unknown
And so it would be interesting to do a lesson going through that with students and having them figure out what's right and what's not. it could lead to some really interesting debates. And then the last idea is something I always like to do is scavenger hunt. There's now getting to be a bunch of stuff on geoengineering out there.
00:17:49:28 - 00:17:53:29
Unknown
So what can the students find about it?
00:17:53:32 - 00:18:28:05
Unknown
Why study this in the classroom? We'll probably need it. So I one of the first slides I showed was that report from the UN Environmental Program. we're not going to stay below one and a half degrees without this. So if we believe that's an important goal, we're doing geoengineering. Today's students are tomorrow's world leaders. They're the people who are going to be making decisions around geoengineering or at the very least, they're going to be the people who are voting for politicians who are making decisions about this.
00:18:28:08 - 00:18:54:02
Unknown
So they need to be informed. This is something I run into all the time, with friends, with my students, everywhere. There is crippling climate anxiety. And when I teach climate change, I always do a lesson on geoengineering. And I do not give it a rosy picture, but the students seem to resonate with it. It's sort of like, oh, thank God they're something.
00:18:54:02 - 00:19:16:18
Unknown
We're just not going to we're not just going to die. and so I think this is a valuable tool to have in your toolbox. And also, it's hard to find ways of bringing engineering into the classroom. This is a ready way to do it and still teach about climate change. And let me talk about that one a little bit more.
00:19:16:22 - 00:19:55:07
Unknown
So the next generation science standards here's HS. Yes 3 to 4. Earth and human activity. And I want to zoom in on the clarifying text in there. More specifically, large scale geoengineering design solutions. This is in the next generation science standards. So the Department of Education wants teachers looking into this. And teaching their students about it. So some learning objectives that I think would be useful, and that we're going to cover in our modules.
00:19:55:10 - 00:20:18:03
Unknown
A basic understanding of climate change. You can't talk about geoengineering unless you talk about climate change. So also under geoengineering what's going to happen if we do this? The physical climate effects. and that starts to get very complicated. It's an active area of research, but there are ways to cover it simply. And I hope I gave you a few examples of that.
00:20:18:06 - 00:20:42:33
Unknown
The engineering of geoengineering is a lot of fun, and you can get students involved in design activities. Also encouraging evaluation of evidence to draw conclusions. There are a lot of people who have a lot of opinions on this topic, and believe me, I do too. I don't particularly like the fact that geoengineering looks like it's necessary. I'd like it if we didn't have to use it.
00:20:42:36 - 00:21:06:23
Unknown
But there are, given that we might add a. At the very least, we should consider it and talk about it. There are lots of people who like to share their opinions, and not all of their opinions are right. So being able to pick those apart is really important. And the broader implications. So decision making should hopefully include science.
00:21:06:26 - 00:21:30:34
Unknown
But it can't be solely based on science. There are a lot of other things that are really important. And so understanding how science fits into this discussion is a useful lesson. So some topics that need to be covered. climate change and energy balance is essential. That's basically you know what geoengineering is manipulating volcanic eruptions and how they cool the planet.
00:21:30:37 - 00:21:53:04
Unknown
Aerosol cloud interactions. So that deals with marine cloud brightening. And Paul is going to show you a cloud brightening activity that will do the effects of geoengineering as revealed through climate models. And that's really important because we've never done this in the real world. So we don't have observations what those effects mean. So I've talked a lot about temperature, precipitation.
00:21:53:04 - 00:22:09:26
Unknown
You can talk about sea ice, but how do you translate those into food security, water security, trade geopolitics. and then the ideas for how to do it and how much it would, would it take. So that's all I've got.