Slow Carbon - The Slow Carbon Cycle
Dr. Jesse Reimink: [00:00:00] Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
Chris Bolhuis: Did he get it?
Dr. Jesse Reimink: I got it. I, I'm on my, I'm on my B minus game today, Chris.
Chris Bolhuis: That's all I ever get, Jesse.
Dr. Jesse Reimink: I know that's
Chris Bolhuis: that's all I ever get. I've never seen the A game,
Dr. Jesse Reimink: Ah, [00:00:30] how exciting for you though when you do. It'll be, it'll just be amazing.
Chris Bolhuis: seen it. Will it, though?
Dr. Jesse Reimink: Oh, you'll be just totally blown away when you see my A game.
Chris Bolhuis: I cannot wait. I can't
Dr. Jesse Reimink: I know, like everybody else. Everybody in my life is waiting for the A game to come out.
Chris Bolhuis: You're just one huge mammoth
Dr. Jesse Reimink: just all the time. It's been a minute, man. It's good to, uh, it's good to see your face. Over zoom
Chris Bolhuis: Is it? Hey, how do you [00:01:00] like my beard?
Dr. Jesse Reimink: it looks better in 2d than I imagine it does in 3d. So I, I'm glad we're over zoom.
Chris Bolhuis: so you're not a fan then. That's what you're saying.
Dr. Jesse Reimink: you know what? It's not my opinion that counts really. So
Chris Bolhuis: Jenny did depreciate the gray pelt laying across my face joke that you made last time we got together.
Dr. Jesse Reimink: I, I'm proud of that one. I thought that was a pretty good one.
Chris Bolhuis: Yeah, she uses that quite often. It's come up like five or six times in the last week. So, but she likes that. She does. She's the reason I'm doing this. She said, I want to braid [00:01:30] it. So that's what we're doing.
Dr. Jesse Reimink: there we go. Two questions. Does Jenny give me credit for that turn of phrase or no?
Chris Bolhuis: she hasn't listened to the episode where we talked about it yet, cause I don't know if we've released it yet. And so I took credit for
Dr. Jesse Reimink: Okay, fair enough, as long as somebody's getting credit around here.
Chris Bolhuis: what I do. Well, speaking of that, hey, this is hilarious, right? I have to own something. I, cause I like to pronounce things correctly. Okay.
Dr. Jesse Reimink: [00:02:00] Oh boy, not the
Chris Bolhuis: about We've gotten emails and I own it it is totally on me and I didn't know this but I have been pronouncing Asphalt incorrectly and we've gotten numerous emails that are like what is going on guys?
It is asphalt not asphalt
Dr. Jesse Reimink: Yes, let me interrupt, let me interrupt because I agree you have been, but also it turns out like all of the state of Michigan pronounces it asphalt and also a decent chunk of like that part of Canada, you know, [00:02:30] Ontario, that region of the world, we have a tendency to mispronounce things and going back to our common you know, we talk about this a lot.
Pronunciations of geological things. I kind of absorbed the Britishisms and the Canadianisms while I was in Canada. And I, unlearned asphalt. And, uh, I learned, you know, correctly, asphalt. So, we have gotten a bunch of emails, maybe not a bunch, but several emails where I'm getting blamed for pronouncing it like an idiot, like ash fault.
And it's not [00:03:00] me, people. It's Chris. Chris is the one who's saying ash fault all the time,
Chris Bolhuis: that, but it did make my day. You got blamed for it. And it was, it was all me. I own it. I will never make that mistake again. and I appreciate the corrections because like stuff like that, Jesse, we get these emails and people are upset because I. I, or presumably you, mispronounced the word asphalt.
I don't think it's, it's not pedantic. I appreciate it.
Dr. Jesse Reimink: Well, I mean, some things are like pronunciations, like, I don't know, [00:03:30] the way you pronounce basalt or basalt. It's like, who cares? But asphalt and asphalt are kind of significantly different,
Chris Bolhuis: yeah, they are. Yeah. I did not know it was a Midwestern thing. So
Dr. Jesse Reimink: I'm guilty by association with you. So, but hey, that's life.
You know what? Yeah. What's the phrase? I'm going out on the horse I rode in with or
Chris Bolhuis: Yeah, that's true. That's why I've stuck with you for this long. I mean, I don't, yeah,
Dr. Jesse Reimink: So, today Chris, uh, we're talking about the [00:04:00] slow
Chris Bolhuis: Hold on, Jesse. Hold on. Let me interrupt you a second. we have not done introductions in a long time. It's been like, we just forget about this
Dr. Jesse Reimink: you know what? Hey, you're right. And actually we just went through this exercise where we went back and for various reasons, listen to some old episodes, some really old episodes.
Is a little painful. I'll be honest. Uh, is a little painful, but we did do introductions a lot better. So let's do them.
Good idea. Let's do them real quick. You are Chris Bolhuis, nationally recognized earth science teacher from the great state of Michigan. You taught me all [00:04:30] the basics of geology in what is effectively an AP geology class. You taught me field geology. you taught me earth science. I was in your classroom during 9 11 actually, if that dates me.
But, you know, you taught me three or four classes in high school and the basics of geology.
Chris Bolhuis: I did. I had you a lot as a student. and you're Dr. Jesse Reimink. You went on after you left Hudsonville, the little, hold on, and, and you're Dr. Jesse Reimink. And after you left Hudsonville, you went to Hope College right here in West Michigan. And, uh, after you got your bachelor's degree in [00:05:00] geoscience, you went to the University of Alberta to get your PhD.
that was a, not really the, yeah, you are, but that wasn't really the intended path. You switched directions a couple times, but you ended on a, you ended on a good note, you know, you got your doctorate and, uh, now you work at the Penn State University, which is awesome. Sometimes I'm actually proud of you, Jesse.
Dr. Jesse Reimink: oh, thanks. Appreciate it. and I, I would appreciate if you call me Dr. Reimink from now on for this episode. Thank you very much. Um, so...
Chris Bolhuis: You [00:05:30] are.
Dr. Jesse Reimink: Yeah, exactly. so today, the reason we went back and listened to old episodes is because this is in a theme that we kind of started in episode number three of Planet Geo or two or something like that, which was the greenhouse effect, which we're gonna redo, I think, here in the near future as well.
But with this episode, we're talking about the slow carbon cycle, because in that episode, we went back and listened to it. And we're sort of like, Okay, how much do we cover? What do we need to hit harder? And I think this is one of the things we thought we needed to hit harder was the slow carbon cycle.
Is that accurate, Chris?
Chris Bolhuis: I agree. We never really devoted [00:06:00] an episode to this. We've alluded to it a little bit, but we never said, all right, let's, parse this out. Let's talk about the slow carbon cycle. Then let's talk about the fast carbon cycle. We just never really did that. And, and this is more of a, well, we've been talking about it for a long time.
This is just more intentioned, I think, in, in what we're doing here.
Dr. Jesse Reimink: That's right. And so what we're going to do today is we're going to give an overview of what the slow carbon cycle is, it's really the rock based thermostat. a negative feedback loop that can warm and cool the earth.
It's related to carbon. [00:06:30] You guessed it. Greenhouse gases, CO2, but it's also related to rocks. And that's why it's. Interesting and exciting to you and I specifically, but we're going to go through that, the basics. We're going to talk about how it works. We're going to talk about a couple of examples, how it relates to big questions like plate tectonics.
and then the interaction of atmospheres and oceans. And we'll use a couple of examples. We will probably talk about Venus throughout this because Venus is kind of a good, greenhouse planet. It's like an end member of, of, you know, what happens if the carbon cycle gets disrupted too
Chris Bolhuis: That's right. And again, too, I'm [00:07:00] reminded we started preparing for this, how complicated the carbon cycle is. it's It's hard to, and we're going to try to like stay on track with this and, and be, you know, as succinct as we can, but it's very, very complicated, all of these interactions, you alluded to it right there in terms of what we're going to talk about, how in the world does the carbon cycle relate to weathering of rocks and plate tectonics and, know, the Himalaya mountains, like, what is this all [00:07:30] about?
It's, it's a very complicated yet. I think fascinating, mental exercise. That's kind of how I
Dr. Jesse Reimink: Totally. Fascinating and incredibly important and very timely, like to society, important to society, important. We understand what's going on here because there's a whole bunch of new stuff in the geoscience space that is specifically on this reaction or this process that we're talking about.
The slow carbon cycle. So let's start out with some numbers. We're talking about carbon, moving carbon through the earth system, which we're In my mind, the earth system [00:08:00] includes atmosphere, ocean, rock, deep earth, mantle, maybe even core carbon. We won't really talk about that, but moving carbon through these systems, you know, up and down and up and down in a circular motion.
That's what we think of with the cycle. Most of earth's carbon, this is 65, 000 billion metric tons. So, uh, a lot, a lot, a lot of carbon is stored in rocks. That's really first principles thing. It's stored in rocks.
Chris Bolhuis: The rest of it, though, well, where do you think it's going to be stored? If it's not [00:08:30] stored in rocks, what else? What other basins, what other kind of carbon sinks are there, right? And think everybody knows that the oceans are a pretty well known carbon sponge or carbon sink. So we have, there's a lot of carbon in the oceans.
There's carbon in the atmosphere, obviously, and that's where we, you know, we've talked about this before with the greenhouse on with unpacking that there's carbon in plants and soils. And then also, obviously, I think a ton of it stored in fossil [00:09:00] fuels like petroleum, natural gas and coal being like the big three, I think,
Dr. Jesse Reimink: Absolutely. And, and carbon is, through the process of, respiration and photosynthesis, carbon is flowing through these reservoirs. Metamorphism produces carbon. You know, the carbon is going through these reservoirs. We also think if you think of volcanic gases, Chris, I think, you know, carbon CO2, carbon dioxide is probably number two or number three that comes to mind.
Like we think water vapor, maybe sulfuric acid. Carbon dioxide is, immediately in our [00:09:30] headspace as geologists of like a gaseous phase that comes out of volcanoes, and that's part of the carbon cycle, the slow carbon cycle that we'll get to here. But it really is the thermostat. It is the knob that reacts to changes in your system that, what's called a negative feedback loop. So it kind of controls the thermostat. So you think of a thermostat in your house. Let's say you set it to, I don't know, Chris, somewhere. What do you keep your house at? Maybe 68 to 66 or something like that in the
Chris Bolhuis: is a little too chilly for me, but I'm burning wood too. I, so [00:10:00] I've got a fireplace and so I can crank it how I want it. You know, I like to be toasty. You know that about me.
Dr. Jesse Reimink: Yeah, well, you do. You, you like your toasty slippies and you put on your little hat and yeah, absolutely. I mean, that's the good life of winter in Michigan. You got to have that stuff. So let's say you set your thermostat to 68 degrees or whatever it is, you know, your thermostats not going to keep it right at perfectly 68.
000000 degrees. It's going to detect when the temperature drifts up half a degree and it'll turn off the heat. If the temperature drifts down half a degree, it turns [00:10:30] on the heat. The thermostat is going on and off, on and off. to keep the temperature in some interval. This is the same thing as this low carbon cycle.
Earth's weathering is controlling this, is keeping it in between these bounds, these temperature bounds, that change over time. But, but there is a
Chris Bolhuis: That's right. But we need to do a really good job, I think, of delineating how chemical weathering specifically regulates this thermostat. How does chemical weathering regulate carbon dioxide in the atmosphere or [00:11:00] carbon dioxide in the rocks and the oceans? So that's what we need to
Dr. Jesse Reimink: Yeah, I agree completely. I'm And so what we need to talk about, Chris is, is sort of three things. What do we need to do to drive this weathering or to create this cycle? We need to have one exposed rock, exposed to the atmosphere. That's a key requirement because.
That's how, that's where stuff gets weathered, right? I mean, I think that's kind of intuitive. You think of weathering, you think of mountains, you think of land, rocks exposed to the atmosphere. Two, we need oceans and rain. This is really important. We need water. We need a [00:11:30] hydrologic cycle. And three, we need plate tectonics.
And we're going to work through Why we
Chris Bolhuis: That's right. And actually though, if you think about it, numbers one and three, the exposed rock and plate tectonics, I think that they play hand in hand. And I think that that's fairly intuitive, you know,
Dr. Jesse Reimink: Okay, Chris. Yeah. Let me, let me ask you the question. Like, how does they play? Which one controls the other? okay. They're
Chris Bolhuis: well, okay. I mean, let me give this a go. Cause we didn't really talk this through, but you know, I think in [00:12:00] geoscience, there are two. broad, general categories of things that are going on. We have forces that build things up and we have forces that wear things down. And plate tectonics is the force that builds things up.
And this is exposing fresh rock, you know, you're, you're, you're shoving rocks to the surface and also your accelerating the process. It's harsher when you shove things up, weathering and erosion is more of an active process, which then also exposes fresh rock beneath them. So it's, this is kind of [00:12:30] this positive feedback loop, if you will, where you shove them up, you expose fresh rock.
And then because of that, you get more exposed fresh rock.
Dr. Jesse Reimink: really, really nicely said there. And so we need this exposed fresh rock and plate tectonics, like, as you said, is this beautiful conveyor belt of like pushing stuff up, keep pushing stuff up. And it keeps getting eroded down more fresh rock exposed at the surface, oceans and rain, then sort of go to work and start to control the cycle.
So Earth does a really good job of balancing this on long timescales. And [00:13:00] I think this is important. Let's define slow real quick here, because slow is over For hundreds of thousands, if not millions of years the feedback loops take a really long time, and that's why it's called the quote unquote, slow carbon cycle.
It takes a long time for this thing to activate, for the thermostat to switch on. It takes a long time for like your furnace to kind of kick on and warm up and start kicking out heat. That's a long process in this, slow carbon cycle as the name implies. That's what happens on earth. Now, Venus, we're going to talk about [00:13:30] Venus sort of near the end here, but Venus is kind of a greenhouse planet. It's where the carbon cycle went to die. Like there's no carbon cycle on Venus. And so it's a greenhouse planet and.
Chris Bolhuis: That's a good way of putting it.
Dr. Jesse Reimink: You know, the cycle stopped, our thermostat broke there.
and so we'll, we'll come back to kind of how that interplay works on Venus relative to earth
Chris Bolhuis: well, Jesse, can we just walk through an example then of this thermostat loop involving chemical weathering and so on? You know, should we do that now? So it really has to start off, well, I'm going to start anyway, with rain.
Okay? [00:14:00] You take rain that is slightly acidic. You know, I mean, if you have carbon dioxide at the atmosphere, H2O plus the carbon dioxide, create this weak acid called carbonic acid. And this then gets into the regolith, the kind of skin covering the earth. And bottom line is this slightly acidic rainwater is going to dissolve.
rocks. It's going to make ions, particularly like calcium and magnesium with these are the really important ones for this. and calcium and magnesium, these ions are found in [00:14:30] mafic rocks or ultra mafic rocks as well.
Dr. Jesse Reimink: And Chris, let me interrupt real quick and ask you a question that I know we've covered in Camp Geo, uh, before we were talking about this thing. So, ultramafic, ultramafic minerals, we're talking about like olivines and pyroxenes. Those things have a lot of calcium, a lot of magnesium, a little bit of silica, but not as much as like quartz or feldspar for instance.
But they're found in the deep earth, the mantle, right? So, are those more happy or less happy on the
Chris Bolhuis: I love it that you asked this question. We did not plan this out at all. [00:15:00] They're less happy at the surface of the earth, just kind of this basic rule, and I think it's, I think it's intuitive. Rocks and minerals are most stable when they exist in the conditions in which they form in. And the bottom line is, is that the more mafic a rock is, these form under the most extreme temperatures and pressures that exist near the surface of the earth, or even deeper in the earth.
And so, because those, conditions are so extreme, they're less happy at the surface, because that's a longer [00:15:30] ways away from the conditions in which they formed.
Dr. Jesse Reimink: that's the beautiful explanation is they're very unhappy when they hit the surface, they're easy to weather. That's the point. They're easy to chemically weather. And this is an interesting stat. Ultramafic rock. peridotite, like mantle rocks, mantle minerals, olivines, and pyroxenes.
If you bring that rock to the surface, it has 1 percent of the energy density that is stored in fossil fuels. And this is like chemical potential energy. That's a surprising amount of energy, cause like hydrocarbons are some of the most energy dense [00:16:00] materials we know of on earth.
And so, this is a lot of chemical energy, and what this is, is it's like energy stored in the minerals that's ready to be released when they're weathered. So this weathering process produces some energy, as the minerals in their very, you know, compressed high Temperature stable state, when they get to the surface, they wanna relax down and they relax down and release some energy.
But what that does is it releases calcium and magnesium ions, which are kind of dissolved in the water. Again, see above your, bicarbonate or your [00:16:30] carbonic acid. That stuff picks up some of the ions. It's carried in water, in streams or in groundwater, whichever way it's happening and it's.
brought into the oceans. Ultimately, all water flows into the ocean, right? So it's brought into the ocean. And then Chris, what happens? We've got calcium, magnesium, HCO3, which is that bicarbonate. What, what happens in the
Chris Bolhuis: Well, once it gets saturated in these compounds now, it's going to start to lay down rocks. It's going to start to precipitate rocks like [00:17:00] limestones and dolostones, right? so when the oceans get quote unquote too salty, they can't hold it anymore. And so as a result, they start to precipitate these rocks, right?
And the net effect is, is that carbon dioxide Well, first of all, you know, the carbon dioxide got dissolved in the oceans and you've alluded to it. It forms carbonate and bicarbonate anions, which that then is attracted to the positively charged calcium and magnesium ions. Electrical nature of matter takes over band and, they [00:17:30] just, they bond together and that's the makeup of those rocks, dolostone and limestone.
Dr. Jesse Reimink: and let me add in here, Chris, that on the modern earth we have a lot of stuff, a lot of creatures that build their homes out of calcium and bicarbonate, like a lot of stuff makes their shells out of calcite, aragonite, a lot of critters are going around soaking this stuff up, so on the modern earth this is often biologically mediated, meaning life is grabbing these parts and putting them together to make their house out of, and then they die and their shell becomes part of a fossiliferous [00:18:00] limestone or something like that.
It doesn't need to happen that way. There are times when the ocean, especially back in history, that the ocean gets like super saturated in the constituent parts and it just chemically precipitates without life involved, but on the modern earth it's sort of biologically mediated. Either way, we're making, we're taking those parts, calcium, magnesium, bicarbonate, and we're making rock out of it.
Chris Bolhuis: That's right. So, again, just to reiterate this process, carbon dioxide gets dissolved in the oceans, chemical weathering brings [00:18:30] calcium and magnesium ions to the water, through chemical reactions, these compounds combine to form rocks, or like you just said, organisms, these marine organisms are using those ions to make their shells, to make their protective hard parts, if you will, um, so it's forming rocks, right?
Well then, what happens to these rocks? These rocks are gonna get shoved down in a subduction zone.
Dr. Jesse Reimink: Well, Chris, let me. let me interrupt right there because we have to think about where are the rocks being formed. Well, they're formed in the ocean basin. Well, what [00:19:00] happens to oceanic crust? What's the oldest oceanic crust we have on earth? It's like 200 million years old. Why? Well, it goes down in subduction zones.
It gets recycled. It dives down into the mantle. What happens to the sediment on the top of that slab? It gets scraped off. It gets used to melt the mantle and ends up going into magmas. And ultimately, out volcanoes, like you love Mt. St. Helens and Mt. Shasta, it's coming out there.
Chris Bolhuis: And to your point, what you're saying, what Dr. Jesse Reimink is [00:19:30] saying, is that there is no such thing as old oceanic crust. 200 million years compared to a 4. 5 plus billion year old earth. that's not old. And that's because it continually gets recycled and limestone is often made up of these crushed marine organisms that took calcium carbonate out of the water.
That is also going to be a part of these subduction zones, which then comes out and forms carbon dioxide and it gets put back into the air. And we've fulfilled this loop then. with this one example right
Dr. Jesse Reimink: [00:20:00] Yeah, okay, th this is really great. Great. I mean, we've made the loop now, right? Cause it's, you've got Mount Shasta, Mount St. Helens, you've got big arc volcanoes. Think of the Andes, these volcanoes, they're like venting. There's gas coming out of there. We've got water and CO2 coming out of there.
And that CO2 ultimately came from subducted sediments going down or, or subducted altered oceanic crust going down into the subduction zone. Now it's coming out and it's being released into the atmosphere, being vented into the atmosphere where it can start this process all over again. I have to take a little [00:20:30] side tangent, Chris, and just say that there is carbon CO2 that makes it past this quote unquote subduction zone filter, like the sponge that squeezes out the slab and those often get stored in diamonds actually.
And so we've got, one of my PhD students is working on some of these diamonds that are stored in the deep earth, because carbon is brought from the surface down into the deep earth and can be stored in there. So. You know, if you're thinking about this, you're thinking, Oh, wait, there are diamonds. I know they come from deep.
That's carbon. How does this fit into the carbon cycle? It does. It's a [00:21:00] relatively small amount that makes it past this subduction zone filter. is carbon down in the mantle that came from the surface that forms diamonds now, but it's a relatively minor amount compared to the amount coming out of volcanoes.
Chris Bolhuis: Right. But what I would, what I want to do, Jesse, that's a really good point, I want to pose a question then to everyone out there, to our listeners. What happens if more CO2 then is put into the atmosphere? just total natural natural process non anthropogenic carbon dioxide. [00:21:30] So let's say that you have Circumstances that create abnormal high levels of volcanic activity.
Dr. Jesse Reimink: What if, Chris, let's say this, let's say the Atlantic ocean. Is spreading apart. You know, we've got Europe and Africa are going one direction and North America and South America going another. What if all of a sudden we start subduction there and we start funneling all the sediments that are in the Atlantic Ocean down into the subduction zones there and coming out in volcanic gases?
Okay, what's going to happen? This is the key, the thermostat part. [00:22:00] So what happens, Chris, if I put a ton of CO2 into the atmosphere? Again, I have to qualify this over very long timescales in a million years what will happen because this doesn't happen quickly. It's not a solution to climate change right now.
This is what we're talking about. It takes too long, but what
Chris Bolhuis: Carbon dioxide levels go up and therefore temperatures go up, but as temperatures go up, causes more weathering. It creates more acidic water, it creates more weathering, and This chemical weathering [00:22:30] is going to pull CO2 out of the atmosphere, which is then going to slowly result in cooling. And so earth is regulating itself through these natural processes. Volcanism can drive up the temperatures, which increases then weathering. Weathering draws carbon out of the atmosphere and puts it into the oceans again, so it's, it's resetting.
It's own temperature over long periods of time. It's a beautiful thing.
Dr. Jesse Reimink: It's a really beautiful thing and I just want to drive the point [00:23:00] home. I want to do it in the inverse. You said, okay, what happens if we put too much CO2, a bunch of CO2 in the atmosphere? What happens? Okay. I want to play the opposite. What happens if we start taking CO2 out? Let's say we start to have whole bunch of life, blooms of life of little creatures making shells and they suck a bunch of CO2 out of the oceans and therefore the atmosphere as well.
What's going to happen? Well, the planet is going to cool. There's less CO2, less greenhouse gas. So the planet's going to cool. What does that do? Well, it [00:23:30] forms glaciers. It forms larger ice caps. there's less sort of rain. It's not as humid. It's not as hot. What slows down when stuff gets cool and dry and not exposed to the surface?
Well, chemical weathering slows down. So all of a sudden we stopped drawing down as much CO2. which means that volcanic, gassing is still going on, those volcanoes are still popping off, and that's still pumping CO2 into the atmosphere, and that drives it back up, because we slow down chemical weathering, CO2 goes back up, and so, [00:24:00] can see how this thermostat is working now, it oscillates between kind of end members, it goes up, and then it gets drawn down, and then it goes up, and it hits the negative feedback loop, and it gets drawn down, goes down, hits the negative feedback loop, and goes back up, like, and This really beautiful oscillation that again, I want to come back to it.
Chris, we need fresh exposed rock. We need weathering. We need plate tectonics and we need water. We need oceans and rain going on.
Chris Bolhuis: This is like mental gymnastics a little bit, if you think about it.
Dr. Jesse Reimink: I know
Chris Bolhuis: You just think of a scenario, you think of a natural geologic process, right? And then plug in [00:24:30] the carbon cycle to that natural geologic process. And you just kind of work through it. It's, I like doing this. I like thinking about this.
I like, practicing this with my students. like, okay, well let's work through these scenarios. If you have the basics of how the carbon cycle works, right? Let's play this out. Let's work process through. I I'd love doing this to me. This is, this is really what gets me excited as like an educator, thinking through these processes and watching them think it through.
Dr. Jesse Reimink: absolutely. It's a really [00:25:00] powerful, I mean, this is like one of those mind blowing, once you get it, once you understand it, once you're, you're like, Oh, eye opening, like, whoa, this makes so much sense here. So Chris, let's work through just a couple of examples really quickly here. All right. Is that, is that that time in the, in the episode?
Chris Bolhuis: that's what we said we were going to do right at the top
Dr. Jesse Reimink: Okay, perfect. So let's think about Chris, the Himalayan uplift. That's kind of one of the big dogs here in earth events, right?
Chris Bolhuis: Yep. Well, let's set the stage, right? What [00:25:30] happened? what is the Himalayan uplift? comes down to about 50 million years ago, this continental collision took place. The subcontinent of India collides with the continent of Eurasia. so the bottom line is, is that subduction stopped, but what did happen is a massive amount of uplift.
Exposing what we talked about at the top of the episode, tons and tons and tons of fresh rock at the surface.
Dr. Jesse Reimink: So, Erosion is happening fast. It's also being [00:26:00] uplifted, which is keeping this whole plateau really high. So, lots of erosion, the conveyor belt of fresh rock is happening really quickly here, okay, and has been for the last 50 million years or so.
Chris Bolhuis: That's right. So what is the effect on temperature? what are we doing here? We're pulling carbon into the slow carbon cycle due to chemical weathering. That is going to result in a drop in global temperatures, I mean, that's, that's how this whole process works.
Dr. Jesse Reimink: So again, let's just work through the cycle again, because I think it requires [00:26:30] belaboring this thing, right?
Yeah. So slightly acidic rain. Falls or snow, whatever. We're getting water in with rock and it dissolves the rock. this bicarbonate ions start to dissolve the rock, especially rocks rich in calcium, magnesium. Those are, again, minerals that are easy to break down, easy to weather. We need the calcium and magnesium ions.
Potassium and sodium goes in there too. It's sort of less important, but it does. They're carried to the ocean by the rivers. Those calcium ions and magnesium react with the carbonate ions in the water. Again, we need water here [00:27:00] to have. This HCO3 negative, and those react together and we get limestone or dolostone or whatever you want to make out of it.
But calcium, magnesium plus CO3, and we get limestone in this case.
Chris Bolhuis: And organisms aid this immensely. That is the most important thing that's doing this right. But there is another rock, Jesse, that, is also related to this. And that's coal. you know.
Dr. Jesse Reimink: totally.
Chris Bolhuis: Coal, ancient swamps, where you have these relatively like stagnant, [00:27:30] anoxic swamps where this foliage, this organic material settling down to the bottom of the swamp, it gets buried, it gets compressed, it gets heated due to the geothermal gradient, and it's basically driving all the other volatiles out except the carbon, and again, pulled it out of the system, it put it into the rocks, now it's slow carbon cycle.
Dr. Jesse Reimink: exactly. And, and, you know, this is where sort of, we'll come back to this theme, but are burning hydrocarbons that are [00:28:00] stored in rocks. And so we're kind of pulling stuff out of the slow carbon cycle, injecting it into the atmosphere at a rate that's faster than the slow carbon cycle can kind of work.
But, we're ultimately storing carbon in these rocks here. that's a really kind of, it's a really important point. Rocks are part of the slow carbon cycle. It's a natural phenomenon here. So, add some numbers to this process. We've kind of talked about it generally, but this carbon stored in rocks, usually at the ocean floor, is a part of this thermostat cycle.
so a carbon [00:28:30] atom can take a hundred to two hundred million years to move through this cycle. We're talking like rocks, atmosphere, water, volcanic gases, to move through this cycle can take a really long time, hundreds of millions of years.
And we're talking a large amount, a hundred to four hundred million metric tons of carbon that's somewhere in this cycle, moving between Places in the cycle moving between reservoirs every year.
Chris Bolhuis: right.
Dr. Jesse Reimink: a lot, this is a lot of carbon that's moving through the cycle. It's really important in other words.
Chris Bolhuis: That's right. But the [00:29:00] burning of fossil fuels, the burning of coal for electricity, natural gas for home heat and electricity, petroleum for transportation purposes, and so on, enter us. And now the balance is offset here. anyway, that's another episode. Okay. Talking about that and the fast carbon cycle,
Dr. Jesse Reimink: Yeah, absolutely.
Chris Bolhuis: so sorry. That's a prelude to what's coming,
Dr. Jesse Reimink: No, that's exactly right, Chris. Cause you know, the, the important thing is the climate change. We're connecting different cycles. We're kind of, we're getting in the middle of these cycles here a little bit, which is, why the [00:29:30] concern and why things are changing. Right? so Chris, let's work through one other really kind of interesting compelling, uh, example, potential example. This is a hypothesis.
I think it's a kind of a decently well accepted hypothesis, but a hypothesis. There's debate about this one,
Chris Bolhuis: but I don't think that debate matters, right? That debate doesn't matter into this logical exercise
Dr. Jesse Reimink: that's a really good point. That's a really good point. Yeah. Well, let's focus on the thought exercise, which is up for debate, whether it's right or not, but it's a re but it fits really nicely within this. So, [00:30:00] Let's think about a planet, Earth, that all of a sudden has what's called a snowball Earth, has glaciers covering all of the land surfaces and much of the ocean. And this, we think, has happened a couple times in Earth history, but let's imagine that scenario. Huge, glacial, global ice caps. That are covering everything.
Now what has shut off? That shuts off the connection between the atmosphere and the ocean and actually weathering. So we've, we've like cut off that weathering link.
Chris Bolhuis: You cut [00:30:30] out the middleman, which is
Dr. Jesse Reimink: exactly. What hasn't stopped in that scenario? Well, volcanism hasn't stopped, and plate tectonics, that has not stopped. So, volcanism's still kicking CO2 into the atmosphere, right?
There's no silicate weathering that's pulling it down, though. So we drive up CO2, CO2, up to, some people think, 100, 000 parts per million, like a ton of CO2 in the atmosphere. Okay. What does that do? yeah.
Chris Bolhuis: I answer this? Hold on, hold on. Let me play this game. You're not letting me play it, I don't like that. You [00:31:00] gotta let me, come on, throw me a bone every now and then. I mean, we haven't really worked through this scenario, so let's do it. it's really kind of cool. So you're talking about a situation that creates a very cold earth.
snowball earth, you said, right? which shuts off the middleman, which is chemical weathering, and so, you're not drawing carbon out of the atmosphere, but plate tectonics is still going on, volcanism is still going on, subduction is still going on, which is gonna gradually then increase CO2 into the atmosphere, which is gonna reset the thermostat.[00:31:30]
continue though to work through because there's more to the story. It's not just, all right, it warms up. The ice is gonna melt gradually and now what? What happens next?
Dr. Jesse Reimink: Well, if you drive up the CO2 concentration to 100, 000 parts per million, that planet is hot. And you can rapidly melt this glacial ice cap, this global glacial ice cap that we have. Melt that thing. We've now reconnected the system. We've reconnected to weathering.
We've got a thousand parts per million CO2 in the atmosphere. That is going to be really, really fast [00:32:00] weathering. Also what's happened, the glaciers have scraped off all the soil. And so we have like huge continents full of fresh rock to weather. All of a sudden, boom, we start this silicate weathering. It happens really quickly in the, oceans are saturated in CO2.
Chris Bolhuis: I have a question though. You threw out a big number and I wanna know why, and maybe this is not relevant to the discussion, but you did throw it out, so I'm gonna ask Why did you say a thousand parts per million? I mean, that's a ton of CO two. Why did it have to get to that level? it didn't have to get to that [00:32:30] level to
Dr. Jesse Reimink: No, that's right. I, I threw out a hundred thousand parts per million, which is, you know, one hypothesis that people have sort of, uh, worked through chemically the parts per million that we needed. Um, The point is, is this can happen quickly.
If you, if you disrupt this cycle, if you stop silicate weathering, Globally, you can drive up CO2 pretty quickly, and we get these kind of like wild oscillations in climate, like snowball earth, not snowball earth, snowball earth, not snowball earth, like wild oscillations really quickly, because the process is turning on and off, your thermostat is like shorting out [00:33:00] and shorting on, so your house would get really cold and really hot, really cold, really hot, that's the kind of example here.
Chris Bolhuis: Got you. but that's a great segue actually into this last thing. And then we're about ready to wrap this up, which is a slightly faster version of what we've been talking about that can happen maybe on the scale of thousands of years, or maybe even faster than that. and this is basically what I think of it as the ventilation of the oceans and atmosphere.
So this interaction between the kind of like inhaling and exhaling of the
Dr. Jesse Reimink: that's a really good way to [00:33:30] phrase it. Can I, can I try an analogy here?
Chris Bolhuis: go, go. Let me, I don't know what
Dr. Jesse Reimink: The way I, the way I kind of think about this is like, circulating air between your attic and your basement, maybe know, we're, we're kind of circulating the warm air around the house a little bit, you know, thermostats working, but, this is a part of the process.
It's a, part of the thermostat, but it's not quite, connected in the same way. Close.
Chris Bolhuis: yeah,
that would be, I guess, I don't know.
Dr. Jesse Reimink: okay. Fair enough. Fair enough.
Chris Bolhuis: You know,
it was B minus, Jesse.
Dr. Jesse Reimink: All right. Well, Hey, [00:34:00] that's what, you know, that's what I came with.
Chris Bolhuis: Par for the course. No, it was good. It was good. I'm just kidding. I'm just kidding. But what we're talking about is carbon dioxide from the atmosphere just gets dissolved right into the oceans. We need this deep ocean
Dr. Jesse Reimink: That's a good one. It's like the, the, upper ocean here is kind of the, the skin that's reacting. It's like the skin of your body that's reacting with the air around you, right? And, and is regulated. But if you over, you need to mix that up. And so the deep ocean needs to mix with the shallow ocean and, if the ocean overturns or big [00:34:30] ocean circulation patterns change, we can start to absorb or out gas a lot more CO2, uh, because there's this kind of
Chris Bolhuis: Yeah, That's right. So basically you just hit it I mean we're talking about this kind of equilibrium where the amount of co2 that's dissolved in the oceans depends upon the co2 concentration in the atmosphere and vice versa it's this, uh, interesting feedback loop between the concentrations in the ocean and the atmosphere and temperature plays a role in this too, and that's where overturn [00:35:00] plays in because carbon dioxide can dissolve more readily in cold water versus warm water, and so that overturn helps to
dissolve more and so
Dr. Jesse Reimink: You know what, Chris? I think ocean circulation modeling and understanding deep ocean circulation patterns is probably one of, I view it as one of the hardest things to do. Like the people who make these models and study this process, it is complicated and very, very, hard to like put our finger on and therefore hard to predict how [00:35:30] these deep ocean circulation patterns will, you know, adapt to climate change and changing global weather patterns and stuff.
It's like this. Knob that you can turn whichever way you want. It's super complicated to understand, but immensely important.
Chris Bolhuis: but just watch Finding Nemo, and it's greatly simplified,
Jesse.
Dr. Jesse Reimink: That's a good one. I was not expecting that one to come up.
Chris Bolhuis: It's
Dr. Jesse Reimink: That's awesome. Yeah. Yeah. It's great. It's a great one. That's a good shout out. Finding Nemo shout out. Oh, you know, Chris, I think that's a heck [00:36:00] of a place to end on a finding Nemo shout out there. I love that. That's awesome.
Chris Bolhuis: so
Dr. Jesse Reimink: Well done.
Chris Bolhuis: Jesse? Are we good? Like, did we cover
Dr. Jesse Reimink: Yeah, I think so. I mean, it's, it's just such an important thing. And I think it's really interesting as well, because, you know, I, well, I teach this, this sort of entrepreneurship class here at Penn State, and we just talked about a couple of sequestration companies that are basically what we're trying to do is just take this process and speed it up, take this weathering [00:36:30] cycle, speed it up artificially.
Because we're putting CO2 in the atmosphere artificially you know, we're already getting ourselves in this cycle humanity. And so, you know, maybe we can try and draw down CO2 just by enhancing rock weathering, doing it faster. So, it's a really interesting process and a really interesting thing, fundamental thing to understand.
Chris Bolhuis: And very fun thought experiments, or thought exercises, if you will. Yeah. Love it.
Dr. Jesse Reimink: Um, all right, Chris. Well, hey, that's a wrap for this episode.
You can find all of our content, including past episodes. You can subscribe, [00:37:00] support us, send us an email, go to our website, Planetgeocast. com. Send us an email planetgeocast at gmail. com. We've gotten a lot of questions. You can also correct Chris's pronunciation if you've made any mistakes.
And please don't blame it on me. It's not me. It's Chris. Jeez. He's the idiot. So
Chris Bolhuis: Nah, you, you,
Dr. Jesse Reimink: I know, I know my B minus is, uh, Well, it was a B minus performance today. you can also download our app, the Camp Geo app in your app store there. You can listen to all of our content, our Camp Geo course content. you can also purchase the [00:37:30] geology of Yellowstone there.
Chris Bolhuis: Cheers.
Dr. Jesse Reimink: Peace.
