Q&A: Hydrologist Charles Harvey
The carbon sequestration political landscape is complicated. Harvey's MIT lab is the only one that doesn't take oil industry money.
Hello readers! Another extended Q&A in the newsletter this week. Here’s the context:
I recently wrote an op-ed for Undark magazine about geologic carbon sequestration in the Midwest. Basically, this is an industry that’s popped up in the last decade or so to prop up another—ethanol. We already pump carbon dioxide underground all the time, mostly to squeeze the last bits of oil and gas out of mostly drained fossil fuel reservoirs. Now, lucrative Biden-era subsidies have made it more profitable to store CO2 underground “permanently” in deeper geologic formations to reduce industrial carbon emissions. The result—new pipelines and facilities springing up across Illinois, Iowa and beyond to hide ethanol plant emissions underground so the unsustainable industry can keep trucking and call itself environmentally friendly.
The interview I’m sharing today is one (along with many others) that didn’t make the final cut for that piece. But, I think it’s a good one.
Charles Harvey is a professor of civil and environmental engineering at MIT and identifies as a hydrologist and biogeochemist. He’s an expert in how chemicals flow and react in groundwater. He studied geology and applied Earth science at Stanford in the ‘90s, then got into carbon sequestration back when—he says—it seemed like a promising climate solution. Geologic sequestration is basically hydrology—pumping liquid CO2 underground into saline reservoirs and trying to figure out what happens next. But long ago he realized the tech wasn’t the panacea he originally thought it might be. And the only people still pushing it, he says, are ones with skin ($) in the game. So today, a little classic “follow the money” look at sequestration…
CHRISTIAN ELLIOTT: First, I’d love to hear a bit about your research background—how did your lab at MIT first get involved in studying carbon sequestration?
CHARLES HARVEY: For me, it was a means to do some research that could reduce greenhouse gas emissions. 17 years ago I wanted to move in that direction from what I was doing, mainly hydrogeology—how water and other fluids flow around underground. Carbon capture and sequestration seemed like an area where I could contribute, because it’s also basically fluids flowing around deep underground. And at that time, it seemed like it might be the best way to reduce power plant and industrial emissions.
Things were very different back then—this is around 2007 when we were still building more coal-fired power plants. Everyone seemed to agree that was going to continue. And there was talk of a bipartisan cap and trade or even a carbon tax at the time. So the politics have changed a lot since then and the economics have changed a lot. We've gotten rid of half of our coal-fired power plants now, right? Attaching carbon capture and sequestration to them at this point, I know people are proposing it, but it's kind of ludicrous, because it's cheaper just to take the whole thing down and build wind, solar and energy storage. Cheaper by a lot, actually.
So I just sort of quit thinking about it, because it seemed like a bad idea. But back then, with some students and postdocs around here, I’d actually started this company to do it. We’d realized there were a lot of academics researching carbon sequestration because oil companies provided money for it, but it wasn't really a research question because oil companies were already doing it at large scale. It's just called enhanced oil recovery. You inject the CO2 underground to push the oil out. So the issue was more a matter of doing it for sequestration rather than researching it.
So that was part of the reason to set up the company. And we raised a lot of money. We even unitized area of Illinois where we bought all of the mineral rights. Part of our company's idea was that you would want to control where the CO2 goes, because if it goes under people's property, you can get in trouble. I don't think the industry really worries about that so much today, but at the time, it seemed very important that we had a clear delineation of where it could go, and that we have the property rights to everything. So in Illinois, it was about finding a place to put the carbon dioxide from the FutureGen project.
CHRISTIAN: Yeah, I’m familiar. The project to retrofit a coal-fired power plant for carbon capture.
CHARLES: Yeah, and one of several points where I realized that the whole thing was a little sketchy was when we got it all set up, and we were all sort of naively excited, because we realized we could save FutureGen, an enormous project, an enormous amount of money. So we went and presented it to them, and they were not happy. And their sort of argument on the thing was, we don't want to do it the easy way. And that was when I think a lot of us realized, what kind of startup company doesn't want to do something the easy way? What's going on here? That was a key in that it was mainly a subsidy harvesting operation, not one particularly interested in storing CO2.
CHRISTIAN: And this was well before the 45Q subsidies for sequestration jumped way up, right?
CHARLES: That’s right, they were just harvesting straight DOE grants. The 45Q subsidies might have motivated them more, because then you do get paid by the ton that you put underground. But from their point of view, it didn’t even matter if they succeeded.
CHRISTIAN: So at that point you realized this wasn’t something you wanted to keep working on?
CHARLES: Yeah, because renewables were getting so much better so quickly that we couldn’t find any project where that wouldn’t be the better way to go. Now we were looking at ethanol. And the reason to do ethanol is that the CO2 that comes off of ethanol plants is fairly pure, so it takes a lot less energy to capture it than other emissions from coal-fired power plants where you have to separate it from the nitrogen. But from a climate perspective, money would be much better spent moving toward EVs than subsidizing CO2 capture from ethanol.
CHRISTIAN: Unless you want to keep ethanol profitable by decreasing the ethanol plant emissions?
CHARLES: Right. But I was interested in doing something about climate change and about spending taxpayer money wisely, not giveaways to the ethanol industry.
CHRISTIAN: So, this thing about not taking oil company funding. I do not track closely where universities are getting their money. But for this story I talked to a scientist from Lawrence Livermore National Lab and a one from the Illinois State Geological Survey that was very involved in the Decatur carbon sequestration project in the initial monitoring stage, and someone at the University of Texas. And the line that I'm getting again and again is that it's safe to do, we know how to do it, we've been doing underground injection for a long time, there's not really any risk to water, and we have to do it, at least the industries that are hard to abate, like cement. So I'm just curious to what degree other research labs specifically focused on carbon sequestration do get money from the oil industry? Or are influenced in some way?
CHARLES: When it comes to universities, they all do. Where else would you get the money? You can get some from the DOE. But it’s a branch of the DOE essentially captured by oil companies. It’s almost no different than getting it from oil companies. It’s sort of amazing to see. They’ve created an academic discipline. There’s journals and meetings and stuff. The whole point is to create this discipline to bring in industry money. So there are basically no researchers that are analyzing it from a skeptical or objective point of view.
CHRISTIAN: I guess if it’s your area of research, you need it to continue. You don’t want to prove it doesn’t work…
CHARLES: You don’t even want to ask that question. You’ll get thrown out of the club if you do. But what were you saying, that it’s perfectly safe?
CHRISTIAN: Right, I got this explanation from a couple of people, this metaphor that injecting carbon dioxide underground is like household plumbing. Like, we do it all the time, we know how to prevent leaks. And if there’s a leak, it’s typically minor and you just call a plumber.
CHARLES: So the thing that’s unique about the Decatur site in Illinois you’re writing about is that it’s the only site not doing carbon injection for enhanced oil recovery. So when people say we do it all the time, no. It’s never been done, except for enhanced oil recovery. And it’s not really a fair comparison. The big difference is when you’re doing enhanced oil recovery, you’ve already pumped out a lot of oil. And you're pumping out more oil than the CO2 that you're putting in, and therefore you're not driving the fluid pressures up, because you’re net reducing the volume of material underground, right? If you start to do this not for enhanced oil recovery, then it's a very different physics. And no, we don't have any data on that.
CHRISTIAN: So I guess that’s where we get into these questions about induced seismicity and whatnot.
CHARLES: Yeah and that’s not studied either. We can debate theoretically about levels of risk and all that. But it’s just not something we have any experience with, except for at this site in Decatur. The one that just leaked.
CHRISTIAN: Yeah, so that makes me, as a person who lives here and seeing there are something like 20 permits in the works for a large scaling up of carbon sequestration across the state, it makes me think there’s still a lot of questions about what happens when we punch a bunch of holes down into this reservoir to scale things up. I think Decatur has sequestered 4 million metric tons in 10 years. And they’re talking about expanding that by like 50 or 100 times in scale.
CHARLES: That’s where things get interesting. I have no concerns about putting a small amount of CO2 underground, but when you put a lot, it’s different. You hit thresholds on pressures. You have large plumes, large buoyant plumes underground.
CHRISTIAN: And over time it mineralizes to some extent, I was told, but at least some amount stays buoyant for a long time, right?
CHARLES: Some of it has to mineralize, but how much of it has to do with things we don’t understand. A lot of the studies that are done to show how much mineralizes are just numerical models, ones that artificially mix fluids a lot and always get more mineralization than could happen in nature.
CHRISTIAN: So it sounds like we’d just have to start doing it to figure out what would happen…
CHARLES: You’d have to do something you’d never get funding to do, and that’s to actually construct experiments to ask the question of how it could go wrong. What are the safety issues? You cannot get funding if you ask that question. The answer is supposed to be that it's safe. When I talk to people I say, “Well, OK, but if it's a really small reservoir and you start to inject hundreds of megatons, surely there's a place where it's no longer safe?” And yeah, everyone agrees to that. Now we can disagree about where that is, but couldn't we do an experiment to try and figure that out? You'll never, you'll never get to do that.
About the scaling up, who knows what's going to happen? There are two different political points of view within the Republican Party who control what's happening now. One is the senators that are funded by oil companies who want to increase the subsidies, and then there are the Project 2025 folks, who explicitly want to eliminate the subsidies. So if they eliminate the subsidies, then carbon sequestration is gone. No one would ever do this without subsidies. If they increase them by a lot, maybe the scaling up will actually happen, and then we will learn more.
CHRISTIAN: I’m very curious to see what happens. Other researchers I’ve talked to emphasized there needs to be a strong, well-funded and staffed EPA to actually make sure permits are approved in a way that’s reasonable.
CHARLES: Well, no matter which of these sides win out, that’s not going to happen, right? The EPA at this point, their power is already basically gone to do anything. And most of these carbon injection sites are enhanced oil recovery sites, so there’s no data. Nobody from the EPA goes to measure. The EPA is not allowed on oil company land. So that’s the other thing that’s unique about the Archer Daniel Midlands project in Illinois—it was actually monitored.
CHRISTIAN: I didn’t realize enhanced oil recovery sites weren’t EPA monitored.
CHARLES: Not at all. The subsidies are just given to the oil companies based on self-reporting. There was an investigation into these subsidies and something like half of them were found out to be fraudulent. So the thing I would like to see in the press is that lot is people talk about CCS as if it was being used to for the hard to decarbonize industries. And the oil companies love that, because that's the argument that they use to get the subsidies. But the subsidies are all used for enhanced oil recovery, so it’s a bait and switch that's gone on for for two decades now.
CHRISTIAN: I mean, it seems like the whole ethanol push for CCS is the same deal where it’s like, “We need to make ethanol more sustainable so we can sell it in California and then as an aviation fuel. And if the emissions are too high we can just sequester them all and qualify.” I don’t know to what degree that even matters in a Trump administration, but…
CHARLES: Yeah. And again with safety, the thing that’s worth noting is we only have one site that’s not for enhanced oil recovery and that’s injected 4 megatons, a significant amount, and it has leaked. Now, it hasn’t leaked to the surface.
CHRISTIAN: Right, but it’s gone above where they were allowed to store CO2. It sounds like the material in the well corroded.
CHARLES: Right, it’s in a different aquifer. It’s gotten through a thick layer of shale, which is upsetting, but it’s hard to generalize from that. I don't know how, given the amount of money they've spent on this project, how they could have used the wrong material for their observation wells. Way back when we had that company, we knew you had to buy this very expensive kind of steel or it would corrode. Right? I don't know how they could have gotten that wrong, but apparently they did. So maybe that's the only issue that caused their leak.
But you don't really know. I mean, it's not like we know what's going on down there. It’s not like they know where it all is, where it's all going. I mean, maybe there’s another well, maybe there's a fracture. So it’s really hard to generalize from this about whether this is a fluke or whether it's sort of an indication that things are not as safe as we thought. So the only way I can think to look at it more is to look at natural gas storage sites in Illinois, because it's the same issue. You're storing a buoyant gas deep underground and and for those, the companies have a real motivation to keep it from leaking, because it's their product. You don't want to lose it, which is different than the CO2 sequestration, where, if it leaks and they get away with it, probably all the better.
CHRISTIAN: They've already gotten the tax break.
CHARLES: So, have those natural gas storage sites ever leaked? I know some of them have.
CHRISTIAN: Yes, even in this same area.
CHARLES: So that’s not good because that gives the lie to any argument that we understand all the physics, we know how to prevent leaks. Clearly that’s wrong if they’re losing valuable natural gas to the atmosphere.
CHRISTIAN: There’s this case in central Illinois, underlying the Mahomet Aquifer near ADM’s plant. It’s a company called People’s Gas and it was a natural gas leak, methane. Manlove Storage Field.
CHARLES: Oh yes, I remember this from our FutureGen days. The Manlove formation. Much mirth came from the Manlove formation. Now, methane is different. It doesn’t mobilize heavy metals like CO2. It’s a better leak, because it is explosive but it’s lighter than air, so when it breaks the surface it goes straight up and no one’s worse for it, where CO2 is dense, it hugs the surface and can asphyxiate every living thing, right?
CHRISTIAN: That also happened in Mississippi, right?
CHARLES: yes, that was a pipeline leak.
CHRISTIAN: Now I did want to also ask you if you’ve seen any research on actual risks to water for CO2 leaks underground. You mention mobilizing heavy metals. I talked to that researcher at the University of Texas who said she’s done lab tests and there’s no way to do that or to carry saline brine up into a drinking water aquifer. But I’ve seen some other studies taking those risks seriously. Environmental groups are using the risk to drinking water as their main talking point. Is there any weight to that?
CHARLES: Like you said there are a few research papers that show CO2 does mobilize heavy metals in some cases, but I don’t know about this specific aquifer. And I don’t know if anyone understands the at-scale issues, with massive amounts what would happen.
CHRISTIAN: Got it. Lastly, is there anything else that the media really gets wrong about CCS, like you mentioned earlier?
CHARLES: Well, one thing you brought up is this argument that we need CCS for particular industries. That’s often just said as if somehow we knew it were true. Like, obviously we need it for cement or steel. I don't think we do. That's the sort of fallback position now of the industry groups that promote it, right? So it used to be, we need it for coal, we need it for natural gas, we need it for blue hydrogen. Now that they’ve sort of given up, they’re retreating, and now they're on to cement. And what do you mean by we need it? It’ll be incredibly expensive to do CCS for cement. So I don't think that's even really plausibly going to happen in the short term, because the amount of money you have to spend per ton of emissions, if you were to spend that on so many other things, you would do much better. So any rational allocation of climate change mitigation funds would not do cement now. Maybe in 10, 20, years. But that argument is used to promote CCS and promote these subsidies which will not be used for cement. They’ll be used for enhanced oil recovery.
With cement, there are other ways to go about reducing emissions. And it’s just not making CO2 to begin with. Cement is touch because it produces CO2 from not just burning fossil fuels but from the calcination process. It’s CO2 that comes out of the rock that you use to make cement. But there are are promising methods to make cement differently to avoid producing CO2. I don't think anyone's going to do that at scale in the next six months or anything, because it's a pretty new technology. But these tech approaches can't get the CCS subsidies, because you have to make the CO2 to get the subsidy for sequestering it.
CHRISTIAN: That seems to always be the case, that anytime you can avoid making CO2 in the first place, you’re better off than if you make it and then have to find a way to get rid of it.
CHARLES: That’s the beauty of it. That’s the reason the oil companies love these subsidies, because they are, in a sense, subsidies for making CO2. If you construct the economic and political system differently, if you create subsidies for reducing emissions instead of sequestering CO2, I don’t think you’d ever have any carbon capture and sequestration, you’d just straight up reduce emissions, right?
CHRISTIAN: Wow. Thank you so much, Charles, really appreciate you explaining all of this to me. Have a nice evening.
CHARLES: Same to you!