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Green and Bold: Conversations from the CSU Spur Climate Hub podcast series will arm listeners with reliable climate knowledge and inspiration by featuring some of the most innovative climate champions in the U.S. Mountain West, from academia, industry and the public sector – all actively moving the needle in climate. Our conversations are science-based, non-partisan, hopeful, and timely. We focus on positive change in the region, and the people behind the change. Through punchy, bi-weekly conversations, we explore climate change through the lens of solutions and meaningful action.
00:04 - Veera Mitzner
Hello and welcome to the Green and Bold podcast. I am Veera Mitzner, the director of Colorado State University's Climate Hub. Today we are discussing a topic that was quite new to me and that might be new to many of our listeners as well - Methane removal from the atmosphere. Why should we be concerned about methane? It's a potent greenhouse gas that is responsible for 30% of all global warming. It is also an air pollutant. Much work is being done to address methane emissions mitigation, but major gaps in science and solutions remain, including hard-to-abate emission sources such as the global livestock system and climate feedback, such as rising methane emissions from permafrost thaw to tropical wetland.
00:51
Existing mitigation tools may not be enough to manage climate risks, and we need to know if removing methane from the atmosphere is an option or not to this risk.
01:03
My guest today is Dr. Megan L. Melamed, who is the Program Director for methane removal at Spark Climate Solutions, where she works to assess the viability of proposed methane removal approaches across scientific, social, economic, and governance dimensions. Before joining Spark, she served as Deputy Director of NOAA's Chemical Sciences Laboratory and earlier as Executive Director of the International Global Atmospheric Chemistry, IGAC project, building a global coalition of scientists dedicated to understanding the changing atmosphere. She has also served as an AAAS Science and Technology Policy Fellow at the US Environmental Protection Agency and as a National Science Foundation International Research Fellow in Mexico City.
01:50
A Colorado native, Megan holds a PhD in Environmental Engineering from the University of Colorado, Boulder. I cannot imagine having a better person to speak about this topic. Megan is an atmospheric scientist who has studied methane for over two decades. She also works for an organization that has been one of the early movers in the methane removal space. What I found very refreshing when speaking with Megan was that she was openly quite skeptical about the methane removal pathways she is studying. They might actually not work. But Megan also advocates for more scientific research on climate intervention.
02:28
It is critical that we understand what works and what doesn't work. And given where we are headed with climate change, that research needs to happen now. Please join me for my conversation with Dr. Megan L. Melamed.
02:44 - Dr. Megan L. Melamed
And understand whether this process is really happening under atmospheric conditions or could happen under atmospheric conditions. So again, we're trying to follow the science and we're trying to say, okay, there's this proposed mechanism out there. Models indicate it might be promising. Let's see if it is or not. And we're funding the research behind that.
03:05 - Veera Mitzner
Good morning, Megan, and welcome to the Green and Bold podcast. Megan, you're the Program Director, Methane Removal at Spark Climate Solutions. There is a lot of talk about carbon dioxide removal, but methane removal seems like a less well-known area of research and action to me. We know that methane is a very potent greenhouse gas, and it contributes to the warming of our planet. Can you tell us why you decided to study methane and atmospheric methane removal in particular? Perhaps you can start by telling why methane is such an important greenhouse gas and how it contributes to the problem of global warming.
03:43 - Dr. Megan L. Melamed
Yeah, thank you for having me Veera. It's very nice to talk and see you again. So I've been studying methane for decades. It comes and goes in its attention in the climate community. And part of the reason that it is getting a lot of attention right now is it is the second largest producer of the warming we see today since the pre-industrial era. It is responsible for about 30% of the warming or 0.5 degrees of the warming that we see. In addition, not only is methane contributing to climate change, it's also contributing to air pollution.
04:14
So I've also studied it in that capacity as well. It produces tropospheric ozone, which is both another greenhouse gas and an air pollutant. And so methane is a very unique molecule in that sense in that it's both a warming agent and it also contributes to human health directly, which is slightly different than carbon dioxide.
04:35
So as I mentioned, I've been studying methane and been in this space for about two decades and studying at the intersection of climate and air quality on it. And the reason that we are beginning to look at whether or not atmospheric methane removal could be a possibility is that we're not seeing the mitigation responses that we want to have on CO2 or any of the other climate enforcers such as methane or nitrous oxide. We're just not getting there.
05:04
And so we have to ask the question of - Is the risk that we're going to have from the warming of these gases in the atmosphere going to be higher than what it might take to get them out of the atmosphere, whether that's doing carbon dioxide removal or, in my case, methane removal. And methane, in particular, has a very unique lever because methane, in comparison to carbon dioxide, only lasts in the atmosphere about 10 years, whereas carbon dioxide lasts about 100 years.
05:31
And so if we can address methane, we will have a near-term response that will decrease the warming impacts that we are currently seeing. And so it's really a unique lever to work on methane. Mitigation, of course, is always the first thing we want to be looking at. However, there's kind of an issue there with methane in that we have current technologies that can account for about 50% of the reductions in emissions from methane, but there's a remaining 50% from what we refer to as hard to abate sources. So this includes things like agriculture.
And then also we're seeing that there is a response happening that as the planet warms, we're seeing more emissions of methane happening from tropical wetlands and permafrost thaw.
06:22
And then there's another factor in there too, is that I mentioned methane's lifetime is about 10 years in the atmosphere, but that length is not set. It's driven by different chemistry that can happen in the atmosphere and that lifetime could increase or decrease depending on what's happening in the atmosphere. And if methane lifetime were to increase, which is a possibility, then we would also see, even with rigorous mitigations, methane becoming more of a climate change issue. But still will be less of a lifetime than carbon dioxide.
06:55 - Veera Mitzner
Great. So there seems to be a lot of opportunity, especially with the near-term response and the significance of this greenhouse gas. What is methane removal?
07:08 - Dr. Megan L. Melamed
Yeah, that's a great question. So methane removal is not some far-out technology or anything. In fact, the Earth already does it naturally. So it does it in two ways. These are called the sinks for methane. And one of them is through atmospheric oxidation. This is primarily why it lasts only 10 years in the atmosphere. And that is methane can be broken down by what we call cleaning agents of the atmosphere. So the hydroxyl radical is one of them and the chlorine radical is another one. It reacts with methane and cleans it out of the atmosphere.
07:39
That is happening in the atmosphere right now. It's a natural process and is why methane has a lifetime of about 10 years right now.
We also know that there are processes in the soils and in ecosystems that uptake methane. And most of this is through microbes that are often referred to as methanotrophs.
07:58
So methane is getting uptake naturally via atmospheric processes and biological processes. And what methane removal is looking at in two cases is whether or not we can enhance those natural processes that are happening so that you can have more removal of methane from the atmosphere than otherwise would happen just naturally.
08:20 - Veera Mitzner
That's great. How is it different from carbon dioxide removal? Because I would assume that our listeners are mostly familiar with those approaches.
08:30 - Dr. Megan L. Melamed
Great question, because they are very different in nature, but they're both about removing a greenhouse gas from the atmosphere, and that's how I would say it. So carbon dioxide removal is about taking carbon dioxide out of the atmosphere and storing it back into either the oceans or into rock surfaces, for example. And that is because CO2 lasts a long time in the atmosphere. And so you need to get it out and store it somewhere. On comparison, what methane removal is doing is taking methane out of the atmosphere, making it degrade via chemical reactions.
09:05
And so those chemical reactions produce CO2 and water. But I just want to point out that even though it produces CO2, methane's concentration in the atmosphere is so small compared to carbon dioxide. It's two parts per million.
09:18
Whereas carbon dioxide is at over 400 parts per million, that if you convert any methane to CO2, you're not substantially increasing the carbon dioxide concentration in the atmosphere by converting methane to CO2.
09:39 - Veera Mitzner
You have described four different approaches to removing methane from the atmosphere. What are those approaches?
09:47 - Dr. Megan L. Melamed
Yeah, so I've kind of addressed two of them. One is what we often refer to as atmospheric oxidation enhancement. And this is, again, about whether or not we can enhance the natural process that's already happening in the atmosphere to speed up how methane is destroyed in the atmosphere. So that's atmospheric oxidation enhancement. The other one is called ecosystem uptake enhancement. And that includes the microbes in the soil. Are there ways we can enhance either their ecosystems or can we get them to eat methane faster? Can we provide them as surfactants in certain ways where they would be uptaking methane?
10:23
And there's also questions about ecosystem management. Can you change an ecosystem from being either neutral or methane producer to one that uptakes methane? So those are the ones that are more enhancing the natural processes that we already see happening in the environment.
10:38
And then under ecosystem uptake enhancement, there's another kind of subcategory, which would be trying to genetically modify plants to express an enzyme that can uptake methane. So that's still under the ecosystem uptake enhancement category, but it's fundamentally a little bit different in that right now we know like trees and so forth uptake methane. But to genetically modify a plant so that it can do that, it's slightly different.
And then the next two I like to put into one category, and those I call engineered approaches. And that's because they're not happening currently in the natural system. And so one of those is a reactor, which where you would try to concentrate the methane into a closed or semi-closed system.
11:30
And then have either processes that enhance the oxidation or microbes eating the methane within more of a semi-closed system. And so you have to concentrate the methane into that system. So that's a reactor. And then the other one is surface treatments, which is, could you put something like on the roofs of all the buildings, for example, that would cause the breakdown of methane to happen faster than it does now? Is it can be a catalyst to produce these, cleansing agents that I had talked about prior.
12:02
Right now, Spark doesn't focus that much on the engineered approaches because the energy cost to concentrate methane and get them into reactor, for example, really makes it not net climate beneficial. And then also because methane is only at two parts per million in the atmosphere, which is a very low concentration, you can't get enough methane onto surfaces for it to react to have a significant impact at this point.
So our focus really right now at Spark is on atmospheric oxidation enhancement and ecosystem uptake enhancement.
12:36 - Veera Mitzner
Okay. So it seems that those two are the most viable options. I've understood that the deployment has still not really happened and there are some questions around viability. What would it take to deploy some of these technologies?
12:53 - Dr. Megan L. Melamed
Right now, we know these processes happen in the natural environment. What we don't know is whether or not we can enhance them. And so there isn't yet the thing to do, which makes it not open for being deployed because there's no proven methodology to enhance these current natural processes that are happening. So the first step of course would be showing that there is a mechanism that we could use to actually enhance these processes and have that happen. So it's in the very early stages of research, and it's really in the discovery phase still on all of those.
13:30
And microbes similarly. Methane is a hard molecule for a microbe to eat, and it's amazing that microbes even eat it at all. And so trying to figure out how to accelerate that or what you would do to an ecosystem or a microbe itself to consume it faster is in the very, very early stages of research.
13:49 - Veera Mitzner
So would you say that the main barrier at this point is lack of research and knowledge?
13:54 - Dr. Megan L. Melamed
Yes, I think there's some other barriers that are also present. So one is that in the very early stages, we're not sure yet whether or not it can be a solution. And that's really what we set out to do at Spark is that we're accelerating the assessment of the viability of methane removal. So we're trying to understand whether or not this can be something that can be part of the toolkit to address climate change or not. At Spark, determining not is just as important as determining it is, because we don't want investments to go into places that aren't going to be a tool that we can use.
14:31
So some of the other areas that are hard is that Spark is really the only funder in this area of methane removal. To date, there's been probably about $12 million put towards research on methane removal, and the majority of that has come from Spark Climate Solutions.
14:47
And so we really need more public funding to come into this space, not just methane removal, but other climate solutions to be giving funding to the academic and national labs that can really accelerate the science behind these proposed solutions. So that's one barrier.
The other one is that methane is reactive and it reacts in the atmosphere and it doesn't do that alone. It's involved with a whole bunch of other things. And so if you start messing with methane, you're probably going to start messing with other things.
15:20
And so the impacts that may happen from doing methane removal are a barrier. So you may or may not increase air pollution, for example. You may or may not increase ozone, which is both an air pollutant and greenhouse gas.
15:37
And so you could be in a world where you could remove methane, but you increase ozone so much that you're not having a net climate benefit. So that kind of defeats the purpose.
So all those things need to be better understood as we move forward, exploring these different approaches I've talked about to make sure that the approaches are net climate beneficial, that they're economically viable.
And then the last one is that they also have governance on them. We're messing with an open system, right? We're talking about doing something to ecosystems or doing something to the atmosphere, which makes the governance side very tricky to do.
16:13
And we're doing a lot of work as we speed up or as we accelerate the science on this, we're also doing a lot of work on the governance.
16:25
A lot of it learning from other areas that have been here. So you mentioned carbon dioxide removal, and then another proposed intervention, which is solar radiation management. So we're trying to also learn from those about like, what would the governance look like around something like this if there is an approach that turns out to be viable?
16:44 - Veera Mitzner
I did want to ask you about the risks and you already covered some of them. Was there anything that you left out you would like to emphasize in terms of risk?
16:53 - Dr. Megan L. Melamed
I think just on the risk side is that you have to be looking at the whole risk portfolio of everything you're addressing. And I think sometimes that can get lost when you're trying to just address climate change. There's so many risks that a decision maker will take into account of whether or not they want to even mitigate methane or they want to mitigate CO2. You know, for example, we know oil and gas is a huge producer of methane and CO2, but our economies drive off of that right now, right?
17:26
And so it's a tough decision policy because they're not just taking into account climate in that portfolio when they're making a decision whether or not to mitigate methane or CO2. Similarly, if you were to look at the agriculture side of things, Cows across the world have very different meanings to very, very many different cultures.
17:44
And you can't just go in and tell a culture, sorry, you can't do cows anymore. That's not going to work in India where they're considered a sacred animal, right? And so you have to be understanding that climate is one of the things that gets taken into consideration when we're trying to address these issues. And there's a whole bunch of others that also are being taken into consideration amongst decision makers.
18:07 - Veera Mitzner
Yeah. It's a complex space, for sure.
18:11
You partially responded to this question as well. It seems that Spark is the main funder of this work. But I'm curious about this field. Who else is doing this work? Who else is active? How does the field look like right now?
18:25 - Dr. Megan L. Melamed
Yeah, that's a great question. So in the beginning, it was kind of just Spark. But what we're seeing now is that there is more funding going towards this from national countries. So countries themselves are starting to fund research in this area. There's more institutes looking at it. And there are also various startup companies that are also looking at doing this, which is also part of the motivation for Spark to be doing what it's doing to make sure that we're not investing in solutions that aren't going to be viable.
18:57
So the space has grown. There's many publications out there that have nothing to do with Spark funding that are on methane removal. And I think that this is just more of a recognition across the world that climate is becoming a bigger and bigger risk and that we need to do something about it and we need to explore all possible tools to address it.
19:19 - Veera Mitzner
Yeah. And science has a critical role to play. We want these decisions to be informed.
19:25 - Dr. Megan L. Melamed
Yes, yes. Science is very critical to this, yeah.
19:28 - Veera Mitzner
Great. So how do you feel about the future of this field and this research? How optimistic are you that some of these approaches would actually be deployable in a couple of years? And if the answer is yes, what's the timeline?
19:47 - Dr. Megan L. Melamed
I know nature does these things. Whether or not we can enhance them, I'm a little skeptical about, to be honest. And that's part of the reason Spark actually hired me is because they wanted a true assessment of whether or not this was happening, not somebody who's going to be advocating for it. So we are going to follow the science and see what it says.
20:09
In particular, right now, kind of the “most promising,” and I say that with quotes, method is something called iron-salt aerosols. And the reason right now that that's considered kind of promising is in modeling studies, it seems that you can get chlorine radicals produced off of these particles that will then consume methane in the atmosphere. And what Spark has set out to do is we're funding MIT, a group of scientists at MIT in the broader community to actually do chamber studies where you kind of mimic the atmosphere and understand whether this process is really happening under atmospheric conditions or could happen under atmospheric conditions.
20:52
So again, we're trying to follow the science and we're trying to say, Okay, there's this proposed mechanism out there. Models indicate it might be promising. Let's see if it is or not. And we're funding the research behind that.
21:06
So I don't know a timeline yet. That one should tell us in the next three to four years whether or not iron cell aerosols and chlorine just by itself could be a potential approach. And we're exploring others as that one moves forward.
21:23 - Veera Mitzner
That's great. So what gives you hope? What keeps you doing this work?
21:28 - Dr. Megan L. Melamed
Yeah. Well, one is I'm an atmospheric chemist by training. I got my degree at the University of Colorado, PhD student from there. So it's nice to be talking to local universities. And one, just the science behind methane removal is really fascinating. The chemistry and how it interacts with air pollutants and what it does with climate. And also, another intersection that will happen is that as the climate warms, we're seeing these emissions changing. There's also other proposed climate interventions like solar radiation modification, ocean alkaline enhancement, marine cloud brightening that might also influence what would happen to methane lifetime in the atmosphere.
22:10
And then you also have this proposal of moving to a hydrogen economy. And hydrogen actually is not as… Messes with the chemistry of the atmosphere quite significantly and so will likely have an impact on methane's lifetime. And so part of my motivation is like the fundamental science behind what is kind of the methane risk is how I like to talk about it. What potential futures do we have of methane? And in that, it kind of addresses the, if we understand the risk really well, we can understand is mitigation going to be enough or is something more like methane removal going to be needed? And the work I'm doing at Spark right now is really about if it is shown that methane removal is needed, we will have already done a significant amount of the work so that you don't start from zero 10 years from now when that decision gets made that you need to do something about it. So we're setting that foundation right now.
23:03 - Veera Mitzner
That's great. So how can the listeners find out more about your work and is there a way for them to be involved?
23:09 - Dr. Megan L. Melamed
Yeah, so that's a great question too. I'm always personally willing to talk to anybody and anyone about many different topics including methane removal. So one, you can go to Sparkclimate.org and has information there on the methane removal program amongst other programs that we do and there's newsletters people can sign up for. The methane removal team also does a quarterly newsletter and we also host webinars that are open to the public. In addition to that, we are often at events like Colorado Climate Week that was out earlier this year, London Climate Action Week.
23:47
And then we also are at scientific conferences. So we tend to have a session and a town hall at the American Geophysical Union Conference every year in December, which is huge for scientists, amongst some other conferences.
23:59
And then for scientists in particular, they can keep their eye out. There's eyes open on our website for solicitations we have coming out to support research in this area. And then, of course, I'm on LinkedIn if people want to follow me there.
24:14 - Veera Mitzner
That's great. So multiple ways to get involved in this work and follow Megan's work. Thank you so much, Megan, for joining us on the Green and Bold podcast. Yeah, and I look forward to seeing where this leads.
24:28 - Dr. Megan L. Melamed
Great. Thanks, Veera, for having me.
24:30 - Veera Mitzner
Thanks
24:34
Thank you so much for listening to Green and Bold. I'm Veera Mitzner, the director of CSU Climate Hub at Spur. You can learn more about Dr. Megan L. Melamed and her work with Spark Climate Solutions through the links in the show notes. This show is produced by me, Kevin Samuelson, and Alison Sylte, with audio engineering and editing by Kevin.