News Roundup: Live from the American Geophysical Union

Dr. Pete Irvine: [00:00:00] Welcome to the December 2024 News Roundup of the Climate Reflections Podcast. Each month we release a roundup of news related to sunlight reflection methods or solar radiation modification, SRM. I’m your host, Dr. Pete Irvine.

This month, we are coming to you live from the American Geophysical Union, the AGU, their annual meeting in Washington, DC. Each year, the AGU annual meeting brings together more than 25,000 scientists, educators, policymakers, and more from around the world. Many of whom are interested in climate, past, present, and future, and some of whom are interested in sunlight reflection methods.

So I’m joined by some of those experts now. Would you mind each introducing yourself, giving your name, affiliation, and where you came in from?

Lili Xia: Hi, I’m Lili Xia. I’m an assistant research professor at Rutgers University. So I’m working on climate modeling and crop modeling on solar radiation management impact.[00:01:00]

Chris Lennard: And I am Chris Lennard. I work at the University of Cape Town in South Africa. I also do a little bit of climate modeling, but my main research aim is to try and understand regional climate risk in the context of climate variability, global warming, and solar radiation management.

Tyler Felgenhauer: And I’m Tyler Felgenhauer. I’m a senior research scientist at Duke University in Durham, North Carolina. I look at the risks and benefits and societal implications and governance of potential climate interventions.

Dr. Pete Irvine: First, let’s discuss some of the SRM-related headlines in the past month. On November 28th, The New York Times published an article about U.S. efforts to develop an early warning system to detect SRM deployment. Now, I’ve spoken with David Fahey, who explained that this is not the only purpose of what they’re doing. What they’re doing is trying to observe and monitor the stratosphere so they can build up a background understanding of what’s going on there[00:02:00]  and in doing so, they’d be able to detect the deployment that someone else was doing and monitor how it’s developing.

But Tyler, this is something you’ve thought a bit about. What kind of value could developing or collaborating over, uh, this kind of stratospheric monitoring do for the field?

Tyler Felgenhauer: So there’s several benefits to why we might want, why we would want a monitoring arrangement, uh, for solar radiation modification.

First, it could help us detect unilateral or non-cooperative deployments, uh, in advance, helping to avoid international conflict over these issues. From a scientific basis, it could help us just basically understand the basic science of the deployment, understanding the characteristics, um, and risks, um, of any, uh, deployment, and help improve our understanding of the stratosphere in the meantime.

It could help assess claims of adverse impacts from any deployment. Um, and most [00:03:00] importantly, it could help with the governance of any deployments, potential deployment, um, allowing future decision makers in helping them to decide whether to deploy these technologies, uh, how to ramp them up or ramp them down, how to revise and adapt their deployments over time based on the information that they gained from the monitoring.

Dr. Pete Irvine: Could this also have a, a kind of political trust building, uh, value? Cause I’m thinking this is a relatively non-controversial thing that might help nations feel a little more comfortable with what each other were doing if they were to work together on such an activity.

Tyler Felgenhauer: Yeah, certainly. Uh, we, we’re looking at those, uh, two different types of environments, one where, where the deployment is potentially done cooperatively, but even in that case, nations would want to have some sort of verification or double checking of each other’s information, even triangulation of information. Not because they don’t trust [00:04:00] the other entity that’s embarking on such a program, but because the information might be uncertain.

So future scientists would use satellite measurements, air-based measurements from airplanes or balloons, ground-based measurements to try to assess, uh, what, uh, deployment, what type of deployment is going on as well as self-reported information. So that’s in a cooperative, uh, environment. In a non-cooperative environment, uh, there’ll be further uncertainty.

Scientists are fairly certain that a deployment could be detected, but it would be great to have much more information about how to characterize any future deployment.

Dr. Pete Irvine: Great. Also in the U.S. this month, a Florida State Senator, Ileana Garcia, submitted a bill for consideration in 2025 that would ban all weather modification activities and would prohibit acts intended to affect the temperature, the weather, or the intensity of sunlight within the atmosphere of the state. [00:05:00] Now that would cover SRM, and this is just the latest in a string of proposed bills in U.S. statehouses. Although only Tennessee has actually passed a bill so far. Um, how, now I think we’re quite familiar that this kind of conspiratorial thinking is quite widespread in the U.S. Uh, Lili, Chris, is this the, is this kind of concern coming up in, in South Africa and China?

Chris Lennard: In, in South Africa and perhaps Africa as a whole, I thought not until I had a chat with someone, uh, two days ago here at the AGU who actually showed me that there are some high impact policy folks who do actually buy into chemtrails, for example. And I was very surprised and rather disappointed, but yeah, I guess it’s there. But since this is the first time I heard about that, um, maybe it’s not as widespread as here in the U.S. [00:06:00].

In South Africa, we have historically had very strong weather modification competencies, particularly in the summer rainfall region of the country. Those efforts, depending who you speak to, were successful or not, and unfortunately, our, um, research capacity in the space has teetered off, but a lot of the folk who were involved in that process are now working in, uh, or with, rather, the UAE with their weather modification, uh, rainfall enhancement programs. So, it is still very much alive, despite the Tennessee governor’s ambition.

Lili Xia: And for China, I think the research of solar radiation modification, I think there was a big program, not a big program, but there was a program, uh, I think focused mostly in Beijing Normal University years ago, and that one ended, and I can see some scattering publications from China [00:07:00] researchers looking at SRM impact and I think recently there has been two projects funded. One is on SAI, another one is on marine cloud brightening. It’s not as big as the one from UK, but yeah, I think right now they started to look at the, uh, the strategies and also impacts.

Dr. Pete Irvine: Well, China has quite a large weather control or cloud seeding effort, like a famously very large effort. Has that, has that led to some suspicion by neighboring countries about China’s activities?

Lili Xia: That I’m not sure. I know there has been a lot of weather modification projects there. It’s really big projects. Most of the data I don’t think those are really open yet.

Dr. Pete Irvine: Well moving to the international, um, the United Nations framework convention on climate change the UNFCCC met in Baku, Azerbaijan [00:08:00] for their 29th annual conference of the parties and Tyler was there! Um, Tyler, what is the UNFCCC and what is a conference of the parties like?

Tyler Felgenhauer: Yes, so the, uh, UNFCCC is in essence the world’s only and oldest climate change treaty, uh, negotiated in the early 90s and started to be ratified in 1992. And it’s now been ratified by nearly all nations of the world. So over the years, there have been various sub agreements to the UNFCCC, notably the Kyoto Protocol in 1997, and then most recently, the Paris Agreement on Climate of 2015.

So Paris has an ambitious goal of having the world reach no higher than 2 degrees of warming above preindustrial levels by the year 2100. With efforts to be more ambitious and really achieve 1.5 degrees of warming. It would do this through a series of voluntary, uh, or called nationally determined contributions where each nation [00:09:00] decides how much it can reduce its emissions and then report on that every few years. And then finally, these efforts would be aided by a further aid from wealthier countries to the developing world. So every year, the treaty has what’s called a conference of the parties all parties to the treaty, meaning all of the countries who have signed the treaty, uh, meet to assess progress and push it forward.

The latest one was in, uh, the caucasus oil state of Azerbaijan in its capital, Baku. I had the opportunity to attend for my first, my first COP ever. And it was enlightening, um, mainly because it was a political conference, uh, rather than a scientific conference. For those who’ve been to cops, it’s, it’s a lot of people observing what happens behind closed doors.

Dr. Pete Irvine: Well, how, how big is COP? We’re here at AGU, which I think is 25,000 attendees. How many people turn up to these big UNFCCC COPS?

Tyler Felgenhauer: So it’s, my understanding it’s tens of thousands, I think it was 50 or [00:10:00] 60,000 in Baku over the course of two weeks. A lot of the meetings are open for, for observing, but those, uh, the key negotiations over key numbers, such as the one that came out of Baku, this level of $300 billion, um, in aid from the global north to the global south by the year 2035.

These key negotiations over such numbers happened behind closed doors among the diplomats, the parties to the conference. I was able to attend the side events focused on solar radiation modification. SRM was not on the agenda at the COP and it never has been, but there might be a time in the future when it is under discussion and it’s good to have these side events to discuss how it might play a part in an overall climate change policy portfolio.

Dr. Pete Irvine: Well, and you’ve helped draft and gather together some reactions to the UNFCCC COP on SRM for us. We’ll feature a link to that, uh, in the podcast description and also on our [00:11:00] website, so check that out there. But here we are at AGU, the American Geophysical Union Conference, 25,000 attendees or so and I think all of us had various presentations or things we were attending. I just want to – Lili, you had a presentation. Could you give us, our listeners, a sneak peek of the findings of your work in progress?

Lili Xia: Well, uh, the work I presented is really a project on progress. Our group has been looking at food security for a long time using agriculture models but now, uh, I think we are also interested in general human health, how human health, um, is impacted under SRM. So we looked at heat index to see whether the SRM can really reduce heat stress for human over those high populated regions. And we’re also interested to look at how the PM 2.5 and surface ozone, those [00:12:00] air pollutants change under SRM.

So the basic idea is using this new scenario proposed for CMIP 7 and using multiple climate models and analyze those data, uh, over across high populated regions and look at in general, what’s the human health impact.

Dr. Pete Irvine: Yeah, and so we have this idea in this field of a risk, risk analysis, because there’s risks that come with climate change and Stratospheric Aerosol Injection comes with its own risks. And it’s about sort of balancing those or considering both sides. So you kind of looked at these, well, three different risks. How did the balance weigh up between climate change without risk SAI and climate change with?

Lili Xia: Well, right now, based on very preliminary results, I think SAI will reduce planet temperature. That definitely will reduce the heat stress based on the index we’re looking at; heat index and in [00:13:00] terms off our prudence, it really depends on the model, and we really need more multi climate model into comparison and to look into it. And also, it’s regionally, it’s unevenly affected.

Dr. Pete Irvine: Cool. Well, at the time of recording, it’s been only a couple of days since the European Commission’s chief scientific advisors released some recommendations on SRM. So I’m not sure if anyone has really had a chance to read that yet, but I’ll just run through what those headline recommendations were and then maybe you can react.

So first up, keep emissions cuts and adaptation as the highest priorities. It seems very reasonable. Um, then announce a Europe wide moratorium on the use or deployment of SRM. Relatedly, negotiate a global governance for SRM where the European commission should push for a moratorium on deployment or to not deploy. Uh, then they had whole broad and inclusive public deliberations about all approaches for fighting [00:14:00] climate change. So not just for SRM, but in context, uh, then, you know, make sure that research is rigorous, ethical, critical, and comprehensive. Sounds all quite reasonable. And then reassess the evidence on risks and potential opportunities every five to 10 years.

Um, any reactions to this, uh, development, to these recommendations?

Tyler Felgenhauer: I would agree those are very reasonable. I would tweak one part to note that moratorium is not a prohibition or a ban. The way I would see governance is a little bit broader. It’s not only to enforce a moratorium, most would agree that these technologies are not well understood enough to be able to deploy at this time. However, there might be a point in the future when this governance that needs to be developed before any deployment, which allows for this political decision making, there might be a point in the future when the decision is made that these technologies are needed, and the moratorium would be lifted.

This point about revisiting the [00:15:00] issue um, regularly, is very important as the science community researches the risks and the benefits and as the political community starts to develop governance in advance of any deployment.

Chris Lennard: I’ve read the executive summary and the recommendations, and I think it falls quite reasonably because, as Tyler said, moratorium has a particular meaning, so that word is used deliberately. And there are many caveats in the recommendations when you read them. So there’s one about, um, when you said, Pete, that the EU position in these negotiations should be for the non-deployment of SRM in the foreseeable future, that’s a time limit that they have set there. And there’s an exemption part in that recommendation that says, include an exemption in the international treaty, with a clear permitting process that specifies conditions under which to authorize some limited outdoor SRM research.

So it’s not [00:16:00] banning outdoor SRM research, it’s saying we acknowledge there’s a problem. We don’t want to go full tilt right now because there’s so many questions that we still need to understand. Do the research first and let’s see what the research produces.

Dr. Pete Irvine: Yeah. I mean I guess one reaction I had, um, was that it sort of stressed the moratorium first and then assessment last, which I felt was perhaps, you know, yes, if you’re going to move from moratorium, that makes sense but to assess in five or ten years, seems a little late. I’d have thought they’d recommend studying this further, perhaps with a bit more priority. And I guess this kind of pushes me on to sort of put this in context that, you know, just as, or a few months before this was announced, the UK has announced $10.5 million for modeling the effects of SRM in a new set, a new set of funding and then another 57 million pound for doing field experiments and lab work to develop the technology and explore the feasibility of these different ideas. And I think it’s worth stressing that [00:17:00] I don’t know how there’s not been a great deal of funding for this research across Europe in the past decade or so.

There’s been a few million spent but Europe is actually now with the UK investing so much quite far behind, especially the U.S. And I think if they want to influence this debate, they’ll need to make governance moves, but, but also learn more about it and be engaged in the research.

Chris Lennard: Yeah, we actually were joking about a year ago. So I was part of the team that produced the first ever paper on SRM research over in Africa, as a continent. And we were joking that we should reproduce that paper for Europe because that doesn’t exist. They don’t actually know what we know in the African context. But yeah, I think through this, the European research funding will come to the party. It might take a little bit of time because I think also in Europe is a very strong anti SRM and anti SRM research community who will push back against what the EU have produced. So it’s going to be an [00:18:00] interesting two or three years to see how this flies.

Tyler Felgenhauer: I would just add that the further the globe delays on needed emissions cuts, bringing total emissions down to net zero and below, the more and more motivation or incentive there, there would be that would arise for deploying these new technologies.

I remember when I first got into the climate change field, um, a while ago that the calls were to “stop” climate change. And then those seem to, these are ones I just read in the popular press to stop climate change, and then they turned to “slow” climate change, and then they turn to “prevent dangerous” climate change.

And then I go to the COP in Baku and it says on the walls, keep 1.5 alive, but 1.5 is not alive. We’re heading past 1.5. and the further we delay on needed mitigation efforts, the more and more that, that climate intervention technologies will come to the fore.

Dr. Pete Irvine: Well, uh, turning to the developing world, uh, this [00:19:00] month, the journal Science published a great opinion piece by Rose Mutiso titled Neither Climate Laboratory Nor Knowledge Vacuum, What’s at Stake for the Global South in the Debate Around Solar Geoengineering Research. Uh, so Chris, you’re based in Cape Town and work with researchers across Africa studying climate change and SRM. Uh, what are your thoughts on this piece?

Chris Lennard: Yea, it’s a great piece. You should also listen to Rose’s podcasts, they’re amazing. The piece is really good because it’s very balanced in my opinion. She refers to a meeting held in Cape Town and full disclosure; I ran that meeting. And she was invited there as an observer really, and as someone who we knew had good experience in the in the energy space and had built really good networks and is very efficient in what she does. So we invited her to this meeting.

And at that meeting, we had scientists in the DEGREES program, [00:20:00] and the DEGREES program is a program that has created the ability for researchers in the global south to do research into climate intervention and in particular, um, solar radiation management science. So without the degrees work, there would be no or very little global south participation in the space.

And what we did was we gathered all of the African degrees, principal investigators and the deputies brought them down to Cape Town to have a two and a half day meeting really to think about if SRM is coming, which as Tyler alluded to, it probably is at some stage, we need to, as Africans have an African based narrative that we can present at global negotiations, not a narrative that is given to us by the Europeans or by the Americans, but a narrative and a story and an understanding that is born of African research in Africa.

With this in, [00:21:00] in mind, we brought these folk to Cape Town, we brought some NGOs, uh, representations to Cape Town. We brought representatives from African academic institutions also and we sat down for two and a half days thinking about this and Rose was a part of that. So that’s what she’s reflecting on in this piece, are the discussions that we had. [Which] is how do we, how do we build African capacity to conduct the type of research that we need to do for Africa, and then turn that into knowledge that our policy community and our negotiators can use at time of negotiations?

If Tyler is right about COP, that this SRM might feature as a bullet point in the next three or four years at a COP meeting, we’ve got to have our negotiators capacitated to speak authoritatively into that discussion. And that’s what we’re trying to do and that’s what Rose’s piece, uh, Rose’s piece is alluding to. It’s really about building capacity in Africa and more extensively in the global South. So that when this discussion [00:22:00] does happen at UNFCCC levels, um, we have representation there that is knowledgeable.

Dr. Pete Irvine: Well, I think now I’d like to move on to some questions from the audience. So, we’ve got a place on the website where you can add your question at the bottom of every page and Jonathan wrote in to say, ground-based reflection methods, so mirrors, white surfaces, etc., are immediately available and without controversy. Shouldn’t there be a focus for researchers working on SRM? That might be slightly paraphrased, Jonathan, but that’s roughly what he was asking. Um, so anyone, does anyone have a thought on that question? Should we be focusing on surface albedo modification?

Lili Xia: I don’t know. I just feel that’s a scale issue for me when I first, uh, I think there has been some modeling study, um, like is there increased albedo over desert or what if we just widening all the roof over the city area. I think it’s a scale issue. It’s how much we can really reduce the solar radiation by reflecting. It’s probably just a small [00:23:00] part of the surface, so that should be like my first impression is to think about whether it will be efficient.

Dr. Pete Irvine: So it would just have a small cooling effect.

Lili Xia: Yeah.

Tyler Felgenhauer: Yeah, I think it’s important to distinguish between alleviating the urban heat island effect, which could be done through such things as painting roofs white.

There’s some research done by David Carlson and Mike Bergen at Duke looking at white roofs and alleviating urban heat islands. There’s also, maybe we can have a link to this, there’s a new newly invented super white paint from Purdue University. Apparently, it’s the whitest paint ever invented, but that’s as Lili said, painting all roofs white is still a very small amount of surface area compared to what might be needed to change global temperatures using surface albedo modification.

Dr. Pete Irvine: Well, and a new study just came out this week or the last couple of weeks by Cheng and McColl in the Journal Geophysical Research Studies. They actually found this idea might not necessarily be so benign. They found that the areas cooled by it would be [00:24:00] cooled, but there would also be a reduction in rainfall in the area affected that would spread to other areas nearby. And the areas nearby would be drier, and as a result of being drier, they would warm up more. And so actually it could have a warming effect adjacent to the areas that were applied.

So another question we had from Carrie, would the temperature decreases from stratospheric aerosol injection be offset by the emissions from the aircraft used to deploy it? How big a deal would that be?

Tyler Felgenhauer: I think the amount of emissions, so this is following a work by Wake Smith and others looking at the number of flights per day, the number of planes, while that’s a huge number of flights, it’s equivalent to a small fleet of airplanes in the case of stratospheric aerosol injection. I think it is minuscule, from my understanding, minuscule compared to the amount of cooling that, that would happen from those flights.

Dr. Pete Irvine: Yeah, I guess one sort of rule of thumb I have, I think aircraft or aircraft travels like 3 percent, 2 percent of all emissions and this would be a few percent of a few percent. So it’d be a small contribution, but [00:25:00] could do a very large cooling event.

Chris Lennard: The other thing to remember about aircraft is the warming effect from aircraft primarily comes through contrails and not through their emissions.

I think it’s more than half comes through the contrail so blocking outgoing long wave radiation and trapping that in the system. So in terms of emissions, it’s probably not that much.

Lili Xia: And this is just some new research I heard from this AGU from the aviation industry. I think they are really working hard to trying to design the engine and have the spread of their emission in a like optimum stage to trying to reduce the contrail and trying to reduce the warming effect. So maybe we will have a totally different engine at that time.

Chris Lennard: And what they are actively trying to do now is, is steer the aircraft into air pockets that do not have enough moisture to create a contrail. So the [00:26:00] contrails are the important bit here, but not the fuel. Although there’s also if it’s going to clean up the soot content of the exhaust that comes out of the aircraft too.

Dr. Pete Irvine: I guess it’s probably worth noting that contrails don’t form in the stratosphere. So if you’re flying in the stratosphere, you shouldn’t create any contrails there. So, another question we had from Eliad was: what would the effects of dimming the sun be for plants and algae? I’ll pass that over to Lili.

Lili Xia: Yeah, uh, we have been looking at how this SRM will impact the plants for a while. So when you block the sunlight, it will reduce the total solar radiation but with all those, but with all those aerosols there, it will increase diffuse radiation. That actually has benefits for plants because the leaves underneath can really get more sunlight and then you will have a little bit cooler temperature, but you will keep the high CO2 concentration, [00:27:00] which has a real CO2 fertilization effect. So it’s probably good for the plant growth in general and then algae, that’s a little bit different, it’s in the water. So it’s probably well through the temperature change and a little bit less of total solar radiation. Um, so for that part, I’m not sure.

Dr. Pete Irvine: Yeah because I guess if we’re talking, say a one celsius cooling, we’re only talking about a 1 percent reduction in sunlight, something in that territory and the effects of CO2 are really large on labs.

Lili Xia: That’s right.

Dr. Pete Irvine: Well, I guess we’ll just close. Any final takeaways from AGU?

Tyler Felgenhauer: Just an interesting takeaway, there was some really great discussions and posters on Monday and Tuesday. One of the takeaways I saw was there’s been a, seems to be a, a practice in, in modeling and, and in, uh, uh, social science studies of looking at the, the, uh, I would say the top down effects of climate interventions, the effect on temperature and the effect on weather [00:28:00] patterns and the climates and, and every, these large, large scale variables.

There’s been several suggestions to look at the flip side in, in that what is the effect on humans? What, how would SRM affect people directly? I was in part of separate conversations looking at CDR (carbon dioxide removal) and most people might not really, they wouldn’t feel the effects of carbon dioxide removal in their community, but they would feel the effects of the actual facility that’s being constructed in their community. So it’s been a great reminder to focus on human-centric impacts of these potential interventions.

Chris Lennard: Perhaps a takeaway for me was a session on Tuesday, I believe, where climate intervention got a AGU lecture thing. So there were thousands of people in the hall listening to a panel discuss the largely ethical framings and technology. Not so much the technology, but [00:29:00] that it was actually at that level being discussed at the AGU, I think was really impressive. I don’t know if that’s first, but I would guess it has been.

Lili Xia: So for me, I think the biggest takeaway is like combination from Tyler and Chris. I think I noticed more and more researchers and communities get interested in this topic and I feel as we, our group are working on really like look at the human health impacts, but I think except for that there’s a large community working on ecosystem and the other expertise. When they get interested, I think this community needs to have the responsibility to really pass the information of SRM to all the research communities and ask all the scientists to bring their own expertise and really have a really great full assessment on this topic instead of just this small community.

Dr. Pete Irvine: Well, great. I’m sure an excellent place for them to start getting up to [00:30:00] speed would be srm360.org, so they should check out our website. Well, anyway, thanks Lili, Chris, and Tyler for joining me for this sometimes noisy recording of the SRM 360 podcast, Climate Reflections. Thank you!

Thanks for joining us for our monthly news roundup live from AGU. Tune in for more episodes of Climate Reflections. If you like this episode, please rate and review us wherever you got this podcast. The Climate Reflections podcast is a production of SRM360, a nonprofit knowledge hub, supporting an informed, evidence-based discussion of sunlight reflection methods. To learn more about SRM or to ask us a question, visit srm360.org, where you can also find a transcript of this episode with links to the articles we discussed.