Building Climate Knowledge Infrastructures

A Lead Author of the IPCC Sixth Assessment Report, Paul N. Edwards, talks about knowledge infrastructures and geoengineering, as well as policy and visual aspects of the landmark report on climate change.

Unless you’ve been living under a rock, you’re probably familiar with the Sixth Assessment Report released by the International Panel for Climate Change (IPCC) in August 2021. According to the IPCC itself, the report addresses “the most up-to-date physical understanding of the climate system and climate change, bringing together the latest advances in climate science, and combining multiple lines of evidence from paleoclimate, observations, process understanding, and global and regional climate simulations.”

What the scientists found is far from encouraging—UN Secretary-General António Guterres described the document as “code red for humanity,” and for good reasons. In the best of the possible scenarios, a 1.5 degree Celsius temperature increase relative to the pre-industrial period is in place; in the less rosy ones, civilization is threatened by catastrophic events that follow one another as a result of a 4.5+ degree Celsius warming.

The scientific prognoses are clear, less so are the policy interventions needed to avoid walking down the most destructive paths. We are interested in understanding and mapping out the context within which the knowledge production of the IPCC report happens, as well as the ways in which its visual and narrative elements influence its interpretations. Ultimately, these elements are crucial in shaping policy responses to the scientific assessment.

A few weeks and many headlines after the report’s release, we interviewed one of its lead authors, historian Paul N. Edwards. We were drawn to Edwards because of his work on the science and history of global warming, which he masterly laid out in his book A Vast Machine (MIT Press 2010) and further articulated in numerous publications.

Paul N. Edwards is a William J. Perry Fellow in International Security and a Senior Research Scholar at CISAC, as well as a Professor of Information and History at the University of Michigan. At Stanford, his teaching includes courses in the Ford Dorsey Program in International Policy Studies and the Program in Science, Technology & Society. His research focuses on the history, politics, and culture of knowledge and information infrastructures. He focuses especially on environmental security (e.g. climate change, Anthropocene risks, and nuclear winter).

The conversation has been edited for clarity and brevity.

Chiara Di Leone: You are one of the lead authors of the Sixth IPCC Assessment Report, as well as one of the few social scientists involved. Can you speak about your role in authoring the report, and about the disciplinary composition of the working groups?

Paul Edwards: The latest IPCC report that was released in August 2021 is the Working Group I report, which is about the physical science of climate change. It is unusual to have social scientists involved in Working Group I at all. I’m in it because I’ve been studying climate change as a historian for the last 30 years, and occasionally write things that are more directly relevant to the scientists—and they seem to like what I’ve done.

I was nervous going into it, because I’m not a card-carrying physical scientist, but I absorbed a lot over many years of working on climate sciences from a historian’s perspective. I was a member like any other in the Working Group I, so I really enjoyed working on the writing of the IPCC report. Working on this subject is never fun, but my colleagues were great and very hard working and it’s an amazing effort because it’s all voluntary work.

Vlad Afanasiev: It seems like one of the most tedious tasks was to review all the comments that were sent after the internal version was distributed.

PE: Overall the Working Group I report received 74,000 comments, which is approximately 2.5 times more compared to the Third Assessment Report in 2001.

The response process is very intensive; we are required to respond to every comment. Most of them were made in good faith, in a spirit of contributing to better knowledge and telling us about literature we might not have viewed and to correct false statements and bad numbers. There were also a few people who were just critical of everything and really did not have any background in science to support it. It is frustrating, but strangely, once in a while, even some of those comments turn out to be valuable. So it’s worth going through the process, but it’s annoying when the comments are just sniping and not really serious about contributing.

CDL: It sounds a lot like being on Twitter.

PE: Yeah, very much.

VA: Can you contextualize the International Panel for Climate Change (IPCC) within your concept of knowledge infrastructure?

PE: A knowledge infrastructure is like a physical infrastructure, like electric power or sewer systems or roads. We build it and then we rely on it; it becomes a major part of our lives. We don’t really think about it very much, because it mostly works in the background. Knowledge infrastructures, by analogy, create robust and reliable knowledge that can be used to make policy. There are a lot of knowledge infrastructures around; the one that produces weather forecasts is a global infrastructure of instruments, computer systems, and human beings. Their forecasts aren’t always right, but they usually are. They’re much more often right than they are wrong, so people tend to trust them—at least within limits.

Since 1988, when the IPCC was founded, and since its first report was released in 1990, this body has been through six assessment cycles. The IPCC has gotten an institutional routine together that includes the review process we were just talking about and others. It is the most authoritative knowledge we have about climate, and it is widely accepted and used by the Framework Convention on Climate Change.

Most importantly, the purpose for which it was created is to aid national governments setting their own climate policies—as well as any other body that wants to know what’s going on with the climate, how it developed in the past, and where it might go in the future. It is a regular, repeated, relatively standardized production of knowledge; it uses widely trusted knowledge in the form of scientific publications that have already been peer-reviewed. That’s most of what goes into an IPCC report.

CDL: The IPCC report is policy neutral, meaning the panel “provides knowledge about what’s already happened to the climate (...) but does not recommend specific policies.” The climate projections it produces are based on a set of socio-political scenarios, Shared Socio Economic Pathways (SSPs). These scenarios rely on “business as usual” economic conditions and therefore end up being quite conservative. Do you think the panel should model more progressive economic systems in their projections? Do you believe the economic indicators and imaginaries currently in use are sufficient to picture the spectrum of possible societal configurations needed to reach emission targets? But most importantly, if the socio-economic scenarios are so close to the status quo, can the IPCC really speak of the report as being “policy-neutral?”

PE: That is a really great question. I would say a couple of things up front. First of all, the Shared Socioeconomic Pathways are now created from storylines about possible future worlds, directions that we could go: more globalization, retreat to nationalism, more trade, less trade, all kinds of things like that, which could happen. I think you’re completely right that they don’t imagine a radical change in our economic systems—but at the same time, the reason to create them is to generate profiles of possible trajectories of carbon emissions. Since they’re based on the use of energy, the levels of the nature of agriculture, deforestation, and other major factors that contribute to climate change, emissions would not necessarily differ very much from one economic model to the other.

Society needs to develop, because we’re close to eight billion people now and,we’re heading towards ten billion probably in the next twenty or thirty years—all those people have to eat, live a life of some sort. That’s going to take energy, no matter what kind of economic system is behind it. So it might matter, you might be able to imagine an economic change that would really drastically reduce emissions, but in terms of what we’re projecting for future climate change, I think it’d be hard to convince me that the range that is presented would be any different than the ones that are actually in the reports. So that’s one thing.

The second thing is that I’ve thought about this from the opposite perspective, which is RCP 8.5 (Representative Concentration Pathways)—that’s the highest emissions trajectory considered. There’s been a lot of news about it in the last few years, pointing out that that’s not the direction that we’re actually going because it assumes a really enormous amount of coal being burned, and we’re actually starting to move away from that. So it’s unlikely that that’s what will develop. But my point of view on that is that people used to say RCP 8.5 is “business as usual,” and it’s not business as usual now. But on the other hand, to dismiss it as completely unlikely is misguided because we don’t know how governments will develop in the future. If we assume stable governments and ongoing application of climate policy, that’s one world—but you can also imagine a world in which all of that just falls apart and it’s everyone for themselves and we go right back to mining and burning coal. That one is not an unimaginable future.

Now, you’re saying, could we imagine a future drop at the low end that would come from a really radical transformation of social and economic systems? I think that’s already imagined in the lowest end scenarios, because they include things that are really, at this point, just fantasy: net negative emissions, getting to zero carbon emissions, and then removing it from the atmosphere by artificial means. I don’t see it, and I don’t think that. There’s a lot of people working on it. I wish them all the luck in the world, because it would be great, but it’s not happening on the scale that we would need to see in the future.

VA: The Economist refers to geoengineering in the Sixth Assessment Report as being “conspicuously absent.” Is the IPCC planning to integrate technologies such as carbon dioxide removal and solar radiation management more substantially in the upcoming reports? What are your views on geoengineering as it relates to climate modeling and climate projections in general?

PE: There will be a lot of that in the Working Group III report, because that’s the mitigation and adaptation, and they’re going to be thinking really hard about all possible strategies for dealing with it. On the physical science side, there is the Geoengineering Model Intercomparison Project that looks at all the different schemes for carbon and solar radiation management, and tries to model what would happen to the earth system under those schemes. And the news is not good.

It’s definitely possible, and even actually cheap, to limit temperature rise with some of those techniques. The problem is that they don’t limit it in a kind of uniform way, they change things like water distribution around the planet. And it would be impossible to really know for sure what the effects would be without actually trying it. So if you were going to do solar radiation management, you’d want some kind of scheme that could be stopped almost instantly if it turned out to have really bad effects. But it could also cause unknown effects, like tipping points that we just aren’t aware of that would create permanent changes, even if you stop a particular scheme. Anyway, Working Group III is going to consider that, and they’re going to consider carbon dioxide removal and carbon dioxide capture and storage from burning fossil fuels. So all those strategies will be much in the news later on. Those reports will come out probably in the next six or eight months.

CDL: Let’s go back to the history side of things. There has been a strong media response to the Sixth Assessment Report, also because the document finally and unequivocally spells out the anthropogenic nature of the phenomenon, quoting from the report itself: “[anthropogenic climate change] is now an established fact.” Do you think this is an important step in producing an effective climate change policy? Can you tell us about the historical background of establishing a causal link between human actions and the climate?

PE: The first person to ever talk about what we would now call the greenhouse effect of carbon dioxide was a woman named Eunice Foote (Eunice Newton Foote) in 1856. She did a study where she put glass tubes containing air and pure oxygen and impure carbon dioxide and some other gases. She just put them in the sun with thermometers inside them and watched what happened. By the time the air had gone up ten degrees, the carbon dioxide could go up to thirty degrees. So she said, this is more or less a quote, an atmosphere that contained more of this gas would be warmer than the present one. And then, partly because she was a woman, she wasn’t allowed to read her own paper at the meeting where it was published. But her husband read it for her when it was published, and it’s even discussed a little bit, but then it sort of disappeared.

Some other famous work is the one of chemist Svante Arrhenius in 1896, who published the really detailed calculations of the effects of doubling carbon dioxide, but also of cutting it in half. He was really interested in the causes of ice ages and in why the Earth was colder in the past, and attributed that to less carbon dioxide in the atmosphere. And he speculated that if it doubled it would be a five or six degree centigrade warming if we got to doubling of carbon dioxide.

Later, this theory was kind of wiped out, because the famous physicist Anders Jonas Angstrom published a paper that seemed to say that water vapor would absorb all the same radiation that carbon dioxide did, so it wouldn’t make any difference. But he was wrong about that. Once there were more sensitive instruments, it turned out that carbon dioxide absorbs in a different [absorption] band than water vapor and does contribute quite a bit to planetary temperature. So there were a couple of people who kept working on that theory in the 1920s and 1930s. But really, it was G.S. Callendar in 1938 who revived it and kept publishing papers saying “this is a serious issue.” He thought he could see a carbon dioxide warming effect already in the time between 1890 and 1935. And then many other scientists began to study it in the 1950s and they established it as a piece of the climate puzzle.

By about 1965, it was an established element of climate knowledge that carbon dioxide change would be very important and that its concentration was increasing. It has been measured every year since 1957, and it goes up every single year. We know why we can tell that it’s anthropogenic because you can burn fossil carbon so it has no carbon-14 isotope. That’s all decayed and we can see that change in the atmosphere.

Every US president since John Kennedy has been briefed on climate change. There has been report after report. In 1979, there was the famous Charney Report (Carbon Dioxide and Climate: A Scientific Assessment), where scientists reached the consensus of about a three degree Celsius warming on carbon dioxide doubling. The amazing thing is that today we still think it is going to be exactly the same 3 degrees. This report did a remarkable thing, which was to narrow the range of uncertainty around that number. We used to say this range is between 1.5 degrees to 4.5 degrees, and now what we’re saying is it’s 2.5 degrees to 4 degrees. That means we took out a whole degree at the bottom of the range, meaning the lower end is less likely now than we previously thought. So there has been a very steady, significant, and increased understanding.

The 1995 IPCC report said the balance of evidence suggested human causes of climate change, but still couldn’t distinguish the signal from the noise of natural variability; the 2013 report said “unequivocal,” but here in the Sixth Assessment Report it says it is an “established fact”—that’s a rare declaration in science. This means that we’re at the 99.5% certainty level. Nothing ever comes with 100% certainty in science, but we’re about as certain as we can be about this particular issue.

CDL: In A Vast Machine you talk about the history of cartography and specifically about the history of representing Earth as a totality. Would you like to speak a bit more about that?

PE: Maps and globes are really old ways of representing the Earth. The thing that’s been such a huge contribution of computer modeling is being able to “see” dynamic processes. The Earth is turning, gravity is pulling everything; forces move things North and South, East and West, in the air and in the ocean, and create currents.

The remarkable thing to me is that so much of these visualizations are relatively recent (1980s) and most of them were done with static figures. There was a very famous video made in the early 1960s by Chuck Leith, who was one of the earliest climate modelers. He made the film just by taking pictures of the output of his climate models with an animation camera, so that he could take a whole series of shots and blend them together, like a filmstrip. He went across the country showing that little film of five or six minutes (The grandfather of today’s climate models). People were amazed because for the first time they could see in moving images the thing that they had only been able to visualize as a static thing before.

CDL: Were you involved in the IPCC interactive Atlas? What is its role within the broader IPCC knowledge production and communication strategy?

PE: The interactive Atlas was really aimed at a policy audience. All along, the goal has been to get down below the scale of the globe and the scale of continents to the scale of smaller places. One of my favorite quotes from one of my early interviewees in climate science, Bob Sherman, is “climate models will start to really matter when the grid scales get to the size of a congressional district.”

VA: That’s a very good prediction.

Yeah, it’s brilliant because that’s exactly right. If you can say to somebody “here’s how climate change is going to affect you, here is where you are,” that’s much more powerful than saying “the whole world is changing.” I expect that over time, we’ll get to even finer scales.

VA: In March 2020, during the first lockdown of COVID-19, global emissions fell drastically, giving us a glimpse into atmosphere composition if we were to stop industrial production. During this time, did the pandemic reveal something new about Earth’s climate?

PE: We got a few percent reduction in global CO2 output in the early lockdown phase of the pandemic, but even by the end of 2020, emissions had gone right back up to where they were, and they did not drop again this year. The one thing this does tell us is about the scale of change we could anticipate from individual action; in most places, lockdowns weren’t heavily enforced by police. People also just stopped going to work, they stopped commuting, and doing all those kinds of things. So those were mostly all individual decisions, in response to the lockdown policies. In general, people could have still gone somewhere, but they didn’t. So it tells us that really, those levels of change are not nearly enough to deal with the problem that we’re looking at; this is an infrastructural problem, it’s not an individual action problem. Working really hard, any of us can maybe cut our carbon footprint by ten or twenty percent, but we will not get to zero. We just can’t, because it’s embodied in the goods we buy, the food we need, and everything else. So we really need policy change, and technology change, to get to a place where we can at least have some hope of limiting climate change.

CDL: Speaking of pandemics, in A Vast Machine you mention that alongside meteorology, the epidemiology of infectious diseases contributed to the development of global information. The current pandemic has shown how important fast and precise informational models at planetary scale are. We are not simply making sense of Covid-19 through testing and modeling of the infection curve; our governing response on the pandemic depends on these very models. Can you speak about the relationship between climate sciences and epidemiology?

PE: A really interesting thing is that the techniques that weather forecasters use to pull data into the weather forecast system, while also using a model to project the future of weather, is called data assimilation. In the early 2010s, Google created a system called Google Flu Trends to project influenza spread. Their idea was to map the geographic location of Google users’ searches for flu symptoms and to use that as an indicator that they might have the flu, or that someone they know might have the flu. If you can see the geography of the searches, you might know something about where the flu is, and then you can use that to infer how neighboring areas are going to get infected soon. That worked really well for about three years, and then it failed. The problem was that models based on searches, like Google's model, had no causality in it; the mechanism was not about how actual viruses spread.

Epidemiologists, conversely, have models of that spread [which include causality]. Later, there was a contest to create a better way of predicting flu spread. The winners used weather forecast techniques, data simulation techniques, and search results from Google and combined them. They ended up doing better than any of them acting alone. I think we are going to see more and more uses of prediction techniques like those in the near-term future.

Chiara Di Leone

Chiara Di Leone is a writer and researcher on economic narratives, anticipatory governance, and climate interventions, among other things. Her essays appear in several publications including TANK, KALEIDOSCOPE, Foam, Strelka Mag, and RealReview. Chiara regularly advises institutions through design research. Her clients include BBC R&D and Serpentine Galleries.

Vlad Afanasiev

Vlad Afanasiev is an architect, designer, and researcher. He focuses on environmental governance, predictive modeling, simulations, and public policy through the lenses of visual and design practices.