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S3 Ep 10 - Aja Watkins & Miguel Ohnesorge on 'Philosophy of the Geosciences'

Episode Transcript

Hello all and welcome back to The HPS Podcast where we discuss all things history, philosophy, and social studies of science for a broad audience. I'm Samara Greenwood, your host, and today I'm excited to introduce you to an emerging subfield of HPS called the philosophy of the geosciences. To discuss this topic, I am joined by two very talented early career historians and philosophers of science, Aja Watkins and Miguel Ohnesorge.

Aja and Miguel recently co-authored an article titled ‘What is the Philosophy of Geosciences?’ with the aim of introducing this new subfield to a broader academic audience. In today's episode, we discuss many of the themes they introduce in the paper, including some of the common problems found across such diverse geoscientific disciplines as palaeontology, the study of the deep past via fossilized animals and plants, seismology, the study of earthquakes, and climatology, the study of Earth's climate.

Aja and Miguel highlight how all these fields have to continually develop novel strategies for studying such macro scale and often inaccessible phenomena. As global sciences, they also face many common ethical challenges, including rectifying a history of often extractive, exploitative, and colonial practices, as well as navigating the continued ramifications such wide scale research has on human welfare and the environment.

It has been a real pleasure hearing about exciting developments in what is a rich and growing area of research in HPS. I hope you enjoy it too.

Samara Greenwood: Aja and Miguel, thank you so much for coming on the podcast. It's great to have you both here. 

Aja Watkins: Thanks for having us. 

Samara Greenwood: Now, first, I'd love to know the backstory to your collaboration. How do you two know each other and how did this project on ‘what is philosophy of the geosciences?’ come about? 

Aja Watkins: Yes, thanks. So, Miguel and I were first introduced through my dissertation advisor, Elisa Bokulich.

Elisa also directs a group called the Philosophy of the Geosciences Research Group. When Miguel came to Boston to spend some time with Elisa and the group, we spent a lot of time together. Alisa also organized a Boston Colloquium for the Philosophy of Science session on Philosophy of the Geosciences that both Miguel and I presented at last May.

As we spent some time reading things together, getting each other’s feedback on our work, it became really apparent that Miguel and I had a lot of common interests and common aspirations for philosophy of the geosciences as a distinct sub discipline of philosophy of science. That's how we came up with the idea to propose an article that would both give an overview of research in the area so far and also do some agenda setting and suggest future work in philosophy of the geosciences.

Miguel Ohnesorge: This philosophy of the geosciences colloquium that Aja already mentioned, in many ways it was the first of its kind. The discipline is just getting institutionalized, hopefully becoming more institutionalized as time moves on. It was quite inspirational because some very early figures like Rachel Laudan and Carol Cleland were there as well.

So, we had that sense that there is this long term effort of people trying to understand foundational questions about the geosciences and we're finally in a position where we can come together as a community and try to think about which of these questions matter and how do they differ and all the things that we then discussed in the paper.


Samara Greenwood: So, turning more directly to philosophy of the geosciences, I'm really interested in what are some of the key research problems in this area that you talk about in your paper? 

Miguel Ohnesorge: One big question that helps us to clarify what we're talking about and what we're interested in is: what are the geosciences are and can we demarcate them?

It's a tricky question because the label ‘geoscience’ is quite young. It didn't really exist before the 1940s. Then if you look at the methods that we're using in different typical geosciences, say, you can think of something like quantitative branches of geophysics, like seismology, where we study earthquakes. Or you can think of something that's a predominantly biological discipline, like palaeontology, studying ancient life and evolution on earth. And if you compare those different disciplines, they look quite different. The theories are different: theories of gravitation and elasticity theory in seismology, and evolutionary theory on the other side. The mathematical techniques are different, if they're mathematical techniques at all.

So, it's quite a tricky question. If you press geoscientists themselves, they'll probably say something like ‘geosciences are the sciences studying the earth’. And then they add a little qualifier, ‘and other planets.’ Because nowadays, we're also interested in all these other things like astrobiology and life in the universe and planetary geophysics.

That's a helpful starting point, but it's clearly not sufficient to demarcate what is a geoscience and what is not. In our own view, that is probably not really a solvable problem, as with most demarcation problems. We won’t have hard, clear, technical criteria. Instead, we should best understand the philosophy of the geosciences as a field concerned with foundational problems that most disciplines consider geosciences have in common. The kinds of things that they study. That's picked up by this very common definition, ‘they study properties and processes at a planetary scale.’ Fortunately for us, recent work in philosophy of the geosciences has already zoomed in on exactly such common problems. The first one is epistemological.

Many kinds of geosciences face a problem of accessing the things that they're talking about. Think about the interior of the earth. It's locked away from us. Think about the complexity of climate, because once you zoom in on the surface of planets, it's really, really messy. Or think about studying things in the deep past.

So, many features of planetary processes and properties, they're not accessible to direct measurement or experimentation. For this reason, geoscientists across very different fields on the face of it face similar problems and had to devise similar techniques for tackling these problems and to measure and model planetary phenomena successfully.

So, it's really exciting to look at how geoscientists managed to build quantitative measurements because they didn't have access to those usual resources that we have in experimental sciences and yet they still managed to build, say, quantitative measures in seismology or in climate science. 

Aja Watkins: A lot of other common questions that geoscientists face have to do with how to appropriately use data and how to appropriately use models to try to help address these problems of inaccessibility.

A lot of philosophers of the geosciences, I think, have made some really good progress at actually helping geoscientists figure out how to use data and models well here. So, for instance, one of the things that's really interesting about paleontological data is that they're relatively sparse. And in addition to this, paleontological data are really tied to material artifacts with particular histories in a way that some data in other areas of science aren't necessarily tied to those material histories. I've used some of these unique features of paleontological data to sort of push back on or try to refine or clarify existing philosophical accounts of data ontology. 

And models, in addition to data, are also really important in the geosciences because of this issue that Miguel raised concerning how many of the subjects in the geosciences are relatively inaccessible. So, if we can't very easily study something like a whole mountain range, or an object in the past, or other planets, or the whole of Earth's climate directly, there's a really good substitute way to study it, which is to build a model of those systems. That model is going to be something that we can more easily understand and manipulate at the spatial and temporal scales that science actually happens at.

So, a lot of insights from philosophy of modelling have come from philosophy of the geosciences, and in particular, in philosophy of climate science. Including: how to evaluate them, what, if anything, we can conclude when multiple climate simulations agree or disagree about the prediction about climate change, and how climate models and climate data are related or should be related. 

There have been a bunch of what I think are surprising insights generated in this area. So, for example, that climate simulations are not always improved by making them more accurate. Sometimes keeping a climate simulation inaccurate in particular ways is actually part of what makes it useful. Another one is that sometimes climate models are actually better at tracking climate change than climate data are. These are just some of the insights that have come out of a philosophy of climate models. 

Miguel Ohnesorge: The second important commonality that we stress in the paper, which is more historical, has to do with the political and ethical history of the geosciences, because they are what historians sometimes call survey sciences. Historically, they were funded by colonial trading companies, industrial conglomerates, the military very often, because you need them to get resources out of the ground, to navigate ships and airplanes and so on and so forth. 

We think there's special moral and political challenges that the geosciences face because of that history and because of resulting current inequities in knowledge production and distribution. If you look at research in palaeontology, this often relies heavily on specimens that are collected in low-income countries, though research in palaeontology is usually funded by institutions and researchers from high income countries. This bears the risk of what's sometimes called parachute science, where scientific credit and specimens are accumulated in established and prestigious institutions with sufficient funding and expertise and so on, usually in the global North, and the expertise and the institutional growth that would be required in other countries where the specimens are from is usually excluded entirely, or at least does not receive sufficient credit.

Perhaps even more dramatically, many geosciences study matters that bear on what political philosophers would call fundamental interests of citizens: access to clean water, habitable environments, and protection from all sorts of natural hazards. Because the knowledge about these things is so asymmetrically distributed globally and within countries, this really raises important issues. For example, to what standards of justice should we hold scientific institutions that produce knowledge about such fundamental interests? My colleague, Ahmad Elabbar, from Cambridge wrote a really nice paper that's in the British Journal for the Philosophy of Science, where he argued that we have good reasons to think that institutions like the Intergovernmental Panel on Climate Change sometimes violate such standards. They are in fact not just, and they should be just, given how consequential that sources are and so on and so forth. 


Samara Greenwood: Do you have a sense of why this particular subfield of philosophy of science is emerging now? 

Aja Watkins: My perception is that for decades, philosophy of physics was really the only way to do philosophy of science, and philosophy of physics meant doing philosophy of a particular kind of physics.

A few decades ago now, philosophy of biology came on the scene and started being really respected as, another area in philosophy of science. And philosophers of science started thinking about philosophy of science as the kind of thing that even had sub disciplines that were associated with different sciences or different scientific practices. One of the things that we've seen more recently is just an expansion of this trend. It's not the case now that we just do philosophy of physics or philosophy of biology. You can do philosophy of any science. 

Miguel Ohnesorge: As a personal anecdote, I came into philosophy of the geosciences in some sense by accident and by necessity. My dissertation was on a very basic problem in history and philosophy of physics, which is how do we ever come to have strong evidence for Newton's theory of universal gravitation, given that it makes such outrageously general claims and it's really hard to test in the real world. 

The only major phenomenon for most of the history of gravitational physics, whether it was the case, was the equilibrium figure of planets. And the one we had access to was the earth. So, we had to figure out what shape the earth is and whether it fits the predictions derivable from Newtonian theory. 

So I got interested in that. And then you have to ask questions about, well, ‘how do we come to test claims about a system like the earth?’ And you realize, ‘oh, this is quite different from experimental physics and it's quite different from astronomy in some respects.’ Then I realized, ‘Oh, there's this whole field, there are people who are worried about seismology, climate science, and, even in such distinct fields, there are some common problems.’ But without the diversity of philosophy of science that we've seen in the last decades, that Aja mentioned, I think I would have never thought of myself as being a philosopher of the geosciences and explore those perspectives. So, it's, I think, an absolute precondition that people who are interested in physics and people interested in biology and all sorts of things come together. 


Samara Greenwood: So that leads well into the next question. How does philosophy of the geosciences differ from philosophical work in other areas of science?

Aja Watkins: One of the things that obviously differentiates philosophy of the geosciences is subject matter or emphasis placed on different parts of the scientific process or different kinds of scientific tools. For instance, a lot of philosophers of science work in areas of science where experimentation in a lab is the main way of generating new knowledge or testing hypotheses or gathering data. Although geoscientists do lab work sometimes on a regular basis, they also rely quite heavily on other methods like field work and simulation studies. So, within philosophy of the geosciences, these practices are emphasized more heavily. 

Additionally, as Miguel has already said a little bit about, although lots of philosophers of science nowadays are interested in science and values, or in how political processes shape or are shaped by scientific ones, the specific emphasis on political philosophy of science or values in science is distinct in philosophy of the geosciences, mostly due to the markedly exploitative and colonial history of the geosciences that continues through to today.



Samara Greenwood: And so next, could you both tell us a little bit about the work that you do in this area? 

Miguel Ohnesorge: As I said before, I sort of stumbled into the philosophy of the geosciences from history and philosophy of physics. I was really interested in this problem of the shape of the earth and how it offered this really important source of evidence for Newtonian gravitational theory. In fact, I'm writing a book with Oxford UP now about this. 

The reason why I got so interested and so excited about that problem is that you couldn't test it in the branches of physics that philosophers usually were interested in, and historians had looked at in detail, like astronomy and laboratory physics. But it is through what was back then a quite important, but now often forgotten field, called Physical Geodesy, the science of deriving the figure of the Earth and then measuring its parameters empirically. 

It turns out, we didn't really have strong evidence for universal gravitation before the early 19th century. And then agreeing on the empirical dimensions of the Earth's shape, even the rough bits of it, took another 100 years, so we're in the 20th century. The reason it was so hard to figure out is that it's really hard to measure complicated systems like the Earth to a high standard of precision, especially because there's so many aspects of the Earth that can cause errors that are just buried deep beneath its surface, and we couldn't access it. I really had to understand how we can measure a system like the Earth reliably, because this is where the evidence came from in this case. That is one big chunk of my work, and it leads into many different questions about measurement. When does measurement provide strong evidence? How many theoretical presuppositions do you need to call something a measurement? What's the role of statistical inference? I spend a lot of time tackling this particular problem, and I think it's a really important and cool one, so it's good to give it some promotion. 

A second big project that I'm really excited about that I'm working on now - part of that work is with a colleague of mine, Cristian Larroulet Philippi, who is originally an economist and philosopher of social science - is seismology, quantification in seismology. A very deep philosophical question is: how do we come to represent a part of the world quantitatively in the first place? It's much deeper in a way than asking just about measurement because it's the thing that we presume in most measurements. And seismology is exciting for the reasons I already mentioned, that it's another case that looks very different from the standard picture that most people have of what measurement is, But it's also shot through with moral and political issues because lots of people's life depend on the decisions that seismologists make.

In that research, I really try to understand how seismologists came to quantify earthquakes, how they build earthquake scales. That was a project that, as often happens in geosciences, took them centuries. This was because the conditions that affect earthquakes are complicated by all sorts of factors - structural features of the earth and complicated physical conditions that affect how seismic waves propagate, and seismic mechanisms that produce these earthquakes, which can be hundreds of kilometres buried beneath the surface of the earth.


It's for that reason that for most of its history, seismometry, the measurement of earthquakes, look much more like social science measurement than physics. So, you'll find researchers up to the mid-20th century, and to some extent still today, rank earthquakes not based on abstract physical units with clear dimensional parameters, but they assign numbers based on how many buildings were destroyed in an earthquake, so how much panic was created. Yet, if you look to the 1980s, we have a quantitative scale for recording and describing earthquakes, and that again looks very much like what we know from physics. It has physical dimensions, it contains a model of the earthquake. 

My colleague, Cristian, and I, we got really excited. How did they manage to do that? How did they manage to go from whatever we had in the early 20th century to the highly sophisticated theoretical quantitative scale? Even more importantly, what kinds of problems did this transition address and which perhaps we're not addressed, right? Could we really do all the things we did with our qualitative knowledge with a fancy quantitative knowledge that we achieved along the way? Our opinion is no. It's actually really complicated. And for that reason, we still use lots of subjective data in seismology, which one wouldn't think. 

Again, it's just such a different case from the ones that philosophers usually use to make claims that they assume to hold for all of measurement and all of quantification. It's very different from cases like time or temperature. Looking at it very closely, I think it's a fantastic case to understand both the epistemic and the moral and political facets of quantification in a way that I think other cases might not allow us to do. 


Samara Greenwood: Aja, what about you? What kind of work are you doing in this area?

Aja Watkins: A lot of my existing work is in philosophy of climate science, although I tend to focus on slightly different parts of climate science than most. Most work in philosophy of climate science has been about climate simulations. That's because these are one of the main sources of evidence that have been used to detect contemporary climate change, attribute it to human behaviour, and make predictions about its trajectory under different emission scenarios in the future. But in addition to climate simulations, there are still other sources of evidence that climate scientists use. 

My research, which has come out of my dissertation research, focuses on the use of what are called paleoclimate analogues. So, paleoclimate analogues are episodes of climate change in Earth's deep past that significantly resemble contemporary climate change. But, in order to use paleoclimate analogues, researchers have to do three really difficult things. The first thing they have to do is they have to actually reconstruct that past climate episode. This is super nontrivial and depends on the use of some really complicated measurement techniques called paleoclimate proxies. The second thing they have to do is to establish the degree of analogy between the past climate episode and contemporary climate change, which will then constrain the sorts of ways we could use that analogy. The third step is to then go about actually using that analogy to either refine our predictions or enhance our understanding of what's happening to us right now in the contemporary climate change episode. 

So, in my work, I've tried to say something kind of interesting about each of those three steps. One example in that middle step of comparing contemporary climate change to past episodes of climate change. It's actually quite hard to do this comparison in part due to some major differences in the types of data that we have about the past and the types of data that we have about the present. So, one of the things I've done in my work is try to give some recommendations for folks who are in the business of using paleoclimate analogues or trying to check whether certain episodes of climate change in the past are actually analogous to contemporary climate change. I'm trying to give some recommendations for how they can handle their data in order to actually make those comparisons meaningfully. 

Now my newer research is also related to climate change but is more in what I would consider philosophy of the environmental sciences. Philosophy of the environmental sciences is going to sit really interestingly at the intersection of philosophy of the geosciences and also philosophy of biology or philosophy of ecology.

So far I have some nascent projects related to topics like forest fire management, soil science, limnology, which is the fancy way of saying study of lakes, and wildlife health. Like climate science, these are all really important scientific areas for figuring out how to deal with the effects of climate change. Meanwhile, also figuring out how to do things like incorporate interests of various stakeholders and inform public policy in a timely fashion. That's where my research is headed now. 


Samara Greenwood: Is there anything our listeners might find particularly surprising about work in philosophy of the geosciences? 

Miguel Ohnesorge: I think what is surprising about the philosophy of the geosciences is that it's one of the best places to do political philosophy of science.

For many reasons, some of them we've already mentioned have to do with the history, the way that knowledge production has been shaped by the colonial history of the geosciences particularly, but they also have to do with the importance of the geosciences in policy ranging from bodies like the Intergovernmental Panel on Climate Change to the US Geological Survey, that records earthquakes and studies them in the US. I think that's a surprising thing, but something I hope listeners take away from the podcast. Really, if you are interested in political questions, as they pertain to science and scientific institutions, geoscience is a fantastic place to look at.


Samara Greenwood: Turning to a broader question, what are some aspects of this research you think practicing scientists might find relevant? 

Aja Watkins: I think a lot of philosophers of the geosciences are really interested in and invested in doing their research in the kind of way that practicing scientists are going to find relevant, and I take myself to be in that group.

For example, as part of my research on paleoclimate analogues, there I made some explicit recommendations for how paleo-climatologists should process their data in order to make those data more easily compared to contemporary climate data. Another example is work that I did with some of the other members of that philosophy of the geosciences research group at Boston University. We worked together on a project that raises some similar concerns about comparability of past and present information in the context of trying to use past mass extinction events to understand contemporary ecological crises. 


Samara Greenwood: What about taking it even broader? Can you think of insights that might be important for everyone to consider?

Watkins: One of the things is that philosophy of science over the last several decades has really been trending more and more towards these local circumscribed insights that apply to specific scientific contexts or scientific research programs. And the emergence of philosophy of the geosciences as a unified subdiscipline of philosophy of science is, I think, really part of that trend. But many people are still told in school that there is, for instance, such thing as the scientific method, as though science is this monolithic, unified way of studying the natural world. 

So if I had to say something that I think is really important for everyone to consider, it's that - at least according to contemporary work in philosophy of science - there really isn't such thing as a paradigmatic science. It's valuable in its own right to investigate a bunch of different scientific areas, like the geosciences. 

I also think, in addition to this, that there are some lessons that come out of philosophy of the geosciences that have to do with trust in science. Lots of people don't even consider all the ways in which sciences like seismology, limnology, oceanography, mineral geology are also used all the time to inform policymaking efforts and the ways in which these sciences also have to be trusted and trustworthy in societies that really rely on democratic decision making.


Samara Greenwood: So my final question is, where do you see research in philosophy of the geosciences heading in the future? And also, where would you like to see it head in the future? 

Miguel Ohnesorge: Yes, great question. Because I think there are more open questions than settled ones in the field. In many ways, we're just getting started as a field as philosophy of the geosciences and we really need as many philosophers and scientists and perhaps historians as possible to get involved.

I'd say you should get involved in philosophy of the geosciences, even if you are just interested in philosophy and not per se in the geosciences. You should still care about this research because such a big share of current science is geoscience, and it just hasn't attracted the attention it deserves so far.

The second thing I want to say, that I hope is really taken up, is that recent work by philosophers on values in science has really shown how much we can learn by looking closely at what political philosophers have to say about say issues of legitimacy and justice. When we think about scientific institutions, they are institutions that wield power and make consequential decisions, et cetera, et cetera. But there are many other questions that will hopefully emerge as our field develops and matures and gets bigger over time. 


Samara Greenwood: And Aja, you have something to add?


Aja Watkins: I think we also both see some more structural and social changes on the horizon within philosophy of science. We're just starting to see things like conferences, workshops, sessions at conferences, research groups in the area of philosophy of the geosciences. And I think we can expect to see more of that in the coming years and we would both be thrilled to see that happen. 

We are also in agreement that philosophy of the geosciences really deserves its own community, its own publication venues, this sort of thing. So luckily for us and for people who work on similar things to us, there are now a lot of people, especially a lot of junior scholars, who are getting more and more interested in philosophy of the geosciences. And I think we can expect that those changes are coming and are really just looking forward to that happening. 


Samara Greenwood: Thank you and thank you both so much for being on the podcast. It's been wonderful to hear about such an exciting and emerging new area, and you have both described it so well for us. Thank you for being on. 

Aja Watkins: Thank you for taking the time. I know it's really early in the morning for you. 

Miguel Ohnesorge: Unique challenge with coordinating three time zones. Not just two. Props to you, Samara. 

Samara Greenwood: Well, thank you guys for helping with that. We managed to get there in the end. 

Thank you for listening to season three of The HPS Podcast.

If you're interested in the detail of today's conversation, you can access the transcript on our website at Stay connected with us on social media, including BlueSky for updates, extras, and further discussion. We would like to thank the School of Historical and Philosophical Studies at the University of Melbourne for their ongoing support. And thank you for joining us in the wonderful world of HPS. 

We look forward to having you back again next time.


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