Q&A with geography professor Justin Mankin

by Kyle Mullins | 4/23/19 2:00am


Geography professor Justin Mankin's research focuses on the impacts of climate change.

Source: Courtesy of Justin Mankin

Justin Mankin is an assistant professor of geography at the College who specializes in climate change and climate modeling. A Norwich, VT native, he attended Hanover High School before attending Columbia University to study political science. He worked in the intelligence services overseas before returning to academia, studying economics and environmental science at the London School of Economics and Stanford University. Mankin completed his postdoctoral fellowship at Columbia’s Lamont Doherty Earth Observatory and NASA’s Goddard Institute for Space Studies. Just this year, he published two papers, one on the relationship between climate change and violence and another on the causes of increased rainfall in the southeastern United States.

Could you talk about your time in the intelligence services before you came to Dartmouth?

JM: So after college, I worked as an intelligence officer deployed overseas for a few years, a lot of which was in Afghanistan. That was the thing that piqued my interest in this role of the physical climate system and how it shapes possibilities for people. I was part of this post-9/11 recruiting boom that the intelligence community did when everybody needed to be forward deployed and supportive of these two massive war efforts that were going on in Iraq and Afghanistan. 

I realized pretty early on that it wasn’t a career for me. I liked the field work component, and I liked being out working with people, but I wasn’t convinced that I was doing good. So, with the support of my employers, I went back to graduate school at the London School of Economics, where I studied development economics and development studies and global politics — the politics of globalization. That kind of broke down some myths about this notion of globalization as this rising tide that’s going to lift all ships and how it was actually generating a lot of systemic inequities, not just across countries but within countries as well. It gave me a lens through which I could reinterpret my experiences on the ground in these words.

Some of your past research has been on the relationship between climate and violence. Can you tell me more about that?

JM: If you just take the data about violence and temperature, and you do some statistical modeling on it with econometric methods, it emerges that warmer temperatures increase the likelihood of violent conflict. The two are related. And if you were to say, “Let’s control for GDP,” or, “Let’s think about why climate is positively selecting for violent outcomes,” it turns out that’s when things get really, really messy. It becomes very hard to process to trace a changing climate — say, a warmer temperature — and how that actually manifests as somebody’s decision to pick up a gun and fight. 

So it’s a background factor more than a direct influence? 

JM: Unclear. Is it a permissive cause? Is it a proximate cause? Somebody who’s investigating the recent Syrian drought and its relationship with the Syrian Civil War may say that it was a straw that broke the camel’s back. But against the background of very legitimate political grievances in the region, that same drought of that same magnitude in a different location at a different time — or even in the same location at a different time ­­— may or may not have contributed to violence. The weather doesn’t give people guns and teach them how to shoot them, right? The weather doesn’t necessarily give people political grievances, but what is clear from the data is that there is this relationship and the precise nature of that relationship is really challenging to tease out.

Your current research focuses on climate modeling. If you had to explain these models to someone with no background in climate change, how would you do so? 

JM: The most fundamental thing is that we can’t conduct a controlled experiment on a planetary scale, so we use models of the Earth’s system of varying complexity. Models are always reductions of reality, but we still require them because they force us as scientists to formalize and integrate and abstract important scientific concepts. They position us to test hypotheses that we otherwise wouldn’t be able to test.

There’s this exploratory modeling side to understand the physics of why a system behaves the way it does, and then there’s also this predictive side, which is increasingly where the climate community has gone. There’s this massive political imperative to say what the future is going to look like. The water manager wants to know. The owner of the Dartmouth Skiway wants to know.

Climate models are essentially just big computer programs, some of the most complicated computer programs on earth. They’re just millions and millions of lines of code, and they’re national lab scale endeavors — the products of nations — not of individuals. 

Climate change has been very prominent in the news lately, mostly due to United Nations reports and proposed policies like the Green New Deal. What’s your take on climate change policy going forward?

JM: As a scientist, I try to make this distinction between my attempts to objectively describe the world as it is and how it may evolve based on our understanding of fundamental physics, versus my place as a citizen — a person with loved ones and as somebody who cares about equity and justice. 

I think there are some massive, unanswered questions about what it looks like for a developing country to develop in a world where it can’t industrialize in the way that other countries did in the 20th century. You have this tension between human well-being and environmental well-being, but then the environmental well-being also shapes human well-being. How do you reconcile those things for the billions in the developing world who have daily risks that are very different than here in comfortable Hanover, New Hampshire? What does it look like for those countries to develop in a way that that’s equitable but also doesn’t do this kind of planetary insult? 

I definitely think it’s up to the big polluters to change course. They’re the ones who have the ability to do so from a technological perspective. The point is, from a citizen perspective, something big needs to happen. In the absence of that, it’s going to be these kinds of emergent policies at the local scale: cities trying to reduce their own carbon footprints, individuals trying to reduce their own carbon footprints. It seems like it’s a drop of the bucket, and maybe it is from a carbon accounting standpoint, but it’s about shifting a generation’s understanding of their role in shepherding the earth. If we start to raise people with an understanding that their choices matter, then I think there can be an emergent place where it’s commonly accepted among your generation of people that, yeah, of course we need to mitigate climate change.

This interview has been edited and condensed for clarity and length.