A Scientist's Life: Kate Ricke

Climate scientist talks about how she models the societal risks posed by climate change

Kate Ricke is a climate scientist and an assistant professor at Scripps Institution of Oceanography and the School of Global Policy and Strategy at UC San Diego. She received a PhD in engineering and public policy in 2011 from Carnegie Mellon University, and a bachelor’s degree in earth, atmospheric and planetary science from Massachusetts Institute of Technology in 2004.

explorations now: What do you do for a living?

Kate Ricke: I am a climate scientist and an assistant professor. Specifically, I study risks associated with climate change and how to mitigate them, especially those related to the global economy. I am interested in how we expect the climate to change as we continue to perturb it with greenhouse gases, how it will change globally, how it will change regionally, and then in particular what that means in terms of impacts on human society and how we will respond to those impacts.

en: What are some of the main questions in your field?

KR: There's a lot of uncertainty associated with how the climate will actually change as we continue to alter it with human activities. And when you go down to the regional level that uncertainty increases. Therefore, a lot of the questions that I work on – and the things I'm most excited about – are putting pieces together that have never been considered before. For example, one of the main questions is how climate change will affect different countries and how each will respond. A related idea is the social cost of carbon, which is a measure of the economic harm resulting from climate change, usually expressed as the dollar value of damages done from emitting one ton of carbon dioxide into the atmosphere.

One big question is: Which countries will be most affected economically? By looking at the outputs of large climate models, we found that large emitters, like the U.S., actually have the most to lose, meaning the U.S. has a large social cost of carbon. 

Another big question is whether it’s more efficient for countries to act somewhat independently or cooperatively in their efforts to cut emissions. Currently, we have this United Nations-style system where countries come together to make agreed-upon decisions about what to do to cut emissions. Under this method, there are more diverse interests you have to contend with, and oftentimes countries agree to a lower carbon price and some big countries don't participate.However, our models have shown that other types of coalitions, for example just among the large emitters, are equally effective. The end result is that basically it doesn't matter from a global outcome standpoint which way you do it. Perhaps politically it's easier to do it in the way with fewer countries, and no one's ever been able to show that before because we didn't have the dataset until recently.

en: What tools do you use in your research?

KR: I use tools both from the natural and the social sciences to try and quantify risks associated with anthropogenic climate change and identify the most effective ways to mitigate those risks.

In essence, I am a modeler. I use computers to do mathematical simulations. Some of the climate models I work with have been developed over decades by hundreds of people. Usually we simplify results from these physical climate models. But I'm interested in the policy implications in that full range of uncertainty and regional diversity, which require more detail to drill down to the regional level. These require a lot of processing power. One of those is a coupled Earth system model, a type of modeled planet that has an atmosphere, an ocean, and land. By running models based on certain scenarios, we can make future projections. For example, we can run global scenarios under the conditions of the Paris Agreement.

en: Why did you come to Scripps?

KR: Scripps is an amazing, beautiful place, and there's a lot of cool research happening here. But the uniqueness of my position is the main reason I chose to come here. I have a joint appointment between Scripps and the School of Global Policy and Strategy at UC San Diego. These are pretty unique positions because they’re actually split half and half between two departments. So I actually do both natural and social sciences, and it's a pretty unique opportunity to be able to find an academic position where I'm not only allowed to do both of the things that I do, but encouraged to do so. Another perk is that I'm immersed in two departments where I've got colleagues who are really challenging me on both sides of what I do, and by being challenged, I develop stronger research.

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