Paleoclimate Modeling and Simulation

Philosophical attention on climate simulation has focused primarily on empirical methods aimed at the 20th century, entirely neglecting the historical study of Earth’s climate by paleoclimatologists. This dissertation integrates historical climatology into the broader philosophical context, articulating its import for understanding future climate. In Chapter 1, I present a taxonomy of models used by paleoclimatologists, arguing that simulation models are an amalgamation of theoretical models and data models designed to emulate the behavior of some system over time. A product of theoretical and data driven considerations, I argue that climate simulation models should not be identified with theory. In Chapter 2, I argue that neither should climate simulation models be identified with scientific experiment. After analyzing the epistemically significant features of experiment, I argue that experiment and simulation are distinct as a result of exhibiting different justificatory focuses. I defend this account from an apparent counterexample: numerical experiment. In Chapter 3, I argue that climate simulations are inferential tools. I consider Otávio Bueno’s (2014) inferential account of computer simulation, arguing that revisions must be accepted to ensure externally valid climate simulation. I argue that climate simulation models allow for two kinds of inference: dynamic inference and variable inference. Chapter 4 surveys a number of empirical methods required for externally valid paleoclimate simulation. I conclude with a discussion of what credentials a simulation earns through successful performance, and when we should expect credentials to carry from contemporary contexts to the past. Chapter 5 considers the three predominant views of future-directed climate simulation assessment. I argue that each of the views suffers epistemic shortcomings. I introduce the threshold problem, an important shortcoming for the adequacy-for-purpose view. I conclude with an argument that the adequacy-for-purpose view, however, can apply to paleoclimate simulation modeling. Chapter 6 tackles the threshold problem discussed in chapter 5. I argue that the threshold problem can be dissolved with the right paleoclimate partial analogues. I articulate three homomorphic conditions required for a past climate system to serve as an analogue for a future climate system. Paleoclimate simulations thus play a crucial role in supporting future-directed climate simulations