Since the 1970s, climate scientists have developed increasingly sophisticated models of the world climate system. These models are converging on predictions about climate changes that are likely to occur in coming decades. Such changes are certain to provoke human responses and many commentators have suggested what those responses are likely to be in particular parts of the world. Nevertheless, human populations are complex systems in which changes in one part of the system can have significant consequences for other, perhaps quite remote, parts of the system - meaning that human responses to climate change must also be studied as processes in a complex system involving, potentially at least, all human societies. To date, however, the social sciences have not produced models of large scale human population systems that integrate predictions from climate models. One reason for this neglect may be that such work requires knowledge not only of the basic principles of human behavior and the techniques for modeling it, but also of (1) current climate models; (2) geographic information systems (GIS) which provide a means for organizing geographic data worldwide, including human population data; (3) statistical techniques for analyzing the large amounts of data produced from population simulations; and (4) actual human responses to climate changes both in the recent past (e.g., Darfur) and in the more remote past (e.g., ancient Maya). Accordingly, the present project includes two political scientists with background in behavioral modeling; a climatologist who has worked extensively on climate modeling; an expert in geographic information systems; an expert in applied mathematics and statistics; and an archaeologist. Initial steps toward the behavioral model will be tested against known cases of climate change in the recent past (e.g. Darfur) and the more remote past (e.g., the Mayan collapse). To the extent predictions from the developing model do not match known human responses in such cases, its parameters will be adjusted - and, subsequently, tested against further such cases.
Archaeological evidence shows that climate change has undermined many civilizations in the past but also that the climate changes per se were often less damaging than the human responses to those changes - including mass migration and armed conflict. In the interdependent modern world, human responses to climate changes have the potential to ripple well beyond an immediately affected area, and responses to such changes in different and perhaps quite remote areas might interact in negative ways. Thus, well developed models of likely human responses to expected climate changes - including abrupt changes - will allow policy makers to anticipate not only local consequences of local climate changes, but also geographically perhaps quite remote consequences. The project takes initial steps toward more fully developed models of human responses to climate change, just as early climate models can now be seen as initial steps toward the more fully developed climate models that presently exist.
