Paper short abstract:

This paper highlights the spatial scale represented in environmental computer simulation models as constituted in hybrid practices. A study of negotiations about scale in an interdisciplinary modelling project provides the starting point for discussing climate change models and policy.

Paper long abstract:

Climate change is constructed as a global phenomenon; to address impacts scientists 'scale down' global Earth System Models to spatial areas of more relevance to environmental decision making. Such downscaling creates an expectation that science will be eventually able to 'zoom in' and predict local impacts of climate change and that political decisions makers will make use of this 'scale-appropriate' knowledge. In contrast this paper insists that the spatial scales at which environmental computer simulation models represent physical processes are constituted in research practices that involve particular understandings of political scales. I approach the issue by way of an empirical example of modellers negotiating scale of representation.

Environmental computer simulation modelling is conducive to ethnographic investigation because it requires explication of all the assumptions made about the processes modelled. For example, hydrological modellers cannot simply assume that water runs downhill, they have to decide how to represent this mathematically and then code it for their models to work. I will present a case study of drought modellers in an interdisciplinary project negotiating the spatial scale of representation in order to accomplish the shared objective of representing the drought process. The negotiation was triggered by modellers from different disciplines discovering that they could not simply pass information between them to create a sequence of models covering sections of the physical process to gain a comprehensive understanding.

The example is followed by reflection on the implications for climate change science and policy of approaching model scale as constituted in hybrid practices.