Geoengineering has the potential to fundamentally change climate politics. The suggestion by scientists that intentional manipulations of the climate system may be possible in the foreseeable future has recently sparked debates about the ethical and social implications of geoengineering. Reports and articles on the topic have thus raised questions of economic viability, participation, political regulation, and the potential for international conflict. Thus far, however, little attention has been paid to the relation between scientific and political discussions of geoengineering. Since assessments of geoengineering – particularly solar radiation management – strongly rely on computer simulation studies, the logics that characterize these virtual geoengineering experiments have implications for political debates. Drawing upon developments in assemblage theory and the field of Science and Technology Studies, I consider computer simulation studies as heterogeneous assemblages in which scientific, computational and political logics interact to produce a ‘possibility space’ of geoengineering interventions. This possibility space is formed by i) initial assumptions about social objectives and trajectories, ii) characteristics of the model, such as temporal and spatial scales, and iii) assessments of impacts, either as part of the model (integrated assessment) or by interpretations produced based on the modeling results. I critically explore some of the political implications of current geoengineering simulations based on my work conducted at Heidelberg University and at the Institute of Advanced Sustainability Studies in Potsdam (IASS). I argue that political conclusions drawn from simulation studies are problematic because they remain relatively insensitive to socio-political differences and treat vulnerability as a static expression of local environmental conditions. Furthermore, the global scientific world view on which simulation studies rely may considerably constrain the potential for cross cultural participation, a frequent demand in current geoengineering debates.
