Abstract for: Limits to Planetary Fresh Water Use: A Multi-Model Investigation

There has been a renewed interest over the last few years in limits to various earth bound systems and processes. This has been instigated by the work of Rockström and colleagues on planetary limits. Essentially, the planetary limit concept can be understood as a modern update to the seminal system dynamics work on limits to growth. The central idea of planetary limits is to identify thresholds in various earth bound systems and processes that, if crossed, would push the earth system out of its Holocene state. This work has been criticized for overlooking key feedbacks between the various earth bound systems and the ignoring the uncertainty that is intrinsic to any assessment of these limits. In this paper, we address these issues by using integrated system dynamics models in an exploratory way. We demonstrate this approach by investigating limits to planetary fresh water use using two world water models, namely ANEMI and WorldWater. The initial results suggests that sever water shortage is driven by the need to dilute waste water, and food demand and production. We discuss directions for improving the overall methodology and the case specific application.