Water in the anthropocene: New perspectives for global sustainability

Humans are changing the global water system in a globally-significant way without adequate knowledge of the system and thus its response to change. So read the central tenet of the Global Water System Project (GWSP), proposed by its founders back in 2004 1,2. It was hardly an accepted notion. Before year 2000, global-scale water studies based on modern data sets and modeling frameworks that explicitly combined the geophysics of water with its human dimensions were still in their infancy, and the scientific underpinnings for such a statement had yet to be articulated. The statement, at best, could reasonably be called an educated best-guess or some might argue more of a ‘‘hunch’’. At that time, world water assessments prepared by the U.N. 3 or as revealed in now-classic Russian monographs 4,5 relied on highly aggregated national if not regional indicators to define the state of the system and failed to appreciate many of its rich spatial and temporal details that were uncovered only over the last 10–15 years.