Global water assessment and potential contributions from Earth Systems Science

Abstract. Earth Systems Science has made significant strides over the last decade in developing consistent, high quality, spatially-contiguous, and in many cases real-time bioegoephysical data sets. Many of these data sources depict key elements of the land-based water cycle. To date, this information has been poorly integrated into global water assessment and vulnerability studies. This paper presents a review of newly-emerging Earth Systems Science products together with a strategy for entraining these into global water assessments. The text highlights several conceptual, technical, and institutional obstacles that require attention before a successful integration can be realized. A major challenge rests in developing a common conceptual framework and nomenclature to bridge gaps between the physical sciences and current generation of water resource assessments, which have traditionally relied heavily on descriptive case studies and a socioeconomic approach. Another goal of this paper is to better articulate the scope of human control of the terrestrial water cycle – beyond climate change alone – and to quantify its impact on sustainable water supplies. Opportunities for integration across disciplines are identified, and specific recommendations are formulated. An argument is made for the unique role that geographically-referenced continental and global-scale analysis can play in future assessments of freshwater resources and water-related vulnerability.