1. Earth System Science Partnership Global Water System Project Holger Hoff

3. Earth System Science Partnership a new phase of integrated research focusing on human-environment interactions assessing vulnerabilities, limits and critical thresholds of Earth system components addressing policy relevant science questions that cannot be answered by any of the programmes individually

4. Pielke et al., (2001) Ecol. Appl. 7 Biosphere Interactions Land use change effects

5. River Basins & Coasts Impact of riverine carbon, nutrients, water, sediment and toxins on the coast Critical loads and thresholds Buddemeier et al (2002), LOICZ Report 24

6. CLIVAR – Climate Variability and Predictability e.g.: Will there be an El Niño next year? Will the next monsoon cause drought or flooding?

7. GEWEX – Global Energy and Water Cycle Experiment to observe, understand and model the global hydrological cycle, predict the variations and impacts on regional hydrological processes and water resources

8. Continental Scale Experiments

9. GECHS - Global Environmental Change and Human Security Water Security i. Effects of dams and other development projects on access to water resources ii. Teleconnections in the hydrological cycle, e.g. through links to agriculture and trade iii. Extent and causes of scarcity, wrt existing allocation arrangements (equity issue see food – Mohamed Salih)

10. IT – Industrial Transformation e.g.: decoupling the need of cities for water from effects on the hydrological cycle

11. Diversitas Freshwater biodiversity assessment and drivers of change Freshwater biodiversity changes, e.g related to climate change, species introduction or eutrophication Ecosystem resilience or adaptation to human impacts

12. Rational : Humans have begun to affect the Global Water System significantly without adequate understanding of how the system works Global Water System Project Mission: Improve knowledge of, and responsible interaction with the GWS e.g. throughglobal observation consolidation of global data sets predictive and coupled modelling

13. Global Water System Project Overarching question: How are humans changing the global water cycle, the associated biogeochemical cycles, and the biological components of the Global Water System, and what are the social feedbacks arising from these changes?

14. Integrative questions I. What are the magnitudes of global-scale changes in the Global Water System, attributable e.g. to changing water use, water management, land use, and climate variability and change? II. What are the main mechanisms by which human activities are affecting the Global Water System? III. To what extent is the Global Water System resilient to global change? How adaptable is the Global Water System and how capable are water management systems and ecosystems to cope? Global Water System Project

15. Tasks Short term : identify data needs, and early efforts to construct first generation global data sets, via synthesis and coordination with other programs ( + conceptual framework) Medium term: facilitate the development of first-generation models that would allow prediction of physical, chemical, biological, and socioeconomic aspects of human manipulation of the Global Water System Long term promote development of interactive models capable of predicting possible responses and feedbacks of the Global Water System (and especially its terrestrial components) to human use and abuse with reliable uncertainty estimates Global Water System Project

16. GWSP Pilot Project on Virtual Water Trade IGBP: nitrogen and nutrient effects IHDP: institutional settings of water allocation at all scales WCRP: climatic hotspots (aridification, droughts) that will induce additional VWT Diversitas: ecological consequences South Asia: “New export opportunities are emerging, for non- traditional items” Aggarwal, Joshi, Ingram, Gupta, 2003 Hoekstra et al 2003

17. Water & Food Shiklomanov 2003

18. Common interests of GWSP & GECAFS GWSPGECAFS about water securityabout food security (provision) adaptability of the Global Water System adaptation strategies for food provision supporting water policiessupporting food policies effects of changing food preferences on the GWS analysis of changing food preferences

19. Production (million tons) 1999-20002020 Rice85.4122.1 Wheat71.0102.8 Vegetables84.5149.7 Meat and eggs 3.77.8 Virtual water content (per kg) Potatoes: 100-150 l Wheat: 1000-2000 l Rice: 1500-3500 l Beef: 15,000 – 20,000 l Consequences for regional water resources and the GWS ? Common interests of GWSP & GECAFS South Asia Aggarwal, Joshi, Ingram, Gupta, 2003

20. Water & Food in the IGP Increasing competition for water with non-agricultural users Increasing hydrological variability and extremes (glacier melting) Need to improve utilization of groundwater Need to improve reuse of wastewater in agriculture Nepal: decreasing dry-season flow – why ?

21. The Global Water System Project invites your contribution contact www.gwsp.orgholger.hoff@pik-potsdam.de