Sustainable Resource Management: A Holistic View

1. 1.2 Resources: Where are the unlimited resources? What might be the problem to access them? energy From waste via reuse to sustainability ? Learning objective: to familiarise with a coordinated view on resources, and to understand the context and role of sanitation. Jan-Olof Drangert, Linköping University, Sweden

2. Water molecules cannot be manufactured or destroyed Water is renewable (sun-driven cycle) everywhere Water available in situ (rural, peri-urban) or imported (cities) Energy supplied by humans (rural) or electricity (urban) 70% of global water use is for crop production A balanced diet requires a loan of 1300m3/yr p person based on current practice. This is 70 times greater than the basic water need of 50 l per person per day. Phosphorus (P) cannot be manufactured or destroyed P is immobile and mined in only a few countries Food available in situ (rural) or mostly imported (cities) Energy supplied by humans and sun (rural) or fossil(urban) 90% of global rock P extrac-tion is for crop production A balanced diet results in depletion of 22.5 kg/yr of phosphate rock or 3.2 kg/yr of P per person based on current practices, of which 0.5 kg is found in the food. Reflections on water and plant nutrients Jan-Olof Drangert, Linköping University, Sweden

3. Input to and output from the food chain fertilizer rain & irrigation water manure choice loss excreta organics agri- culture households no choice evapo- transpi-ration food Losses on farm Jan-Olof Drangert, Linköping University, Sweden

4. The water cycle – dynamics does the trick Instant snap shot: Shortage of freshwater ! Clouds 0.001% 8 days A dynamic perspective gives a better description: ” but, H2O is always on the move ...” Renewable rain gives in 2000 yearsas much water as is in the oceans!!! Rivers 0.0002% 16 000 years Lakes 0.007% 280 days Oceans 96.5% Ice caps 2.7% 3 000 years Groundwater 0.7% 4 600 years Jan-Olof Drangert, Linköping University, Sweden

5. Annual renewal and use of fresh water Source: P. Gleick, 1993

6. Global scarcity of plant nutrients - a new driving factor for sanitation • Phosphorus is a limited resource, and large untapped reserves will eventually only be found on sea shelves and as anthropogenic depositions in lake sediments. • 95% of mined potash goes to the fertiliser industry and has no substitute. Mines exhausted in some 50 years. • 60% of mined sulphur goes to fertilizer industry and has no substitute. Mines exhausted in some 20 years. • Costly to recover these plant nutrients from lake sediments compared to trapping them directly at the source i.e.as output from households and industries. • Nitrogen can be manufactured from the N in the air, but this requires much energy (1 litre of oil to produce 1 kg of nitrogen). D. Cordell & J-O Drangert, Linköping University, Sweden

7. Phosphate Rock – Worldwide Estimates(thousands of metric tons) P scarcity is worse than oil scarcity because P CANNOT be substituted in food production Courtesy of Ian Caldwell, Stockholm Envrionment Institute, Sweden

8. Food, water and nutrient flows 0.9 l transpiration & evaporation H2O 1.5 l food 1.1 l Urine: 1.5 l Faeces: 0.15 l + nutrients Virtual water 4 cu.m. + nutrients Jan-Olof Drangert, Linköping University, Sweden

9. NUTRIENTS – and demography Billion people 9 World Total 16th - 21st century 6 21th century 20th century urban 3 rural 1500 1600 1700 1800 1900 2000 2100 Jan-Olof Drangert, Linköping University, Sweden

10. Actual reuse of nutrientsfor urban agriculture & food security(in Swedish towns 1850 – 2000) Proportion nutrients being reused 100% Glass, tins, ceramics Heavy metals 50% waste pits + urine diversion +WC stop only WC +WWTP 1870 1910 1950 2000 Jan-Olof Drangert, Linköping University, Sweden

11. Human resources: capacity to manage sanitation arrangements Level of management WWTP, biogas Utility sewerage flush toilet, water supply, Organic waste sewerage drainage wetland urine-diverting toilet septic tank Grease trap, Household Organic waste pit latrine biogas User contribution Work hours Paying fees Jan-Olof Drangert, Linköping University, Sweden

12. ”Manpower blindness”: driver of new responsibility sharing • We tend to account only for what is done by governments and projects in water and sanitation • What is done by residents and small entrepreneursis rarely appreciated, if at all recognized (blindness) • Yet, many urbanites survive thanks to such local initiatives • Here, we pledge that both kinds of activities are needed to solve current sanitation problems Our pre-conceived views play a role Jan-Olof Drangert, Linköping University, Sweden