Nexus City: Operationalizing the urban Water-Energy-Food Nexus for climate change adaptation in Munich, Germany

- Cities need to exploit synergies between mitigation and adaptation approaches.
- In Munich, urban agriculture could cover local fruit and vegetable demand.
- Wastewater recycling and reuse can save 26% of water demand.
- Decentralized biogas generation from human sewage can save 20% of energy demand.
- Implementing this approach may be less costly than renovating the centralized sewage system.

The contemporary capitalist growth-dependent economy infers that natural resources are without limit. This has caused over-consumption of these, which has dangerously altered the climate. Despite this issue, with on-going economic growth, especially cities continue to consume even more such natural resources. Radical new urban planning approaches linked to a paradigm shift are urgently needed. Integrated urban planning can help cities exploit potential synergies of climate change mitigation and adaptation approaches to act on climate change more effectively. In this study, a case study neighbourhood of the City of Munich, Germany, is used as a model. By applying the Water-Energy-Food Nexus approach, the study finds that intensive urban agriculture could provide for 66% of local demand for fruit and 246% of local demand for vegetables; wastewater recycling and reuse coupled with rainwater harvesting can save 26% of current freshwater supply; biogas generation from human sewage can save 20% of current electricity supply; and the cost of decentralized wastewater management may be significantly lower than the planned renovation of the centralized sewage system. The study advocates implementation of pilot projects to study the effectiveness of such an approach, which is also relevant to other cities worldwide.