In the near future, humanity will be challenged by the converging trends of energy depletion and climate change. It will be necessary for us to transition into a culture that consumes drastically less, and to shift away from the paradigm of perpetual material growth. As part of this transition, the means for securing food, water, energy and waste management must be re-localized into people’s home communities. As currently more than 50 percent of the world’s population lives in urban areas, it will be critical to make our cities more sustainable.
The book Toolbox for Sustainable City Living: A Do-It-Ourselves Guide, written by Stacy Pettigrew and myself (South End Press, 2008), is a collection of skills, tools and technologies usable by urban residents wanting to have more local access and control over life's essential resources. Through practical descriptions and wonderfully vibrant illustrations, the book describes how to build sustainable infrastructure using affordable, simple designs that utilize salvaged and recycled materials. In addition, the book promotes radical sustainability, a philosophy that emphasizes the interconnection between ecological and social justice struggles.
Useful ideas for aspiring sustainable city dwellers include:
Make a duckweed pond: Raise duckweed, a tiny, floating protein rich water plant in a kiddy pool. Using only sunlight and nutrients, duckweed can double its mass every other day. The duckweed can then be harvested and used as a food for humans, chickens and fish, or be used as a “green manure” for building soil fertility.
Raise edible and medical mushrooms on logs: Many urban spaces don't receive adequate sunlight for gardens. Mushrooms only require indirect light and moisture, making them suitable for marginally sunny spaces such as alleys and shady backyards.
Build a floating trash island: Inspired by a natural phenomena, floating trash islands create habitat for plants and microorganisms to assist in purifying contaminated storm water runoff — a major urban problem. They are made buoyant by floating debris, such as bottles and polystyrene, stuffed into a giant life-ring. Water plants are zip-tied onto the island’s surface, and develop an extensive submerged root network that hosts water cleansing critters.
Cook with an old satellite dish: When the parabolic curve of a satellite dish is lined with a mosaic of mirror shards and aimed at the sun, it can focus the sun’s rays onto a pot of water and bring it to a boil in minutes!
Construct a small scale biogas digester: Using a five gallon bucket, organic matter such as plants, chicken manure and dead leaves can be turned into methane gas. The gas then can then be stored and used for cooking and heating. Why pay money for natural gas when you can make it in your back yard?
Clean up contaminated soil with compost tea: Made with worm castings from a vermicompost box, compost tea can be used to help clean up toxic soils. The multitude of hungry microorganisms in the tea can help speed up the degradation of certain pollutants in city soils.
All these systems, plus many others, are described in much further detail in Toolbox for Sustainable City Living. (You can find the book at www.radicalsustainability.org.)
About the authors: Stacy and I are co-founders of Austin, Texas’ Rhizome Collective, a non-profit urban sustainability project. Toolbox is a culmination of eight years of research and experimentation at Rhizome. In addition, they are the organizers and teachers of R.U.S.T., The Radical Urban Sustainability Training.