WHAT is urban food production?
Being able to provide for a sustainable and sufficient food supply is one of the most important functions of a city. We think that a symbiotic city’s food system must be designed to be productive enough to supply the basic needs of the city, while at the same time function sustainably within the ecological limits of its bio-region -- including nutrient cycles, soil replenishment, and the preservation of biodiversity.
We believe that to create a truly regenerative, symbiotic food system, cities will need to develop the means of both supplying increasingly greater percentages of a city’s food supply from local sources, while at the same time eliminating the negative ecological impacts of agriculture on local and regional ecosystems. Food production will therefore need to be an appropriately balanced mix of both urban high-intensity, high-productivity hydroponic and aquaponic food production, in combination with regional ecologically sensitive agriculture. The intensification of agriculture in cities will require the radical transformation of current agricultural practices in order to facilitate the relocalization of food production. Moreover, not only will we need to intensify the production of food within our cities, but we think it will be very important to maintain and increase our cultural connection with food, and understand food as more than simply a commodity.
There are 3 important reasons why developing a sustainable, regenerative food supply for cities is one of the most important transformations in moving towards symbiosis:
First, although the rate of growth of the world’s population is decreasing, the actual growth in total population is still increasing. So clearly, in aggregate, more food will be required. In 1960 there were approximately 3 billion people on earth, today there are just over 7 billion. By 2050 the United Nations Department of Economic and Social Affairs predicts there will be somewhere between 9 and 10 billion of us. To meet the increasing demands for food that this increase in population will necessitate, the UN FAO estimates that we will need to double the world's food production by 2050. And, achieving this increased production will be even more challenging given that 80%[g1] of the world’s arable land is currently in use, with the mounting impacts of climate change expected to significantly reduce arable land capacity.
Second, even at our current population level, we are no longer able to produce food sustainably. Not only do we not have enough arable land to sustainably satisfy the global diet’s projected growth, we are also reaching the limits of a sustainable water supply. Today, although an average person requires only 2-4 litres of drinking water per day, it takes between 2,000 and 5,000 liters of water daily to produce food for one person [UN Water Program]. Agricultural is currently responsible for over 70% of the world’s total water consumption, putting tremendous stress on ground water supplies and aquifers around the world. The world’s fishing fleets have also brought most fish stocks to near collapse, with 6 million square miles of sea floor destroyed annually by bottom trawling [Abundance pg 101]. In addition to the world having a food quantity supply problem, the negative externalities associated with our current industrial agriculture system are significant, including soil erosion, loss of biodiversity from cleared rain forests, destruction of aquatic ecosystems due to eutrophication, CO2 emissions from livestock and depleted soils.
Third, it is predicted that climate change will significantly decrease the total available arable land area on the planet as a result of a combination of drought, flooding, and rapid changes in local ecologies. A study published in Science suggests that, due to climate change, "southern Africa could lose more than 30% of its main crop, maize, by 2030. In South Asia losses of many regional staples, such as rice, millet and maize could top 10%".[see: Lobell DB, Burke MB, Tebaldi C, Mastrandrea MD, Falcon WP, Naylor RL (2008). "Prioritizing climate change adaptation needs for food security in 2030". Science 319 (5863): 607–10.]. With “high confidence”, the IPCC (2007:14) projected that in Southern Europe, climate change will reduce crop productivity. In Central and Eastern Europe, forest productivity is expected to decline. [see: IPCC (2007). "Summary for Policymakers: C. Current knowledge about future impacts". Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [M.L. Parry et al. (eds.)]. Cambridge University Press.]
Clearly, going forward, to survive as a species, and to allow our fellow species to survive along with us, we are going to have to radically change the way we produce and consume food. As populations continue to urbanize, we believe that it will be critical to bring agriculture into urban centers, while using existing arable land in a more ecologically responsible and regenerative fashion.
To be successful a sustainable, regenerative, symbiotic food system must not only meet the growing food needs of an increasing world population, it must also be designed to restore existing ecosystems damaged by existing high-intensity industrial, fossil-fuel-based farming, and be an ongoing and future positive contributor to the ecosystems it exists in.
We think that the following three food production strategies, implemented in a coordinated fashion, will be most likely to succeed in allowing cities to supply their populations with a sustainable food supply that both provides the necessary types and quantities of food for an increasing population size, and also does so in a way that is compatible with the world’s precious ecosystems:
- High-intensity organic indoor farming - likely hydroponics and aquaponics,
- Ecologically sensitive “field” farming to replace existing fossil fuel based industrial farming, and,
- Shifting the balance of protein production from both land-based meat production, and ocean and lake based wild-fish production, to aquaponic fish production, and hydroponic vegtable production.
1. High-intensity organic indoor farming:
New high-intensity hydroponic and aquaponic agriculture technologies are being developed, and old ones are being revived, which hold the potential to significantly increase food productivity while at the same time greatly reduce the ecological footprint of food production. New concepts in soilless controlled environment agriculture, such as vertical farming and warehouse farming- use only a fraction of the water and nutrients required with conventional industrial agriculture while emitting none of the toxic chemicals. At the same time, urban fish-farming techniques such as aquaponics allow for production of sustainable protein source with a very small ecological footprint.
2. Ecologically Sensitive “Field” Farming:
The development of sustainable field farming has yielded many variants. These can be roughly grouped into two main philosophical streams; one encompassing methods focused on sustainably increasing agricultural productivity (referred to as eco-agriculture) and the other on methods focused on improving ecosystem health and biodiversity (referred to as agro-ecology).
The most promising example of eco-agriculture may be “Biointensive farming”. Developed at the University of California during the 1970s by Alan Chadwick and John Jeavons, this method aims to intensify agricultural yields through cultivation practices that simultaneously regenerate the fertility of the soil, thus creating both an efficient and self-sufficient food production system.
A key aspect of Biointensive farming is the practice of “double-digging”, which is a two-step tilling process that results in raised, aerated beds that enable deeper root structures and much more intensive planting. Another important aspect of the concept is companion planting, which enables mutually advantageous relationships to form between the crops. Soil fertility is also maintained through plant selection, as each harvest includes a carefully balanced ratio of carbon-rich crops (used to enhance composting) with calorie-rich crops. Studies have shown Biointensive farming can increase productivity more than two-fold over traditional farming methods, while also reducing water and fertilizer consumption by more than 50% and overall energy consumption by over 90%. [see: Jeavons, J.C., (2001). Biointensive Mini-Farming Journal of Sustainable Agriculture (Vol. 19 (2), 2001) and Jeavons, J.C., (1991). How to Grow More Vegetables: Than You Ever Thought Possible on Less Land Than You Can Imagine. Ten Speed Press; Revised edition. ISBN 0898154154.]
The most prominent example of agro-ecology is known as “permaculture”. In permaculture the focus is on the intensifying relationships created among elements in an agricultural ecosystem by the way they are placed together; the whole becoming greater than the sum of its parts. Permaculture design therefore aims to minimize waste, human labour, and energy by building systems that maximize the benefits between design elements to achieve a high level of synergy.
The core tenets of permaculture are: care of natural ecology and systems, care of human species, and reinvestment of surplus. These design principles, which are the conceptual foundation of permaculture, were derived from the science of systems ecology and study of pre-industrial examples of sustainable land use. Permaculture draws from several disciplines including organic farming, agroforestry, integrated farming, sustainable development, and applied ecology. [see: Mollison, Bill (1988). Permaculture: A Designers' Manual. Tagari Publications. p. 2. ISBN 0-908228-01-5; and Holmgren, David (2002). Permaculture: Principles & Pathways Beyond Sustainability. Holmgren Design Services. p. 1. ISBN 0-646-41844-0.]
3. Shifting the balance of protein production:
One of the most important changes in both method and culture required to create a regenerative symbiotic food system will be shifting the balance of protein production from land-based meat production, and ocean and lake based wild-fish production to aquaponic fish production and hydroponic vegetable protein production.
Current meat production is highly energy, fossil fuel, and water intensive and is not sustainable given the current and growing population size. The Food and Agriculture Organization of the United Nations (FAO) has documented the environmental impacts of industrial-scale meat production, and reports that livestock production is an important contributor to a number of the world's most pressing environmental problems, including global warming, land degradation, air and water pollution, and loss of biodiversity. It estimates that livestock production is responsible for 18 percent of greenhouse gas emissions, a bigger share than that of transportation. Livestock production also has a significant impact on the world's fresh water supply, accounting for more than 8 percent of global human water use, primarily for the irrigation of feed crops. Moreover, the FAO notes that livestock production, especially industrial agriculture production, is the largest sectoral source of water pollutants, principally animal wastes, antibiotics, hormones, chemicals from tanneries, fertilizers and pesticides used for feed crops, and sediments from eroded pastures. However, very positively, the FAO says that the livestock sector's potential for assisting in solving environmental problems is equally large, and major improvements could be achieved at reasonable cost.