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Vorlage:Essay

Proposed designs for vertical farms

Vertical farming is a proposed agricultural technique involving large-scale agriculture in urban high-rises or "farmscrapers".[1] Using recycled resources and greenhouse methods such as hydroponics, these buildings would produce fruit, vegetables, edible mushrooms and algae year-round. Their proponents argue that, by allowing traditional outdoor farms to revert to a natural state and reducing the energy costs needed to transport foods to consumers, vertical farms could significantly alleviate climate change produced by excess atmospheric carbon. Critics have noted that the costs of the additional energy needed for artificial lighting and other vertical farming operations might outweigh the benefit of the building’s close proximity to the areas of consumption.[2]

Background

Dickson Despommier, a professor of environmental health sciences and microbiology at Columbia University in New York City, developed the idea of vertical farming in 1999 with graduate students in a medical ecology class. He had originally challenged his class to feed 50,000 Manhattanites using 13 acres of useable rooftop gardens. The class calculated that, by using rooftop gardening methods, only 2 percent of the 50,000 people would be fed. Unsatisfied with the results, Despommier thoughtlessly suggested growing plants indoors, vertically. The idea sparked the students’ interests and gained major momentum. By 2001 the first outline of a vertical farm was introduced and today scientists, architects, and investors worldwide are working together to make the concept of vertical farming a reality. In an interview with Miller-McCune.com; Despommier described how vertical farms would function:

"Each floor will have its own watering and nutrient monitoring systems. There will be sensors for every single plant that tracks how much and what kinds of nutrients the plant has absorbed. You'll even have systems to monitor plant diseases by employing DNA chip technologies that detect the presence of plant pathogens by simply sampling the air and using snippets from various viral and bacterial infections. It's very easy to do.

Moreover, a gas chromatograph will tell us when to pick the plant by analyzing which flavenoids the produce contains. These flavenoids are what gives the food the flavors you're so fond of, particularly for more aromatic produce like tomatoes and peppers. These are all right-off-the-shelf technologies. The ability to construct a vertical farm exists now. We don't have to make anything new.[3]

Architectural designs have been produced by Chris Jacobs of United Future, Andrew Kranis at Columbia University and Gordon Graff [4][5][6] at the University of Waterloo.

Mass media attention began with an article by Lisa Chamberlain in New York magazine.[7] Since 2007, articles have appeared in The New York Times[8], U.S. News & World Report[9], Popular Science[10], Scientific American[11] and Maxim (magazine), among others, as well as radio and television features.

Advantages

Several potential advantages of vertical farming have been discussed by Despommier.[12] Many of these benefits are obtained from scaling up hydroponic or aeroponic growing methods. Others relate to vertical farming building designs that would allow the use of renewable energy sources (wind and solar) and the recycling of materials of production such as water.

Preparation for the future

It is estimated that by the year 2050, close to 80% of the world’s population will live in urban areas and the total population of the world will increase by 3 billion people. In order to feed 3 billion more people using traditional farming techniques an estimated 10^9 hectares of new farmland must be created. Scientists are concerned that this large amount of required farmland will not be available and that severe damage to the earth will be caused by the added farmland. Vertical farms, if designed properly, may eliminate the need to create additional farmland and help create a cleaner environment by using recycling techniques rather than harming the environment by using traditional farming techniques.[13]

Increased crop production

Unlike traditional farming, indoor farming can produce crops year-round. All-season farming multiplies the productivity of the farmed surface by a factor of 4 to 6 depending on the crop. With some crops, such as strawberries, the factor may be as high as 30.[14][15]

Furthermore, as the crops would be sold in the same infrastructures in which they are grown, they will not need to be transported or refrigerated between production and sale, resulting in far less spoilages and infestations than conventional farming encounters. Research has shown that 30% of harvested crops are wasted due to spoilage and infestations[11].

Despommier suggests that, if dwarf versions of certain crops are used (e.g. dwarf wheat developed by NASA, which is smaller in size but richer in nutrients[16]), year-round crops, and "stacker" plant holders are accounted for, a 30-story building with a base of a building block (5 acres) would yield a yearly crop analogous to that of 2,400 acres of traditional farming.[11]

Crops grown in traditional outdoor farming suffer from the often suboptimal, and sometimes extreme, nature of geological and meteorological events such as undesirable temperatures or rainfall amounts, earthquakes, monsoons, hailstorms, tornadoes, flooding, wildfires, and severe droughts.[12] The protection of crops from weather is increasingly important as global climate changes take place more and more rapidly. “Three recent floods (in 1993, 2007 and 2008) cost the United States billions of dollars in lost crops, with even more devastating losses in topsoil. Changes in rain patterns and temperature could diminish India’s agricultural output by 30 percent by the end of the century.”[17]

Because Vertical Farming provides a controlled environment, the productivity of vertical farms would be mostly independent of weather and protected from extreme weather events. Although the controlled environment of vertical farming negates most of these factors, earthquakes and tornadoes still pose threats to the proposed infrastructure, although this again depends on the location of the vertical farms.

Conservation of resources

Each acre in a vertical farm could allow between 10 and 20 outdoor acres of farmland to return to its natural state[18], and recover farmlands due to development from original flat farmlands.

Vertical farming would reduce the need for new farmland due to overpopulation, thus saving many natural resources[11], currently threatened by deforestation or pollution. Deforestation, desertification, and other consequences of agricultural encroachment on natural biomes would be avoided. Because vertical farming lets crops be grown closer to consumers, it would substantially reduce the amount of fossil fuels currently used to transport and refrigerate farm produce. Producing food indoors reduces or eliminates conventional plowing, planting, and harvesting by farm machinery, also powered by fossil fuels. Burning less fossil fuel would reduce air pollution and the carbon dioxide emissions that cause climate change, as well as create healthier environments for humans and animals alike.

Furthermore, vertical farms would make maximal use of the locally most efficient sources of renewable energy: farms in Iceland, Italy and New Zealand would benefit from geothermal energy, desert environments such as in the Middle East would make use of abundant solar energy (in which case the structures would have to be wider than they are tall, to maximize solar energy input), and coastal areas would benefit from wind, wave or tidal energies[11].

Vertical Farms would also be designed to convert waste water and polluted air into clean, useable resources for crop production. Also, pure Oxygen produced by photosynthesis of the crops would be released into the environment adding to the improvement of air quality surrounding the Vertical Farm.

Organic crops

The controlled growing environment reduces the need for pesticides, herbicides, and fertilizers. Advocates claim that producing organic crops in vertical farms is practical and the most likely production and marketing strategy.

Water recycling

Because water recycling is more practical and economical in a controlled agricultural environment, vertical farming would use much less water than traditional farming. New York City dumps 1.4 billion gallons of “treated waste water” into its rivers daily. Vertical farming would convert this blackwater (waste) and greywater into potable water by collecting the water released into the air by evapotranspiration.

Vertical Farming supports the concept of “addressing food production in a modern city, where urban wastes, like black water will be composted, recycled and used for farming inside a standard tenement-like building. This will be expected to improve the living conditions since transportation costs in handling food supply and wastes will be greatly reduced.[19]

The city's sewage sludge will enter a machine called “SlurryCarb”, to break down the sludge into carbon and water. The remaining slurry will be burned like coal to power steam turbines that will generate electricity. Part of the sludge will be treated with chemicals to kill the bacteria and will undergo heating and drying process that will convert the treated sludge into topsoil. Water extracted will undergo bio-remediation processes using cattails, sawgrass and zebra mussels, until it becomes clean enough for agricultural use. It can also be subjected for further refinement until safe enough to be used as drinking water.”[20]

Today, over 70% of the liquid fresh water on Earth is used for conventional agriculture which often pollutes the water with fertilizers and pesticides. Furthermore, by using waste-water for irrigation, vertical farming would contribute to ameliorating problems with ocean dead zones, caused by algae blooms which are in turn enhanced by runoff fertilizers[11].

Halting mass extinction

Withdrawing human activity from large areas of the Earth's land surface may be necessary to slow and eventually halt the current anthropogenic mass extinction of . conventional farming.[21] In comparison, vertical farming would cause very little destruction of insects and other wildlife deaths.[22]

Impact on human health

Traditional farming is a hazardous occupation with particular risks that often take their toll on the health of human laborers. Such risks include: exposure to infectious diseases such as malaria and schistosomes, exposure to toxic chemicals commonly used as pesticides and fungicides, confrontations with dangerous wildlife such as poisonous snakes, and the severe injuries that can occur when using large industrial farming equipment. Whereas the traditional farming environment inevitably contains these risks (particularly in the farming practice known as “slash and burn”), vertical farming – because the environment is strictly controlled and predictable – eliminates them altogether.[12] Currently, the American food system makes fast, unhealthy food cheap while fresh produce is less available and more expensive, encouraging poor eating habits. These poor eating habits lead to health problems such as obesity, heart disease, and diabetes. The increased availability of fresh produce created by a Vertical Farm would encourage healthier eating habits of the surrounding population, decreasing the occurrences of major health issues related to poor dieting. [23]

Urban growth

Vertical farming, used in conjunction with other technologies and socioeconomic practices, could allow cities to expand while remaining largely self sufficient. This would allow for large urban centers that could grow without destroying considerably larger areas of forest to provide food for their people. Moreover, the industry of vertical farming will provide employment to these expanding urban centers. This may help displace the unemployment created by the dismantling of traditional farms, as more farm laborers move to cities in search of work.[12] It is unlikely that traditional farms will become obsolete, as there are many crops that are not suited for vertical farming.

Energy production

Proponents claim that vertical farms could generate power. Methane digesters could be built on site to transform the organic waste generated at the farm into biogas which is generally composed of 65% methane along with other gasses. This biogas could then be burned to generate electricity that can either be consumed at the farm or added to the grid.[24]

Technologies and devices

Vertical farming relies on the use of various physical methods to become effective. Combining these technologies and devices in an integrated whole is necessary to make Vertical Farming a reality. Various methods are proposed and under research. The most common technologies suggested are:

Plans

Professor Despommier argues that the technology to construct vertical farms currently exists. He also states that the system can be profitable and effective, a claim evidenced by some preliminary research posted on the project's website. Developers and local governments in the following cities have expressed serious interest in establishing a vertical farm: Inchon (South Korea), Abu Dhabi (United Arab Emirates), and Dongtan (China), [25] New York City, Portland, Ore., Los Angeles, Las Vegas, Seattle, Surrey, B.C., Toronto, Paris, Bangalore, Dubai, Abu Dhabi, Incheon, Shanghai and Beijing. The Illinois Institute of Technology is now crafting a detailed plan for Chicago. It is suggested that prototype versions of vertical farms should be created first, possibly at large universities interested in the research of vertical farms, in order to prevent failures such as the Biosphere 2 project in Oracle, Arizona.[26]

Economic analysis needed

The analytical work needed to establish the feasibility of vertical farming has not been done. A detailed cost analysis including operation, transportation, fertilization and soil preparation costs, crop success rates, and health-care, recycling, renewable energy, and employment benefits is required to determine the cost effectiveness of vertical farming compared to traditional farming. The extra cost of lighting, heating, and powering the vertical farm may negate any of the cost benefits received by the decrease in transportation expenses. Because the stacked growing surfaces of a vertical farm would receive far less sunlight than the equivalent land area in a rural farm, the vertical farm would require a significant level of artificial lighting and heating to operate in all seasons. Critics have observed that high levels of artificial lighting would be needed for crops growing in areas of the building unexposed to sunlight.[27] Bruce Bugbee, a crop physiologist at Utah State University, believes that the huge power demands of vertical farming would be too expensive and uncompetitive with traditional farms using only free natural light. He notes that the levels of light needed by growing crops is about 100 times the amount used by people working in offices.[28] The economic and environmental benefits of vertical farming rest partly on the concept of minimizing food miles, the distance that food travels from farm to consumer. However, a recent analysis suggests that transportation is only a minor contributor to the economic and environmental costs of supplying food to urban populations. The author of the report, University of Toronto professor Pierre Desrochers, concluded that "food miles are, at best, a marketing fad."[29]Nevertheless, Despommier has argued that vertical farming is feasible. He estimates that, using currently available technologies, one vertical farm occupying one square city block and rising 30 stories would feed 10,000 people.[12] In other sources, he claims this number to be up to 50,000.[30] As of now, very little data is available to support or contradict the theory that vertical farms could be a cost effective alternative to traditional farms.

See also

Notes

Vorlage:Reflist

de:Vertical farming

  1. Urbanism and the environment | Gristmill: The environmental news blog | Grist. Gristmill.grist.org, abgerufen am 14. März 2009.
  2. Nelson, B. (2008).Could vertical farming be the future? MSNBC.
  3. Arnie Cooper. May 19, 2009. "Going up? Farming in High Rises Raises Hopes." http://www.miller-mccune.com/science_environment/farming-in-high-rises-raises-hopes-1226
  4. Murray Whyte: Is high rise farming in Toronto's future?, Toronto Star, 27. Juli 2008. Abgerufen am 12. August 2008 
  5. High Density Urban Agriculture. SkyFarm, abgerufen am 14. März 2009.
  6. Sky Farm Proposed for Downtown Toronto. TreeHugger, abgerufen am 14. März 2009.
  7. Lisa Chamberlain: Skyfarming, New York Magazine, 2. April 2007. Abgerufen am 26. Juni 2009 
  8. Bina Venkataraman: Country, the City Version: Farms in the Sky Gain New Interest, New York Times, 15. Juli 2008 
  9. Nancy Shute: Farm of the Future? Someday food may grow in skyscrapers, U.S. News & World Report, 20. Mai 2007 
  10. Amy Feldman: Skyscraper Farms, Popular Science, 11. Juli 2007 
  11. a b c d e f Dickson Despommier: The Rise of Vertical Farms. In: Scientific American. 301. Jahrgang, November 2009. Scientific American Inc., November 2009, ISSN 0036-8733, S. 60–67 (scientificamerican.com).
  12. a b c d e D. Despommier: Vertical Farm Essay I. Vertical Farm, 2008, abgerufen am 26. Juni 2009.
  13. The Vertical Farm Project. 2009. “Agriculture for the 21st Century and Beyond.” http://www.verticalfarm.com/
  14. D. Despommier: Vertical Farm Essay I. Vertical Farm, 2008, abgerufen am 26. Juni 2009.
  15. Vertical Farm Video. Discovery Channel, abgerufen am 26. Juni 2009.
  16. Dwarf Wheat grown aboard the International Space Station. NASA, abgerufen am 17. November 2009.
  17. Michael Pollan. September 9, 2009. “Big Food vs. Big Insurance.” http://www.nytimes.com/2009/09/10/opinion/10pollan.html?_r=3&ref=opinion
  18. A Farm on Every Floor, The New York Times, August 23, 2009
  19. Ciel S Cantoria. June 17, 2009. “Vertical farming- Providing Alternative Resources for Food Production.” http://www.brighthub.com/environment/science-environmental/articles/39036.aspx?p=2
  20. Ciel S Cantoria. June 17, 2009. “Vertical farming- Providing Alternative Resources for Food Production.” http://www.brighthub.com/environment/science-environmental/articles/39036.aspx?p=2
  21. S.L. Davis: The least harm principle suggests that humans should eat beef, lamb, dairy, not a vegan diet. 2001, S. 449–450.
  22. S.L. Davis (2001). "The least harm principle suggests that humans should eat beef, lamb, dairy, not a vegan diet". Proceedings of the Third Congress of the European Society for Agricultural and Food Ethics. pp. 449-450.
  23. Michael Pollan. September 9, 2009. “Big Food vs. Big Insurance.”http://www.nytimes.com/2009/09/10/opinion/10pollan.html?_r=3&ref=opinion
  24. Case Study — Landfill Power Generation, H. Scott Matthews, Green Design Initiative, Carnegie Mellon University. http://gdi.ce.cmu.edu/gd/education/landfill-case.pdf Retrieved 07.02.09
  25. Kathryn McConnell: Vertical Farms Grow Food by Growing Up, Not Out. In: Bureau of International Information Programs. United States Department of State, 1. Juli 2008, abgerufen am 12. August 2008.
  26. Dickson Despommier. November 2009.“ Growing Skyscrapers: The Rise of Vertical Farms.”http://www.scientificamerican.com/article.cfm?id=the-rise-of-vertical-farms
  27. Nelson, B. (2008).Could vertical farming be the future? MSNBC.
  28. Roach, J. (June 30, 2009). High-Rise Farms: The Future of Food?. National Geographic News.
  29. Evans, P. (July 22, 2009). Local food no green panacea: professor. CBC News http://www.cbc.ca/consumer/story/2009/07/22/consumer-local-food.html
  30. http://www.youtube.com/watch?v=Scs2SIeIkkM