SUSTAINABILITY TheRISEof VERTICAL FARMS Growing crops in city skyscrapers would use less water and fossil fuel than outdoor farming, eliminate agricultural runoff and provide fresh food By Dickson Despommier ogether the world’s 6.8 billion people use eating in most places worldwide between 2005 KEY CONCEPTS land equal in size to South America to and 2008. grow food and raise livestock—an as- Some agronomists believe that the solution ■ Farming is ruining the T environment, and not tounding agricultural footprint. And demogra- lies in even more intensive industrial farming, enough arable land re- phers predict the planet will host 9.5 billion peo- carried out by an ever decreasing number of high- mains to feed a projected ple by 2050. Because each of us requires a mini- ly mechanized farming consortia that grow crops 9.5 billion people by 2050. mum of 1,500 calories a day, civilization will having higher yields—a result of genetic modifi- have to cultivate another Brazil’s worth of cation and more powerful agrochemicals. Even ■ Growing food in glass high-rises could drastical- land—2.1 billion acres—if farming continues to if this solution were to be implemented, it is a ly reduce fossil-fuel emis- be practiced as it is today. That much new, ara- short-term remedy at best, because the rapid shift sions and recycle city ble earth simply does not exist. To quote the in climate continues to rearrange the agricultural wastewater that now great American humorist Mark Twain: “Buy landscape, foiling even the most sophisticated pollutes waterways. land. They’re not making it any more.” strategies. Shortly after the Obama administra- Agriculture also uses 70 percent of the world’s tion took office, Secretary of Energy Steven Chu ■ A one-square-block farm 30 stories high could yield available freshwater for irrigation, rendering it warned the public that climate change could as much food as 2,400 unusable for drinking as a result of contamina- wipe out farming in California by the end of outdoor acres, with less tion with fertilizers, pesticides, herbicides and the century. subsequent spoilage. silt. If current trends continue, safe drinking wa- What is more, if we continue wholesale de- ter will be impossible to come by in certain forestation just to generate new farmland, glob- ■ Existing hydroponic greenhouses provide a densely populated regions. Farming involves al warming will accelerate at an even more cat- basis for prototype verti- huge quantities of fossil fuels, too—20 percent astrophic rate. And far greater volumes of agri- cal farms now being con- of all the gasoline and diesel fuel consumed in cultural runoff could well create enough aquatic sidered by urban planners the U.S. The resulting greenhouse gas emissions “dead zones” to turn most estuaries and even Mondolithic Studios Mondolithic in cities worldwide. are of course a major concern, but so is the price parts of the oceans into barren wastelands. —The Editors of food as it becomes linked to the price of fuel, As if all that were not enough to worry about, a mechanism that roughly doubled the cost of foodborne illnesses account for a significant KENNBROWN 80 SCIENTIFIC AMERICAN November 2009 © 2009 SCIENTIFIC AMERICAN, INC. www.ScientificAmerican.com SCIENTIFIC AMERICAN 81 © 2009 SCIENTIFIC AMERICAN, INC. [THE AUTHOR] number of deaths worldwide —salmonella, chol- Do No Harm era, Escherichia coli and shigella, to name just Growing our food on land that used to be intact a few. Even more of a problem are life-threaten- forests and prairies is killing the planet, setting ing parasitic infections, such as malaria and up the processes of our own extinction. The min- schistosomiasis. Furthermore, the common imum requirement should be a variation of the practice of using human feces as a fertilizer in physician’s credo: “Do no harm.” In this case, do most of Southeast Asia, many parts of Africa, no further harm to the earth. Humans have risen and Central and South America (commercial to conquer impossible odds before. From Charles fertilizers are too expensive) facilitates the Darwin’s time in the mid-1800s and forward, spread of parasitic worm infections that afflict with each Malthusian prediction of the end of the Dickson Despommier is profes- 2.5 billion people. world because of a growing population came a sor of public health and microbiol- Clearly, radical change is needed. One stra- series of technological breakthroughs that bailed ogy at Columbia University and president of the Vertical Farm tegic shift would do away with almost every ill us out. Farming machines of all kinds, improved Project, which functions as a just noted: grow crops indoors, under rigorous- fertilizers and pesticides, plants artificially bred clearinghouse for development ly controlled conditions, in vertical farms. for greater productivity and disease resistance, work (see www.verticalfarm.com). Plants grown in high-rise buildings erected on plus vaccines and drugs for common animal dis- As a postdoctoral fellow at the now vacant city lots and in large, multistory eases all resulted in more food than the rising Rockefeller University years ago, he became friends with rooftop greenhouses could produce food year- population needed to stay alive. René Dubos, a renowned agricul- round using significantly less water, producing That is until the 1980s, when it became ob- tural sciences researcher who little waste, with less risk of infectious diseases, vious that in many places farming was stressing introduced him to the concept of and no need for fossil-fueled machinery or the land well beyond its capacity to support vi- human ecology. trans port from distant rural farms. Vertical able crops. Agrochemicals had destroyed the farming could revolutionize how we feed our- natural cycles of nutrient renewal that intact selves and the rising population to come. Our ecosystems use to maintain themselves. We meals would taste better, too; “locally grown” must switch to agricultural technologies that would become the norm. are more ecologically sustainable. The working description I am about to ex- As the noted ecologist Howard Odum re- plain might sound outrageous at first. But engi- portedly observed: “Nature has all the answers, neers, urban planners and agronomists who so what is your question?” Mine is: How can we have scrutinized the necessary technologies are all live well and at the same time allow for eco- convinced that vertical farming is not only fea- logical repair of the world’s ecosystems? Many sible but should be tried. climate experts—from officials at the United Nations Food and Agriculture Organization to [PROBleM] sustainable environmentalist and 2004 Nobel Peace Prize winner Wangari Maathai—agree Feeding the Future: Not Enough Land that allowing farmland to revert to its natural Growing food and raising livestock for 6.8 billion people require land equal in size to grassy or wooded states is the easiest and most South America. By 2050 another Brazil’s worth of area will be needed, using traditional direct way to slow climate change. These land- farming; that much arable land does not exist. scapes naturally absorb carbon dioxide, the most abundant greenhouse gas, from the ambi- ent air. Leave the land alone and allow it to heal Present our planet. ) Examples abound. The demilitarized zone Uses cropland = the size of South America between South and North Korea, created in illustration 1953 after the Korean War, began as a 2.5-mile- 6.8 billion people wide strip of severely scarred land but today is lush and vibrant, fully recovered. The once bare ); LAURIE GRACE ( corridor separating former East and West Ger- 2050 many is now verdant. The American dust bowl of the 1930s, left barren by overfarming and Despommier drought, is once again a highly productive part = + of the nation’s breadbasket. And all of New Would require added England, which was clear-cut at least three 9.5 billion people cropland the size of Brazil times since the 1700s, is home to large tracts of healthy hardwood and boreal forests. COURTESY OF STEVEN CHEN ( 82 SCIENTIFIC AMERICAN November 2009 © 2009 SCIENTIFIC AMERICAN, INC. faRMING EXactS a heavy toll The Vision were produced hydroponically on South Pacific on the environment: fertilizer For many reasons, then, an increasingly crowd- islands for Allied forces there. Today hydropon- runoff feeds large algae blooms ed civilization needs an alternative farming that create ocean dead zones ic greenhouses provide proof of principles for method. But are enclosed city skyscrapers a (left; blue and green swirls); indoor farming: crops can be produced year- practical option? irrigation and vehicles waste round, droughts and floods that often ruin en- Yes, in part because growing food indoors is massive quantities of water tire harvests are avoided, yields are maximized ); already becoming commonplace. Three tech- and fossil fuels (top right); because of ideal growing and ripening condi- niques—drip irrigation, aeroponics and hydro- and pesticides contaminate tions, and human pathogens are minimized. ) ponics—have been used successfully around the food, land and ground water Most important, hydroponics allows the world. In drip irrigation, plants root in troughs (bottom right). grower to select where to locate the business, phytoplanktonbloom ( of lightweight, inert material, such as vermicu- without concern for outdoor environmental spraying pesticide spraying lite, that can be used for years, and small tubes conditions such as soil, precipitation or temper- ( running from plant to plant drip nutrient-laden ature profiles. Indoor farming can take place water precisely at each stem’s base, eliminating anywhere that adequate water and energy can Getty Images the vast amount of water wasted in traditional be supplied. Sizable hydroponic facilities can be irrigation. In aeroponics, developed in 1982 by found in the U.K., the Netherlands, Denmark, K.