Photo credit: Wikipedia. This picture was taken by Acatenazzi at La Vieja Island, Paracas National Reserve, Departamento Ica, Peru. The nest of the Peruvian Booby is made of almost pure guano
The linkage between access to energy resources and the level of social development and complexity of a given civilization was noted in the work of Tainter, who states that “Human societies and political organizations, like all living systems, are maintained by a continuous flow of energy … More complex societies are more costly to maintain than simpler ones, requiring greater support levels per capita. As societies increase in complexity, more networks are created among individuals, more hierarchical controls are created to regulate these networks, more information is processed, there is more centralization of information flow, there is increasing need to support specialists not directly involved in resource production, and the like.”1 Not only is a given amount of energy required to support a given level of social complexity, but that society may suffer diminishing returns on new investments in complexity. The early societal cost for scientific endeavour was very low, as most activities were carried out by individuals or small groups of scholars who developed such things as modern geometry and the theory of gravity. An extreme example of modern science is the Large Hadron Collidor particle accelerator, which took 16 years and $10 billion to build2. Tainter proposes four concepts through which to understand why complex societies collapse:
- Human societies are problem-solving organizations;
- Sociopolitical systems require energy for their maintenance;
- Increased complexity carries with it increased costs per capita; and
- Investment in sociopolitical complexity as a problem-solving response often reaches a point of declining marginal returns.
The colonization of vast new land surfaces, but then much more fundamentally, the utilization of non-renewable fossil fuels that provided new energy sources, allowed eighteenth century society to temporarily overcome the limitations inherent in the above concepts. These new fuels, with energy intensities many times greater than previous energy sources, allowed for the rapid development of societies with a level of complexity many times that of preceding civilizations. This increased level of complexity also supported a much greater level of consumption of ecosystem resources, which may have pushed human society into ecological overshoot with respect to overall planetary ecosystem capacity. As Catton identifies, “the past four centuries of magnificent progress were made possible by two non-repeatable achievements: (a) discovery (sic) of a second hemisphere, and (b) development of ways to exploit the planet’s energy savings deposits, the fossil fuels”3. The temporary addition to the energy available to society has allowed human civilization to overshoot the earth’s carrying capacity, and thus this period of greatly increased societal complexity will eventually come to an end through either ecological limits, or the exhaustion of the finite fossil fuel resources in the absence of the discovery of a new source of energy. The ability of modern societies to realistically deal with these dangers, and take the actions required to become truly sustainable is greatly reduced due to the dangerous set of hegemonic beliefs, such as the possibility of endless exponential growth; the treatment of environmental services as inexhaustible or replaceable with social ones; and the efficacy of capitalism, which were developed during the period of rapid growth facilitated by colonization and non-renewable energy sources.
The discovery of new lands to exploit, and new energy sources, helped reinforce the notion that human societies can always find a way around limitations upon its growth. In the nineteenth century the degradation of European soils due to modern intensive farming practices and the separation of town and country (as human waste products containing vital soil nutrients were not returned to the land), which threatened lower yields, was at first remedied by the trade in guano4. The impact of modern farming practices is well described by an advertising document for fertilizers, which states “the small amount of reactive nitrogen in the soil limits biomass production in natural ecosystems. Agriculture further depletes reactive nitrogen from the soil. Nitrogen is absorbed during plant growth and then exported from the fields by harvesting. It needs to be restored by organic or mineral sources of nitrogen. Fertilizers, whether applied as manure or as mineral nitrogen, are therefore a key element of sustainable (sic) agriculture. Lack of nitrogen results in declining soil fertility, low yields and low crop quality.”5
The highest quality guano deposits, located on islands off the Peruvian coast, was the product of thousands of years of accumulated droppings by the islands bird population. The trade in Peruvian guano parallels the “resource curse” experienced by many less developed countries with resources important to the industrial economy. Firstly, the revenues were predominantly utilized for the benefit of the Peruvian elite and to pay off national debts to the more developed countries, with little or no benefit to the average Peruvian. Secondly, the workforce utilized for the resource extraction were paid as little as possible, with Chinese coolies, convicts, army deserters, and slaves being used to dig up an average of five tons of excrement per person per day from the huge mounds, using picks and shovels4. An inability to meet this daily quota was met with physical punishment. One visitor likened the workers to “over-worked beasts of burden” forced to “live and feed like dogs” and another stated that the cruelties were “scarcely believable and very few, if any, Chinese survived more than a few months.”4 The metabolic rift that Marx identified as being created by modern agriculture was matched by the human rift between those that made great profits from the guano trade, and those that worked in horrendous conditions to dig up that guano. The demand for guano continuously escalated to replenish the nutrients of European and North American soils. Between 1840 and 1880 it has been estimated that Peru excavated over 20 million tons of guano for export, and by 1909-10 Peru’s guano reserves were severely depleted and could only yield 48,000 tons of guano that year6. As the guano fields started to be depleted in the 1860’s, mining of Peru and Bolivia’s natural nitrate fields started7. Attempts by Peru and Bolivia to extract a greater percentage of the nitrate mining profits angered the foreign interests that controlled the guano and nitrate trade. This lead to the British-backed Chilean invasion of Peru and Bolivia, which resulted in the annexation of the nitrate fields by Chile and the continuing control of those resources by foreign (mostly British) capital. This manipulation of other countries to gain access to required ecological resources, and the uncontrolled depletion of those resources, can be seen many times in recent history. The advanced “core” industrialized countries escape their ecological limits, with little or no benefit to the countries where the resources are located except for small elites.
The dependence upon these natural sources of nitrate was then superseded by the Haber-Bosch process of nitrogen fixation in the early twentieth century, which has been used extensively ever since8. Natural gas (methane) is the predominantly utilized source for the hydrogen required by this process. This new process removed the dependence upon rapidly depleting natural sources of nitrogen, by replacing them with a seemingly endless source of nitrogen based upon the supply of fossil fuels. The amount of nitrogen so supplied to farming activities has increased exponentially since the inception of this new process, with over 139 million tonnes of nitrogen fertilizer forecast to be used in the 2011/2012 season. Added to this are 40 million tonnes of phosphates (from phosphate rock), and 36 million tonnes of potash (mined potash)9. The utilization of inorganic fertilizers was intensified in the post-WW2 period due to the impacts of the Green Revolution in the lesser developed nations. This utilized crops that could both thrive in the tropics and sub-tropics, while at the same time being able to utilize high levels of inorganic fertilizer. Due to this ability to respond to high levels of fertilizer, and to provide two or even three crops a year, the Green Revolution seeds brought substantial increases in food production. For instance, rice and wheat production in developing countries increased 75% between 1965 and 1980, with only a 20% increase in the area of cultivated land10. In the past few decades the high yielding crop varieties and the related intensive agriculture has displaced more traditional methods across the developing world. For instance, in 1983 95% of the cultivated rice area in China, and 82% of the cultivated wheat area in Latin America used these crop varieties. In India less than 100 hectares of land was used to grow these varieties in 1965, but by 1980 over 50 million hectares had been converted with the Punjab utilizing 95% of the cultivated area for such varieties11. The intensive mono-cropping of the new genetically uniform plant varieties, also required the use of pesticides and herbicides predominantly derived from oil products, together with large amounts of water provided through hydrocarbon fueled irrigation. Modern agriculture is also highly mechanized, replacing manual labour with oil fueled tractors and other machinery. Thus at all stages, modern crops has become totally dependent upon non-renewable hydro-carbon resources, both as a fuel and as a feedstock for the production of agricultural products. The Green revolution increased the energy required for agriculture by a factor of at least 50 times, and in some cases 100 times, when compared to the previous agricultural methods12. The sources of energy available prior to the discovery of fossil fuels could in no way have provided such prodigious amounts of energy at an acceptable cost to be used in such a way. Only the incredibly concentrated energy in non-renewable fossil fuels can support such practices. At each stage greater and greater amounts of energy have been utilized to overcome the threat of food shortages.
Modern agricultural methods are open to the diminishing returns that Tainter1 identified. The use of herbicides and pesticides both drives genetic mutations that are resistant through natural selection, and indiscriminately kills the natural enemies of the weeds and pests that are being targeted. As noted by Shiva12 “research on DDT-induced changes to pest population showed population increases up to twelve-hundredfold. The aggravation of the problem is directly related to the violence unleashed on the natural enemies of the pests.” Such impacts require the heavier usage of pesticides and herbicides, and the continual development of new ones. The logical outcomes of this process are such things as “Roundup Ready Corn” which is genetically modified to be resistant to herbicides containing glycophosphate, allowing such herbicides to be sprayed on them, and bt-Corn which is genetically modified to produce the Bacillus thuringiensis (Bt) delta endotoxin. Over time the yields of the new crop varieties tend to fall, as shown in an experimental plot where the same variety of high yielding rice was grown and a 40% reduction in yield was experienced10. Biotechnology is also being called upon to overcome these problems, but the length of time to develop these new seed varieties and the incremental increase are respectively significantly longer and significantly less than for the Green Revolution varieties. Thus, greater and greater inputs both on the farm, and in the research and development facilities are required to gain smaller and smaller incremental gains. For instance, an emerging feature of Indian agriculture as requiring greater and greater inputs to produce a given level of output has been noted by some researchers10, and thus a phase of diminishing returns has been entered, threatening the profitability of the Indian farming industry.
Soil erosion is also exacerbated by modern farming methods, with topsoil eroding at 30 times its natural formation rate, resulting in agricultural production declines in some parts of Africa by 50%.11 In addition, soil becomes depleted of minerals resulting in the continuous need to replenish those minerals. As Pfeiffer notes for North America “Much of the soil in the Great Plains is now little more than a sponge into which we must pour hydrocarbon-based fertilizers in order to produce crops.”11 Only the minerals required for plant growth are replenished though, resulting in food that may provide relatively empty calories without the minerals required for human health. An example is that of selenium, which has been shown to reduce Prostate Cancer rates in men13, 14. With the products of modern agriculture not containing such health supportive minerals, separate industries are required to produce supplements containing those minerals and increased disease-treatment facilities are also required to treat the increased cases of such malnourishment-induced diseases. The negative health effects produced by pesticide and herbicide residues on such food only adds to the resulting healthcare cost. Again, greater and greater inputs are required to provide the same, or even a reduced, overall output if overall health outcomes are the measure.
The prodigious amounts of food produced have not reduced hunger in the long term though, since the human population has increased as food has become less scarce and rising income levels have changed eating habits towards a greater dependence on less efficient produce such as meat in the richer countries. The numbers of human beings have grown at an exponential rate over the past few hundred years due to the ability to continuously increase food production, together with fossil fuel dependent water purification and antibiotics. In 1800 the human population reached 1 billion15, after centuries of very slow and uneven growth marked by the impacts of repeated famines and plagues which could kill significant percentages of the population in relatively short periods of time. Then, in the next 150 years, the human population advanced more than in all of previous human existence, another 1.5 billion, to 2.5 billion. The population growth rate then accelerated further with population increasing to 6.5 billion in the next 55 years, again adding more than in all of the previous human existence. Future trends are highly dependent upon the rate of decline in the rates of birth, which tend to fall as rising per capita wealth increases the cost of each child and the parents recognize the increased survivability of each child. In addition, government programs such as those that increase the availability and use of contraceptives also play a part. The decreased birth rate offsets the already decreased death rates, with the lag between the latter and former effects being the reason for the rapid population increases. United Nations projections assume that at some point the birth rate matches, or falls slightly below, the replacement level in all geographic areas. These projections show total human population reaching 9.2 billion in 2050, an increase of 2.7 billion in 45 years, with still some increase after that. These projections assume that world food production will continue to increase, both due to the number of humans to feed and the increase in per capita consumption as per capita income increases. The estimated high point for the human population will be approximately 10 times that which was in place prior to the successful societal utilization of fossil fuels.
Without ongoing increases in energy inputs into agriculture, and other forms of food production, the current and future scales of human population could not be supported within the modes of modern food production and levels of economic wealth. Some studies have shown that yields for organic farming can approach the yields for modern agriculture16, and also a reduction in the consumption of animals would improve the food calories available by removing the calories lost in utilizing plant food to grow animals. The latter possibility is the opposite of current trends, as increases in wealth produce increases in animal food intake. Such changes would be resisted by populations who currently enjoy, and who aspire to, the levels of affluence in the more wealthy nations. The former would require a wholesale reversal of the trends towards energy-intensive agriculture, and significant increase in the population devoted to agriculture. In addition, a large scale transition to organic agriculture would be hampered by the ecosystem damages, such as soil degradation, created by modern agriculture. The social resources for such a transition have also been greatly denuded as traditional farming knowledge, and crop varieties, being lost as modern agricultural methods have usurped the more traditional forms of food production. During the period of ecosystem regeneration the farmers would receive no, or greatly reduced incomes, and thus without external support there would be a great amount of economic inertial forces pushing farmers to stay with modern agricultural techniques.
The scale of societal effort required to change from industrial to organic agriculture was shown in the forced transition of Cuba, during the “Special Period in Time of Peace”17 after the removal of the Soviet bloc as a provider of fertilizers, pesticides, oil, and food imports and a tightening of the United States regime of economic sanctions against Cuba. Imports dropped overall by 75%, and oil imports by 53%. A large part of the success of the Cuban transition was the breaking up of large state agricultural organizations into smaller entities with a much greater level of local decision making and control, together with the fostering of urban agriculture. The former facilitated the intense local management required for more organic and non-mechanized types of agriculture, and leveraged the ability of smaller farms to provide more output per area of cultivation. If productivity is measured by the total output of a farm, instead of the yield of a single monoculture, then smaller farms can be seen to have greater outputs, “Though the yield per unit area of one crop—corn, for example—may be lower, the total output per unit area, often composed of more than a dozen crops and various animal products, can be far higher.”17 The location of farms closer to, or even within, urban populations also greatly reduced fossil fuel dependent transportation requirements. The transition was also greatly aided by a government focused scientific and infrastructural efforts to support and improve organic methods. For example, “Cuba is practically the only country in the world to begin implementing on a national scale a biological pest-control program based largely on parasitoids—parasitic insects and other biological agents that prey on pests that can damage crops. For example, wasps in the genus Trichogramma have been used to manage lepidopteran pests of tobacco and tomatoes. While this in itself is innovative, the effort has been reinforced by the establishment of Centers for the Reproduction of Entomophages and Entomopathogens. Over 200 centers have been set up to provide decentralized, small-scale, cooperative production of biocontrol agents, which farmers can use instead of pesticides to protect their crops”. In addition to the above, the national diet was moved away from animal sources to plant sources, thus boosting the efficiency of food calorie production. This successful transition was forced upon the Cuban nation by the external pressures of the Soviet-bloc collapse and the United States directed economic sanctions, which meant that Cuba had no other way of moving forward. In addition, Cuba is a communist society where the central government has the ability to direct major social changes such as the breaking up of large farms and changes to diets without resistance from democratic forces or other large economic and socially powerful organizations such as private corporations. The relatively small scale of the country, with a population of approximately 11 million (smaller than many of the major cities of the world), also aided a rapid centrally initiated and planned change process. Without all of the above factors supporting a successful transition, would Cuba have been able to move to its current food system configuration? Even with all of the supporting factors there was a significant period during the transition where food calories per capita dropped significantly and there were severe economic impacts. Only a number of years into the transition did calories per capita return to previous levels. The sustainability of the agricultural transition could also be threatened by the removal of one or more of these supporting factors, for instance Warwick notes that “Ironically, Cubans worry about what would happen if the U.S. embargo were to be lifted. In the event of a trade free-for-all, Cuba’s tentative steps towards environmental sustainability could be trampled under the feet of the Cuban exiles”.
The Cuban example shows that a nation can move away from industrial agriculture dependent upon non-renewable fossil fuels, but what if such a transition was required on a global level because of fossil fuel depletion and/or the need to reduce fossil fuel use to curtail Climate Change? Such changes, especially if they required moves to smaller locally managed farms with less dependency upon industrially produced inputs, would greatly challenge large vested interests which yield significant economic and social power. As Fitzgerald-Moore and Parai point out the Green Revolution new high yielding crop varieties require a package of inputs “which includes not only chemical fertilizers and irrigation, but also biochemical programs to control for disease, insect and weeds, and increased mechanization”10. Without these inputs the new varieties would underperform the traditional seeds, which have been bred for the previous much less modified ecosystems. The high level of investments required to provide the required package of inputs for modern agriculture encourages a move from subsistence to commercial agriculture, and a consolidation of farms into larger entities. Thus, traditionally more self-sufficient communities were integrated into the global market environment, reliant upon the large conglomerates that provided the seeds, other agricultural inputs, and the financing for the purchase of these inputs together with modern agricultural machinery. The net result was a wide dispersion in incomes, with the larger farms and the providers of the new inputs and machinery taking the majority of the economic benefits. This economically-driven Darwinian process removed both the knowledge of, and the political support for, the traditional agricultural processes. Within a matter of generations the traditional ecological knowledge gained over centuries that supported the previous low energy input farming methods was lost in one area after another. Even the memory that proved that industrialized high energy agriculture was not the only way of growing crops disappeared over time. The separation of people from the land through the urbanization that was facilitated by the labor-saving mechanization of food production in general, also separated the vast majority of the population from any first-hand knowledge of food production. In the rich countries of today the average person is used to food magically appearing on the shelves of the supermarket, disembodied from the actual crops and animals that were the living inputs to the production of that food. With populations disconnected from the actual processes used to produce their food, questions about the current, and long term impacts and sustainability, of the food industries rarely enters into public discourse. On some occasions aspects of this industry do burst into public consciousness, as in a significant case of food poisoning, or an investigation of horrendous practices in slaughterhouses. These instances quickly fade away from public consciousness though, and do not trigger wider ranging and more systemic questions. Limited scientific solutions are provided, such as food irradiation, and working practices are changed to assuage public concern. All such actions are incremental changes to the hegemonic industrial food production systems rather than any fundamental change to them.
The production processes for many of the inputs required for industrialized agriculture have large scale efficiencies which benefit larger organizations. In addition, the large development of many new agricultural products requires extremely large and lengthy research and development activities, with a scale of investment only open to larger organizations. These factors supported the consolidation of supplying companies into a few very large organizations, with the process of consolidation accelerating in the past few decades. The top 10 pesticide producing companies now control almost 90% of the agrochemical business worldwide, the top 10 biotechnology companies have 75% of industry revenue. There has also been significant concentration in seed providers, with 6 of the leading seed companies also being within the top 10 companies for pesticides and biotechnology. With such significant concentration only a handful of profit maximizing companies have control over the majority of plant production that has been integrated into the world market economy18. The fossil fuel inputs to the production processes for such things as herbicides and fungicides, as well as the agricultural and food transport machinery, are provided by the highly concentrated fossil fuel industry which includes some of the largest private corporations in the world, such as Exxon Mobil, Royal Dutch/Shell, and Gazprom together with huge state owned organizations such as those of Saudi Arabia and Iraq. Some of the producers of farm and transportation equipment used by farmers are also very large corporations. In addition to the above levels of economic concentration, there are numerous industry associations that concentrate the political weight of a given industry. An example is the International Fertilizer Industry Association which “has some 540 members in about 85 countries. About half of the membership is based in developing countries. IFA member companies represent all activities related to the production, trade, transport and distribution of every type of fertilizer, their raw materials and intermediates.” 19 These trade organizations, as well as individual companies, employ large numbers of lobbyists and other staff to help direct government policies, and international agency decisions, in ways beneficial to them.
In addition, they actively attempt to affect societal discourses on such things as the future course of agriculture through media contacts, commercials extolling the benefits of the agricultural methods that they support, and the funding of research supporting industrial farming methods. The dependence of many media organizations upon advertizing revenues as the major source of income, also allows for at both passive control of media output through “self-censorship”, and active control through the decisions of which media outlets and content advertisers will support. For instance large agro-chemical corporations are highly unlikely to sponsor media outlets, or specific content, that is highly critical of industrialized farming methods. Herman & Chomsky raise the example of a proposed documentary on environmental problems to show the reality of such influence, “although at the time a great many large companies were spending money on commercials and other publicity regarding environmental problems, the documentary series failed for want of sponsors. The problem was one of excessive objectivity in the series, which included suggestions of corporate or systemic failure, whereas the corporate message was one of reassurance.”20
These large corporations tend to be publicly traded companies that have the maximization of profits as their legally enshrined raison d’etre, and are required to report on the continued allegiance to that objective on a quarterly basis. As Bakan states corporate law compels, “corporate decision makers always to act in the best interests of the corporation, and hence its owners. The law forbids any other motivation for their actions, whether to assist workers, improve the environment, or help consumers save money”, and likens the modern corporate structures to institutional psychopaths21. Such institutions operate as the rationally self-interested actors that are assumed in Hardin’s formulation of the “tragedy of the commons”22, which is very different to individual human beings which have been empirically shown to act in unselfish altruistic ways. The actions of agro-chemical companies such Monsanto in pressurizing governments and society in general to support rapid deployment of new chemical products and Genetically Modified Organisms, contrary to the precautionary principal and in the absence of any long term studies of environmental impacts, can be seen as an individual company placing the general ecological commons that supports humanity at risk to drive short term profit. As Bakan characterizes such behavior, these corporations are excellent externalizing devices which internalize profit and externalize the cost of the negative consequences of their actions21.
From the above exploration of the development of modern agriculture over the past few hundred years certain overall patterns can be seen. Firstly, the seeming ability of humanity to evade limits through the extraction of ecological resources at rates far faster than natural renewal processes, whether guano from Peruvian islands or hydrocarbon fuels produced over millions of years. The success of this limit evasion over a period of a few hundred years has embedded a belief that continuing exponential growth is normal and sustainable. The resulting development of industrialized agriculture has displaced much of the societal resources and support required for previous forms of agriculture while at the same time degrading their ecological basis through soil degradation and pollution, making it extremely difficult to resurrect the previous agricultural practices. The scale of enterprises necessary for modern agriculture, and the supporting industries, has produced economically and politically powerful entities focused on the ongoing development and further spread of industrialized farming practices which favor the larger corporations. The example of Cuba does show that a transition to organic and low energy input farming is possible, but only under extreme external pressures and with a central authority able to drive rapid changes and manage the impact of such changes in a relatively equitable fashion. On a global scale humanity may be presented with the external pressure that forces change, either through a reduction in available hydrocarbon supplies, or through the need to reduce hydrocarbon usage to stem Climate Change. As Heinberg notes, global oil production has been on stagnant since 2005 with new oil fields only making up for the depletion of current ones, even as oil prices doubled23. This inelasticity of demand in the face of rising prices may show that geological limits may have trumped the demand and supply assumptions of modern economics. Higher prices have not produced increased supply. If the peak oil proponents are correct, this plateau may soon turn into a decline, reducing the amount of oil available to society and marking the beginning of a decline in available energy from hydrocarbon extraction in general. Given the factors noted above, it is hard to be optimistic about the ability of human civilization to undergo the transition necessary to lower energy farming in a well controlled and equitable manner.
1. Tainter, Joseph (1988), The Collapse of Complex Societies, Cambridge
2. Mezriotti, Valerio (2011), Large Hadron Collidor, New York Times. Accessed at http://www.nytimes.com/2010/03/31/science/31collider.html April 19th, 20112
3. Catton, William (1982), Overshoot The Ecological Basis of Revolutionary Change, University of Illinois Press
4. Foster, Clark, York (2010), The Ecological Rift, Monthly Review Press
5. Accessed at http://www.yara.com/doc/33521_Nitrate_-_Pure_Nutrient.pdf April 19th, 2012
6. N/A (1997), Guano Trade, TED Case Studies. Accessed at http://www1.american.edu/TED/guano.htm April 19th, 2012
7. Blakemore, H. (2011), John Thomas North, the Nitrate King, History Today. Accessed at http://www.historytoday.com/h-blakemore/john-thomas-north-nitrate-king April 20th, 2012
8. N/A (N/A), New Chemicals: Ammonia, Making the Modern World. Access at http://www.makingthemodernworld.org.uk/stories/the_second_industrial_revolution/05.ST.01/?scene=5 April 20th, 2012
9. N/A (2008), Current world fertilizer trends and outlook to 2011 and 2012, Food and Agriculture Organization of the United Nations. Accessed at ftp://ftp.fao.org/agl/agll/docs/cwfto11.pdf April 20th, 2012
10. Fitzgerald-Moore and Parai (n/a), The Green Revolution, accessed at http://people.ucalgary.ca/~pfitzger/green.pdfApril 20th, 2012
11. Pfeiffer, Dale Allan (2006), Eating Fossil Fuels, New Society Publishers
12. Shiva, Vandana (2011), India Divided: Diversity and Democracy Under Attack, Seven Stories Press
13. Clark et al (1998), Decreased incidence of prostate cancer with selenium supplementation: results of a double blind cancer prevention trial, British Journal or Urology. Accessed at http://www.cardiocrusaders.com/assets/files/pdf/research_articles/studies_britishjurology_selenoexcell.pdf April 19th, 2012
14. Yoshizawa et al. (1998), Study of Prediagnostic Selenium Level in Toenails and the risk of Advanced Prostate Cancer, Journal of the National Cancer Institute. Accessed at http://jnci.oxfordjournals.org/content/90/16/1219.full.pdf April 18th, 2012.
15. Bongaarts, John (2009), Human population growth and the demographic transition, Philosophical Transactions of the Royal Society. Accessed at http://rstb.royalsocietypublishing.org/content/364/1532/2985.full.pdf.
16. Can Organic Farming Feed Us All?, World Watch Magazine May/June 2006, Volume 19, No. 3. Accessed at http://www.worldwatch.org/node/4060 April 19th, 2012
17. Warwick, Hugh (2001), Cuba’s Organic Revolution, Forum for Applied Research and Public Policy Summer 2001. Accessed at http://forum.ra.utk.edu/Archives/Summer2001/cuba.pdf April 19th, 2012
18. Various (2008), Who Owns Nature?, ETC group
19. International Fertilizer Association web site. Accessed at http://www.fertilizer.org/ April 19th, 2012
20. Herman, Edward & Chomsky, Noam (1988), Manufacturing Consent, Pantheon Books
21. Bakan, Joel (2004), The Corporation: The Pathological Pursuit Of Profit And Power, Penguin Canada
22. Hardin, G. (1968). The Tragedy of the Commons. Science, 162, 1243-1248
23. Heinberg, Richard (2011), The End of Growth: Adapting to our New Economic Reality, New Society Publishers