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Nathan LeggeProfessor Alex BlockWriting 10015 May, 2015Course Paper Final Draft
A Case for Sustainable Agriculture
Global climate change is destabilizing ecosystems across the planet. This has diminished
the function and output of natural and agricultural ecosystems globally, with economic impacts
in the form of rising food prices. The complex nature of ecosystems has led many agriculturalists
to rely on unsustainable methods of overexploiting soil with environmentally destructive
petrochemicals. One strategy of diminishing this reliance, here called the Ladder program, is to
enact organic methods in an effort to grow crops intelligently. The purpose of this program is to
create efficient, self-sustaining ecosystems from which sustenance can be pulled, one project at a
time. Despite criticisms that can be leveled against organic methods, they may inevitably become
necessary for the stabilization of food markets in the face of growing populations, dwindling oil
resources, and increasing global climate change.
In order to properly discuss the current global climate crisis, it is important to understand
the fundamental behavior of the Earth’s biosphere. Atmosphere and oceans absorb and
redistribute heat from solar radiation, and this regular process has created the mosaic of climates
found around the world today (Hannah 22). The rotation and revolution of the Earth around the
Sun creates a seasonal alternation of temperature and circulation of moisture to which all species
have adapted like a biological clock. The metabolism and growth of plants and bacteria are
highly sensitive to moisture and temperature in air and soil (Svenning and Sandel 1266). A given
plant has very slow and fragile biochemistry that relies on subtle temperature cues to guide its
maturation, so that it does not try to grow when water resources are too low (1267-1268). Thus,
when seasonal temperatures shift and rain patterns become irregular, only a certain number of
plants can cope with the increased stress. Those that do not cope either die or fail to properly
mature. In turn, the insects and animals which depend on the maturation of these plants
experience a lack of resources, which in extreme cases can lead to extinctions of species
(Srivastava and Vellend 278-279). Therefore, stable climatic conditions are desirable for species,
like humans, that depend on plants for sustenance. However, the Earth’s climates are in a
growing state flux, caused primarily by increasing atmospheric carbon dioxide.
Carbon dioxide (CO2) has been identified as the leading cause of global climate change.
Levels of atmospheric CO2 released by the decay of plants and burning of fossil fuels have risen
since the widespread use of coal and oil in 1940 (Svenning and Sandel 1266). Since 1960,
industrial emissions of carbon dioxide have quadrupled, and the total amount of CO2 in the
atmosphere has risen by nearly a quarter (Groot et al. 32; Ingram and Malamud-Roam 191). This
CO2 traps heat more readily than nitrogen and oxygen in a process known as the greenhouse
effect, and the natural absorption of CO2 by the Earth’s oceans is beginning to break down
(Groot et al. 34-35). The many ocean and air currents which distribute heat from the equator to
the poles are made unstable by this average temperature increase, resulting in erratic weather
patterns experienced in different ways by different regions (Leakey et al. 228). This can lead
relatively moderate climatic behavior to suddenly be divided between floods in California and
droughts in Indonesia, for example (Ingram and Malamud-Roam 53-54). The seasonal variation
in a given region may also be divided between extremely wet winters and extremely dry
summers, with an increasingly brief period of moderate weather needed for farming (196-197).
Shorter growing seasons have obvious implications for the output of human agriculture, but
changing temperatures also impact biodiversity, specifically.
As stated above, the maturity and reproduction of plants is interrupted when seasonal
temperatures and precipitation are shifted by the greenhouse gases like CO2. Normally, plants in
temperate regions increase growth in the presence of higher ambient CO2, thereby countering the
greenhouse effect and keeping local temperatures stable (Leakey et al. 233). However, crops
grown in other biomes may react differently as their climates become more erratic. In tropical
environments, a warmer atmosphere brought on by increased CO2 leads to more precipitation
and floods in the wet seasons and less precipitation and droughts in dry seasons. In arid
environments, precipitation is always low, so warmer conditions will spark prolonged droughts.
In frozen tundras, increased CO2 is predicted to increase thawing and release even more CO2
trapped in the ice (Leakey et al. 235). In each of these cases, there is a threshold beyond which
plants cannot counteract increased CO2 because the rate of temperature increase is too high. Rice
has been observed to cross this threshold and decrease productivity in spite of higher CO2 levels
(Leakey et al. 234). If such a threshold exists for temperate plantlife, the biological
counterbalance to increased CO2 will begin to break down in what is most likely an irreversible
cycle of increased atmospheric CO2, increased ambient temperature, and decreased CO2
absorption through photosynthesis. Should such a chain reaction prove unstoppable, biodiversity
loss will not be halted by human efforts. The result is hard to predict, but this breakdown is
expected to decrease the function and output of ecosystems on a global scale.
The utility of ecosystem function demonstrates itself through food prices around the
world. India’s agricultural industry employs over half the nation and provides nearly a fifth of its
Gross Domestic Product. This makes one of the top-ranking agricultural powerhouses, owed in
large part to the adoption of expensive and destructive industrial farming practices (Ahmad,
Alam, and Haseen 131). These practices are the leading producers of greenhouse gases to date,
and were adopted by a list of third world countries over the last century. In a study of this
industry in India, Jamil Ahmad, Dastgir Alam, and Shaukat Haseen (130) estimate an increase in
global temperature by two degrees could offset the growth cycle of crops enough to cost India
nearly half of its GDP. This, combined with an ever-growing population, will have destructive
effects that will not be unique to India. As climates shift, established farms will find it more
difficult to grow crops, and this will drive food prices higher. The cost of basic necessities will
disproportionately impact the poor and impoverished, with potentially destabilizing results for
developing nations (Cohen, Shepherd, and Brown 250; Berazneva and Lee 2013). Knowing this,
the necessity to protect ecosystem function is undeniable.
In 2007, Groot et al. (50) reviewed a dataset of 320 ecological studies to estimate the
monetary value of different biomes. Coral reefs, coastal wetlands, and inland wetlands are ten to
sixty times more valuable than all other biomes, including tropical forests (55). Needless to say,
the exact values of these biomes are and controversial (Svenning and Sandel 1266). The most
accurate statement is that human economies could not exist without crops growing and natural
water distribution the way it is today. In unstable climatic conditions, large predators at top
trophic levels are at highest risk for extinction, which means food webs crumble from the top
rather than from their foundations (Srivastava and Vellend 278-279). This means humans, who
depend on higher trophic levels than lower levels, will suffer greatly from climatic instability.
Through their research, Clewell and Aronson (425-426) claim that mature, complex ecosystems
regulate climate better than less complex ones by absorbing and distributing solar radiation in the
form of biomass. This is one ecosystem function that is directly dependent on biodiversity,
though its contribution to climatic stability may be infinitesimal compared to geological
processes (Groot et. al 22). In short, the necessity of ecosystem function is absolute, but the
importance of biodiversity to that function is not well understood.
Rising global temperatures caused by ambient CO2 levels can spark a feedback loop that
divides mild climates into extreme drought and extreme floods. Ecologists have estimated the
threshold of this loop at two degrees centigrade above 2001 levels (Ahmad, Amal, Haseen 130).
The vast majority of green policies aim to keep global temperatures from crossing this threshold
through plans to reduce carbon emissions and increase renewable sources of energy. Current
trends, however, show that this strategy has not been as successful as was hoped or needed
(Everard et al. 358). This is due to a number of obstacles, including political gridlock and lack of
public funds. Additionally, well-established farmers remain convinced that private gains at
public loss, such as slash-and-burn agriculture and soil overexploitation, are necessary in a
competitive market (Petersen and Snapp 7). Though rising global temperatures present the most
universal cause of ecosystem collapse, a loss of biodiversity has a number of causes which may
or may not contribute to poor agricultural performance.
In a journal concerning environmental policy, Jorge Soberón (11) identifies immediate
and mediate causes of biodiversity loss. Immediate causes include overexploitation of biological
resources, introduction of invasive species, and use of artificial chemicals. In short, any practice
which depletes biomass or otherwise impacts a given ecosystem is liable to interrupt long-
standing equilibriums between species. Doing so creates artificial pressures on certain species,
increasing tendencies towards extinction and threatening the stability of entire foodwebs. Each of
these causes will be discussed in turn.
One of the most obvious stressors on local ecosystems is the overexploitation of certain
species (Soberón 12). Farming has isolated most desirable species from their natural habitats to
prevent them from being eaten by other organisms. A ready example of overexploitation leading
to ecosystem instability is in the harvesting of fish. By harvesting vast quantities of fish, humans
are effectively draining the oceans of biochemical matter to such a degree that other fish are
prone to extinction (Beamish MacFarlane and Benson 289). Overgrazing can leave otherwise
lush grassland as uninhabitable desert (Ahmad, Alam, and Haseen 130). Deforestation and
improper irrigation causes ecosystems that have developed over thousands of years to
disintegrate. Such erosion has immediate and undeniable effects upon human subsistence
practices. Soil erosion has been a known symptom of overexploitation since the 1930s Dustbowl
sandstorms (Ingram and Malamud-Roam 42). Since that time, however, agricultural practices
that lead to erosion have continued in many countries (Ahmad, Alam, and Haseen 130; Soberón
12-13). More specifically, artificial fertilizers have become an industry standard that would not
be necessary if crops were grown in self-sustaining ecosystems.
The introduction of invasive species is another destabilizing influence on ecosystems
(Soberón 12). Some species have been introduced to foreign environments through direct human
action. Certain species, if they are particularly successful in a new environment, have the ability
to take over a biological niche, driving indigenous species to extinction and possibly causing
further reverberations throughout an ecosystem. In a more global and indirect trend, invasive
species are introduced by migratory trends spurred by global climate change. Warming trends
have affected the hospitable range of certain species, along with their maturation times and
population size (Rosales 1410). For example, increased temperatures in the Southern California
mountains allowed bark beetles to proliferate throughout vast tracts of pines, which ultimately
led to giant wildfires (Ingram and Malamud-Roam 194). The destructive nature of such pests has
led conventional farmers to rely on pesticides, herbicides, and rodenticides derived from fossil
fuels to effectively kill all organisms in a given area besides the crops themselves (Mahmood,
Bilal, and Jan 423). These protect crops at the expense of all other living creatures, and deserve a
deeper explanation for the purposes of this paper.
Because ecology is so little understood, farmers rely on nebulous foodwebs to foster the
growth of microbes and insects that enable the growth of their crops. These foodwebs are
threatened by climatic instability, and any negative impacts on them will translate to lower crop
yields (Ahmad, Alam, and Haseen 130). To buffer these negative climatic effects and maximize
profitability, farmers have come to rely on petrochemical pesticides, herbicides, and fertilizers
that extract more food than soil would naturally be able to support (Connor 187). Roughly 99.7
percent of agriculture around the world is directly supported by petrochemicals (Ibid). These and
other chemicals released by human practices have proven toxicological effects, as should be
expected from industrial poisons (Mahmood, Bilal, and Jan 423; Snow 37-42; Soberón 12).
Setting aside the detrimental effect that these chemicals undoubtedly have on natural ecosystems,
their use on arable cropland has created ecosystems that are unsustainable by design. This is
enough reason to abandon conventional agriculture as quickly as possible, but there are others.
The conventional method of growing crops is to throw petrochemicals on soil to the
extent that it is capable of growing only the crop and nothing else (Crowder and Harwood 2). By
destroying a natural ecosystem to keep crops safe from pests, farmers create tracts of land wholly
dependent on artificial fertilizers to produce food (Mahmood, Bilal, and Jan 423). When this
supply of fertilizer stops, the crops die and the bare soil erodes (Ingram and Malamud-Roam
2013 44-45). So long as petrochemicals are used, crops can be protected from invasive species
and disease. Yet even this petrochemical buffer faces increasing pressure from global climate
change. Ecologists have placed the global temperature threshold at two degrees centigrade above
2001 levels (Ahmad, Amal, Haseen 130). Past this threshold, global temperatures will overpower
the stabilizing capability of temperate plants and CO2 levels will spiral out of control (Nemergut
et al. 2005 782). In the ensuing temperature rise, farmers will come to rely on petrochemicals
more than ever at continuously rising prices. This reliance on petrochemicals makes the price of
gas the most important factor for farmers when they could instead hire skilled entomologists,
surveyors, and biochemists to make their crops self-sustaining. In time, even the most costly
alternatives will seem viable, and farmers will be looking for any way to reduce their dependence
on oil products. This is where the Ladder program comes in.
The Ladder program is an attempt to construct a functioning ecosystem with as few
species as possible, so that those species can be easily monitored and protected by human
biochemists. This will also maximize the efficiency of the ecosystem, as less energy will be
diverted by unnecessary or redundant species. In addition, the Ladder program calls for an
increase in organic methods to reduce dependence on expensive and toxic petrochemicals. In this
case, organic methods range from genetic modification to microbial pesticides. The most
promising and least expensive of these methods includes promotion of natural enemies, meaning
species which naturally eat or attack pests. In short, this plan calls for more intelligence about
farming than is currently practiced in conventional agriculture. Plants and soils will need to be
closely monitored and treated for infestations and diseases using organic materials—preferably
produced with organic methods. The ultimate goal of this program is to create an ecosystem with
as few trophic levels as possible between humans and soil. If humans harvest a measured amount
of this ecosystem’s produce and contribute enough waste products to compensate, this ecosystem
will end by needing very little human oversight.
The first Ladder project will be the most difficult, and will set the template for other
projects in the same biome. First, an isolated tract of land free of petrochemical contamination
must be properly irrigated. If the soil is already irrigated and fertile, constructing the ecosystem
will be much faster. Before commercial crops can be planted, a functioning ecosystem must be
established to support them. This means transporting manure from livestock farms and beneficial
insects from their natural habitats. Properly irrigated, a project requires evergreens or
myrmecophytes to serve as nests for natural enemies. Natural enemies can be ants, spiders, or
some other natural insectivore. If these insectivores do not also serve as pollinators, bees must be
included and serve as food for the insectivores. This would make pollinators a primary resource
for the whole project, so they must be monitored carefully. This means beekeepers, surveyors,
biochemists, and botanists must be employed year-round to counteract environmental impacts
and diseases within this ecosystem. Such would require a deeper understanding of botany and
soil ecology, so a major element of the Ladder program is research into every aspect of this
artificial ecosystem. Surprisingly, the vital field of ecology remains underdeveloped.
The difficulty in understanding the ecosystem function stems from a limitations in the
field of ecology. Most practical tests of biodiversity deal with number of species as a lump sum
and assume all species perform unique functions. By contrast, Thompson et al. (689) recommend
a foodweb approach, which charts the links between one niche and the next. Such an approach
would allow fluctuations of a given resource (nitrogen, calcium, etc.) in a given niche (riverbed
soil microbacteria) to be observed for its effects on one species and its predators. Through this
method, ecosystem function may be observed to depend on a select number of keystone species.
Unfortunately, the intensive nature of such a study precludes it from being carried out as these
authors suggest (Nemergut et al.776). Despite these limitations, less thorough species-removal
tests suggest that the biomass needed to maintain large animals at the highest trophic levels is
dependent on a select number of species (692). In every case, the necessary species for any
ecosystem to function begins with bacteria in soil.
Unfortunately, microbial species are the least understood and most difficult to observe.
Molecular phylogentic methods have recently been used to help identify microbial taxa, but these
have yet to see widespread use (Nemergut et al. 776). On this subject, Hillebrand and
Matthiessen (1406) raise an interesting point. The list of keystone species that contribute a given
function may be short, but there is usually little overlap between this list and the list for another
function (Hillerbrand and Matthiessen 1406, 1409). In other words, it is a mistake to assume that
the keystone species necessary for growing corn can also be used to grow oaks or oxygenate air.
It is often the case that certain species are optimized for utilization of a specific resource to the
detriment of other resources, so variety of species is needed to efficiently process all resources.
This complicates the reduction of ecosystem function to a handful of keystone species, and
requires consideration of most or all necessary functions together, rather than letting one function
speak for the rest.
Niche theory offers a way around this problem (Hillebrand and Matthiessen 1413; Bent
and Forney 689). A niche is a specific place in an ecosystem occupied by one or multiple
species. These species prey on certain other species, and are in turn preyed upon by their
predators. In this way, biomass and energy are transferred between niches, and fluctuations in the
growth of one niche have effects on all the niches that prey upon it. Supposing an invasive
species of ant drives several others to extinction, so long as it fulfills the same niche, ecosystem
function has not been disrupted. In the same way, the specific species dedicated to oxygenation
can be ignored for practical purposes, and the soil itself can be treated as a single species. In
other words, if humans can identify the chemical inputs (carbon, nitrogen, water, etc.) necessary
to make soil produce a useful output (heat, proteins, biomass, etc.), what happens in between can
remain a mystery. In short, keystone microorganisms are so difficult to identify that, for the
purposes of this paper, soil will be considered as a single species. Thus far, research is
inconclusive as to the impact of climatic behaviors like increased temperatures on soil
production and biodiversity (Nemergut et al. 782). If soil biology were properly understood, a
Ladder project would have a stable foundation from which to introduce other useful species to its
artificial ecosystem.
Once microbial colonies have been established, the task of project managers is far from
over. Soils and the species that grow to depend on them must be carefully monitored, especially
in the initial years of a project. Most importantly, managers must refrain from the temptation to
accelerate growth with artificial fertilizers, as this may cause a population explosion and
subsequent starvation. For the purposes of this program, organic materials are those that are not
chemically treated or converted from fossil fuels. This does not mean gasoline transport of
materials is forbidden, nor does it mean livestock from which manure is obtained must also be
organically fed. If, however, any element apart from water is needed that the ecosystem cannot
eventually produce on its own, it cannot be called self-sustaining. For this and other reasons, the
Ladder program calls for total abandonment of petrochemical usage. The real question remains
how farmers can convert irrigated land from conventional crops, which are essentially grown on
dead land, to fully developed ecosystems prescribed by the Ladder program. This cannot be a
smooth transition, but the success of the first project will entice farmers to try.
One legitimate criticism of the Ladder is that it cannot work without a proper water
supply and gives no indication of how one can be attained. Water supplies promise to become a
major concern, given the current transformations of the Earth’s climates. The Ladder plan
deliberately leaves water management out of the equation. Since water is a basic resource very
obviously needed for crops to grow, this plan will treat it as a variable. In other words, both
conventional and organic methods are successful to the degree that they have a supply of water.
Therefore, improving and protecting irrigation will be left for some other plan.
The primary task of botanists and surveyors will be to repel unwanted pests and diseases
through the stimulation of natural enemies. There are a host of organic methods for biological
control ranging from plant pathogen to microbial pesticides (TeBeest 116). Some plants are
currently being genetically modified to passively combat pests, but other methods are more
reliable (Petersen and Snapp 6). One promising area of biological utility lies in the use of
insectivores to kill pests in place of chemical pesticides. Decreased use of pesticides in turn
allows lady beetles, spiders, and other natural enemies to increase their numbers (Crowder and
Harwood 5). Examples of natural enemies which may prove ideal for organic agriculture are
myrmecophytic ants, which have symbiotic relationships with benignly parasitic plants in
tropical regions (Perfecto and Castaneiras 269-276). These plants emit chemicals that attract the
ants to defend against herbivores, in return providing shelter for the colonies. Myrmecophytic
ants are receiving attention from farmers in South America, Africa, and Indonesia for their
perceivable benefits to commercial crops (Ibid). For the most part, however, use of living
creatures to counteract pests has had limited and poorly documented success (Crowder and
Harwood 4). Additionally, there is the problem of natural enemies killing pollinators like honey
bees (Crowder and Harwood 4; Grixti et al. 76). If this becomes a problem, pollinators may
become the most vulnerable elements in Ladder projects, as they are in conventional agriculture
(Brittain and Potts 322). Successful natural enemies, pollinators, disease resistance, and soil
cultures combine to create what should be a stable ecosystem ready for farming.
Should a Ladder project prove fruitful, there are unforeseen consequences that arise if
these organic methods work too well. For example, invasive species emigrate from managed
farm land to unmanaged natural land and vice versa. Blitzer et al. (35) provide an overview of
this dynamic. Most current literature shows the impacts, both positive and negative, of natural
species encroaching on managed land. What seems to be missing are records of impacts, mostly
negative, of species moving in the opposite direction. A common occurrence is a pest explosion
caused by the concentration of crops in such a small area (Blitzer et al. 36). Once these crops are
consumed or harvested, the exaggerated pest population emigrates and overexploits the untamed
plants in the surrounding countryside. The use of territorial insectivores is one way of avoiding
this. The unintended success of domesticated over wild species can prove problematic, but next
to pesticide use, these consequences are comparatively benign and manageable (Mahmood, Bilal,
and Jan 423). The nature of pesticides means they cannot be used in conjunction with natural
enemies—at least in the absence of genetic modification (Dewhurst 2001 67-68). In this and
many other ways, the destructive nature of many conventional methods disrupts natural
functions. Consequently, the only way to maximize organic output is by omitting petrochemicals
altogether, and this is one requirement of the program.
Funding for these projects will be most difficult. As of 2008, organic crops represent only
0.3 percent of total agriculture on the planet (Connor 2008 187). There have been three major
initiatives to adopt organic agriculture, all of which have fallen through (Ibid). It is time to
acknowledge that conventional agriculture and perhaps the whole of human civilization is
hopelessly dependent on petrochemicals. However, this does not make organic farming a lost
cause. Dwindling oil resources and increasing populations mean petrochemicals will inevitably
become more expensive. This means more farmers will opt for organic methods, and the Ladder
is intended to maximize these farmers’ production while minimizing costs. Because the program
requires the complete absence of petrochemicals, individual transitions from conventional to
organic methods is not a smooth process. However, in the event of oil decline, this program will
enable a smooth transition to organic methods on a national and global scale. In fact, as long as
climates remain favorable and societies refrain from overexploiting organic ecosystems,
agricultural land may become so self-sustaining as to survive a major economic collapse that
would leave conventional cropland dead and eroded. As with any renewable resource, the initial
investment will pay off more over time than immediate conventional methods.
One obvious criticism of the Ladder program is that it aims to distract from green
initiatives by minimalizing the economic impact of climate change. There is no doubt a drastic
reduction in biodiversity and global ecosystem function is catastrophic. It is true that a reduction
of human misery works against efforts to solve the larger goal of counteracting climate change,
but since the end goal of green policies is to reduce human misery, this is hardly a criticism.
Unfortunately, even a successful Ladder program will not reduce global reliance on
petrochemicals. It is more than likely that organic methods on some crops will reduce the price
of oil such that other farmers will continue to use oil products on certain crops. However, if
organic methods prove successful, trends such as population growth and peek oil will eventually
force the majority of agriculturalists organic methods. Hopefully, a successful Ladder program
will make the resulting transition from conventional to organic methods less sudden than it
would be otherwise.
The most damning criticism of organic agriculture is that it simply cannot support the
current human population of the planet. If this is a criticism of organic methods, it is an even
greater criticism of the agriculture industry as a whole, which is now overwhelmingly dependent
on non-renewable resources (Connor 2008 187). This means any fluctuations in the price of oil
can have catastrophic results, as witnessed in the African food riots during the 2008 recession
(Berazneva and Lee 2013). Furthermore, if so-called “Peak Oil” is a reality, this situation will
most assuredly deteriorate, but these are not the only reasons to adopt organic methods. The
negative impact of pesticide and herbicide use to human health and that of other species has been
extensively documented (Dewhurst 2001 67-68). Supposing organic methods have failed to
improve since 2008, this does not change anything stated above. The current state of affairs is
unstable and unhealthful. To the degree that conventional methods become too expensive, the
Ladder program will be more enticing. However, this program is not simply encouraging or
greater use of organic methods; it demands total disuse of petrochemicals in order to build self-
fertilizing ecosystems. If this cannot support human economies, it is time for societies around the
world to reassess their futures with respect to static or dwindling oil resources.
In light of global climate change, the Ladder program or something very similar must be
implemented. A progressive dogma has convinced so many people that energy and resources will
continue growing to support human populations. A combination of population growth, dwindling
oil production, and rising climate instability threatens the reliability of conventional agriculture.
It is time to take steps away from the gasoline high while there is still time left for a smooth
transition to self-sustaining agriculture. If organic methods seem impractical now, the simple
passage of time may change this opinion. Until that time, the Ladder program will be waiting.
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