1. 1
Intersectionality Activity Guide:
Broadening the focus of feminism. Explain how specific
populations of women
challenged white, middle class feminists to address
Intersectionality (the ways in which
a person’s multiple identities interconnect to impact a person’s
experience as well as
how institutions and systems influence power and privilege
based upon multiple
identities).
Use the Week 16 Module Resources and Chapters 11 and 12 of
Through Women’s Eyes,
to complete the following guide. The guide is intended to help
focus on key concepts
and will not be submitted. It also duplicates many of the
questions in the Chapter 11
Reading Guide.
Explain intersectionality:
2. Lesbian Activism and Sexual Politics:
African American Women’s Influence:
Latinx Activism and Influence:
Asian American Women’s Influence:
2
Native American Women’s Influence:
Women’s Influence in the Disability Rights Movement:
3. By the 1970s and 1980s, how inclusive was the women’s
movement and how effectively
did it address the multidimensional nature of women’s
inequality and obstacles in the
path to equality?
What were the most severe obstacles blocking women’s path
toward equality in the late
twentieth- and early twenty-first-centuries?
What were the most significant accomplishments women
achieved in the struggle for
equality in the late twentieth- and early twenty-first centuries?
4 Sustaining Our Agricultural Resources
branex/iStock/Getty Images Plus
5. In October 2018 the scientific journal Nature published a major
research report that pre-
sented a troubling picture of the future of food, agriculture, and
the environment (Spring-
mann et al., 2018). The authors of the report—including
scientists from the United States,
Europe, and Australia—argue that, based on current trends, we
will see an increase of 50% to
90% in the negative environmental impacts of food production
by the year 2050.
Their prediction is based on three key factors. First, as
presented in Chapter 3, global popu-
lation is expected to increase from roughly 7.7 billion people
today to almost 10 billion by
2050. Second, the demand for food is actually growing faster
than the population is, as ris-
ing incomes in countries like China result in more demand for
meat and other animal pro-
teins, which require more resources to produce. And third,
current agricultural practices are
already a significant contributor to major environmental
problems like deforestation, air and
water pollution, and global climate change.
The Nature report used the planetary boundaries concept
described in Chapter 2 to argue
that we need to change the way we produce, distribute, and
consume food if we are to feed
10 billion people and not ravage the environment. We already
use half of Earth’s ice-free
land surface for grazing livestock and growing crops to feed
animals, and 77% of the Earth’s
land surface has already been developed or modified by human
activities, up from just 15%
6. a century ago. Every year, more and more forests, including
biodiversity-rich tropical rain
forests, are cleared for agriculture. Agriculture uses roughly
70% of global freshwater sup-
plies. Meanwhile, roughly one third of global food production
ends up being discarded as
waste each year. This last fact is especially troubling, given that
roughly 3 billion people are
malnourished and that 1 billion suffer from outright food
scarcity and shortages.
Given these trends, and given the fact that agriculture and food
production are essential
human activities, the Nature report focuses on the need to
reduce the environmental impact
of current agricultural practices. This chapter will contrast the
unsustainable approaches
to agriculture, which currently dominate, with sustainable
approaches that we will need to
adopt in the decades ahead. It starts with a brief review of the
origins and history of agricul-
ture and how it has shaped human history through time. This is
followed by a review of the
basics of soil, climate, and plant growth. We then examine how
current agricultural practices
are affecting the environment and why these practices are not
sustainable. This is followed
by a discussion of sustainable agricultural practices, including
ideas presented in the Nature
report, designed to help us stay within key planetary
boundaries. Finally, the chapter will
explore the somewhat controversial issue of genetic engineering
and genetically modified
organisms.
4.1 The Origins and History of Agriculture
8. communities to grow more food on
a given amount of land, and the first crops that were
domesticated were easy to grow, dry, and
store. Early agriculturists also began to settle in specific
locations and to domesticate animals
like dogs, goats, sheep, and pigs. Eventually, these more settled
communities grew into small
villages and even cities, and over the next 8,000 years, the
human population of the planet
grew from a few million to hundreds of millions of people.
Beyond crop selection and plant and animal domestication,
other developments and tech-
nological advances helped increase agricultural productivity
over time. The domestication
of cattle was soon followed by the invention of the plow,
allowing early farmers to cultivate
more land using less human energy. Evidence of irrigation—the
deliberate diversion of
water to crops—dates back at least 5,000 years, and this helped
expand the area under culti-
vation. Improvements in metal production, crop storage, and
transportation also contributed
to increased agricultural productivity over thousands of years.
Despite these developments, however, agriculture in the year
1500, 1600, or 1700 would
have looked similar to what was being practiced 2,000 to 3,000
years before that. Increased
land under cultivation allowed for more food production and
population growth, but these
increases occurred slowly over centuries and millennia.
The Modernization of Agriculture
That situation began to change around the begin-
ning of the industrial period, roughly 200 years
10. on an industrial scale, enabled continued increases in food
production. Fertilizers are sub-
stances that add nutrients to the soil, thereby encouraging plant
growth. While traditional
farmers had long made use of available organic material for
fertilizer, it’s estimated that with-
out the development, mass production, and use of synthetic
nitrogen fertilizers, the world’s
population would never have exceeded 4 billion (Smil, 1997).
The Green Revolution
By the 1960s world population had reached 3 billion people,
and another 1 billion were being
added every 12 to 14 years. Massive famines in China, sub-
Saharan Africa, and southern Asia
claimed millions of lives and led to a return of Malthusian
thinking about population and food
security, whereby everyone has access to an adequate and
reliable food supply. It was at this
time that ecologist Paul Ehrlich published The Population
Bomb, warning of mass starvation
and upheaval due to human population growth. However, a
series of advances in agricultural
production that came to be known as the Green Revolution also
occurred.
The Green Revolution was not the result of a single scientific
breakthrough or technological
development but rather the collective result of a number of
changes in the way humans grew
food. Plant breeders developed new, high-yielding varieties of
wheat, rice, and corn that pro-
duced as much as four times the amount of grain per acre as
conventional varieties. Expanded
use of irrigation systems, synthetic fertilizer, and chemical
herbicides and pesticides allowed
11. farmers to grow even more crops on the same fields. The results
of these changes were dra-
matic. From 1960 to 2014 global production of the five main
cereal crops—corn, rice, wheat,
barley, and sorghum—increased by an estimated 280% and
yields by an estimated 175%,
while the land area devoted to cereal production increased by
only 16% (Ritchie, 2017).
The Challenges of Today
Today we may need another Green Revolution to keep up with
continued population growth,
changes in diet, and the environmental impacts of modern,
industrialized approaches to agri-
culture. The impressive increases in yield achieved in the first
few decades of the Green Revo-
lution have begun to level off. At the same time, we continue to
add roughly 75 million new
people to the planet each year. Perhaps more importantly, many
of the agricultural practices
that emerged during the Green Revolution—including the heavy
use of irrigation, synthetic
fertilizers, and chemical pesticides—are taking a severe toll on
the environment.
Rapid advances in science and technology have allowed us to
feed a population that has
grown from 1 billion to over 7.7 billion in just 200 years.
However, there is overwhelming
evidence that our current approaches to feeding the world are
pushing us close to or beyond
planetary boundaries and environmental limits. Clearly, feeding
the world as human popula-
tion reaches 8, 9, or 10 billion will require a change if we are to
once again avoid the worst
Malthusian predictions of the past.
13. is focused mainly on inputs
(pesticides, fertilizers, seeds, water) and outputs (corn, wheat,
soybeans, meat). The primary
goals are to increase production and yield while decreasing
costs of production.
A traditional farm will likely raise a variety
of crops and be home to animals like horses,
cows, pigs, chickens, goats, and so on. These
animals’ waste products in the form of
manure are used as fertilizer on crops, some
of those crops are fed to animals, and the
cycle begins again.
In contrast, an industrial farm will likely
focus on raising a single crop. The farmers
“import”—rather than generate on their
own farms—seeds, fertilizers, pesticides,
herbicides, water, and energy for equipment
to grow that crop. In the United States and
other developed countries, much of the pro-
duction from these types of farms is soy and
corn that is then fed to animals (mainly cows, chickens, and
pigs). The animals are then fed to
people, and waste products from both the animal production
facilities and people are treated
in sewage treatment facilities before finally ending up in water
bodies (in the case of liquids)
or landfills (in the case of solids). After that, the farmer goes
back and “imports” a whole new
set of inputs to start the process all over again.
Designed to Maximize Output
Second, whereas traditional agriculture focuses on the
production of a wide variety of crops,
animals, and other products, industrialized farming is designed
15. mechanization combined with heavy
inputs of agricultural chemicals allows a single farmer to grow
the same crop on thousands
of acres of land, something that would have been unimaginable
just a few generations ago.
This kind of agriculture, known as monoculture farming, raises
a number of concerns. The
overreliance on a small number of genetically similar crop
varieties increases the risk that a
widespread insect infestation, crop disease, or fungal infecti on
could wipe out a major global
food source. In addition, large-scale monoculture farming tends
to reduce the number of
farmers and farm families living in rural areas. Some observers
have associated this phenom-
enon with the loss of community and economic diversity in
these areas (Union of Concerned
Scientists, 2019).
Reliant on External Inputs
Finally, whereas traditional agriculture tends to be self-
sustaining, industrialized farming is
heavily reliant on external inputs to survive. Today’s industrial
farmers depend on chemical
pesticides and herbicides to control insects and weeds and must
apply increasing amounts of
synthetic fertilizers to maintain crop yields. Industrial farmers
also require large amounts of
water and fossil fuel energy resources. The environmental
impact of these realities will be the
focus of much of this chapter, and the chapter will also explore
how ideas and practices from
traditional agriculture can be incorporated into modern farming
to make it more sustainable.
Table 4.1 offers a brief comparison of industrial and traditional
17. 4.3 The Importance of Soil
When most people think of the term soil, they automatically
think dirt. And for most people,
dirt is considered useless and something to be avoided whenever
possible. In reality, soil is
much more than dirt, and it is soil that forms the foundation of
virtually all land-based food
production around the world. Because soil health is so critical
to agriculture, sustainable agri-
culture almost always implies sustainable management of soils.
Traditional farming practices
tend to carefully manage soil fertility to ensure the ability to
grow crops year after year. How-
ever, industrialized farming tends to depend on inputs of
synthetic fertilizers to compensate
for declining soil quality.
What Is Soil?
Soil generally consists of five components:
1. mineral matter (sand, gravel, silt, and clay)
2. dead organic material (e.g., decaying leaves and plant matter)
3. soil fauna and flora (living bacteria, worms, fungi, and
insects)
4. water
5. air
Variations in the levels of these components lead to many
different types of soils and soil
conditions. Soils that are sandy drain quickly, whereas soils
with high clay content hold water
and become sticky. Soils with high levels of organic matter tend
to be soft and good for plants,
whereas compacted soils with few air spaces are less conducive
to plant growth. High levels
19. How Is Soil Made?
New soils can form over time and thus might be considered a
renewable resource. However,
because soil formation is such a slow process, it might be better
to think of soils as a finite,
limited resource. Soil formation occurs primarily as a result of
two basic processes: weather-
ing and the deposition and decomposition of organic matter
such as leaves.
Weathering is the process of larger rocks being worn away or
broken down into smaller par-
ticles by physical, chemical, and biological forces. Physical
weathering occurs through wind,
rain, and the expansion and contraction of rocks due to changes
in temperature. Chemical
weathering is caused when water, gases, or other substances
chemically interact with larger
rocks and break them apart. Biological weathering is caused by
living organisms, such as
when tree roots grow and grind against rocks.
The deposition and decomposition of organic matter occurs
when living organisms drop
waste or debris or die. When animals deposit waste or when
plants shed leaves and branches,
this organic material gets added to the soil. Likewise, when
plants, animals, and other living
organisms die and drop to the ground, decomposers and
detritivores break them down and
incorporate that organic material into the soil.
The processes of weathering and deposition and decomposition
are influenced mainly by
climate, topography, and time, allowing soils to form faster in
22. Soil pH is determined by many factors, including the amount of
organic material added to
soils, the mineral composition of soil particles, and temperature
and precipitation levels in
that area. Some plants thrive in more acidic soils, whereas
others do better in soils that are
less acidic or even alkaline. Farmers utilize different soil
additives to make soils more or less
acidic, depending on the type of crops they want to grow.
Lastly, soil structure refers to how much air is in the soil or
how compact it is. Plant roots
and the living soil fauna and flora that improve soil fertility
need oxygen and other gases
to survive, so well-aerated soils tend to be better for plant
growth. In contrast, when soils
are compacted or compressed, such as through repeated pressure
from tractors and heavy
farm equipment, they tend to become less aerated and less
conducive to plant growth. Highly
compacted soils also decrease the ability of water to infiltrate
and enter the ground, and as
this water runs off the surface, it can carry soil with it. The
displacement of this valuable
resource—often caused by water or wind—is known as soil
erosion.
4.4 The Problem of Chemical Pesticides
For as long as humans have farmed, they have had to contend
with crop damage and compe-
tition from insects, fungus, and weeds. Early agriculturists made
some use of chemicals like
sulfur—as well as salt, smoke, and other deterrents—to ward off
pests, but for the most part,
24. ertheless, weeds compete with agricultural
crops for sunlight, water, and nutrients, and
pests can damage or destroy plant roots,
stems, leaves, flowers, and fruit. As a result,
industrialized agriculture makes use of a
wide variety and a large quantity of chemi-
cals to control weeds and pests. Insecticides
kill insects, and herbicides kill weeds. There
are also fungicides that kill fungus, as well as
rodenticides that kill rodents. These chemi-
cals are collectively known as pesticides.
The agricultural chemical industry has
developed thousands of pesticides in the past 50 to 60 years,
and it’s estimated that we apply
close to 454 million kilograms (1 billion pounds) of pesticides
in the United States each year
(Alavanja, 2009). Roughly 80% of this pesticide is applied to
farm fields, with the other 20%
applied to backyard lawns, gardens, golf courses, and parks. It’s
also estimated that over 95%
of all corn and soybean crops planted in the United States are
treated with herbicides each
year (Wechsler & Fernandez-Cornejo, 2016), whereas cotton is
probably the most intensive
user of chemical insecticides (Cubie, 2006).
Biomagnification
One of the earliest chemical pesticides to come into widespread
use was a compound known
as dichloro-diphenyl-trichloroethane, or DDT. First developed
in the late 1930s, DDT was seen
to be an inexpensive, stable, and highly effective insecticide
that was also relatively nontoxic
to humans and other mammals. Because DDT was a broad-
spectrum insecticide, meaning it
25. could kill a wide variety of insects, it quickly became popular
among farmers for controlling
crop pests, as well as mosquitoes and household insect pests.
After more than a decade of widespread use, however, in the
1950s it began to become appar-
ent that DDT might be causing unintended environmental
consequences. Because DDT is a
long-lived and stable compound, it gradually built up in soils
and water bodies. Because DDT
is fat soluble and attaches itself to body fats when ingested, it
was also building up in popula-
tions of wild fish, birds, reptiles, and other organisms.
This poses a particular problem for animals near the top of the
food chain. For example, DDT
sprayed on agricultural fields will eventually flow into streams
or lakes, where it could be
ingested by tiny zooplankton. These organisms are then eaten by
small fish, thereby accu-
mulating all the DDT in the zooplankton. Small fish are then
eaten by larger fish that are then
eaten by birds of prey, like falcons, bald eagles, and pelicans.
Recall from Chapter 2 that only about 10% of the energy
consumed at one trophic level is
available to the next level. This means that birds of prey, l ike
the bald eagle, have to eat a lot
of fish to have sufficient energy. As birds eat, the DDT in fish
becomes more and more concen-
trated in the birds.
fotokostic/iStock/Getty Images Plus
Industrial agriculture relies heavily on
pesticides to ward off pests.
27. ticide use.
First, because insects breed rapidly, they can develop genetic
resistance to insecticides within
a relatively short time. In other words, the insecticide will wipe
out most of the pests ini-
tially—but the ones that survived will multiply, and the
insecticide will become less effective
with each successive generation (see Figure 4.2). Likewise,
weeds can also develop resistance
to herbicides over time. Heavy applications of chemical
pesticides will initially help control
insects and weeds, but over time they prove less and less
effective as these organisms develop
a resistance.
It’s estimated that since the start of widespread chemical
pesticide use in the late 1940s, over
500 species of insects (Gut, Schilder, Isaacs, & McManus,
2015) and 500 species of weeds
(Heap, 2019) have developed chemical resistance, prompting
what is known as pest resur-
gence. Farmers are then forced into what some call a “pesticide
treadmill” or a “pesticide
arms race” and must spend money on either larger doses of
pesticides or new varieties of the
chemicals. And despite the fact that synthetic pesticide use has
seen a 50-fold increase since
1950 and that today’s pesticides are 10 to 100 times more toxic
to pests than those used in
the past (Roser & Ritchie, n.d.; Gross, 2019), it’s estimated that
we still lose over 40% of major
crops to pests and crop diseases each year—a higher proportion
than in 1950 (Elliott, 2015;
Fernandez-Cornejo et al., 2014).
30. 112
Section 4.4 The Problem of Chemical Pesticides
Threat to Biodiversity
Another major environmental problem
associated with the widespread use of
chemical pesticides in agriculture is the
impact these chemicals have on nontarget
species and biodiversity. The case of DDT
and its impact on birds like the bald eagle
was an early and high-profile example of
this problem. Today there continue to be
concerns over the impact of pesticides on
natural predators, other wildlife, and bio-
diversity generally, even if it doesn’t involve
a species as well known as the bald eagle.
Some of the nontarget species whose popu-
lations are reduced or eliminated by chemi-
cal insecticides include the spiders, beetles,
and mantids that help control insect pests
in traditional agricultural systems.
One particular area of concern involves the impacts that some
pesticides appear to be hav-
ing on bee colonies around the world. A newer class of chemical
compounds developed in
the 1990s known as neonicotinoid pesticides are now the most
widely used form of insec-
ticides globally. These chemicals appear to be responsible for
significant declines in honey-
bee populations in agricultural regions and for the complete
collapse of honeybee colonies
through a process known as “colony collapse disorder.” This
development is a significant
31. concern because honeybees provide a critical ecosystem
function by pollinating many major
vegetable and fruit crops, including tomatoes, peppers, apples,
and almonds. In addition to
impacting honeybees, neonicotinoid pesticides appear to be
negatively affecting a variety of
bird and fish species as well.
Threat to Human Health
Lastly, chemical pesticides can pose a threat to human health.
The World Health Organization
(WHO) estimates that every year, at least 3 million agricultural
workers are directly poisoned
through improper handling of and exposure to chemical
pesticides, which results in over
250,000 deaths a year (WHO, n.d.a). Every year, the
Environmental Working Group (EWG)
publishes a Shopper’s Guide to Pesticides in Produce, which
estimates levels of pesticide
residues found on fruits and vegetables sold in grocery stores
around the United States. The
2019 EWG list ranked strawberries, spinach, kale, nectarines,
apples, grapes, peaches, cher-
ries, pears, tomatoes, celery, and potatoes as the “di rty dozen”
in terms of levels of pesticide
residues (EWG, 2019a). While the link between exposure to
pesticide residues from food and
cancer or other health problems is complicated, a number of
studies suggest that people with
less exposure have fewer of these problems (Baudry et al.,
2018; Chiu et al., 2018).
It’s also estimated that well over 90% of chemical pesticides
sprayed on crops never reach the
target insects they were intended for (Duke, 2017). Instead, they
drift through the air, run off
33. weeds develop greater resistance to them. Furthermore,
herbicides and pesticides are having
negative impacts on nontarget species of animals and are also
implicated in a variety of nega-
tive human health impacts.
Learn More: Shopping for Produce
You can learn more about the EWG’s Shopper’s Guide to
Pesticides in Produce, and what you
can do to reduce pesticide exposure in your own life, here.
• https://www.ewg.org/foodnews
4.5 The Problem of Synthetic Fertilizers and Poor
Soil Management
Just as industrialized, monoculture farming requires chemical
pesticides, it also relies on
synthetic fertilizers. Raising the same crop year after year
quickly depletes soils of specific
nutrients and requires the application of synthetic fertilizers to
maintain crop yields. Tra-
ditional farmers use substances already produced on their farms,
applying animal manure
or compost or plowing under old crops to enhance soil fertility.
In contrast, industrialized
farmers apply over 109 million metric tons of synthetic nitrogen
fertilizer alone to crop
fields each year (Pearce, 2018b). This dependence on synthetic
fertilizers is a symptom of
the linear approach to agriculture, which views soil as simply
one input to the production
process, rather than the complex, living ecosystem that it
actually represents. Heavy fertil-
izer use and poor soil management can result in serious
35. to the general population. As a result, many of these areas are at
high risk of groundwater
contamination by nitrate.
In addition to groundwater pollution, excess fertilizer from
farms can contribute to the pollu-
tion problem known as eutrophication (recall the case study in
Section 2.4). Excess nitrogen
and phosphorous fertilizers run off of farm fields (as w ell as
residential lawns, golf courses,
and parks) into bodies of water, where they fertilize aquatic
plant growth and create algae
blooms. This aquatic plant life, or phytoplankton, builds up and
eventually sinks to the bot-
tom, where it is decomposed by bacteria that use up the
dissolved oxygen in the water. This
results in low oxygen or hypoxic conditions that can lead to the
death and displacement of
fish and other aquatic life and eventually to the formation of
low oxygen areas known as dead
zones. As we learned in Section 2.4, the Gulf of Mexico dead
zone is the largest such area in the
United States, and the formation of this dead zone is linked
directly to the large quantities of
nitrogen and phosphorous flowing from the agricultural
Midwest into the Gulf.
Topsoil Erosion
While some soil erosion occurs naturally, industrialized
agricultural practices greatly speed
up this process.
Water is the primary cause of soil erosion from most farm
fields. Because most forms of
industrialized agriculture involve plowing and clearing the land
of vegetation, even small
37. off farm fields, especially in
places that are dry and flat. The 1930s Dust Bowl in prairie
areas of the United States and
Canada was a result of drought conditions and removal of trees
and other ground cover to
expand farm area. While not as dramatic as images from the
1930s, windblown soil erosion
continues to be a major problem in the United States today, and
scientists cannot rule out
the return of dust bowl conditions in periods of severe drought.
In drier regions of Asia and
Africa, overgrazing of livestock and clearance of vegetation is
allowing desert areas to expand
in a process known as desertification. Over the past 3 decades,
China has lost a land area the
size of Indiana to desertification as the Gobi Desert encroaches
into areas that were previ-
ously suitable for some forms of agriculture.
Air Pollution and Climate Change
Excessive use of nitrogen fertilizer can also contribute to air
pollution. Ammonia gas from
nitrogen fertilizer application can contribute to haze great
distances from where the fertil-
izer is being applied. Nitrous oxide gas can also form in soils
fertilized with nitrogen fer-
tilizer. Nitrous oxide is a local/regional air pollutant and also
contributes to global climate
change and even ozone depletion (discussed in Chapter 8). It’s
estimated that two thirds of
global nitrous oxide emissions from human activities are a
result of agriculture. Ammonia
and nitrous oxide can react with other compounds in the
atmosphere to form fine particulate
pollution. These particulates are responsible for haze and are
also a public health risk when
38. inhaled into the lungs. Wind erosion of farmlands can carry soil
particles into the air and also
contribute to particulate pollution.
Overall, heavy application of agricultural fertilizers and poor
soil management practices are
resulting in the degradation of two key forms of natural capital:
water and soil. Excess fertil-
izer can seep into groundwater or run off into surface water and
result in drinking water pol-
lution, eutrophication, and aquatic dead zones. Soil erosion by
water and wind can reduce soil
quality and contribute directly to water pollution.
4.6 The Dependence on Water and Nonrenewable Energy
Unlike traditional agricultural systems that make relatively
limited use of external inputs
and are powered primarily by energy from the sun
(photosynthesis), modern industrialized
agriculture is heavily reliant on external inputs of water and
fossil fuel energy resources.
Traditional agricultural systems and approaches are generally
tailored to local conditions.
For example, farmers in regions with less precipitation and
more frequent droughts know
to depend to a greater extent on crops that require less water
and that are drought resistant.
Likewise, the cyclical approaches used in traditional
agriculture—including the use of animal
manure, composting, and crop rotation—are designed to make
the most of resources that are
already on the farm, rather than importing them.
In contrast, the highly linear approach to industrialized
agriculture enables farmers to ignore
40. or replenishment of that supply. If you think of an underground
aquifer as a bathtub or basin
filled with water, the rate of extraction would be water going
down the drain, while the rate
of recharge would be water coming out of the tap and into the
basin. Obviously, if more water
is going down the drain than coming from the tap, the water
level in the basin will go down.
That is exactly what is happening in many key agricultural areas
around the world today,
especially in parts of North Africa, southern Asia, China, and
the United States. Many aquifers
in these regions contain “fossil water” that was deposited there
over geological timescales.
Heavy extraction of water from these deposits is not offset by
new water recharge, and as a
result water levels are dropping dramatically. As water levels
drop, the land above it can sink
or subside. Overextraction of groundwater in coastal areas can
also allow salt water from the
sea to intrude into freshwater aquifers, making them unsuitable
for residential or agricultural
uses.
Another environmental problem associated with overuse of
irrigation water in agriculture
is soil salinization. Most irrigation water contains small or trace
amounts of salts from the
rocks in underground aquifers. When irrigation water is applied
to farm fields, some of the
water evaporates, leaving a tiny residue of salt behind. Over
time, as more and more water
gets added to a field and evaporates, more of the salt particles
can build up in the soil. Soil
salinization can lower crop yields and damage or even kill some
crop plants. It’s estimated
42. Agriculture’s contribution to global climate change results from
emissions of greenhouse
gases like carbon dioxide, methane, and nitrous oxide. Carbon
dioxide emissions from agri-
culture happen directly as a result of burning diesel, propane,
and other fossil fuels to power
farm machinery and equipment. Carbon dioxide is also released
when forests are cut and
burned to make way for agricultural production. Agriculture is
also a major producer of meth-
ane from livestock operations and rice farming, as well as
nitrous oxide from fertilizer use.
Overall, it’s estimated that the global food system—including
growing, processing, and trans-
porting crops—is responsible for up to one third of human-
caused greenhouse gas emissions
(Gilbert, 2012).
4.7 The Issues With Animal and Meat Production
The global meat and dairy industry is massive and growing.
Worldwide, the livestock sector
produces roughly 120 million metric tons of poultry, 120
million metric tons of pork, 72 mil-
lion metric tons of beef and veal, 15 million metric tons of meat
from sheep and goats, and 827
million metric tons of milk and milk products each year (Food
and Agriculture Organization
of the United Nations, 2018a). If divided equally among all of
the people around the world,
this would result in an average global consumption of roughly
42 kilograms (92 pounds) of
meat per person and 107 kilograms (237 pounds) of milk and
milk products per person per
year. In reality, levels of meat and milk consumption are highly
uneven. For example, the aver-
44. 118
Section 4.7 The Issues With Animal and Meat Production
When looked at this way, we can link virtually all of the
environmental problems associated
with agriculture to animal and meat production. Heavy use of
chemical pesticides, overap-
plication of fertilizers, soil erosion and land degradation, water
pollution and aquatic dead
zones, air pollution, and global climate change can all be linked
to the agricultural production
of crops like corn and soy that are fed to animals.
In addition, feeding grains to animals that are then fed to
humans is an inefficient way to feed
the world. Farm animals are fed well over 1 billion metric tons
of grain a year, and roughly
80% of all farmland is utilized for raising animals or growing
crops to feed animals (Food
and Agriculture Organization of the United Nations, 2019). And
yet meat and dairy account
for just 18% of calories and 37% of protein consumed by
humans each year. For example, it
takes as much as 24 kilograms (53 pounds) of grain in the form
of animal feed to produce 1
kilogram (2.2 pounds) of beef. For pork, that figure is roughly 4
to 1, and for chicken about
3 to 1, as illustrated in Figure 4.3 (Wirsenius, Azar, & Berndes,
2010). This basic inefficiency
associated with meat production and consumption lies at the
heart of debates over how to
feed a global population on track to hit 10 billion in the next
45. few decades.
Waste Management Problems
Many of the environmental and health issues associated with
large-scale, industrialized
approaches to meat production have to do with how these
animals are raised. Today most
of the chicken, pork, and beef consumed in developed countries
like the United States origi-
nates from what are known as concentrated animal feeding
operations (CAFOs). The
USDA defines a CAFO as an animal feeding operation with at
least 1,000 “animal units” con-
fined for at least 45 days a year. Because
an “animal unit” equates to 454 kilograms
(1,000 pounds) of live animal weight, the
USDA definition of a CAFO describes an
animal feeding operation that has at least
1,000 cattle, 2,500 pigs, 55,000 turkeys, or
125,000 chickens. In 2016 it was estimated
that there were just under 20,000 CAFOs in
the United States (USDA, n.d.).
One benefit of CAFOs is that they bring
many animals together in one concentrated
location instead of requiring a larger land
area for grazing. This has the potential to
cut down on overgrazing and soil erosion.
However, concentrating so many animals
together in a small space can create seri-
ous problems with waste management. For example, an average
cow can produce about 30
kilograms (66 pounds) of manure per day, or 11 metric tons
each year. A CAFO with 1,000
cows (most CAFOs are much larger than this) produces as much
waste as a city of 10,000
48. lized on local farm fields. Also, because animals in CAFOs are
often fed antibiotics and grain
treated with pesticides, their waste is often so contaminated that
it is dangerous to apply it to
the soil. Nevertheless, it’s estimated that about half of the
animal waste collected from CAFOs
is applied to nearby farm fields.
Some of this manure slurry runs off of fields and into nearby
rivers, streams, and other water-
ways, where it can cause eutrophication and also contaminate
drinking water supplies with
bacteria and pathogens. Some manure slurry stored in open pits
and lagoons can seep through
the soil and into groundwater deposits. In other cases heavy
rains and flooding can cause
these waste lagoons to overflow or even break open, dumping
massive amounts of concen-
trated animal waste into nearby rivers and streams. When
Hurricane Florence hit North Caro-
lina in September 2018, hundreds of hog farm manure lagoons
either overflowed or failed
completely, severely contaminating nearby drinking water
supplies (Pierre-Louis, 2018).
In addition to water pollution, CAFO waste management
practices contribute to air pollution.
Manure lagoons and open pits found in CAFOs emit many
different types of gases, including
some—like ammonia and hydrogen sulfide—that can be
hazardous to human health in the
immediate area. Many of these gaseous emissions from CAFOs
are also foul smelling, and they
can reduce quality of life and property values for nearby
residents.
50. 121
Section 4.7 The Issues With Animal and Meat Production
While in the short term this antibiotic use helps cut down on
disease and increases productiv-
ity, it has a serious long-term consequence. Just as the overuse
of pesticides and herbicides
has led to the development of resistant insects and weeds,
overuse of antibiotics results in the
rise of antibiotic-resistant bacteria and disease organisms (see
Figure 4.4). These antibiotic-
resistant bacteria can contaminate human food supplies as the
animals are slaughtered and
can spread to drinking water supplies when manure lagoons
overflow or seep into ground-
water. The Centers for Disease Control and Prevention (CDC,
2018) has now established clear
links between heavy antibiotic use in CAFOs and a rapid rise in
antibiotic-resistant bacteria,
including salmonella and E. coli. As a result, the CDC and other
public health experts have
been calling for a phase-out of routine antibiotic use in animal
feeding operations, while the
meat industry has resisted and pointed to the benefits of
antibiotic use on productivity.
Figure 4.4: Antibiotic resistance from farm to table
Antibiotic resistance has serious repercussions for human
health.
“Antibiotic Resistance and Food Safety,” by Centers for Disease
Control and Prevention, 2018
52. grow, distribute, and consume food, we can only expect that the
negative environmental and
health impacts of our food system will get worse as the
population continues to increase.
The remainder of this chapter will examine how to meet the
food and nutritional needs of
a growing population in ways that are sustainable. But what
does it mean for agriculture
to be sustainable? Definitions of sustainable agriculture can be
both simple and complex.
At a basic level, sustainable agriculture is farming that meets
our needs in ways that do
not undermine critical natural capital systems and the ability of
future generations to meet
their own needs. Once we get beyond this basic definition,
however, we see that sustainable
agriculture involves issues of science, technology, the
environment, economics, social equity,
government policy, and personal choices and preferences.
Researchers have concluded that
no single approach or technological breakthrough will be
enough to move us toward sustain-
able agriculture. Instead, we need an “all of the above” strategy
that combines many different
approaches and practices (Springmann et al., 2018; Searchinger,
Waite, Hanson, & Rangana-
than, 2018). The ideas in this chapter should not be considered
in isolation or as “magic bul-
lets” for solving the environmental and health impacts of
industrialized agriculture. Rather,
these practices and approaches should be viewed as being most
effective when implemented
in a synergistic or combined fashion.
Many of the on-farm practices that are promoted as
54. ferent nutrient needs for growth. Some crops can even enhance
soil fertility and reduce the
need for fertilizers. For example, a farmer can grow corn—a
nitrogen-intensive crop—in a
field one year and the following year grow legumes, which add
nitrogen to the soil.
Crop rotation and intercropping also help reduce pest outbreaks,
since pests tend to be crop
specific. By changing the crops grown in one field year to year
or alternating the spacing of
crops in a single year through intercropping, pests are not given
an opportunity to establish
themselves and spread over the area, which thereby reduces the
need for pesticides.
Cover Crops
Common cover crops, such as alfalfa and clover, are planted on
farm fields during the off-
season. Letting a field lay bare can lead to soil erosion through
wind and rain. Using cover
crops can prevent erosion by helping hold the soil in place.
Some cover crops can also enhance
soil fertility and reduce the need for fertilizers by returning
nitrogen to the soil. Cover crops
prevent the influx of weeds and pests and reduce the need for
pesticides.
Cover crops can simply be plowed into the soil at the start of
the next growing season, where
they continue to enhance soil quality and nutrient levels as they
break down and decompose.
Alternatively, these crops can be left on the field permanently
and mowed like a lawn for ani-
mal feed. This latter approach is known as perennial agriculture
because it involves leaving
56. Low-Till and No-Till Farming
Plowing, or tilling, fields for planting helps aerate the soil and
cut down on weeds, but it
also leaves the surface bare, thereby increasing soil erosion,
water evaporation, and water
demand. Low-till farming and no-till farming take a different
approach, inserting seeds
directly into undisturbed soil. Instead of plowing up a field
after each harvest, farmers leave
their fields covered in plants at all times. They use a device
known as a no-till drill to make a
shallow cut in the soil, drop in seeds, and cover them. Low-till
and no-till farming minimize
soil erosion, allow more organic material to accumulate on the
surface, and help maintain
soil moisture much better than plowed soils. These approaches
are commonly referred to as
conservation tillage.
Integrated Pest Management
Integrated pest management (IPM) is an approach to managing
agricultural pests with
few or zero chemical pesticides. Note IPM’s goal of managing
agricultural pests rather than
eliminating them. In IPM, tactics are tailored to the specific
pest problem a farmer faces, as
opposed to simply dousing a field in chemical pesticides and
killing everything in it. IPM strat-
egies might include the use of biological methods (introducing
natural predators), altered
planting practices (crop rotation, intercropping), and even
mechanical devices to vacuum
pests off of crops.
IPM has been used successfully in many different types of
57. agricultural systems in every part
of the world. Apple farmers in Massachusetts, soybean farmers
in Brazil, vegetable farmers in
Cuba, and banana farmers in Costa Rica have dramatically
reduced pesticide use while main-
taining or even improving crop productivity through the use of
IPM.
One of the most dramatic IPM triumphs was with rice
agriculture in Indonesia. Throughout
the 1970s and 1980s, as more and more Indonesian farmers were
adopting Green Revolution
rice varieties, the government heavily subsidized the purchase
and use of chemical pesticides
to control outbreaks of brown planthoppers that threatened the
rice crop.
However, over time, planthopper populations became resistant
to many common forms of
pesticide. As farmers applied increasing amounts of the
chemicals to try to control this pest,
they only succeeded in wiping out populations of beneficial
insects (such as spiders) that
naturally preyed on the planthoppers.
By the late 1980s the Indonesian government took drastic
action, banning most pesticides,
eliminating subsidies for others, and instituting a widespread
IPM education program to
teach farmers how to control the brown planthopper using
biological methods. By all mea-
sures this change in approach was a success. Pesticide use
dropped by as much as 75%, while
rice yields actually increased slightly over time (Thorburn,
2015).
59. Each of these six traditional on-farm practices—crop rotation
and intercropping, cover crops,
contour and terrace farming, low-till and no-till farming, IPM,
and integrated crop–livestock
systems—has been demonstrated to reduce environmental
impacts, increase crop yields, and
save farmers money. However, all six also take careful
planning, knowledge, and patience to
implement. It’s also the case that many of the decisions that
farmers make about what to grow
and how to grow it are influenced by government policy,
economic factors, and the prefer-
ences and personal choices that consumers make every time
they purchase food. These issues
are the subject of Section 4.9.
4.9 Considering Farm Policy, Economics,
and Personal Choices
Like any other business or enterprise, farmers make decisions
about what to grow, how to
grow it, and where to market it based in large part on the policy
environment and market
conditions in which they operate. In the United States and other
developed countries, gov-
ernment policy has a significant impact on decisions that
farmers make about what and how
to farm. Likewise, farmers would be foolish not to consider or
be influenced by consumer
preferences, choices, and tastes. Therefore, in attempting to
move toward more sustainable
approaches to agriculture, it’s important to examine how we
might influence policy, economic
factors, and consumer choices in ways that encourage farmers
and other actors in the food
61. Proponents of these subsidy payments argue that they are
necessary to help farmers man-
age the risk inherent in this line of work and that they benefit
small family farms and local
economies. Detractors point to a number of serious problems
with this subsidized approach.
Issues With Subsidies
First, subsidies allow farmers to sell their crops overseas below
the cost of production. When
cheap exports of corn, wheat, or rice are sold in poorer,
developing countries, they undercut
local farmers and drive them out of business, since governments
in these countries cannot
afford to subsidize their own farmers. This creates a cycle of
dependence in which local food
production drops, more cheap food is imported, and local food
production drops further.
Second, farm subsidies can be linked to some of the
environmental problems described ear-
lier. Subsidies tend to encourage farmers to overproduce, which
brings more land than is
needed into production, including lands prone to erosion
(Edwards, 2018). As production
increases, so does the use of fertilizers and pesticides, as well
as the environmental problems
associated with their application. In addition, since subsidies
are usually targeted at a narrow
range of “commodity crops” (like corn and soybeans), they tend
to discourage crop rotation
and intercropping since farmers are encouraged to maximize
acreage planted with the sub-
sidized crops (Edwards, 2018).
63. that are already financially secure, these billions of tax dollars
could be used in other ways.
Sustainable agriculture advocates argue that simply eliminating
these subsidy programs
could go a long way toward getting farmers to rethink what they
grow and how they grow it.
Alternatively, some of the billions of dollars spent annually on
farm subsidy payments could
be directed to programs that reward farmers for practicing
conservation farming and sustain-
able agriculture.
Ultimately, such a change involves political decisions, since the
beneficiaries of current sub-
sidy programs have a lot of political influence. But there is
strong evidence that such a change
in policy can reduce government spending, bring environmental
benefits, and actually sup-
port those farmers and farm communities most in need of help.
Therefore, it’s possible to
imagine a political alliance across the ideological left–right
spectrum that could advocate for
such a change.
Consumer Choices and Preferences
Perhaps more than any other factor, individual consumer
preferences and decisions can have
the biggest impact on how fast we move toward sustainable
agriculture. What we choose to
buy and eat, and where we choose to buy it, sends direct signals
to farmers and other busi-
nesses in the food system.
Choosing Locally Sourced Foods
Currently, the U.S. commercial food system is dominated by
65. Section 4.9 Considering Farm Policy, Economics, and Personal
Choices
distances before reaching its ultimate consumer. It’s estimated
that a typical food item sold
in a conventional American grocery store travels 2,400 to 4,000
kilometers (1,500 to 2,500
miles) before being purchased (Worldwatch Institute, n.d.). The
environmental impact of all of
those “food miles”—combined with the environmental impacts
of industrialized agriculture
discussed earlier in this chapter—is driving many consumers to
reconsider their food pur-
chases in terms of both what they buy and where they buy it.
This trend has been described
as the “local foods movement” and the “farm-to-table
movement,” and people who buy and
consume more locally produced foods are described as
“locavores.” What these efforts have in
common is an emphasis on purchasing locally produced foods
that are in season.
Consumers can connect with local farmers in a few different
ways. Farmers’ markets—where
local farmers gather to sell their products directly to
consumers—have become much more
common in many areas of the United States in recent years. In
the mid-1990s there were
fewer than 1,800 farmers’ markets across the country. That
number rose to almost 4,700 by
2008 and to well over 8,000 today (Farmers Market Coalition,
2019). Farmers’ markets help
support small-scale local farms, involve much less
transportation and packaging, and offer
consumers fresh fruits, vegetables, and meats in place of many
of the highly processed foods
66. found in supermarkets.
Consumers can also connect with local farmers through a
community-supported agricul-
ture (CSA) program. In a typical CSA program, a consumer
pays up front for a “share” of a
local farmer’s crops or farm products (including meat and
eggs). In return, the consumer
receives a regular delivery of fruits, vegetables, and other
products from that farm over the
course of the growing season. CSA programs often offer
consumers the opportunity to visit
and even volunteer to work on the farm they are supporting.
This helps bring people in closer
contact with where their food comes from, how it’s grown, and
what’s involved in bringing
food from the farm to the table. While estimates of the number
of CSA programs are harder
to come by, a 2015 USDA report estimated that there were over
167,000 U.S. farms that pro-
duced and sold food for local markets through farmers’ markets,
CSA programs, and other
local food initiatives (USDA, 2015a).
One other example of the move toward local
foods is the rise of urban farming. Urban
farming repurposes unused space—such
as rooftops, vacant lots, and even roadside
medians—in heavily populated city areas.
In the United States, urban farming pro-
grams often grow out of need, since many
inner-city areas are food deserts—areas
where it is difficult to purchase affordable,
good-quality fresh food. Urban gardens and
urban farming programs are now wide-
spread in most major cities of the United
68. Local foods provide a number of social benefits as well. They
build community by fostering
relationships between growers and consumers. Some also argue
that local food systems
increase food security by diversifying food production. In our
global food system, crops are
often produced on a small number of very large farms. This
means that diseases, natural
disasters, and market disruptions that impact one region can
have consequences for food
availability all over the world. Local food
systems, on the other hand, must rely on a
large number of smaller food producers, so
consumers have other options if a few farms
have a bad year.
Purchasing local food can also help local
economies generate wealth. Rather than
sending money to a grower on the other side
of the world, local foods support local farmers.
These individuals can then use that wealth to
support other community organizations and
local businesses.
Local foods address several dimensions of
sustainability, and arguments like these have
convinced a lot of people to reconsider their
eating habits and join the local food movement. Most just try to
incorporate a few local
options into their diet, but some try to survive mostly or
entirely on locally produced foods—
all the more impressive when you consider that very few fruits
and vegetables are available
year-round in most locations.
70. https://www.seasonalfoodguide.org
https://www.seasonalfoodguide.org
https://www.localharvest.org
https://www.nal.usda.gov/home-gardening
https://www.nal.usda.gov/home-gardening
130
Section 4.9 Considering Farm Policy, Economics, and Personal
Choices
Choosing Organic
Yet another way individual consumers can push for
sustainability in our food system is
through organic foods. Organic food is produced through
methods that comply with the fed-
eral standards of organic farming. Because organic farming
requires that farmers forgo the
use of synthetic pesticides and fertilizers, among other
requirements, it is generally better for
the environment than conventional approaches to agriculture.
More and more Americans are
choosing to purchase foods that are certified organic, with
organic food sales now valued at
over $35 billion annually in the United States alone (USDA,
2017).
However, organic farming is not always the most sustainable
option. For example, should you
buy organic apples shipped more than 4,000 kilometers (2,500
miles) across the country or
locally grown but nonorganic apples? The more sustainable
choice might be to go with the
latter.
71. Choosing Less Meat
A final dietary decision consumers can make is how much meat
to consume, which can have
a significant effect on the sustainability of our food system. A
typical Western diet is high in
sugar, fats, refined carbohydrates, meat, and dairy. Not only is
this diet a problem in terms of
personal health, it also tends to have a greater environmental
impact than other diet types.
The World Resources Institute (WRI) estimates that beef
production accounts for almost half
of U.S. agricultural land use and greenhouse gas emissions from
farming while only providing
for 3% of the calories consumed by Americans (Ranganathan et
al., 2016). This is because of
the basic inefficiency associated with converting grains to
animal protein. A shift from beef
to less intensive forms of meat like chicken or reducing meat
consumption overall can bring
significant environmental gains and help consumers reduce their
environmental footprint.
Much less agricultural land is required to support a more
vegetarian diet, which translates
into less energy and water use as well. Even small moves
toward lowering meat consump-
tion can have a big impact. One study estimated that if every
American picked 1 day a week
to avoid meat (such as a “meatless Monday”), it would reduce
greenhouse gas emissions at
a level equivalent to taking 30 million to 40 million cars off the
road for 1 year (Center for
Biological Diversity, 2019).
Food Loss and Waste
73. is complex, and waste occurs at every stage of that system. A
2013 WRI report found that
food loss and waste differed significantly from country to
country. In the poorer countries of
Africa, Latin America, and Asia, between one half and three
fourths of all food waste occurs
at the production stage and the handling and storage stage of the
food distribution system.
This is due in large part to a lack of adequate infrastructure in
the form of roads, refriger-
ated warehouses, and other modern food storage facilities. In
contrast, in North America and
Europe, well over half of all food loss and waste occurs at the
consumption stage and can be
tied directly to the behaviors of individual consumers and
businesses like restaurants and
caterers (Lipinski et al., 2013).
The WRI report recommends various programs and initiatives to
help cut down on food loss
and waste. These include
• food redistribution programs that send food that would
otherwise be wasted to food
banks and shelters;
• increased access for poor farmers to food storage facilities;
• standardized and clear food date labeling (such as “use by,”
“sell by,” and “best
before” labels) to reduce unnecessary disposal of food that
hasn’t spoiled;
• consumer awareness campaigns to teach strategies for
reducing food waste; and
• reduced portion sizes in restaurants.
74. Two examples of these kinds of efforts come from the United
Kingdom and New York City.
From 2007 to 2010, the United Kingdom implemented the Waste
and Resources Action Pro-
gramme, which achieved a 13% reduction in household food
waste and an additional 9%
reduction in food waste at the retail stage. These savings came
through simple and com-
monsense strategies that not only cut waste but also helped
consumers and businesses save
money. These efforts included education campaigns targeted at
consumers on reducing food
waste, as well as programs for businesses to channel food that
might otherwise be discarded
to charities or composting facilities (Waste and Resources
Action Programme, n.d.). In New
York City a program known as Rescuing Leftover Cuisine
organizes hundreds of volunteers
every day to collect food that would otherwise be thrown away
by restaurants, grocery stores,
and other businesses and distributes that food to shelters, soup
kitchens, and social service
agencies. The program estimates that since 2013 it has rescued
close to 1.3 million kilograms
(2.8 million pounds) of food and provided over 2.3 million
meals to people in need (Rescuing
Leftover Cuisine, 2019).
4.10 The Role of Science and Technology
This section will examine how science and technology are
enabling agriculture to be more
productive, efficient, and environmentally friendly—another
option in our “all of the above”
approach to meeting the food and nutritional needs of 10 billion
people. The section will
76. For example, almond farmers in water-scarce regions of
California rely on networks of small
moisture sensors buried in the soil throughout their orchards to
determine when and where
water is needed. The sensors feed data to an automated water
pumping system that delivers
just the right amount of water to just the right location.
Likewise, corn farmers can now make use of a device known as
a Rowbot that applies precise
amounts of fertilizers to the crop based on data provided by soil
and crop sensors. Aerial
drones can be mounted with sensors that can detect whether
some plants are diseased or
need nutrients, and that data can be used to target spraying or
fertilizer application to spe-
cific locations. These technologies improve on the conventional
practice of simply irrigat-
ing or spraying pesticides and fertilizers across an entire field
without any consideration for
site-specific differences in conditions across the farm. The goal
of this high-tech, precision
agriculture is to increase productivity, decrease the use of
inputs like water and agricultural
chemicals, and minimize the impact of agriculture on the
environment. All of these outcomes
have the added benefit of improving a farmer’s profitability.
Farming Without Soil
Hydroponics and aquaponics are ways to grow crops without the
use of soil. Hydroponics
grows plants by suspending them with their roots placed in a
water–mineral nutrient solu-
tion. Aquaponics builds on this idea by incorporating
aquaculture, or raising aquatic animals