Environmental Science - 12e - Chapter 10.pdf - po ang - Januszek66

83376_11_ch10_p198-226.ctp 8/10/07 12:40 PM Page 198

Food, Soil, and

Pest Management

Golden Rice: Grains of Hope

or an Illusion?

CORE CASE STUDY

Many of the world’s poor do not have enough land or money to

obtain foods that give them enough protein and essential vita-

mins and minerals to prevent malnutrition. For example, accord-

ing to the World Health Organization (WHO), 120–140 million

children in developing countries, mostly in Africa and Southeast

Asia, do not get enough vitamin A. This makes them more sus-

ceptible to common childhood infectious diseases. Some 250,000

to 500,000 children younger than age 6 go

blind each year from a lack of vitamin A.

More than half of them die within a year

after becoming blind.

In 1999, scientists Ingo Potrykus and Peter Beyer decided

to tackle this problem by genetically engineering (Figure 4-8,

p. 72) a form of rice that contained beta-carotene, a substance

that the body can convert to vitamin A. They transferred snippets

of DNA in genes taken from common daffodils (Figure 10-1,

right) and from a soil bacterium into conventional rice strains to

produce a strain of rice containing beta-carotene.

Pre-school children can get their daily re-

quirement for vitamin A by eating small amounts

of mango, yellow sweet potatoes, or coriander.

But these foods are too expensive to grow or

buy for most of the poor. Children can also be

given two vitamin A capsules each year, but so

far the United Nations, global health organiza-

tions, and governments have not provided

enough money to do this.

Potrykus and Beyer estimate that eating

200–300 grams of their latest golden rice strain per day should

provide enough vitamin A to prevent blindness and susceptibility

to common childhood infections. They also worked out agree-

ments for poor subsistence farmers in several developing coun-

tries to get the new strain free of charge.

Critics view golden rice mostly as a seed industry–financed

public relations ploy to soften up widespread consumer opposi-

tion to genetically engineered crops in parts of the world such as

India and Europe. They also contend that golden rice is drawing

funding and attention away from a quicker and cheaper program

for getting vitamin A capsules to the millions of children who

need them. Also, there is concern over whether the poor can af-

ford to buy yellow rice.

In addition, scientists want more evidence on how much of

the beta-carotene in the golden rice will actually be converted to

vitamin A in the body. They also want evidence that golden rice

strains that perform well in the laboratory will perform as well in

nature where many more factors come into play.

The world faces three major food challenges: reducing

poverty, which blocks access to enough resources to avoid

malnutrition for hundreds of millions of people; providing and

distributing enough food for the 8.9 billion people projected to

be living on the earth by 2050; and doing both in an environ-

mentally sustainable manner that does not deplete or degrade

the soil and water resources needed to produce food.

Figure 10-1 Golden rice is a new genetically engineered strain of rice

containing beta-carotene (giving it its yellow color), which the body

can convert to vitamin A. Some farmers in countries such as India,

Bangladesh, and China may begin replacing some conventional strains

of rice, planted in terraces to help reduce soil erosion (left), with this

new golden rice strain.

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Key Questions and Concepts

10-1 How can we improve food security?

CONCEPT 10-1 Meeting the nutritional needs of the world’s

people requires reducing poverty and the harmful environmental

impacts of agriculture.

10-5 Are there limits to providing more meat and

seafood?

CONCEPT 10-5A Rangeland overgrazing and the harmful

environmental impacts of industrial livestock production may limit

meat production.

CONCEPT 10-5B We can harvest fish more sustainably to

prevent overfishing and use improved types of aquaculture.

10-2 How is food produced and how might food

production change?

CONCEPT 10-2 Producing enough food to feed the rapidly

growing human population will require growing food in a mix of

monocultures and polycultures and decreasing the enormous

environmental impact of industrialized agriculture.

10-6 How can we protect crops from pests?

CONCEPT 10-6 We can sharply cut pesticide use without

decreasing crop yields by using a mix of cultivation techniques,

biological pest controls, and small amounts of selected chemical

pesticides as a last resort (integrated pest management).

10-3 How serious are soil erosion and degradation

and how can they be reduced?

CONCEPT 10-3 We can reduce soil erosion and degradation by

using proven agricultural techniques and restoring depleted soil

nutrients.

10-7 How can we produce food more sustainably?

CONCEPT 10-7 Sustainable agriculture involves reducing

topsoil erosion, eliminating overgrazing and overfishing, irrigating

more efficiently, using integrated pest management, providing

government subsidies for sustainable farming and fishing, and

promoting agrobiodiversity.

10-4 What have the green and gene revolutions

done for food security?

CONCEPT 10-4 Industrialized agriculture has increased global

food production dramatically, but its harmful environmental impacts

may limit future food production.

Note: Supplements 3, 4, 5, and 6 can be used with this chapter.

There are two spiritual dangers in not owning a farm.

One is the danger of supposing that breakfast comes from the grocery,

and the other that heat comes from the furnace.

ALDO LEOPOLD

10-1 How Can We Improve Food Security?

CONCEPT 10-1 Meeting the nutritional needs of the world’s people requires reducing

poverty and the harmful environmental impacts of agriculture.

Many Poor People Have Health

Problems Because They Do Not

Get Enough to Eat

Today we produce more than enough food to meet the

basic nutritional needs of every person on the earth.

Even with this surplus of food, one of every six people

in developing countries is not getting enough to eat.

They face food insecurity, living with chronic hunger

and malnutrition that threatens their ability to lead

healthy and productive lives.

Most agricultural experts agree that the root cause of

food insecurity is poverty, which prevents poor people

from growing or buying enough food. (See Figure 2 on

p. S8 in Supplement 3 for a map showing the world’s

low-income countries.) War and corruption can also

deny poor people access to food.

Food security means that every person in a given

area has daily access to enough nutritious food to have

an active and healthy life. At the national level, gov-

ernment programs that reduce poverty by helping the

poor to help themselves can improve food security.

Such programs promote family planning, education

and jobs (especially for women), and small loans to

poor people to help them start businesses or buy land

to grow their own food.

199

Links:

refers to the Core Case Study.

refers to the book’s sustainability theme.

indicates links to key concepts in earlier chapters.

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Many less-developed countries do not produce

enough food to feed their people, and are too poor to

import enough food, to provide national food security.

One solution is for developed nations and international

lending institutions such as the World Bank to provide

technical advice and funding to help such countries be-

come more self-sufficient in meeting their food security

needs. This would require governments of those coun-

tries to spend more of their funds on helping the rural

poor to help themselves.

Food security also depends on greatly reducing the

harmful environmental effects of agriculture—such as

soil erosion and aquifer depletion—at the local, na-

tional, and global levels ( Concept 10-1 ).

To maintain good health and resist disease, individ-

uals need fairly large amounts of macronutrients (such as

protein, carbohydrates, and fats), and smaller amounts

of micronutrients —vitamins (such as A, C, and E) and

minerals (such as iron, iodine, and calcium).

People who cannot grow or buy enough food

to meet their basic energy needs suffer from chronic

undernutrition, or hunger. Most chronically under-

nourished children live in developing countries. Be-

cause of lack of access to adequate health care, they are

likely to suffer from mental retardation and stunted

growth and to die from infectious diseases such as

measles and diarrhea, which rarely kill children in de-

veloped countries.

Many of the world’s poor can afford only to live on

a low-protein, high-carbohydrate, vegetarian diet con-

sisting of grains such as wheat, rice, or corn. They often

suffer from malnutrition resulting from diet deficien-

cies of protein and other key nutrients. This weakens

them, makes them more susceptible to disease, and

hinders the normal physical and mental development

of children (Figure 1-12, p. 16).

Good news. According to the U.N. Food and Agricul-

ture Organization (FAO), the average daily food intake

in calories per person in the world and in developing

countries rose sharply between 1961 and 2007, and is

projected to continue rising through 2030. Also, the es-

timated number of chronically undernourished or mal-

nourished people fell from 918 million in 1970 to 852

million in 2005. (See Figure 7 on p. S11 in Supplement

3 for a map of the countries with the most undernour-

ished people.) This is a good start but it is far from the

Millennium Development Goal of reducing the num-

ber of hungry and malnourished people to 400 million

by 2015.

Despite such progress, one of every six people in

developing countries (including about one of every

three children younger than age 5) is chronically un-

dernourished or malnourished. In 2005, the FAO esti-

mated that each year, nearly 6 million children die

prematurely from undernutrition, malnutrition, and

increased susceptibility to normally nonfatal infectious

diseases because of their weakened condition. This

means that each day, an average of 16,400 children die

prematurely from these poverty-related causes. How

many people died from such causes during your lunch

hour?

According to the World Health Organization

(WHO), one of every three people suffers from a defi-

ciency of one or more vitamins and minerals, most of-

ten in developing countries and involving vitamin A,

iron, and iodine.

Too little iron —a component of the hemoglobin

that transports oxygen in the blood—causes anemia.

According to a 1999 survey by the WHO, one of every

three people in the world—mostly women and chil-

dren in tropical developing countries—suffers from

iron deficiency. It causes fatigue, makes infection more

likely, and increases a woman’s chances of dying from

hemorrhage in childbirth. New strains of

golden rice ( Core Case Study ) contain more

iron than conventional strains and could help reduce

the severity of this nutritional deficiency.

Elemental iodine is essential for proper functioning

of the thyroid gland, which produces hormones that

control the body’s rate of metabolism. Iodine is found

in seafood and in crops grown in iodine-rich soils.

Chronic lack of iodine can cause stunted growth, men-

tal retardation, and goiter—a swollen thyroid gland

that can lead to deafness (Figure 10-2). According to

the United Nations, some 600 million people—mostly

in south and Southeast Asia—suffer from goiter, and

Figure 10-2 Woman with goiter in Bangladesh. A diet with in-

sufficient iodine can cause this enlargement of the thyroid gland.

Adding traces of iodine to salt has largely eliminated this problem

in developed countries.

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26 million children suffer brain damage each year from

lack of iodine.

THINKING ABOUT

Golden Rice and Children

What do you think is the best way to deal with vita-

min A deficiencies in many of the world’s poor children?

Explain.

We Can Reduce Childhood Deaths

from Hunger and Malnutrition

Studies by the United Nations Children’s Fund

(UNICEF) indicate that one-half to two-thirds of

nutrition-related childhood deaths could be prevented

at an average annual cost of $5–$10 per child with

the following measures:

•

Many People Have Health Problems

from Eating Too Much

Overnutrition occurs when food energy intake ex-

ceeds energy use and causes excess body fat. Too many

calories, too little exercise, or both can cause overnutri-

tion. People who are underfed and underweight and

those who are overfed and overweight face similar

health problems: lower life expectancy, greater susceptibility

to disease and illness, and lower productivity and life quality.

We live in a world where 1 billion people have

health problems because they do not get enough to eat

and another 1.2 billion face health problems from eat-

ing too much. According to a 2004 study by the Inter-

national Obesity Task Force, one of every four people in

the world is overweight and one of every twenty is

obese.

A 2005 study at Boston University found that about

60% of American adults are overweight and 33% are

obese, for a total of 93%—the highest overnutrition rate

in any developed country. The $40–100 billion that

Americans spend each year trying to lose weight is

about two to four times as much as the $24 billion per

year needed to eliminate undernutrition and malnutri-

tion in the world.

Immunizing children against childhood diseases

such as measles.

•

Encouraging breast-feeding (except for mothers

with AIDS).

•

Preventing dehydration from diarrhea by giving

infants a mixture of sugar and salt in a glass of

water.

•

Preventing blindness by giving children a vitamin A

capsule twice a year at a cost of about 75¢ per

child. Other options are fortifying common foods

with vitamin A and other micronutrients at a cost

of about 10¢ per child annually and widespread

planting of golden rice in developing coun-

tries ( Core Case Study ).

•

Providing family planning services to help mothers

space births at least 2 years apart.

•

Increasing education for women, with emphasis on

nutrition, drinking water sterilization, contracep-

tion, and childcare.

10-2 How Is Food Produced and How Might Food

Production Change?

CONCEPT 10-2 Producing enough food to feed the rapidly growing human population

will require growing food in a mix of monocultures and polycultures and decreasing the

enormous environmental impact of industrialized agriculture.

Industrialized Agriculture Has Greatly

Increased Food Production

Three systems supply most of our food. Croplands pro-

duce mostly grains and provide about 77% of the

world’s food using 11% of its land area. Rangelands and

pastures produce meat, mostly from grazing livestock,

and supply about 16% of the world’s food using about

29% the world’s land area. Oceanic fisheries, and more re-

cently aquaculture, supply about 7% of the world’s food.

Since 1960, there has been a staggering increase in

global food production from all three systems. This oc-

curred because of technological advances such as in-

creased use of tractors and farm machinery and high-

tech fishing fleets. Other technological developments

include inorganic chemical fertilizers, irrigation, pesti-

cides, high-yield grain varieties, and raising large

numbers of livestock, poultry, and fish in factory-like

conditions.

We face important challenges to increase food pro-

duction without causing serious environmental harm.

Each day, there are about 225,000 more mouths to

feed. Between 2007 and 2050, the world’s population is

projected to increase by 2.2 billion people. To provide

food security for these individuals, we will have to grow

and distribute more food than has been produced since

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CONCEPT 10-2

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agriculture began about 10,000 years ago, and do so in

an environmentally sustainable manner ( Concept 10-2 ).

Can we achieve this goal? Some analysts say we

can, mostly by using genetic engineering (Figur e 4-8,

p. 72, and Concept 4-5 , p. 71). Others have

doubts. They point out that agriculture, the

world’s largest industry, is increasing pressure on the

earth’s natural capital ( Concept 1-1A , p. 6). They are

concerned that environmental degradation, pollution,

lack of water for irrigation, overgrazing by livestock

(see photo 10, p. x), overfishing, rising temperatures,

increasing fuel costs, and loss of vital ecological services

may limit future food production.

for sale in developed countries. Producing such mono-

culture crops in the tropics increases yields but de-

creases biodiversity when tropical forests are cleared

for the plantations. A new form of industrialized agri-

culture involves widespread use of greenhouses to raise

food (Figure 10-3).

An increasing amount of livestock production in

developed and developing countries is industrialized.

Large numbers of cattle are brought to densely popu-

lated feedlots, or animal factories, where they are fattened

up for about 4 months before slaughter. Most pigs and

chickens in developed countries spend their lives in

densely populated pens and cages, often in huge build-

ings, and eat mostly grain grown on cropland. Such

systems use large amounts of energy and water and

produce huge amounts of animal waste that can pol-

lute surface and groundwater and saturate the air with

unpleasant odors.

A Small Number of Plant and Animal

Species Feed the World

Of the estimated 50,000 wild plant species that people

can eat, only 14 of them supply an estimated 90% of

the world’s food calories. Just three types of grain

crops— wheat, rice, and corn —provide about 47% of the

calories and 42% of the protein people consume.

Such food specialization puts us in a vulnerable po-

sition should the small number of crops we depend on

fail from disease or climate change. This vio-

lates the biodiversity principle of sustainability

(Figure 1-13, p. 20), which calls for depending

on a variety of food crops as an ecological insurance pol-

icy for dealing with environmental change.

Two-thirds of the world’s people survive primarily

on rice, wheat, and corn, mostly because they cannot

afford meat. As incomes rise, most people consume

more meat, milk, cheese, and other products of domes-

ticated livestock. Fish and shellfish are an important

source of food for about 1 billion people, mostly in Asia

and in coastal areas of developing countries.

■ CASE STUDY

Industrialized Food Production

in the United States

In the United States, industrialized farming has evolved

into agribusiness, as giant multinational corporations in-

creasingly control the growing, processing, distribution,

and sale of food in the United States and in the global

marketplace.

Agriculture generates almost one-fifth of the na-

tion’s gross domestic product. Although agriculture em-

ploys more people than any other industry, U.S. farms

use industrialized agriculture to produce about 17% of

the world’s grain with only 0.3% of the world’s farm

labor force.

Since 1950, U.S. industrialized agriculture has more

than doubled the yield of key crops such as wheat,

corn, and soybeans without cultivating more land. Such

yield increases have kept large areas of forests, grass-

lands, and wetlands from being converted to farmland.

U.S. consumers now spend about 2% of their dis-

posable income on food, compared to about 11% in

1948. People in developing countries typically spend

up to 40% of their income on food. And the 1.2 billion

of the world’s poor, struggling to live on less than $1 a

day, typically spend about 70% of their meager income

on food.

However, the actual prices consumers in the U.S.

and other developed countries pay for food are much

higher than what they pay at grocery stores. In addi-

tion to the direct market prices, consumers pay taxes to

give subsidies to food producers and distributors and to

help deal with the massive pollution and environmen-

tal degradation caused by agriculture. They also face

higher health costs and higher insurance bills related to

the harmful environmental effects of agriculture. In-

cluding these harmful costs in the market prices for

food could help to bring about a shift to more sustain-

able and less harmful agriculture.

Industrialized Agriculture Relies

on High-Input Monocultures

Agriculture can be divided roughly into two types: in-

dustrialized agriculture and subsistence agriculture.

Industrialized agriculture, or high-input agricul-

ture, uses large amounts of financial capital, fossil fuel,

water, commercial fertilizers, and pesticides to produce

high yields (the amount of food per unit of land) of

single crops ( monocultures ) or livestock animals for sale.

Practiced on one-fourth of all cropland, mostly in de-

veloped countries, this form of agriculture has spread

since the mid-1960s to some developing countries and

now produces about 80% of the world’s food.

Plantation agriculture is a form of industrialized

agriculture used primarily in tropical developing coun-

tries. It involves growing cash crops, such as bananas,

soybeans (mostly to feed livestock), sugarcane (for

sugar and to produce ethanol fuel for cars), coffee, and

vegetables on large monoculture plantations, mostly

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CHAPTER 10

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