Encyclopedia of Global Resources part 6 pot

Department of Agriculture Agriculture http://www.usda.gov/wps/portal/!ut/p/_s.7_0_A/ 7_0_1OB?navtype=SU&navid=AGRICULTURE See also: Agricultural products; Animal breeding; Animal domesti

second largest energy cost associated with agriculture.

The use of fuel-requiring pumps to irrigate crops is

also a major energy consumer Additional energy is

used in food processing, distribution, storage, and

cooking after the crop leaves the farm The energy

used for these activities may be five times as much as

that used to produce the crop

Current Trends in Agriculture

The development of biofuels, fuels produced from

plants, such as corn and soy ethanol and cellulosic

ethanol (produced from inedible portions of plants),

has been encouraged by the need to find a substitute

for expensive and environmentally harmful fossil

fu-els However, the fluctuating price of oil has caused

this industry to advance in fits and starts Critics point

out that biofuels use cropland that otherwise would

be producing food, and the rise of the electric car

could speed the decline in the use of fossil fuels,

mak-ing biofuels obsolete

The next major development in agriculture will be

the biotechnical revolution, in which scientists will be

able to use molecular biological techniques to

pro-duce exotic new crop varieties In the future, perhaps

agricultural scientists will be able to use these

tech-niques to develop crop plants that can be produced,

processed, and distributed with less impact on other

resources Many scientists feel nanotechnology, the

ability to restructure matter at the level of molecules

and atoms, could meet the need for growth in

agricul-ture through improving the production of both plants

and animals and improving both the safety and

qual-ity of food A wide range of developed and developing

countries, from the United Kingdom to Iran to India,

are providing funding to scientific laboratories to

de-velop nanotechnology products The potential

prod-ucts range from antibacterial agents to technology

that signals when a product is near the end of its shelf

life There remains concern that including

nanopar-ticles in food may pose a health risk, and consumer

advocates are encouraging more research, consumer

awareness, and governance

The trend toward globalization in agriculture has

been good for the developed countries, but it poses a

threat to developing nations For example, countries

in Africa do not benefit from the advances in global

agriculture Rural dwellers have neither the money

nor the natural resources to take advantage of

mod-ern agricultural methods At the same time, the

agri-cultural practices in the developed world bring with

them many negative consequences for the environ-ment Water pollution from fertilizers and pesticides; global warming from increasing land under cultiva-tion and decreasing forests; and decreased diversity of agricultural products in specific regions, which results

in increased energy use to get these products to their global markets Interest in organic farming, which is practiced in more than one hundred countries, offers opportunities for organic farmers from developing countries However, if organic farming follows the pattern of commercial agriculture, with the growth of large farms, specialized products, and need for in-creasing capital, the benefit to the small, local farmer will disappear and the environmental impact will turn negative

Commercial Impact of the Agriculture Industry

Worldwide, some 45 percent of the population makes

a living through agriculture, both subsistence and commercial This also includes those people hired by the agriculture chemical companies, those compa-nies that produce or sell agriculture implements and machinery, processing and canning plants, and whole-sale and retail marketing firms, such as grocery stores There are some eight thousand different agricultural products on the market, and while agriculture is big business, it amounts to less than 5 percent of the gross domestic product of all nations Approximately one-third of the land worldwide is used for agriculture

D R Gossett

Further Reading

Akinyemi, Okoro M Agricultural Production: Organic and Conventional Systems Enfield, N.H.: Science

Publishers, 2007

Brody, Aaron L., and John B Lord, eds Developing New Food Products for a Changing Marketplace 2d ed Boca

Raton, Fla.: CRC Press/Taylor & Francis, 2008

Field, Thomas G., and Robert E Taylor Scientific Farm Animal Production: An Introduction to Animal Science.

9th ed Upper Saddle River, N.J.: Prentice Hall, 2008

Janick, Jules Horticultural Science 4th ed New York:

W H Freeman, 1986

Kipps, M S Production of Field Crops: A Textbook of Agronomy 6th ed New York: McGraw-Hill, 1970 Metcalfe, Darrel S., and Donald M Elkins Crop Pro-duction: Principles and Practices 4th ed New York:

Macmillan, 1980

Southgate, Douglas, Douglas H Graham, and Luther

Tweeten The World Food Economy Malden, Mass.:

Blackwell, 2007

Weis, Tony The Global Food Economy: The Battle for the

Future of Farming New York: Zed Books, 2007.

Wojtkowski, Paul A Agroecological Economics:

Sustain-ability and Biodiversity Boston: Elsevier/Academic

Press, 2008

Web Sites

Agriculture and Agri-Food Canada

Agri-Industries

http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1166532974345&lang=eng

U.S Department of Agriculture

Agriculture

http://www.usda.gov/wps/portal/!ut/p/_s.7_0_A/

7_0_1OB?navtype=SU&navid=AGRICULTURE

See also: Agricultural products; Animal breeding;

Animal domestication; Biofuels; Corn; Cotton; Flax;

Forestry; Forests; Genetic prospecting; Global

Strat-egy for Plant Conservation; Green Revolution; Hemp;

Horticulture; Land ethic; Monoculture agriculture;

Plant domestication and breeding; Plant fibers; Rice;

Rubber, natural; Seed Savers Exchange;

Slash-and-burn agriculture; Soil; Svalbard Global Seed Vault;

United Nations Food and Agriculture Organization;

Wheat; Wood and timber

Agronomy

Categories: Scientific disciplines; environment,

conservation, and resource management

Agronomy comprises a group of applied-science

disci-plines concerned with land and soil management and

crop production Agronomists’ areas of interest range

from soil chemistry to soil-plant relationships to land

reclamation.

Definition

There are multiple definitions of agronomy, as befits

a discipline with many different facets The Oxford

Universal Dictionary defines agronomy as “the study

of land management or rural economy”;

Merriam-Webster’s Collegiate Dictionary calls it “a branch of

agri-culture dealing with field-crop production and soil management.” The word derives from the ancient

Greek agros (field) and nemein (manage): field

man-agement Thus the American Society of Agronomy defines agronomy as “the theory and practice of crop production and soil management.”

Overview Agronomy is essentially the discipline or disciplines that investigate the production of crops supplying food, forage, and fiber for human and animal use and that study the stewardship of the soil from which those crops are grown Agronomy covers all aspects of the agricultural environment, from agroclimatology

to soil-plant relationships; crop science; soil science; weed science; biometry (the statistics of living things); crop, soil, pasture, and range management; crop, for-age, and pasture production and utilization; turf-grass; and agronomic modeling Within each area are subdisciplines For example, within soil science are traditional disciplines such as soil fertility, soil chemis-try, soil physics, soil microbiology, soil taxonomy and classification, and pedogenesis (the science of how soils form) Newer disciplines within soil science in-clude such studies as bioremediation, or the study of how living organisms can be used to clean up toxic wastes in the environment, and land reclamation, the study of how to reconstruct landscapes disturbed by human activities such as surface mining

Agronomy treats the agricultural environment as humankind’s greatest natural resource: It is the source

of our food, the source of our clothing, the source of our building materials, and the environment that purifies the air we breathe and the water we drink Agronomists, whatever their specific field, utilize the soil resources and plant resources around them to benefit society Crop breeders, for example, use the genetic diversity of wild varieties of domesticated plants to obtain the genetic information needed to breed plants for greater productivity or pest resis-tance Soil scientists study landscapes to determine how best to manage the soil resource by integrating agricultural practices with the environment in terms

of maintaining soil fertility and in terms of keeping soil in place so that erosion does not reduce the qual-ity of the surrounding environment

Poor field management leads to reduced produc-tivity and reduced environmental quality Historical examples abound, ranging from the 1930’s Dust Bowl

in the United States to the deforestation on the island

of Madagascar in the late twentieth century It is the

role of agronomy to manage soil and crop resources

as effectively as possible so that the twin goals of

pro-ductivity and environmental quality are preserved

Mark S Coyne

See also: Dust Bowl; Erosion and erosion control;

Farmland; Fertilizers; Monoculture agriculture;

Rangeland; Slash-and-burn agriculture; Soil; Soil

test-ing and analysis; Wheat

Air pollution and air pollution

control

Category: Pollution and waste disposal

An air pollutant is any substance added to the

atmo-sphere by human activities that affects humans,

ani-mals, or the environment adversely Many pollutants

are toxic, while seemingly benign emissions such as

carbon dioxide, a major contributor to global

warm-ing, and chlorofluorocarbons, which decimate the

stratospheric ozone layer, are dangerous in less obvious

ways Significant worldwide resources have been

com-mitted to reducing all such hazardous emissions.

Background

Air pollution, occurring in gaseous, particulate, or

aerosol form, has been problematic since humans

began living in large cities and burning carbon-based

fuels The first known air pollution ordinance was

passed in London in 1273, in an attempt to alleviate

the soot-blackened skies from excessive combustion

of wood From the mid-eighteenth century through

the mid-twentieth century, the increasingly heavy use

of coal for heat, electricity, and transportation

re-sulted in filthy air and an escalation of respiratory

diseases In the latter half of the twentieth century,

governments began attacking the problem with

legis-lation to control noxious emissions at their source

Earth’s atmosphere consists primarily of nitrogen,

oxygen, water vapor, and trace amounts of many other

substances Emissions from human activities can alter

the concentrations of these substances or release

nox-ious chemicals with sernox-ious implications—including

smog, acid rain, the greenhouse effect, and holes

in the ozone layer—for both human and planetary

health

The major air pollutants are carbon oxides, sulfur oxides, nitrogen oxides, hydrocarbons, and particu-late matter Each year the United States adds more than 5.5 billion metric tons of carbon dioxide (CO2)

to the air; China adds approximately 6 billion metric tons Worldwide, the amount of CO2inserted into the atmosphere exceeds 28 billion metric tons annually, contributed in roughly equal proportions by fossil-fuel electric power plants, industry, transportation, and homes and businesses

Air Pollutants

CO2results whenever a carbon-containing fuel—such

as coal, oil, or gasoline—is burned When combustion

is incomplete carbon monoxide (CO) is also pro-duced Although CO2is a relatively benign compound, the vast amount of fossil fuels (coal, oil, and natural gas) burned since the Industrial Revolution has in-creased the atmospheric amount by about 40 percent and continues to increase at an escalating rate Car-bon dioxide molecules, while transparent in visible light from the Sun, reflect infrared radiation emitted

by Earth and reradiate it as heat Eventually, this will likely raise Earth’s average temperature in proportion

to the amount of atmospheric CO2 This “greenhouse effect” poses a long-term risk because a warming trend could increase sea levels, change rainfall pat-terns, disrupt grain belts, cause storms of greater in-tensity, and shift climate zones Carbon monoxide is

a toxic compound that causes death by suffocation by replacing oxygen in the bloodstream, thus depriving cells of their necessary oxygen

Sulfur oxides are created whenever fossil fuels, par-ticularly coal containing sulfur, are burned Inhaling even relatively small concentrations of these gases can damage the upper respiratory tract and lung tissue Another problem is that they react with water vapor in the atmosphere to produce sulfuric acid, a major component in acid rain

Nitrogen oxides are synthesized whenever air is rapidly heated under pressure, followed by quick cooling, such as occurs in internal combustion en-gines and thermoelectric power plants These com-pounds play a major role in the formation of acid rain, photochemical smog, and ozone (O3), a potent reac-tive compound that attacks the lungs Combustion-caused ozone is dangerous to living organisms near Earth’s surface, but in the stratosphere it occurs natu-rally This “ozone layer” prevents most of the Sun’s ul-traviolet light from reaching Earth’s surface

fore, it can cause skin cancer in humans as well as

affect plants and wildlife adversely

Particulates are minuscule solid or liquid particles

suspended in the air They occur from combustion,

dry grinding processes, and spraying The human

re-spiratory system has evolved a mechanism to prevent

certain sizes of particulates from reaching the lungs,

but there is no protection against the smaller particles

of coal dust and the larger particulates in tobacco

smoke Coal dust settling in the lungs leads to black

lung disease, while the particulates from tobacco

smoke are a leading cause of lung cancer

The United States emits millions of metric tons of

suspended particulate matter each year, chiefly from

fossil-fuel electric power plants and industrial

smelt-ing plants Even particulates that do not reach the

lower regions of the respiratory tract can affect

breath-ing, cause emphysema, aggravate an existing

cardio-vascular disorder, or damage the immune system

Smog

The word “smog” is a melding of “smoke” and “fog” to

describe fog polluted by smoke When a local

atmo-sphere becomes stagnant, smog pollution levels can

create “killer fogs.” Three times in recent history

these killer fogs have caused statistically significant

in-creases in the death rate, particularly among those

with respiratory problems The first instance oc-curred in 1948 in Donora, Pennsylvania, when a stag-nated fog became progressively more contamistag-nated with the smoky effluents from local steel mills The second case occurred in 1952 in London when a stag-nant fog mixed with the smoke from thousands of coal-burning homes caused many with respiratory ail-ments to die Finally, during Thanksgiving of 1966, New York City experienced an increased death rate because of choking smog

A second, completely different type of smog is

“photochemical smog,” a noxious mixture of reactive chemicals created when sunlight catalyzes reactions

of residual hydrocarbons and nitrogen oxides from automotive exhaust The first occurrence of such was

in the late 1940’s in Los Angeles, where the abundant sunlight and the dramatic increase of vehicular traffic created ideal conditions for photochemical smog This smog contains, among other things, powerful eye irritants, noisome odors, and dangerous reactive compounds Although first observed in Los Angeles, photochemical smog later became prevalent in most other large cities

Chlorofluorocarbons When first synthesized in the 1930’s, chlorofluoro-carbon (CFC) was hailed as an ideal refrigerant

Data from the U.S Environmental Protection Agency,

Source: National Emissions Inventory (NEI) Air Pollution Emissions Trend Data, 1970-2002.

119.5 36.9

14.9

4.8

0.2

Millions of People

120 100

80 60

40 20

Lead

Ozone Particulate Matter

(2.5-micron-diameter)

Particulate Matter

(10-micron-diameter)

Sulfur Dioxide

NAAQS (National Ambient Air Quality Standards).

Note:

People Living in Countries with Pollution Levels Higher than U.S NAAQS, 2008

(Freon) because it was nontoxic, noncorrosive,

non-flammable, and inexpensive to produce Later,

pres-surized CFCs were used as aerosol propellants and

as the working fluid for air conditioners and

refrig-erators By 1970 scientists realized that the huge

quan-tities of CFCs released into the atmosphere from

aerosol cans and discarded refrigerant units were

migrating to the stratosphere, where they were

de-composed by highly energetic ultraviolet radiation

from the Sun, releasing large quantities of

ozone-destroying chlorine The reduction of ozone was most

pronounced over Antarctica, where an “ozone hole,”

first detected in the early 1970’s, was increasing in

size annually In 1978, pressured by environmentalists

and consumer boycotts, the U.S government banned

aerosol cans and refrigeration units utilizing CFC

pro-pellant, forcing the chemical industry to develop

al-ternatives By 1987 the depletion of the ozone layer

had become so problematic that most industrial

na-tions met in Montreal to ratify an international treaty

calling for immediate reductions in all CFC use with a

complete phase-out by the year 2000 By 2001 the

Montreal Protocol had limited the damage to the

ozone layer to about 10 percent of what it would have

been had the agreement not been ratified

Air Pollution Control in the United States

In the United States, the first attempts to control the

smog or black smoke prevalent in industrial cities

were the Clean Air Act of 1963 and the Motor Vehicle

Pollution Act of 1965 The 1963 act was too weak to be effective; in 1967, the stronger Air Quality Act was en-acted The Clean Air Act Amendments of 1970 man-dated national air quality standards set by the Envi-ronmental Protection Agency (EPA) to be met by

1975 Standards for six major air pollutants (sulfur oxides, nitrogen oxides, particulates, ozone, carbon monoxide, and lead) were legislated When the pollu-tion concentrapollu-tion exceeded these limits, control de-vices were obligatory, regardless of the cost

Although most forms of air pollution were reduced after enactment of the Clean Air Act Amendments, mounting public concern over the continuing deteri-oration of air quality in major cities resulted in several important revisions in 1990 New legislation man-dated that coal-burning power plants reduce sulfur oxide emissions by 9 million metric tons per year from

1980 levels by the year 2000 The revisions also re-quired that industry reduce several hundred carcino-genic airborne substances by up to 90 percent by the year 2000 Because of its smog problem, California set even more stringent standards by legislating that 2 percent of all new vehicles must emit zero emissions

by 1998, a rate that was to increase to 10 percent by

2003 In October, 2006, the EPA’s scientific advisers recommended that the allowable levels of surface ozone be substantially reduced, but industrial lobby-ing and the conservative political climate prevented any substantial change

During the decades following the Clean Air Act Amendments, particulate emissions decreased by 80 percent, carbon monoxide by 55 percent, hydrocar-bon emissions by 40 percent, sulfur oxides by 27 per-cent, and atmospheric lead by 98 percent The partic-ulate emission reduction is attributed to control equipment installed on utility plant and industrial smokestacks, a decreased use of coal, and less burning

of solid wastes Carbon monoxide and hydrocarbon emissions have decreased, despite an increase in auto-motive traffic, because of federal autoauto-motive emis-sion standards The drop in sulfur oxides is directly attributable to a switch to low-sulfur coal and the re-moval of sulfur from the discharged gases at electric power plants The drastic drop of lead compounds in the atmosphere resulted from the switch to unleaded gasoline during the 1970’s

During the first decade of the twenty-first century, concern about global warming caused by CO2created

a consensus that drastic action was needed to reduce this threat Early in 2009, the EPA declared CO an air

Percentage Change in U.S Emissions

(millions of tons per year)

1980 vs 2008

Volatile organic compounds −47

Direct particulate matter

(10-micron-diameter)

−68 Direct particulate matter

(2.5-micron-diameter)

—

Source: Data from U.S Environmental Protection Agency,

Air Quality Trends, 2009.

pollutant, thus empowering the Clean

Air Act to establish national emission

standards for new automobiles and new

coal-fired electric power plants, the two

largest contributors to global warming

emissions

Global Air Quality Control

Air pollution, an ongoing problem in

in-dustrialized nations, has also become

problematic in virtually all undeveloped

countries undergoing rapid

industrial-ization The countries of the European

Union have taken collective action

be-cause pollution generated in one

coun-try affects air quality in neighboring

countries Because road transportation

is Europe’s largest air polluter, beginning

in the 1970’s motor vehicles

manufac-tured on the Continent have had

re-quired exhaust-emission controls

Fossil-fuel emissions from power plants and

factories are also stringently regulated

In the United Kingdom, national air quality objectives

were instituted in 2000 in association with an air

qual-ity network to monitor levels of major pollutants in

vari-ous locations and a daily warning system to indicate

po-tentially dangerous air pollution levels In the summer

of 2006, a directive on emission ceilings for cleaner air

in Europe was passed by the European Parliament

The environmental crisis in the former Soviet

re-publics of Eastern Europe is a direct result of the

poli-cies pursued under the communist regime, when

rapid industrialization ignored local conditions Air

pollution controls were deemed unnecessary because

the biosphere was assumed to be self-purifying With

the advent of glasnost, a state committee on

environ-mental protection was instituted in 1988; this became

a state ministry in 1991 but was abolished nine years

later No significant change in ecological concerns

oc-curred after the fall of the communist regime and the

transition to capitalism Because agencies responsible

for environmental matters are either nonexistent or

severely underfunded, internationally funded

pollu-tion abatement projects are abandoned when the

funds expire

The country with the greatest number of

prema-ture deaths because of air pollution is India, where

rapid industrialization and urbanization combined

with unregulated vehicular emissions and

uncon-trolled industrial effluents have exacerbated a preex-isting problem Legislation to alleviate the crisis in cities such as New Delhi, one of the top-ten most pol-luted cities in the world, has been extremely difficult

to implement Auto emissions account for approxi-mately 70 percent of urban air pollution, and regula-tions required all public transportation vehicles in New Delhi to switch to compressed natural gas en-gines by April 1, 2001 However, the statute had to be rescinded when it removed about fifteen thousand taxis and ten thousand buses from service, creating commuter chaos and public riots India’s high air pol-lution has not happened because of a lack of legisla-tion but because of insufficient enforcement at the lo-cal level

China’s growing economy has removed millions of people from poverty, to the detriment of the environ-ment The increase of urban automotive traffic, the dependence on coal, and a weak environmental pro-tection system have left China with sixteen of the world’s twenty most polluted cities Both urban and rural dwellers suffer from air pollution, which annu-ally causes approximately 400,000 premature deaths and 75 million asthma attacks In 2005, to help allevi-ate the problem, the government proposed that strict fuel efficiency standards and emission controls be required on all vehicles China’s excessive air

pollu-In Bangladesh, workers in a brick field stand adjacent to a chimney emitting black smoke (AP/Wide World Photos)

tion is not contained within its borders Unregulated

airborne effluents from the numerous coal-burning

plants reach Japan and become a major contributor

to acid rain In addition, sulfate-encrusted dust,

car-bon particulates, and nitrates cross the Pacific Ocean,

where they are responsible for almost one-third of the

polluted air over Los Angeles and San Francisco

Arguably, Japan is the Asian country that has taken

air pollution abatement and control most seriously

Laws regulating the emission of sulfur dioxide and

ni-trogen oxides are among the strictest in the world, but

polluted air from China keeps the rain acidic The

huge increase in automotive traffic in recent decades is

a major contributor to urban air pollution as well as

se-vere congestion Several stringent laws regulate

auto-motive emissions in an attempt to control these

re-lated problems In addition, the Japanese environment

agency promotes low-emission vehicles and continues

to strengthen measures to reduce factory emissions

In June, 2001, the Japanese legislature passed a law

strengthening controls on diesel vehicle emissions; two

years later, diesel-powered commercial vehicles were

banned from Tokyo if these limits were exceeded

Context

More than three million premature deaths in the

world occur annually because of air pollution, the

greatest number of these occurring in India In both

developed and developing nations, air pollution from

the escalating number of vehicles, as well as consumer

preference for larger, more powerful vehicles,

con-tinues as a major challenge despite gains since the

1980’s Controlling air pollution is not inexpensive

Pollution control devices increase costs to factories

and to automobiles, costs that are passed to the

con-sumer Unless a radical change away from

conspicu-ous consumption and the overreliance on fossil fuels

occurs, air quality will not improve substantially

The issue of whether global warming is caused by

humans may not be completely resolved, but strong

measures to control carbon dioxide as well as noxious

gaseous and particulate air pollutants began during

the last decades of the twentieth century Because the

preponderance of scientific evidence suggests that

global warming is due to humanity’s excessive use

of fossil fuels, it would seem prudent to curtail the

disproportionate dependence on nonrenewable

re-sources When it was discovered that the ozone layer

was being depleted by CFCs, the Montreal Protocol

was ratified by most industrial nations This precedent

indicates that strong, effective action and interna-tional cooperation are possible when the threat to the environment are grave enough

George R Plitnik

Further Reading Ayres, Jon, Robert Maynard, and Roy Richards, eds

Air Pollution and Health London: Imperial College

Press, 2006

Calhoun, Yael, ed Air Quality Philadelphia: Chelsea

House, 2005

Gribbin, John Hothouse Earth: The Greenhouse Effect and GAIA New York: Grove Weidenfeld, 1990 Jacobson, Mark Z Atmospheric Pollution: History, Sci-ence, and Regulation New York: Cambridge

Univer-sity Press, 2002

Metcalfe, Sarah, and Dick Derwent Atmospheric Pollu-tion and Environmental Change London: Hodder

Arnold, 2005

Miller, G Tyler, Jr Living in the Environment: Principles, Connections, and Solutions 15th ed Pacific Grove,

Calif.: Brooks/Cole, 2007

Seinfeld, John H., and Spyros N Pandis Atmospheric Chemistry and Physics: From Air Pollution to Climate Change New York: John Wiley & Sons, 2006 Somerville, Richard C J The Forgiving Air: Understand-ing Environmental Change 2d ed Boston: American

Meteorological Society, 2008

Vallero, Daniel Fundamentals of Air Pollution 4th ed.

Burlington, Mass.: Academic Press, 2008

Web Sites Environment Canada Clean Air Online http://www.ec.gc.ca/cleanair-airpur/Home-WS8C3F7D55-1_En.htm

U.S Environmental Protection Agency Clean Air Act

http://www.epa.gov/air/caa U.S Environmental Protection Agency Air Pollution Effects

http://www.epa.gov/ebtpages/

airairpollutioneffects.html See also: Acid precipitation; Atmosphere; Carbon; Clean Air Act; Electrical power; Environmental Pro-tection Agency; Greenhouse gases and global climate change; Internal combustion engine; Ozone layer and ozone hole debate

Alaska pipeline

Categories: Historical events and movements;

obtaining and using resources

Date: Congress authorized construction in

November, 1973; construction began April, 1974;

pipeline completed in 1977

The plan to construct a trans-Alaskan oil pipeline

net-work generated considerable controversy After

comple-tion, the pipeline, a triumph of engineering, helped

lower U.S dependency on imported oil during the

1980’s.

Background

The Naval Petroleum Reserve was created on the

north slope of Alaska in 1923, but for two decades, the

exploratory wells drilled there came up dry More-over, the cost of commercial drilling in Alaska ap-peared prohibitive From the 1930’s to the 1950’s, oil was cheap, and interest in Alaska’s unproven reserves plummeted

During the 1960’s, the increasing price of oil and the possibility of a decline in the security of oil sup-plied from abroad combined to revive interest in Alaska’s oil possibilities The Atlantic Richfield Com-pany (later ARCO) obtained the majority of the gov-ernment leases granted for exploratory and develop-mental activity in Alaska On December 26, 1967, in temperatures 30° Celsius below zero, ARCO struck oil and discovered the largest oil field ever found in North America

Huge technological challenges had to be over-come, including obtaining the oil in volume in the subzero temperatures of Alaska’s north slope and

This portion of the Alaska pipeline was designed to trace the path of the Denali fault (USGS)

transporting it safely to the port of Valdez in the south

of Alaska for shipment by tankers to California

Con-struction of a mammoth, nearly 1,300-kilometer

pipe-line seemed to be the only way to transport the oil

across the frozen tundra

The political obstacles to transporting the oil

proved even more challenging Environmentalists

feared that the pipeline would do irrevocable damage

to Alaska’s ecological systems The National

Environ-mental Policy Act (NEPA), which was passed after the

Santa Barbara oil spill of 1969, gave environmentalists

the leverage they needed to oppose the pipeline’s

construction When the Department of the Interior

tried to satisfy the NEPA requirements by filing a

slight eight-page environmental impact statement,

the Friends of the Earth and the Environmental

De-fense Fund obtained a court injunction on April 13,

1970, which halted construction of the pipeline until

a definitive court ruling on compliance with NEPA

could be obtained

Work on the pipeline was suspended for nearly

four years as proponents and opponents battled in

the bureaucracy and the courts Then came the

Octo-ber, 1973, Yom Kippur War, the Arab oil embargo on

Western countries assisting Israel, and the

quadru-pling of the price of imported oil to nearly twelve

dol-lars per barrel A month later, on November 16, 1973,

Congress relieved the Department of the Interior of

further obligations under NEPA and approved the

construction of a nearly ten-billion-dollar

trans-Alaska pipeline from Prudhoe Bay to Valdez In April,

1974, the monumental task of constructing a pipeline

that would not be environmentally disruptive began

Impact on Resource Use

The pipeline was completed in 1977 and within a year

was carrying one million barrels of oil per day to

Valdez By the early 1980’s, the amount being

trans-ported had doubled, reducing the U.S appetite for

imported oil The opening of the Alaska pipeline

came too late to prevent a second oil crisis in 1979

from driving the price of imported oil to more than

thirty-six dollars per barrel but not too late to

contrib-ute to the general decline in Western demand for

Or-ganization of Petroleum Exporting Countries (OPEC)

oil during the 1980’s During that decade OPEC lost

control over the production rates of member states

and was unable to prevent the price of oil from

plum-meting before restabilizing in the 1990’s at

approxi-mately twenty dollars per barrel In 2006, oil prices

spiked again when the Department of Transportation insisted the Alaska pipeline be examined after an oil spill that leaked nearly 6,290 barrels Upon inspection conducted by British Petroleum (BP), the pipeline was found to have a high level of corrosion, forcing BP

to replace nearly 26 kilometers of pipeline and caus-ing a temporary shutdown of service

Joseph R Rudolph, Jr See also: Energy economics; Energy politics; Exxon Valdez oil spill; Oil and natural gas drilling and wells;

Oil and natural gas exploration; Organization of Pe-troleum Exporting Countries

Alloys

Categories: Mineral and other nonliving resources; products from resources

Alloys are solid combinations of metals or of metals and nonmetallic elements that have technologically de-sirable properties The discoveries of various alloys have marked significant turning points in human history.

Background Alloys are mixtures of metal—such as iron, coal, cop-per, tin, and lead—with other metals or with nonme-tallic elements developed to add desirable properties

to those possessed by the metallic elements These properties include strength, hardness, resistance to corrosion, and the ability to withstand high tempera-tures The properties of alloys depend not only on their chemical composition but also on the way they have been prepared Steel, a family of alloys based on the addition of carbon and other elements to iron, is perhaps the most familiar example in modern tech-nology, but alloys based on aluminum, cobalt, gold, nickel, mercury, titanium, and many other elements are also of great practical importance In many cases the role they play in alloy formation is the determin-ing factor in the importance attached to these ele-ments as natural resources The metals used in alloys must be extracted from their ores, a process that often leaves environmentally troublesome by-products such

as sulfur oxides The manufacture of alloys generally requires sustained high temperatures, creating a de-mand for fossil fuels and raising concern about ther-mal pollution

Archaeologists and historians have named the stages

of early civilization after the principal materials used

for tools in each of them Thus at various times in

dif-ferent parts of the world, civilization progressed from

the Stone Age to a Bronze Age, and then to an Iron

Age Bronze, a mixture of copper and tin, was the first

alloy to receive extensive use Bronze artifacts dated as

early as 3500 b.c.e have been found in both Asia

Mi-nor and China The Hittites are believed to have been

the first peoples, in about 1500 b.c.e., to have

discov-ered how to extract metallic iron from its ores The

su-perior strength of iron led to the replacement of

bronze by iron in armor, weaponry, and knives The

iron used by early civilizations was undoubtedly an

al-loy, though it was not understood as such Steel,

formed by the addition of carbon to iron, was made in

India by 1000 b.c.e Brass, a mixture of copper and

zinc, appears to have been known to the Romans

Modern Alloys

Alloys are generally grouped into ferrous alloys, those

containing iron, and nonferrous alloys Bronze and

brass remain among the most common nonferrous

al-loys Bronze is used in numerous industrial

applica-tions and as a durable material for sculptures Brass is

readily machined and widely used in hardware,

elec-trical fixtures, and decorations Aluminum, extracted

from bauxite ore by high-temperature electrolysis, is

alloyed with manganese, magnesium, or other

ele-ments to produce a lightweight rigid material

Ferrous alloys include steels and cast iron Cast

irons are alloys of iron with 2 to 4 percent carbon and

up to 3 percent silicon Steels are alloys of iron that

contain a smaller amount of carbon as well as other

el-ements The manufacture of steel requires extremely

high temperatures Numerous forms of steel exist

Chromium steel has increased hardness and rust

re-sistance Stainless steel is a special form of chromium

steel with admixtures of manganese, silicon, and

nickel Molybdenum, titanium, phosphorus, and

sele-nium may also be added Manganese is added to steel

to increase strength and durability Tungsten steels

are stronger at high temperatures Vanadium steel

has greater elasticity and is suited to parts that must

bend and regain their shape

Alloys of gold and silver are important in coinage

and for decorative purposes Gold is alloyed with

sil-ver and copper for jewelry Sterling silsil-ver is an alloy of

silver with copper

Certain alloys are employed in dentistry and medi-cine Throughout most of the twentieth century den-tists made liberal use of mercury amalgam, a mold-able mixture of mercury, silver, and other elements, as

a filling material for dental caries (cavities) Concern about mercury toxicity led to a reduction in use of this material Orthopedic surgeons frequently use stain-less steel screws, pins, and rods to hold fractured bones in place so that they can heal properly Alloys also play a role in a variety of orthopedic implants used to replace badly worn or damaged joints Another important group of alloys is those used for permanent magnets These include alnico, a combi-nation of aluminum, nickel, and cobalt Other mag-netic materials include iron-nickel and iron-aluminum combinations The rare earth elements also play a role in some magnetic materials

Superalloys are materials based on nickel, cobalt,

or an iron-nickel mixture and contain carefully con-trolled amounts of trace elements designed to exhibit high strength at temperatures above 1,000° Celsius These materials are used in jet engines, in heat ex-changers, and in chemical production plants

Impact of Alloys on Natural Resources The development and refinement of alloy technology have had a dual effect on natural resource utilization

By making a larger variety of consumer goods avail-able, the development of new alloys has tended to ac-celerate the use of mineral ores and energy sources However, the emergence of alloys that are lighter, more corrosion resistant, and amenable to recycling,

as well as the replacement of some alloys by polymer-based materials and other alloys, slowed the rate of re-source use somewhat after its peak in the 1970’s

Donald R Franceschetti

Further Reading

Askeland, Donald R., and Pradeep P Phulé The Sci-ence and Engineering of Materials 5th ed Toronto:

Nelson, 2006

Campbell, F C., ed Elements of Metallurgy and Engi-neering Alloys Materials Park, Ohio: ASM

Interna-tional, 2008

Kranzberg, Melvin, and Cyril Stanley Smith

“Mate-rials in History and Society.” In The Mate“Mate-rials Revolu-tion, edited by Tom Forester Cambridge, Mass.:

MIT Press, 1988

Plowden, David Steel New York: Viking Press, 1981 Raymond, Robert Out of the Fiery Furnace: The Impact of