Greece is believed to have re-serves of more than 100 million metric tons of baux-ite, with most of the deposits concentrated along the central mountain region of Parnassus-Giona-Helikon
Trang 1U.S Geological Survey
Grassland Ecosystems
http://www.usgs.gov/science/
science.php?term=499
See also: Agriculture industry; Desertification; Dust
Bowl; Farmland; Overgrazing; Rangeland; Soil
man-agement
Gravel See Sand and gravel
Greece
Categories: Countries; government and resources
Greece leads the world in the production of perlite and
leads Europe in the production of bauxite and
benton-ite It also produces important quantities of magnesite
and nickel Greece exports about one-half of its
ex-tracted minerals, but its substantial production of
lig-nite is consumed internally The country has few
re-serves of petroleum, and it must import most of its oil
and natural gas.
The Country
Greece is a small, mountainous country occupying
the southern portion of the Balkan Peninsula in
south-eastern Europe It has a deeply indented coastline,
and its more than 1,400 islands and islets make up
about one-fifth of its area Once very weak, Greece’s
economy has expanded considerably since the
mid-dle of the twentieth century, thanks in large part to
economic aid from other countries, trade with the
rest of Europe and the Middle East, and a steadily
in-creasing influx of tourists The rapid industrialization
that the country has experienced since the 1970’s has
encouraged a shift of population from rural areas to
cities and has created serious air and water pollution
In 2008, Greece had an estimated gross domestic
product (GDP) in purchasing power parity of $343.6
billion, making it the thirty-third or thirty-fourth
larg-est economy in the world and the eleventh larglarg-est in
Europe Greece joined the European Union (EU) in
1981, and in 2008, its per capita GDP was estimated to
be thirty-two thousand dollars, which was fourteen
hundred dollars below the average of the European
Union Manufacturing accounts for approximately one-fifth of its GDP, with service industries account-ing for most of the remainder The value of the coun-try’s exports is only about one-third of the value of its imports
Bauxite, Alumina, and Aluminum Greece possesses Europe’s largest known deposits of bauxite, the mixture of minerals from which alumi-num is indirectly refined Bauxite is regarded as the only naturally occurring material that the country ex-ploits at full capacity Greece is believed to have re-serves of more than 100 million metric tons of baux-ite, with most of the deposits concentrated along the central mountain region of Parnassus-Giona-Helikon and on the country’s second largest island, Euboea, in the western Aegean Sea Both underground and open-pit mines are operated
Greece mined an estimated 2.16 million metric tons of bauxite in 2007, while its output of alumina, which represents an intermediate stage in the produc-tion of aluminum, reached an estimated 780,000 met-ric tons the same year The combined value of its ex-ports of bauxite, alumina, and related materials was
$152 million in 2007 Greece is the largest supplier of bauxite in the European Union, although its increas-ing ability to produce its own aluminum has led to greater domestic consumption of bauxite and alu-mina
Bauxites Parnasse Mining Company pioneered the extraction of bauxite in Greece in 1933 However, only with the creation of Aluminum of Greece S.A did the nation’s production of the metal itself begin Alumi-num of Greece—a combine headed by the French-owned firm Pechiney and involving the American company Reynolds Metals as well as public and private Greek funding—began operations in the 1960’s The firm S&B Industrial Minerals S.A supplied the com-pany with ore and went on to absorb Bauxites Par-nasse in 1996, while Aluminum of Greece merged with Mytilineos Holdings S.A in 2007 As of 2009, most Greek bauxite production was under the direction of S&B and its subsidiary, Greek Helicon Bauxites S.A
Perlite According to published figures, Greece produces more perlite than any other nation on earth, turning out an estimated 1.65 million metric tons of the mate-rial in crude and screened forms in 2007 Perlite is a volcanic glass whose particles expand to many times
Trang 2Global Resources Greece • 539
Greece: Resources at a Glance
Official name: Hellenic Republic Government: Parliamentary republic Capital city: Athens
Area: 50,953 mi2; 131,957 km2
Population (2009 est.): 10,737,428 Language: Greek
Monetary unit: euro (EUR)
Economic summary:
GDP composition by sector (2008 est.): agriculture, 3.7%; industry, 20.6%; services, 75.7%
Natural resources: lignite, petroleum, iron ore, bauxite, lead, zinc, nickel, magnesite, huntite, marble, salt,
hydropower potential, perlite, bentenite, kaolin, pumice
Land use (2005): arable land, 20.45%; permanent crops, 8.59%; other, 70.96%
Industries: tourism, food and tobacco processing, textiles, chemicals, metal products, mining, petroleum
Agricultural products: wheat, corn, barley, sugar beets, olives, tomatoes, wine, tobacco, potatoes, beef, dairy products Exports (2008 est.): $29.14 billion
Commodities exported: food and beverages, manufactured goods, petroleum products, chemicals, textiles
Imports (2008 est.): $93.91 billion
Commodities imported: machinery, transport equipment, fuels, chemicals
Labor force (2008 est.): 4.96 million
Labor force by occupation (2005 est.): agriculture, 12.4%; industry, 22.4%; services, 65.1%
Energy resources:
Electricity production (2007 est.): 59.33 billion kWh
Electricity consumption (2006 est.): 55.98 billion kWh
Electricity exports (2007 est.): 269 million kWh
Electricity imports (2007 est.): 5.894 billion kWh
Natural gas production (2007 est.): 24 million m3
Natural gas consumption (2007 est.): 4.069 billion m3
Natural gas exports (2007 est.): 0 m3
Natural gas imports (2007 est.): 4.1 billion m3
Natural gas proved reserves ( Jan 2008 est.): 1.982 billion m3
Oil production (2007 est.): 4,265 bbl/day Oil imports (2005): 527,200 bbl/day Oil proved reserves ( Jan 2008 est.): 10 million bbl
Source: Data from The World Factbook 2009 Washington, D.C.: Central Intelligence Agency, 2009.
Notes: Data are the most recent tracked by the CIA Values are given in U.S dollars Abbreviations: bbl/day = barrels per day;
GDP = gross domestic product; km 2 = square kilometers; kWh = kilowatt-hours; m 3 = cubic meters; mi 2 = square miles.
Athens Italy
Bulgaria
Turkey
Greece
Albania
Macedonia
Adriatic
Sea
Aegean Sea
Black Sea
I o n i a n
S e a
M e d i t e r r a n e a n
S e a
Trang 3their original sizes when heated and is used
exten-sively in construction, horticulture, and industry It
has also proven useful in dispersing oil spills at sea
Perlite is found associated with sites of ancient
volca-nic activity in the northeastern region of Thrace and
on several islands in the southern Aegean Sea,
includ-ing Melos, Kos, and Gyali—the last of which is also a
major source of pumice
S&B is the country’s (and the world’s) largest miner
of perlite The company maintains several open-pit
facilities on Melos, where it discovered deposits in
1954 and opened the continent’s largest facility in
1975 It operates another mine on Kos The company
exports most of its production to Europe, North
Amer-ica (where Armstrong Industries is a major customer),
and Asia Smaller producers include S&B subsidiary
Otavi Mines Hellas S.A., with operations on Melos,
and Aegean Perlites S.A., on Gyali Easy access to
inex-pensive transportation by ship has helped these
com-panies maintain an international price advantage
Thanks to a project sponsored by the European Union,
the expansion process necessary to perlite’s
commer-cial utilization has also been greatly enhanced in
re-cent years, resulting in higher quality
Bentonite and Kaolin
Greece produces more bentonite than any other
country in Europe and is second in world production
only to the United States Its total output (crude and
processed) amounted to an estimated 952,500 metric
tons in 2007, nearly 9 percent of the world’s total
Ben-tonite is a clay utilized in iron ore pelletizing, in
foun-dering, as a binding agent in cement and adhesives,
and in pet litter The material is usually formed from
the weathering of volcanic ash, and deposits are found
on Melos and, to a lesser extent, the island of Cimolus
It is mined from the surface in both locations
As is the case with many of the country’s other
min-erals, the bentonite market is dominated by S&B,
which absorbed the second largest bentonite mining
operation on Melos, Mykobar Mining Company S.A.,
in 1999 Mediterranean Bentonite S.A also operates a
small surface mine on Melos, but S&B accounts for
about 85 percent of the country’s production Most is
exported to other countries of the European Union
and to North America
Greece also possesses deposits of a second type of
clay, kaolin, near Drama in the northeastern part of
the country The country produced an estimated
60,300 metric tons of kaolin in 2007, but because of
its inferior nature, it was used only domestically in ce-ment and ceramic glazes
Nickel The common, industrially important element nickel
is utilized primarily in the manufacture of stainless steel and other alloys Greece mined an estimated 2.7 million metric tons of nickel ore in 2007, a level it had maintained more or less unchanged over the preced-ing several years The country is thought to have nickel reserves of 250 million metric tons, with depos-its concentrated on the Aegean island of Euboea, on the mainland near Larimna opposite Euboea, and
in northwestern Greece near the Albanian border Deposits in the first two regions are “transported,” or secondary, meaning that they have been eroded and redeposited in new locations by natural forces—a situ-ation that makes for easier extraction The deposits of ore in the north evolved in place, and while they are more difficult to mine, they contain a higher content
of nickel
Greece’s primary nickel producer (and one of the largest in the world) is the state-controlled General Mining and Metallurgical Company S.A (LARCO), which was founded in 1963 and operates complexes
of underground, open-pit, and closed-pit mines Its oldest operation is at Agios Ioannis near Larimna, the ore from which it began smelting in 1966 The com-pany’s mines in Euboea went into operation three years later Today LARCO is one of the world’s largest producers of iron-nickel alloys and exports to a num-ber of steel manufacturers in Western Europe
Magnesite and Huntite Magnesite ore and its various processed forms—
“dead burned” magnesia, calcined magnesite, and so on—have a variety of uses, including the manufacture
of refractories (the linings of furnaces and the like) and synthetic rubber The ore is also one of the sources of the important industrial metal magnesium High-grade deposits of magnesite are found in the Chalcidice peninsula in the northern part of Greece
as well as in Euboea, but the latter deposits were not exploited after 1999
Greece produced more than 3 percent of the world supply of the material in 2007, an estimated 628,000 metric tons Grecian Magnesite S.A is the only active producer in Greece and the largest in the European Union The company operates open-pit mines near Yerakina, where it also crushes and processes the
Trang 4magnesite into various application-specific grades,
and exports virtually all its production to other
Euro-pean Union countries
Deposits of the related mineral huntite are found
in the Kozáni basin in the northern province of
donia (not to be confused with the Republic of
Mace-donia) It is used in paper coatings and sealants and as
a component of flame retardants Greece is virtually
the only commercial source for huntite and produced
an estimated 18,000 metric tons of the mineral in
2007, most of it for export White Minerals S.A and
Microfine Hellas S.A are the two producers
Pumice and Related Materials
Greece is the second largest source of pumice in the
world, producing an estimated 960,000 metric tons in
2007 The light, highly porous volcanic glass is used
in horticulture and, particularly outside the United
States, as aggregate in construction Pumice is found
on several Greek islands in the southern Aegean Sea
It was once mined on Thíra (also known as Santorini),
but today the only extraction taking place is on the
is-land of Gyali, where pumice was deposited
approxi-mately 200,000 years ago by a volcano on the nearby
island of Nísiros Lava Mining and Quarrying
Com-pany, a subsidiary of Heracles General Cement, is
Greece’s only pumice producer as well as the largest
pumice exporter in the world The company quarries
the pumice without the use of explosives and loads
ships by means of a complex series of conveyor belts
Lava Mining also quarries and distributes other
in-dustrial materials associated with ancient volcanic
ac-tivity It extracts pozzolanic rock at Xylokeratia on
Melos and gypsum at Altsi on the island of Crete, with
the bulk of its production of both materials going into
the domestic manufacture of cement The
micro-crystalline quartz it quarries on Melos is used in glass
and ceramics
Lignite
Lignite, or brown coal, is Greece’s only important
nat-ural fuel source, and it accounts for about 60 percent
of the country’s power generation The country is the
second largest producer of the material in the
Euro-pean Union (after Germany) and the fourth largest in
the world Greece is thought to possess reserves of
nearly 7 billion metric tons of lignite in more than
forty widely scattered basins, the largest of which is in
Macedonia Lignite is an inferior grade of coal, and
the deposits in the Megalópolis region in the
Pelo-ponnese Peninsula are of particularly poor quality A large deposit in the Drama basin is also of poor quality and remains relatively unexploited Greece produced
an estimated 74 million metric tons of the material in
2007, most of it from open pits
Virtually all Greek lignite is mined by Public Power Corporation (PPC) S.A., which was founded in 1951
to exploit the reserves in Aliveri on the island of Euboea A second company, Ptolemais Lignite Mines (LIPTOL), undertook a larger operation to extract the material from the Ptolemais deposit in the Pindus Mountains of northern Greece, eventually leading to one of the most substantial lignite mining and pro-cessing operations in the world PPC acquired 90 per-cent of LIPTOL in 1959, and the two merged in 1975 PPC owns rights to about 60 percent of Greece’s known lignite reserves, using most of the material it-self The company, which is state-controlled, gener-ates virtually all of Greece’s electrical power
Lignite’s use as an energy source poses serious en-vironmental problems, and Greece is under pressure from the European Union to modernize its operation
to reduce carbon emissions Although it continues
to rely on lignite, PPC also generates small amounts
of hydroelectric power from dams on rivers in the Pindus Mountains
Other Resources Greece possesses modest deposits of gold, silver, chro-mite, lead, barite, and zinc S&B has been active in identifying further deposits of gold, and Thracean Gold Mines S.A (of which S&B is a part-owner) dis-covered a substantial deposit in Thrace in 1998
A small oil field in the northern Aegean Sea has been exploited since 1981 Discovered by the Ameri-can firm Oceanic and developed by the North Aegean Petroleum Company (NAPC)—a consortium headed
by Denison Mines of Canada—the field reached a maximum production of 30,000 barrels per day (bpd)
in 1989 However, production has fallen, while the country’s dependence on foreign petroleum has grown In 2004, a larger field in the same area was identified west of the island of Thásos Believed to contain approximately 227 million barrels, it is being developed by Kavala Oil S.A and Energiaki S.A and may reach production levels of 50,000 bpd
Marble has been quarried throughout Greece for millennia, and the country produced an estimated 150,000 cubic meters of the stone in various sizes of cuts in 2007 The major suppliers are Aghia Marina
Trang 5Marble Ltd., with quarries at Pallini, and Chris G.
Karantanis & Sons Company at Corinth Greece also
produced about 60,000 metric tons of dolomite and
95,000 metric tons of flysch in 2007 Salt production
yielded an estimated 195,000 metric tons the same
year
Grove Koger
Further Reading
Arvanitidis, Nikos “Northern Greece’s Industrial
Minerals: Production and Environmental
Technol-ogy Developments.” Journal of Geochemical
Explora-tion 62, nos 1-3 (1998): 217-227.
Couloumbis, Theodore A., Theodore Kariotis, and
Fotini Bellou, eds Greece in the Twentieth Century.
New York: Frank Cass, 2003
Curtis, Glenn E., ed Greece: A Country Study 4th ed.
Washington, D.C.: Federal Research Division,
Li-brary of Congress; Headquarters, Department of
the Army, 1995
Grossou-Valta, M., and F Chalkiopoulou “Industrial
Minerals and Sustainable Development in Greece.”
In Mineral Resource Base of the Southern Caucasus and
Systems for Its Management in the Twenty-first Century,
edited by Alexander G Tvalchrelidze and Georges
Morizot Boston: Kluwer Academic, 2002
Hatzilazaridou, Kiki “A Review of Greek Industrial
Minerals.” In Industrial Minerals and Extractive
In-dustry Geology, edited by Peter W Scott and Colin
Malcolm Bristow London: Geological Society, 2002
Kavouridis, Konstantinos “Lignite Industry in Greece
Within a World Context: Mining, Energy Supply,
and Environment.” Energy Policy 36, no 4 (2008):
1257-1272
Kennedy, Bruce A Surface Mining Littleton, Colo.:
Society for Mining, Metallurgy, and Exploration,
1990
Kogel, Jessica Elzea, et al Industrial Minerals and Rocks:
Commodities, Markets, and Uses 7th ed Littleton,
Colo.: Society for Mining, Metallurgy, and
Explora-tion, 2006
Konsolas, Nicholas, A Papadaskalopoulos, and
I Plaskovitis Regional Development in Greece New
York: Springer, 2002
Web Sites
Greek Institute of Geology and Mineral
Exploration
http://www.igme.gr/enmain.htm
Hellenic Republic Ministry of Development http://www.ypan.gr/index_uk_c_cms.htm See also: Aluminum; Marble; Perlite; Pumice
Green Revolution
Categories: Environment, conservation, and resource management; historical events and movements
Impending famine in the 1960’s in the underdevel-oped countries of Asia, Africa, and Latin America was averted by the Green Revolution, which was made pos-sible by the introduction of hybrid “miracle grains” of wheat and rice.
Background From 1960 to 1965 a number of poor countries in the world could not produce enough food for their grow-ing populations The Earth’s population had almost doubled to 3.7 billion people in fifty years, with more than 900 million people not getting adequate nour-ishment to lead productive lives Famine had been avoided during the post-World War II period of his-tory only because production was high for American farmers and surplus grains were shipped overseas as food aid
In 1966 and 1967, the Indo-Pakistan subcontinent suffered two consecutive crop failures because of monsoons The United States shipped one-fifth of its wheat reserves to India and sustained sixty million persons in India for a two-year period on American food shipments It became obvious, as populations continued to grow, that the United States would not
be able to continue to supply enough food to feed the world’s growing population adequately In the mid-1960’s, American policy began to change from giving poor countries direct food aid to educating and help-ing them to increase their own food production The United States had, in the 1950’s, responded to
an ailing agricultural economy in Mexico by sending scientists from the Rockefeller Foundation to develop
a new wheat that yielded twice as much grain as tradi-tional varieties The project was successful, and in
1962, the Rockefeller Foundation collaborated with the Ford Foundation to establish the International Rice Research Institute at Los Baños, in the
Trang 6Philip-pines Two strains of rice, PETA from
Indone-sia and DGWG from China, were crossbred to
produce a high-yield semidwarf variety of rice
called IR-8
Both the new rice and new wheat were
de-veloped to have short but strong and stiff
stalks to support large heads of grain Yields
from the rice and wheat seeds were two to five
times higher than traditional varieties as long
as they were grown with large inputs of
fertil-izer, water, and pesticides
Seeds were shipped to ailing countries Asia
expanded acreage planted in the new varieties
from 81 hectares to 14 million hectares
be-tween 1965 and 1969 Pakistan’s wheat harvest
increased 60 percent between 1967 and 1969
India’s production of wheat increased 50
per-cent, and the Philippines’ production of rice
was so successful that it stopped importing
rice and became an exporter
Positive Aspects
The new seeds were dependent on irrigation
by tube wells (closed cylindrical shafts driven
into the ground) and electrical pumps
Irriga-tion methods were installed in poor countries
This new availability of water made it feasible
for farmers to grow crops year-round The dry
season, with its abundant sunlight, had
previ-ously been a time when crops could not be
grown With the advent of irrigation, the dry
season became an especially productive
grow-ing season Poor countries in tropical and
sub-tropical regions were able to grow two, three, and
sometimes four crops a year Approximately 90
per-cent of the increase of the world’s production of grain
in the 1960’s, 70 percent in the 1970’s, and 80 percent
in the 1980’s was attributable to the Green
Revolu-tion
The Green Revolution brought to politicians in
de-veloping countries the realization that they could not
depend permanently on food aid from other nations
Whereas leaders and politicians in these countries
had previously concentrated on developing industrial
projects, the extreme pressure of overpopulation on
their limited food and land supplies caused them to
address agricultural problems and give emphasis to
programs to encourage production of food supplies
Countries that were affected by, and benefited from,
the Green Revolution include India, Pakistan, Sri
Lanka, the Philippines, Turkey, Burma (Myanmar), Malaysia, Indonesia, Vietnam, Kenya, the Ivory Coast, Tunisia, Morocco, Algeria, Libya, Brazil, and Para-guay
Drawbacks and Environmental Impact Large-scale pesticide application not only is costly but also can have an adverse effect on the environment Only a small percentage of insecticides used on crops actually reach the target organism The rest affects the environment by endangering groundwater, aquatic systems, pollinators, various soil-dwelling in-sects, microbes, birds, and other animals in the food chain In addition, large water inputs are needed for proper irrigation of crops Of the farmers who can af-ford to irrigate in poor countries, many do not do so properly, and thereby cause salinization, alkalization,
In this 1970 photograph, Norman Borlaug, considered the father of the Green Revolution, studies grains that he helped develop (AP/Wide World
Photos)
Trang 7and waterlogging of soils, rendering them useless for
growing crops
Large-scale application of fertilizers is costly and
reaches a point where further applications do not
pro-duce the expected increase in yield and begin to cost
far more than they are worth Crop yields also
de-crease because of inde-creased soil erosion, loss of soil
fertility, aquifer depletion, desertification, and
pollu-tion of groundwater or surface waters
The Green Revolution exemplifies monoculture
agriculture, the planting of large areas with a single
type of seed This use of monotypes can create
multi-ple environmental problems In many cases, the
wide-spread use of genetically homogeneous seed caused
old varieties with great genetic variability to be
aban-doned Crops consisting entirely of genetically
homo-geneous rice and wheat are more vulnerable to
dis-ease and insects, requiring inputs of agrochemicals
which can be harmful to both the environment and
human health Planting vast hectares of monotypes
has the potential to result in massive crop failure due
to destructive fungi or chemical-resistant insects
Moreover, Green Revolution techniques rely heavily
on fossil fuel to run machinery, to produce and apply
inorganic fertilizers and pesticides, and to pump water
for irrigation Gasoline is costly and is often in short
supply in many of the poor nations Sociologically, the
Green Revolution in poor countries favored wealthier
farmers with the capital to pay the considerable costs
of irrigation, seeds, fertilizers, pesticides, and fossil
fuels This fact has accentuated the financial gap
be-tween the big and small farmers
Outlook
The drawbacks of the Green Revolution have led
farmers and scientists to seek safer and more diverse
solutions to world food needs Genetic engineers
hope to be able to breed high-yield plant strains that
have greater resistance to insects and disease, need
less fertilizer, and are capable of making their own
ni-trogen fertilizer so as not to deplete the soil of
nutri-ents Proponents of integrated pest management
con-tinue to investigate combinations of crop rotation,
time of planting, field sanitation, and the use of
pred-ators and parasites as ways to control insects without
the use of harmful chemicals Regardless of
develop-ments in food production and technology, however,
in the long term the most important aspect of
address-ing world food needs is to control population growth
Dion C Stewart
Further Reading
Alauddin, Mohammad, and Clement Tisdell The
“Green Revolution” and Economic Development: The Process and Its Impact in Bangladesh New York: St.
Martin’s Press, 1991
Brown, Lester R Seeds of Change: The Green Revolution
and Development in the 1970’s New York: Published
for the Overseas Development Council by Praeger, 1970
Chiras, Daniel D., and John P Reganold Natural
Re-source Conservation: Management for a Sustainable Fu-ture 10th ed Upper Saddle River, N.J.: Pearson
Prentice Hall, 2009
Cotter, Joseph Troubled Harvest: Agronomy and
Revolu-tion in Mexico, 1880-2002 Westport, Conn.:
Prae-ger, 2003
Miller, G Tyler, Jr., and Scott Spoolman
Environmen-tal Science: Problems, Concepts, and Solutions 12th ed.
Belmont, Calif.: Brooks Cole, 2008
Perkins, John H Geopolitics and the Green Revolution:
Wheat, Genes, and the Cold War New York: Oxford
University Press, 1997
Shiva, Vandana The Violence of the Green Revolution:
Third World Agriculture, Ecology, and Politics
Lon-don: Zed Books, 1991
Singh, Himmat Green Revolutions Reconsidered: The
Ru-ral World of Contemporary Punjab New York: Oxford
University Press, 2001
Wu, Felicia, and William Butz The Future of Genetically
Modified Crops: Lessons from the Green Revolution.
Santa Monica, Calif.: RAND Institute, 2004 See also: Fertilizers; Genetic diversity; Monoculture agriculture; Pesticides and pest control; Population growth; Rice; Wheat
Greenhouse gases and global climate change
Categories: Environment, conservation, and resource management; geological processes and formations; pollution and waste disposal
The greenhouse effect protects Earth and all life on the planet from succumbing to extremes of temperature at the same time that it threatens to overheat the planet as the concentration of greenhouse gases increases.
Trang 8The atmosphere is heated directly by carbon dioxide
and water vapor absorbing heat or infrared energy
from the Earth’s surface Without this natural
pro-cess, called the greenhouse effect, the average
atmo-spheric temperature would be around 16° Celsius
lower than it is now—too cold to support life The
ac-tivities of human beings have increased natural
con-centrations of carbon dioxide and other gases,
includ-ing chlorofluorocarbons (CFCs), fluorinated gases
(HCFCs), methane (CH4), nitrous oxide (N2O), and,
to some extent, ozone (O3), all now labeled, along
with water vapor, as greenhouse gases The average
temperature has increased as well This concurrent
rise in temperature and greenhouse gas
concentra-tion is called global climate change or global warming The concern is not with the “greenhouse effect” it-self, which in actuality is necessary for life on Earth The cause for alarm is the intensification or enhance-ment of the greenhouse effect and the resulting changes in climate, weather patterns, and the oceans, and the effect of these on living organisms Thus, the term global climate change is preferred over global warming because the effects are expected to extend
to other aspects of climate beyond that of tempera-ture
The climate of the Earth is not stable; it has changed from natural causes throughout Earth’s history, be-fore human beings existed, and it will continue to change However, increased concentrations of
Atmosphere
Sun Earth
The Greenhouse Effect
The greenhouse effect is aptly named: Some heat from the Sun is reflected back into space (small squiggled arrows), but some becomes trapped by Earth’s atmosphere and re-radiates toward Earth (straight arrows), heating the planet just as heat is trapped inside a greenhouse.
Trang 9house gases from human activities, particularly
indus-trialization, are now recognized as having a warming
effect on the Earth’s atmosphere The U.S National
Oceanic and Atmospheric Administration reported
that measurements from land and oceans show that
between 1850 and 2006 the global mean surface
tem-perature increased between 0.56° and 0.92° Celsius,
while from preindustrial times to 2006, the
concentra-tion of CO2grew from about 280 to about 380 parts
per million (ppm) Much debate occurred in the late
twentieth century about correlation or causality of
temperature increase and the level of CO2 Most
re-spected scientists ascribed the increase to human
causes However, resistance to this assessment existed,
including from the federal government of the United
States In 2007, the Intergovernmental Panel on
Cli-mate Change, created by the United Nations and the
World Meteorological Organization, released a
port based on solid research and analysis of data by
re-spected scientists from many different countries It
stated, at a high confidence level, with 90 percent
as-surance statistically, that human activities were
induc-ing climate change Consequences—such as coastal
flooding, loss of biodiversity, widespread drought,
and extended heat waves—were more likely with
con-tinued increases of greenhouse gases As a result, calls
came for people and governments to act to reduce the
chance of serious or even disastrous impacts
Greenhouse Gases and Resource Use
Fossil fuels—petroleum, natural gas, and coal—have
been identified as the main culprits in global climate
change The name fossil fuels reflects their origin
from decomposed dead plants and animals over
hun-dreds of millions of years Industrialization has been
literally fueled by the carbon in fossil fuels, providing heat energy for factories, electricity production, and transportation Large amounts of carbon, which had been sitting in the Earth’s crust in the form of fossil fu-els, were burned and combined with oxygen, produc-ing CO2, which in the atmosphere absorbed heat from the Earth’s surface, leading to documented increases
in temperature
Methane, a major component of natural gas, is pro-duced naturally and by human activities, including livestock production and rice cultivation Methane’s concentration grew from preindustrial levels of about
715 parts per billion to about 1,774 ppb in 2005, a gain
of about 148 percent Fluorinated gases, replacements for CFCs (contributors to ozone depletion), have grown in concentration They have a higher green-house impact than CFCs Nitrous oxide, produced naturally by plants, also reaches the atmosphere largely
as a result of fertilizer use and fossil-fuel combustion Its concentration increased about 18 percent from preindustrial levels of about 270 ppb to 319 ppb in 2005
Other actions contributing to increased green-house gases include removal of natural vegetation for urban and agricultural purposes The elimination of green plants leads to reduced photosynthesis and therefore less carbon dioxide being removed and re-placed by oxygen Furthermore, economic problems can result from deforestation and desertification as land loses its productivity
Climate Change and Resource Use Sea levels have risen around 12.2 to 22.3 centimeters from partial melting of the Greenland and Antarctic ice sheets, augmented by the physical expansion of
U.S Greenhouse Gas Emissions
(millions of metric tons)
Carbon dioxide 5,017.5 5,890.5 5,875.9 5,940.4 6,019.9 6,045.0 5,934.4
Source: U.S Energy Information Administration, Emissions of Greenhouse Gases in the United States, 2006, 2006.
Note: High GWP (global warming potential) gases are hydrofluorocarbons, perfluorcarbons, and sulfur hexafluoride.
Trang 10the warming ocean water Coastal zones and small
is-lands especially are in danger not only from flooding
but also from effects of enhanced storms Biodiversity
of the oceans, including in the Great Barrier Reef, is
threatened In Europe, although the growing season
is now warmer and crop yields and forest growth have
increased, more intense heat waves and widespread
flooding have caused health and safety problems
Melting of glaciers in the Himalayas and snowpacks in
the mountains of the western United States and
Can-ada is likely to cause floods and maybe avalanches
Be-cause ice reflects sunlight, as Arctic ice melts, the rate
of global warming may accelerate Salinization and
desertification are likely in currently productive
agri-cultural lands in dry regions in South America As the
oceans have become warmer, levels of salinity and
CO2have changed, probably altering ocean currents
and their distribution of heat The acidity of the
oceans has changed as well, perhaps greatly
disrupt-ing fisheries, coral reefs, and marine ecosystems as a
whole
Possible Changes in Resource Use
Calls and actions for reducing carbon emissions and
lessening the output of other greenhouse gases have
intensified around the world Conservation is an
im-portant option, but some people are concerned that
limiting the economic activities that produce CO2will
hurt the economy Yet conservation can build its own
industries, as indicated by the number of “green”
products being introduced
Margaret F Boorstein
Further Reading
Abrahmason, Dean Edwin, ed The Challenge of Global
Warming Washington, D.C.: Island Press, 1989.
Archer, David Global Warming: Understanding the
Fore-cast Malden, Mass.: Blackwell, 2007.
Firor, John The Changing Atmosphere: A Global
Chal-lenge New Haven, Conn.: Yale University Press,
1990
Gore, Al An Inconvenient Truth: The Planetary
Emer-gency of Global Warming and What We Can Do About It.
Emmaus, Pa.: Rodale Press, 2006
Gribbin, John Hothouse Earth: The Greenhouse Effect
and GAIA New York: Grove Weidenfeld, 1990.
Johansen, Bruce E Global Warming 101 Westport,
Conn.: Greenwood Press, 2008
Kraljic, Matthew A., ed The Greenhouse Effect New
York: H W Wilson, 1992
Krupp, Fred, and Miriam Horn Earth, the Sequel: The
Race to Reinvent Energy and Stop Global Warming New
York: W W Norton, 2008
Metz, Beth, ed Climate Change 2007: Mitigation of
Cli-mate Change—Contribution of Working Group Three to the Fourth Assessment of the Intergovernmental Panel on Climate Change New York: Cambridge University
Press, 2007
Rowlands, Ian H The Politics of Global Atmospheric
Change New York: St Martin’s Press, 1995.
Schneider, Stephen H Global Warming: Are We Entering
the Greenhouse Century? San Francisco: Sierra Club
Books, 1989
Solomon, Susan, ed Climate Change 2007: The Physical
Science Basis—Contribution of Working Group One to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change New York: Cambridge
Uni-versity Press, 2007
Somerville, Richard C J The Forgiving Air:
Understand-ing Environmental Change 2d ed Boston: American
Meteorological Society, 2008
Svensson, Lisa Combating Climate Change: A
Transat-lantic Approach to Common Solutions Washington,
D.C.: Center for Transatlantic Relations, Johns Hopkins University, 2008
Tickell, Oliver Kyoto2: How to Manage the Global
Green-house New York: Palgrave Macmillan, 2008.
Web Sites Energy Information Administration, U.S Department of Energy
Greenhouse Gases, Climate Change, and Energy http://www.eia.doe.gov/bookshelf/brochures/ greenhouse/Chapter1.htm
Environment Canada Greenhouse Gas Sources and Sinks http://www.ec.gc.ca/pdb/ghg/ghg_home_e.cfm National Oceanic and Atmospheric
Administration Climate Program Office http://www.climate.noaa.gov U.S Environmental Protection Agency Greenhouse Gas Emissions
http://www.epa.gov/climatechange/emissions/ index.html#ggo
See also: Agenda 21; American Chemistry Council; Climate Change and Sustainable Energy Act; Earth