Some incoming sunlight is reflected by the Earth's atmosphere and surface, but most is absorbed by the surface, which is warmed. Infrared (IR) radiation is then emitted from the surface. Some IR radiation escapes to space, but some is absorbed by the atmosphere's greenhouse gases (especially carbon dioxide, water vapour, and methane) and reradiated in all directions, some to space and some back toward the surface, where it further warms the surface and lower atmosphere.
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Greenland Self-governing island dependency of Denmark, in the North Atlantic Ocean. The world’s largest island (excluding Australia), it covers 836,330 sq mi (2,166,086 sq km). Population (2005 est.): 57,100. Capitaclass="underline" Nuuk. Two-thirds of the island lies within the Arctic Circle. It is dominated by the massive Greenland Ice Sheet. Fishing is central to the economy; there are also commercial mineral deposits, including a large gold deposit dis¬ covered in 1989, as well as offshore oil exploration. About four-fifths of the population are native Greenlanders, principally of Inuit (see Eskimo) descent, residing in coastal areas. The Inuit probably crossed to northwest¬ ern Greenland from mainland North America, along the islands of the Canadian Arctic, from 4000 bc to ad 1000. The Norwegian Erik the Red vis¬ ited Greenland in 982; his son, Leif Eriksson, introduced Christianity in the 11th century. Greenland came under joint Danish-Norwegian rule in the late 14th century. The original Norse settlements became extinct in the 15th century, but Greenland was recolonized by Denmark in 1721. In 1776 Den¬ mark closed the Greenland coast to foreign trade; it was not reopened until 1950. Greenland became part of the Kingdom of Denmark in 1953. Home rule was established in 1979. At the beginning of the 21st century, the movement for full independence began to gain support, as did the belief among many scientists that global warming was responsible for the accel¬ erated melting of the ice sheet. See map above.
Greenland Ice Sheet Single ice cap, Greenland. Covering about 80% of the island of Greenland, it is the largest ice mass in the Northern Hemi¬ sphere, second only to the Antarctic. It extends 1,570 mi (2,530 km) north to south, has a maximum width of 680 mi (1,094 km) near its northern mar¬ gin, and an average thickness of about 5,000 ft (1,500 m). The ice sheet
melted, the sea level would rise 20 ft (6 m).
Greenpeace International environmental organization. Founded in Canada in 1971 to oppose U.S. nuclear testing in Alaska, it later expanded its goals to include saving endangered species, stopping environmental abuses, and increasing public awareness of environmental problems. It has specialized in “direct, nonviolent action” in protests often designed to gar¬ ner wide publicity. Its members have frequently steered small inflatable craft between the harpoon guns of whalers and their prey. In 1985 the Rain¬ bow Warrior, a Greenpeace ship being used to obstruct French nuclear test¬ ing in the South Pacific, was sunk by French agents, resulting in the death of a photographer. Greenpeace has offices in some 40 countries.
Greens, the German die Grunen Environmentalist political party founded in West Germany in 1979. Initially, it arose out of protests against nuclear power in Germany in the 1970s, and later it embraced all forms of environmentalism. In 1979 about 250 ecologist and environmentalist groups merged, and the first “green” representative was elected to the state parlia¬ ment in Bremen. The following year, the organization officially formed itself as a federal party. It called for the dismantling of the Warsaw Pact and NATO and the demilitarization of Europe. It first won representation in the Bundestag in 1983. It experienced almost constant ideological tensions between its left wing and a more pragmatic faction. In 1990 the eastern German Greens joined with Alliance 90, a coalition of various grassroots organizations, and won representation in the German national legislature, though the western German Greens failed to win representation. In 1993 the two parties agreed to merge as Alliance 90/The Greens, and in 1998 the Greens assumed national political power as a junior coalition partner in the government headed by Social Democratic Party leader Gerhard Schroder.
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802 i Greensboro ► Gregory IX
Greensboro City (pop., 2000: 223,891), north-central North Carolina, U.S. Established in 1808 as the county seat, it was named for Gen. Natha¬ nael Greene. Toward the end of the American Civil War, Greensboro was the temporary capital of both the Confederacy and North Carolina. It is a large wholesale distribution point and an important insurance centre. Tex¬ tiles dominate its diversified industries. It is the site of several colleges and universities.
greenschist facies Vgren-.shist-'fa-shezV One of the major divisions of the mineral facies classification of metamorphic rocks, encompassing the rocks that formed under fairly low temperatures (480-660 °F, or 250- 350 °C) and pressure conditions and usually produced by regional meta¬ morphism. The minerals commonly found in such rocks include quartz, orthoclase, muscovite, chlorite, serpentine, talc, and epidote; carbonate minerals and amphibole (actinolite) may also be present.
Greenspan, Alan (b. March 6, 1926, New York, N.Y., U.S.) U.S. economist and chairman of the board of the Federal Reserve System from August 1987 to January 2006. He received a doctorate from New York University in 1977. Having become a private economic consultant, Greenspan served as chairman of the president’s Council of Economic Advisers under Pres. Gerald Ford. From 1981 to 1983 he chaired the bipartisan National Commission on Social Security Reform. In 1987 Pres. Ronald Reagan appointed him chairman of the Federal Reserve Board, a position he continued to hold under Presidents George Bush, Bill Clin¬ ton, and George W. Bush. As Federal Reserve chairman, he became known for his decisive use of monetary policy in steering the economy between the hazards of inflation and recession.
Greenwich Vgre-nich, 'gri-nij\ Outer borough (pop., 2001: 214,403), Greater London, on the southern bank of the River Thames. The meridian that passes through the borough serves as the basis for standard time as well as for reckonings of longitude throughout the world. Greenwich Park was enclosed by the duke of Gloucester in 1433; it was the site of the Royal Observatory (founded 1675). Other historic buildings include the Queen’s House, now part of the National Maritime Museum, and the Royal Naval College (1873-1998). These and other historic places were designated a UNESCO World Heritage site in 1997. The Millennium Dome, constructed in the 1990s, was used for millennial celebrations to usher in the year 2000.
Greenwich Mean Time (GMT) Former name for mean solar time of the longitude (0°) of the former Royal Observatory at Greenwich, England, or Greenwich meridian. GMT was used to avoid potentially confusing references to local time systems (zones). In accord with tradi¬ tion, 0000 GMT (denoting the start of a solar day) occurred at noon. In 1925 the numbering system for GMT was changed so that the day (like the civil day) began at midnight. Some confusion resulted, and in 1928 the International Astronomical Union changed the designation of the stan¬ dard time of the zero meridian to Universal Time, which remains in gen¬ eral use. The term GMT is still used for some purposes (including navigation) in English-speaking countries.
Greenwich Village Residential section, Lower Manhattan, New York, New York, U.S. A village settlement during colonial times, it became in successive stages an exclusive residential area, a tenement district, and, after 1910, a rendezvous for writers, artists, students, bohemians, and intellectuals. The quaintness of its old townhouses led to rising rents in the 1980s and ’90s. Washington Square, in its centre, is dominated by Washington Arch and New York University.