ight to do so) and does not recognize the
claims of any other nation; Republic of Marshall Islands claims Wake
Island

Climate: mostly temperate, but tropical in Hawaii and Florida and
arctic in Alaska, semiarid in the great plains west of the Mississippi
River and arid in the Great Basin of the southwest; low winter
temperatures in the northwest are ameliorated occasionally in January
and February by warm chinook winds from the eastern slopes of the
Rocky Mountains

Terrain: vast central plain, mountains in west, hills and low
mountains in east; rugged mountains and broad river valleys in Alaska;
rugged, volcanic topography in Hawaii

Natural resources: coal, copper, lead, molybdenum, phosphates,
uranium, bauxite, gold, iron, mercury, nickel, potash, silver,
tungsten, zinc, petroleum, natural gas, timber

Land use:
arable land: 20%
permanent crops: 0%
meadows and pastures: 26%
forest and woodland: 29%
other: 25%

Irrigated land: 181,020 sq km (1989 est.)

Environment:
current issues: air pollution resulting in acid rain in both the US
and Canada; the US is the largest single emitter of carbon dioxide
from the burning of fossil fuels; water pollution from runoff of
pesticides and fertilizers; very limited natural fresh water resources
in much of the western part of the country require careful management;
desertification
natural hazards: tsunamis, volcanoes, and earthquake activity around
Pacific Basin; hurricanes along the Atlantic coast; tornadoes in the
midwest; mudslides in California; forest fires in the west; flooding;
permafrost in northern Alaska is a major impediment to development
international agreements: party to - Air Pollution, Air
Pollution-Nitrogen Oxides, Antarctic Treaty, Climate Change,
Endangered Species, Environmental Modification, Marine Dumping, Marine
Life Conservation, Nuclear Test Ban, Ozone Layer Protection, Ship
Pollution, Tropical Timber 83, Wetlands, Whaling; signed, but not
ratified - Air Pollution-Volatile Organic Compounds,
Antarctic-Environmental Protocol, Biodiversity, Desertification,
Hazardous Wastes, Tropical Timber 94

Note: world's fourth-largest country (after Russia, Canada, and China)

@United States:People

Population: 263,814,032 (July 1995 est.)

Age structure:
0-14 years: 22% (female 28,391,451; male 29,845,630)
15-64 years: 65% (female 86,454,415; male 85,474,002)
65 years and over: 13% (female 19,949,978; ma