Definitions and Notes

This information is included in Appendix A: Abbreviations, which includes all abbreviations and acronyms used in the Factbook, with their expansions.

An acronym is an abbreviation coined from the initial letter of each successive word in a term or phrase. In general, an acronym made up solely from the first letter of the major words in the expanded form is rendered in all capital letters (NATO from North Atlantic Treaty Organization; an exception would be ASEAN for Association of Southeast Asian Nations). In general, an acronym made up of more than the first letter of the major words in the expanded form is rendered with only an initial capital letter (Comsat from Communications Satellite Corporation; an exception would be NAM from Nonaligned Movement). Hybrid forms are sometimes used to distinguish between initially identical terms (ICC for International Chamber of Commerce and ICCt for International Criminal Court).

This entry generally gives the numbers, designatory terms, and first-order administrative divisions as approved by the US Board on Geographic Names (BGN). Changes that have been reported but not yet acted on by the BGN are noted. Geographic names conform to spellings approved by the BGN with the exception of the omission of diacritical marks and special characters.

This entry provides the distribution of the population according to age. Information is included by sex and age group as follows: 0-14 years (children), 15-24 years (early working age), 25-54 years (prime working age), 55-64 years (mature working age), 65 years and over (elderly). The age structure of a population affects a nation's key socioeconomic issues. Countries with young populations (high percentage under age 15) need to invest more in schools, while countries with older populations (high percentage ages 65 and over) need to invest more in the health sector. The age structure can also be used to help predict potential political issues. For example, the rapid growth of a young adult population unable to find employment can lead to unrest.

This entry provides a country's ten most important agricultural products, listed by annual tonnage.

This entry refers to specified gases and particulates released by various sources of animals, plants, goods, and processes that can contribute to global warming, poor air quality, pollution, and climate change.

particulate matter emissions - This entry provides the modeled annual mean concentration of particulate matter of less than 2.5 microns in diameter (PM_2.5) measured in micrograms per cubic meter of air. Exposure to PM_2.5 pollutants should not exceed an annual mean concentration of 10 micrograms per cubic meter, according to World Health Organization guidelines. Particulate matter are inhalable and respirable particles composed of sulphate, nitrates, ammonia, sodium chloride, black carbon, mineral dust, and water. Fine particles less than 2.5 microns pose the greatest health risks because they can penetrate the lungs and enter the bloodstream. Sources include combustion engines, solid-fuel combustion, and other industrial activities. Exposure to high concentrations of particulate matter is associated with increased mortality and morbidity, although even low concentrations of particulate matter can impact health. By reducing air pollution levels, countries can decrease the burden of disease from stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma.

carbon dioxide emissions - This entry provides the annual quantity of carbon dioxide emissions for a country, as measured in megatons.  Carbon dioxide is a greenhouse gas emitted through human-influenced and natural processes. Human-influenced sources include the burning of fossil fuels (including coal, natural gas, and oil), solid waste, trees, and other biological materials, as well as certain chemical processes, such as cement production. Natural sources include decomposition, ocean release, and respiration. Carbon dioxide is a major contributor to climate warming, air quality, global warming, and pollution.

methane emissions - This entry provides the annual quantity of methane emissions for a country, as measured in megatons. Methane is a greenhouse gas emitted from the breakdown of organic material from human-influenced and natural processes. Human-influenced sources include the production and transport of coal, natural gas, and oil; the decay of organic waste in landfills; agricultural activities; stationary and mobile combustion; waste water treatment; and certain industrial processes. Natural sources include the decay of plant material in wetlands, the seepage of gas from underground deposits, and the digestion of food by ruminants. Methane emissions cause poor air quality, health issues for animals and humans, and reduced crop yields, and are a contributor to climate change.

This entry gives the total number of airports or airfields recognizable from the air. The runway(s) may be paved (concrete or asphalt surfaces) or unpaved (grass, earth, sand, or gravel surfaces) and may include closed or abandoned installations. Airports or airfields that are no longer recognizable (overgrown, no facilities, etc.) are not included. Note that not all airports have accommodations for refueling, maintenance, or air traffic control.

This entry gives the total number of airports with paved runways (concrete or asphalt surfaces) by length. For airports with more than one runway, only the longest runway is included according to the following five groups - (1) over 3,047 m (over 10,000 ft), (2) 2,438 to 3,047 m (8,000 to 10,000 ft), (3) 1,524 to 2,437 m (5,000 to 8,000 ft), (4) 914 to 1,523 m (3,000 to 5,000 ft), and (5) under 914 m (under 3,000 ft). Only airports with usable runways are included in this listing. Not all airports have facilities for refueling, maintenance, or air traffic control. The type aircraft capable of operating from a runway of a given length is dependent upon a number of factors including elevation of the runway, runway gradient, average maximum daily temperature at the airport, engine types, flap settings, and take-off weight of the aircraft.

This entry gives the total number of airports with unpaved runways (grass, dirt, sand, or gravel surfaces) by length. For airports with more than one runway, only the longest runway is included according to the following five groups - (1) over 3,047 m (over 10,000 ft), (2) 2,438 to 3,047 m (8,000 to 10,000 ft), (3) 1,524 to 2,437 m (5,000 to 8,000 ft), (4) 914 to 1,523 m (3,000 to 5,000 ft), and (5) under 914 m (under 3,000 ft). Only airports with usable runways are included in this listing. Not all airports have facilities for refueling, maintenance, or air traffic control. The type aircraft capable of operating from a runway of a given length is dependent upon a number of factors including elevation of the runway, runway gradient, average maximum daily temperature at the airport, engine types, flap settings, and take-off weight of the aircraft.

This section includes Factbook-related material by topic.

This entry includes three subfields. Total area is the sum of all land and water areas delimited by international boundaries and/or coastlines. Land area is the aggregate of all surfaces delimited by international boundaries and/or coastlines, excluding inland water bodies (lakes, reservoirs, rivers). Water area is the sum of the surfaces of all inland water bodies, such as lakes, reservoirs, or rivers, as delimited by international boundaries and/or coastlines.

This entry provides an area comparison based on total area equivalents. Most entities are compared with the entire US or one of the 50 states based on area measurements (1990 revised) provided by the US Bureau of the Census. The smaller entities are compared with Washington, DC (178 sq km, 69 sq mi) or The Mall in Washington, DC (0.59 sq km, 0.23 sq mi, 146 acres).