an Islands, Dhekelia, Falkland Islands,
Gibraltar, Guernsey, Jersey, Isle of Man, Montserrat, Pitcairn Islands,
Saint Helena, South Georgia and the South Sandwich Islands, Turks and
Caicos Islands
14 US - American Samoa, Baker Island*, Guam, Howland Island*, Jarvis
Island*, Johnston Atoll*, Kingman Reef*, Midway Islands*, Navassa
Island, Northern Mariana Islands, Palmyra Atoll*, Puerto Rico, Virgin
Islands, Wake Island (* consolidated in United States Pacific Island
Wildlife Refuges entry)

MISCELLANEOUS
6 Antarctica, Gaza Strip, Paracel Islands, Spratly Islands, West Bank,
Western Sahara

OTHER ENTITIES
5 oceans - Arctic Ocean, Atlantic Ocean, Indian Ocean, Pacific Ocean,
Southern Ocean
1 World

268 total

Environment - current issues: This entry lists the most pressing and
important environmental problems. The following terms and abbreviations
are used throughout the entry:

Acidification - the lowering of soil and water pH due to acid
precipitation and deposition usually through precipitation; this
process disrupts ecosystem nutrient flows and may kill freshwater fish
and plants dependent on more neutral or alkaline conditions (see acid
rain).

Acid rain - characterized as containing harmful levels of sulfur
dioxide or nitrogen oxide; acid rain is damaging and potentially deadly
to the earth's fragile ecosystems; acidity is measured using the pH
scale where 7 is neutral, values greater than 7 are considered
alkaline, and values below 5.6 are considered acid precipitation; note
- a pH of 2.4 (the acidity of vinegar) has been measured in rainfall in
New England.

Aerosol - a collection of airborne particles dispersed in a gas, smoke,
or fog.

Afforestation - converting a bare or agricultural space by planting
trees and plants; reforestation involves replanting trees on areas that
have been cut or destroyed by fire.

Asbestos - a naturally occurring soft fibrous mineral commonly used in
fireproofing materials and considered to be highly carcinogenic in
particulate form.

Biodiversity - also biological diversity; the relative number of
species, diverse in form and function, at the genetic, organism,
community, and ecosystem level; loss of biodiversity reduces an
ecosystem's ability to recover from natural or man-induced disruption.

Bio-indicators - a plant or animal species whose presence, abundance,
and health reveal the general condition of its habitat.
Biomass - the total weight or volume of livi