species ― a species at risk of extinction because of human activity, changes in climate, changes in predator-prey ratios, etc., esp. when officially designated as such by a governmental or international agency.
Environment ― the air, water minerals, organisms and all other external factors surrounding and affecting a given organism at any time.
Environmentalist ― 1) an expert on environmental problems;
2) a person who advocates or works for protection of the air, water, animals, plants and other natural resources from pollution or its effects.
Erosion ― the process by which a surface of the earth is worn away by the action of water, glaciers, winds, waves, etc.
Extinct ― no longer in existence; having died out.
Extinction ― 1) making, being, becoming extinct;
2) act of extinguishing.
Fertility ― the state or quality of being fertile.
Fertilizer ― chemical plant tool, artificial manure.
Fossil fuel ― any combustible organic material, as oil, coal or natural gas, derived from the remains of former life.
Geo-thermal ― of or pertaining to the eternal heat of the earth.