The number of deaths per 1,000 individuals in a certain period of time.

A rate of change that increases more and more rapidly over time.

Contamination of Earth's land, water, or air through the release of harmful substances into the environment.

A condition in which the number of humans grows beyond what the available resources can support.

The practice of using less of a resource so that it can last longer.

The ability of an ecosystem to maintain biodiversity and production indefinitely.

A specific source of pollution that can be identified.

A widely spread source of pollution that is difficult to link to a specific point of origin.

Pollutants that are released into the air.

A form of oxygen that has three oxygen atoms in each molecules instead of the usual two; toxic to organisms where it forms near Earth's surface.

Rain or another form of precipitation that is more acidic than normal, caused by the release of molecules of sulfur dioxide and nitrogen oxide into the air.

The removal of forests to use the land for other reasons.

The advance of desert-like conditions into areas that previously were fertile; caused by overfarming, overgrazing, drought, and climate change.

The process by which, water, ice, wind, or gravity moves weathered particles of rock and soil.

Using a resource in ways that maintain it at a certain quality for a certain of time.

The water and human wastes that are washed down sinks, toilets, and showers.

Small, solid pieces of material that come from rocks or the remains of organisms; Earth materials deposited by erosion.

A type of pollution caused by factories and power plants releasing superheated water into bodies of water.