is for AIR QUALITY

A measure of the level of pollution in the air.

is for BIODIVERSITY

The variety of life on this planet and how it interacts within habitats and ecosystems

is for CLIMATE

The pattern of weather in a particular region often affected by the amount of rain or snowfall, average temperatures, humidity, and so on.

is for DOWNCYCLING

A form of waste management in which the quality of an item is diminished with each recycling.

is for ECOSYSTEM

A dynamic complex of plant, animal and microorganism communities all interacting as a functional unit.

is for FOOD CHAIN

The feeding relationships between species within an ecosystem.

is for GEOSPHERE

The solid part of planet Earth, the main divisions being the crust, mantle, and liquid core.

is for HABITAT

An ecological or environmental area that is inhabited by a particular species.

is for INDICATOR SPECIES

Any biological species that defines a trait or characteristic of the environment.

is for JOULE

The basic unit of energy; natural gas consumption is usually measured in megajoules.

is for KEYSTONE SPECIES

A species that has a disproportionate effect on its environment relative to its abundance to help and determine the number and types of other species in a community.

is for LITHOSPHERE

The solid outermost shell of a rocky planet.

is for MONOCULTURE

The practice of producing or growing one single crop over a wide area.

is for NATURAL SELECTION

The process by which favorable heritable traits become more common in successive generations of a population of reproducing organisms.

is for OMNIVORE

A species of animal that eats both plants and animals as its primary food source.

is for PHOTOSYNTHESIS

The transformation of radiant energy to chemical energy by plants.