The surroundings and conditions, both natural and human-made, in which living organisms exist and interact.

In a scientific or ecological context, the environment is defined as the sum total of all external physical, chemical, and biological factors — both living (biotic) and nonliving (abiotic) — that surround and influence the survival, development, and evolution of an organism or population, encompassing everything from climate and soil to other organisms and natural resources.

1. The concept of doing something to change unsatisfactory conditions rather than just complain about them — activism.
2. A discreet, short-term effort of activism, e.g. “We planned an action to blockade traffic for an hour to call attention to the need for transportation alternatives such as light rail.”
3. When capitalized, the name of the newsletter of Bay Area Action, e.g. Action.

The organization formed from the merger of Bay Area Action and the Peninsula Conservation Center Foundation in 2001. The name Acterra was formed from action and Terra (Earth).