Environmentalism (noun)

1. The movement or ideology that advocates for the protection and preservation of the natural environment.
2. The principles and practices of protecting and preserving the natural environment.

Origin:

From environment + -alism.

Examples:

1. He was an advocate of environmentalism.
2. The company adopted environmentalism policies to reduce their carbon footprint.
3. The school's environmentalism club organized a beach cleanup.
4. The environmentalism movement aims to protect endangered species.
5. The environmentalism policies of the government were a major factor in the conservation of forests.