Carbon footprint

Carbon offsets

Carbon sequestration

Carcinogen

Carrying capacity (K)

Cellular respiration

Cellulosic ethanol

Chemical Safety Information, Site Security and Fuels Regulatory Relief Act (1999)

Chemical weathering

Clean Air Act (1970)

Clean Water Act (1972)

Climate Change

Compost

Comprehensive Environmental Response, Compensation, and Liability Act (1980)

Dead zone

Deforestation

Ecosystem

Ecotourism

Emergency Planning & Community Right-to-Know Act (1986)

Endagered Species Act