- A negative impact as the result of an action upon the environment. [source: DCNR State Forestry Resource Management Plan, Glossary of Terms: http://www.dcnr.state.pa.us/forestry/sfrmp/glossary.htm]
- The reduction of the capacity of the environment to meet social and ecological objectives, and needs.
Some examples: land degradation, deforestation, desertification, loss of biodiversity, land, water and air pollution, climate change, sea level rise and ozone depletion. [Source: International Strategy for Disaster Reduction, Terminology: http://www.unisdr.org/eng/library/lib-terminology-eng%20home.htm]