Air pollution is a chemical, physical (e.g. particulate matter), or biological agent that modifies the natural characteristics of the atmosphere. The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the earth's ecosystems. - Wikipedia at:  http://en.wikipedia.org/wiki/Air_pollution Amy Sample Ward

Conservation biology, or conservation ecology, is the science of analysing and protecting Earth's biological diversity. The term "conservation biology" refers to the application of science to the conservation of genes, populations, species, and ecosystems. Conservation biology is the scientific study of the phenomena that affect the maintenance, loss, and restoration of biological diversity. - Wikipedia at: http://en.wikipedia.org/wiki/Conservation_biology Amy Sample Ward

Environmental preservation is the strict setting aside of natural resources to prevent the use or contact by humans or by human intervention. The distinct difference between conservation and preservation, is that conservation allows for the sustainable development paradigm, whereas preservation is complete restriction. - Wikipedia at: http://en.wikipedia.org/wiki/Environmental_preservation Amy Sample Ward