What is meant when we refer to "Environmental Impacts?" Changes in the environment caused by mankind, only by mankind, are known as environmental impacts. While we note that volcanoes and naturally-caused forest fires bring about large changes in the natural environment, these are largely dismissed by definition; they are, after all, "natural."
Floods, hurricanes, and tornadoes cause obvious changes in our environment, but, again, they are natural. Earthquakes?, natural.
Only the activities of mankind seem to matter in the popular debate over environmental issues. Environmental impacts are generally those changes in the "natural world" that are caused by mankind in the course of living and working.
Several factors should impact environmental policy:
Type of pollutionEffect(s) of the pollutionOn Human HealthOn WildlifeOn Stream QualityOn neighborhood ambianceTools available to prevent the pollutionCost of the control toolValue of the avoidance of the pollutionEnvironmental cost of the avoidance of the pollutionEnergy required for the pollution control tool selectedAppearancesOdorNoiseLimited Economic Resources