Social and economic inequalities can influence both the distribution of the costs and benefits from environmental degradation and the extent of environmental protection. When those who benefit from environmentally degrading economic activities are powerful relative to those who bear the costs, environmental protection is generally weaker than when the reverse is true. This can lead to environmental inequalities along lines of class, race, ethnicity, gender, and age. At the same time, inequalities may affect the overall extent of environmental quality. There are good theoretical reasons to expect inequalities to reduce environmental protection and exacerbate environmental degradation. The available empirical evidence generally is consistent with this expectation.