Animals and the places where they live are getting pushed aside as households(家庭)decrease in size and increase in number. Smaller numbers of people per household on average use more energy and goods per person. Greater numbers of households require more natural resources for construction. The possible result of this double problems may be that there are not enough natural resources to meet consumers’ demand without endangering habitats important to biodiversity. Personal freedom and social choice may come at a huge environmental cost. Direct costs include visible dam