Although Mongolia is endowed with bountiful natural resources, several factors have combined to put the nation's environment under stress. First, the human population more than tripled during the 20th century (see Appendix 1, Table 1). Second, over the past four decades the country underwent a period of economic development and industrialization that led to dramatic increases in per capita natural resource consumption (Batjargal, 1992ab). Third, urbanization, which was particularly rapid from the mid-1950s to 1980 (Table 1), created burgeoning cities with attendant problems of crowding, pollution, and inadequate waste disposal.