14 of the country's total. The lower elevations occur especially in the western state. The North has served as a source of forest products ranging from "backlands drugs" (such as sarsaparilla, cocoa, cinnamon, and turtle butter ) in the colonial period to rubber and Brazil nuts in more recent times. Specialized environmental agencies were organized at the federal level and in some states, and many national parks and reserves were established. The huge central plateau (Planalto Central) is approximately 1 000 metres or 3 281 feet above sea level. Desertification, another important environmental problem in Brazil, only received international attention following the United Nations Conference on the Environment and Development, also known as the Earth Summit, held in Rio de Janeiro in June 1992. The region is almost as densely settled as the Southeast, but the population is more concentrated along the coast.
High and relatively regular levels of precipitation in the Amazon contrast sharply with the dryness of the semiarid Northeast, where rainfall is scarce and there are severe droughts in cycles averaging seven years. In addition to a dense urban network, it contains the megacities of So Paulo and Rio de Janeiro, which in 1991 had.7 million and.7 million inhabitants in their metropolitan areas, respectively. The World Bank also made loans for environmental and natural resource management in Rondnia and Mato Grosso, in part to correct environmental and social problems that had been created by the World Bank-funded development of the northwest corridor in the 1980s. The river starts in the Canastra mountain range in the central-western part of the state of Minas Gerais. The hundreds of NGOs throughout Brazil produce documents containing both useful information and passionate criticisms. The Mato Grosso swamplands ( Pantanal Mato-grossense) is a Florida -sized plain in the western portion of the Center-West (Centro-Oeste). At the same time, however, basic environmental problems related to the lack of sanitation, which developed countries solved long ago, persist in Brazil. The plateau's uneven terrain has an average elevation of 1,000 meters (3,281 ft). Eastern Standard Time in the United States. The Ministry of Environment was created in late 1992, after President Collor had left office. In 1994 So Paulo boasted an average income of US4,666, while Minas Gerais reported only US2,833.