Many of Nigeria's environmental problems are those typical of developing states. Excessive cultivation has resulted in loss of soil fertility. Increased cutting of timber has made inroads into forest resources, exceeding replantings. By 1985, deforestation claimed 1,544 square miles of the nation's forest land. Between 1983 and 1993 alone, Nigeria lost 20% of its forest and woodland areas. Oil spills, the burning of toxic wastes, and urban air pollution are problems in more developed areas. In the early 1990s, Nigeria was among the 50 nations with the world's highest levels of carbon dioxide emissions, which totaled 96.5 million metric tons, a per capita level of 0.84 metric tons. Water pollution is also a problem due to improper handling of sewage. Nigeria has 221 cubic kilometers of renewable water resources. Fifty-four percent is used for farming activity and 15% for industrial purposes. Safe drinking water is available to 78% of urban dwellers and 49% of the rural population. The principal environmental agencies are the Environmental Planning and Protection Division of the Federal Ministry of Works and Housing, and the analogous division within the federal Ministry of Industry.
In 2001, 26 of Nigeria's mammal species were threatened. Nine types of birds and 16 plant species were also endangered. Endangered species include the drill, Presuu's red colobus, and the Ibadan malimbe. The Sahara oryx has become extinct in the wild.