Norway's plentiful forests, lakes, flora, and wildlife have suffered encroachment in recent years from the growing population and consequent development of urban areas, roads, and hydroelectric power. The forest floor and waterways have been polluted by Norway's own industry and by airborne industrial pollution from central Europe and the British Isles in the form of acid rain. The acid rain problem has affected the nation's water supply over an area of nearly 7,000 sq mi. Annual particulate emissions have averaged 22 tons and hydrocarbon emissions have been about 270 tons. In 1992, Norway was among the 50 nations with the world's heaviest emissions of carbon dioxide from industrial sources, which totaled 60.2 million metric tons, a per capita level of 14.03 metric tons. In 1996, the total rose to 67 million metric tons. Transportation vehicle emissions are also a significant source of air pollution. By the early 1980s, the government had enacted stringent regulations to prevent oil spills from wells and tankers operating on the Norwegian continental shelf. Coastal protection devices have since been installed, and new technologies to prevent oil damage have been developed. Industry, mining, and agriculture have polluted 16% of Norway's lake water. The nation has a total of 382 cu km of renewable water resource; 68% are used for industrial activity and 3% are used for farming. The nation's cities produce on average 2.2 million tons of solid waste per year. Pollution control laws operate on the premise that the polluter must accept legal and economic responsibility for any damage caused and for preventing any recurrence; the state makes loans and grants for the purchase of pollution control equipment. Municipal authorities supervise waste disposal.
Since its creation in 1972, the Ministry of the Environment has been Norway's principal environmental agency. Between 1962 and 1985, 15 national parks, with a total area of more than 5,000 sq km (2,000 sq mi), and more than 150 nature reserves were established. As of 2001, 6.5% of Norway's total land area was protected. Four of Norway's mammal species and three of its bird species were endangered. Four plant species were also threatened. Threatened species include the Baltic sturgeon, marsh snail, and freshwater pearl mussel.