Rapid industrialization has imposed severe pressures on the environment. Japan's Basic Law for Environmental Pollution Control was enacted in 1967 and the Environment Agency was established four years later.
Air pollution is a serious environmental problem in Japan, particularly in urban centers. Toxic pollutants from power plant emissions have led to the appearance of acid rain throughout the country. In the mid-1990s, Japan had the world's fourth highest level of industrial carbon dioxide emissions, which totaled 1.09 billion metric tons per year, a per capita level of 8.79 metric tons per year. Air quality is regulated under the Air Pollution Control Law of 1968; by 1984, compensation had been provided to 91,118 air-pollution victims suffering from bronchitis, bronchial asthma, and related conditions. However, the "polluter pays" principle was significantly weakened in 1987 as a result of years of business opposition. Nationwide smog alerts, issued when oxidant density levels reach or exceed 0.12 parts per million, peaked at 328 in 1973 but had declined to 85 (85% of which took place in the Tokyo and Osaka areas) by 1986, following imposition of stringent automobile emissions standards.
Water pollution is another area of concern in Japan. The nation has 430 cu km of renewable water resources with 64% used in farming activity and 17% used for industrial purposes. Increase in acid levels due to industrial pollutants has affected lakes, rivers, and the waters surrounding Japan. Other sources of pollution include DDT, BMC, and mercury. Environmental damage by industrial effluents has slowed since the promulgation of the Water Pollution Control Law of 1971, but there is still widespread pollution of lakes and rivers from household sources, especially by untreated sewage and phosphate-rich detergents. Factory noise levels are regulated under a 1968 law. Airplanes may not take off or land after 10 PM and the Shinkansen trains must reduce speed while traveling through large cities and their suburbs.
Most of the nation's forests, which play a critical role in retarding runoff and soil erosion in the many mountainous areas, are protected under the Nature Conservation Law of 1972, and large areas have been reforested. Parks and wildlife are covered by the National Parks Law of 1967. In 2001, 6.8% of Japan's total land areas was protected. Japan, one of the world's chief whaling nations, vigorously opposed the 1982 resolution of the IWC calling for a phaseout of commercial whaling by 1986/87. However, since most of its trading partners, including the United States, supported the measure and threatened retaliatory measures if whaling continued, Japan finally agreed to comply with the ban.
Of Japan's mammal species, 29 are endangered, as are 33 bird species, and 537 plants. As of 2001, endangered species in Japan included the Ryukyu sika, Ryukyu rabbit, Iriomote cat, Southern Ryukyu robin, Okinawa woodpecker, Oriental white stork, short-tailed albatross, green sea turtle, and tailless blue butterfly. The Ryukyu pigeon, Bonin thrush, Japanese sea lion, and Okinawa flying fox have become extinct.