on Environment and Development of 1992. Exception for excusable ignorance The polluter pays principle (PPP) has been doubted in cases where no one recognized that a type of pollution posed any danger until after the pollution began. An example occurs in the history of climate change science which shows that considerable carbon dioxide was emitted into the atmosphere by industrialized countries before there was scientific awareness or consensus that it could be dangerous. See also References Further reading International Law and Naval War: The Effect of Marine Safety and Pollution Conventions during International Armed Conflict, by Dr. Sonja Ann Jozef Boelaert-Suominen (December 2000). Doswald-Beck, ICRC Review (1997), No. 316, 35–55; Greenwood, ibid., 65–75. Environmental economics Environmental law Environmental social science concepts Industrial ecology Pollution Waste management concepts Legal doctrines and principles