The number and range of international agreements on environmental practices and policies have grown tremendously in recent years. According to an estimate by Keohane, Haas and Levy (1993) in The Effectiveness of International Environmental Institutions, of 140 international environmental agreements instituted since 1921, more than half entered into force after 1972. In International Environmental Law, Brown Weiss, Magraw, and Szasz (1992) estimate the total at a much higher 900 agreements in force in 1992, including regional and bilateral treaties. Major accords reached on issues related to global environmental change include The Montreal Protocol on Substances That Deplete the Ozone Layer (1987), The Framework Convention on Climate Change (1992), The Convention on Biological Diversity (1992), and the various agreements forged as part of the United Nations Conference on Environment and Development (UNCED) in 1992. (The CIESIN Thematic Guide essay on Formulating International Global Environmental Change Policy presents a general discussion of treaty formation and the role of treaties in environmental policy.
Treaty texts and other information can be found in various Sources of Environmental Treaties, some of which are on-line. Another potential source of information on the relationship between international agreements and global environmental change is the organizations currently conducting Environmental Agreements Research Projects in this area.