International Law. The History of International Environmental Law

International environmental law provides the rules and norms that countries must follow when they take actions that affect the human environment. Most of these rules are contained in treaties or other written international agreements that countries have explicitly agreed to. Some of the rules reflect customary international law, which means that they have arisen from a consistent practice among states, which felt obligated to follow that practice.

(In international law, the term state is used to refer to countries, not subunits—which are often called states—within a country.) Binding international agreements can be referred to as treaties, conventions, international agreements, or sometimes protocols. There are also many other instruments, such as declarations, that countries are not obligated to follow, but often do. These are sometimes referred to as "soft law" or nonbinding legal instruments.

The History of International Environmental Law. International environmental law developed during the twentieth century. Most of it was negotiated after the June 1972 United Nations Stockholm Conference on the Human Environment. In 1972 there were only about three dozen multilateral environmental agreements; in 2002 there were more than 1100 important legal instruments concerned with the environment.

There are agreements to control pollution in the oceans, air, and freshwater; to protect regional seas; to conserve biological diversity, wetlands, and world natural and cultural heritage sites; to control international trade in endangered species of fauna and flora, hazardous wastes, and toxic chemicals; and to protect global commons such as the high-level ozone layer, the climate, the high seas, and Antarctica. Many of these are binding agreements, although some are nonbinding legal instruments.

In 1900 international law was based on the principle that countries could exercise almost unfettered national sovereignty over the natural resources within their territory or jurisdiction. International agreements addressed boundary waters, navigation, fishing rights in shared rivers, and the protection of commercially valuable species of birds, fur seals, and other specific species of fauna. The 1909 Boundary Waters Treaty between the United States and the United Kingdom (now Canada) is noteworthy as an early treaty that addressed water pollution. Article 4 of the Treaty provides that water "shall not be polluted on either side to the injury or health or property on the other."

The most famous early adjudication of a pollution problem that crossed national borders is the Trail Smelter Arbitration between Canada and the United States. Settled in the late 1930s, it affirmed Canada's responsibility for the fumes from a copper smelter in British Columbia that harmed crops and acreage in the state of Washington. The arbitral tribunal established for this dispute awarded damages to the United States and set up a regime to monitor the pollution in the future.

During the 1930s and 1940s countries negotiated international agreements that were intended to ensure sustainable harvesting of whales, to protect fisheries, and to conserve other fauna and flora. In the 1950s and 1960s international agreements were concluded that addressed oil pollution of the oceans and liability for nuclear-powered ships.

The surge in bilateral and multilateral environmental agreements came after 1970. In 1972, countries established the United Nations Environment Programme (UNEP), the first international intergovernmental organization dedicated to protecting the environment. It is headquartered in Nairobi, Kenya. Under the UNEP, countries negotiated many regional agreements to protect regional seas, such as the Mediterranean and the Baltic.

These were framework agreements that set forth general obligations and usually called for research, monitoring of the conditions of the seas, and exchange of information. The detailed obligations relating to emergencies, land-based sources of marine pollution, or other specific problems were contained in separate agreements (called protocols) attached to the main framework agreement. Countries must join a protocol at the same time that they join the framework agreement for a particular regional sea.

During the 1980s and 1990s countries negotiated international agreements that addressed the problems of high-level ozone layer depletion (by human-made chemicals) and climate change (from human activities); loss of biodiversity; contamination by organic pollutants that persist in the environment, such as dioxin, polychlorinated biphenyls (PCBs), and DDT; and trade in pesticides and in chemicals that have been banned or severely restricted in the country of production.

They concluded regional agreements on air pollution and water quality. In 1982, after almost a decade of negotiations, countries concluded the Law of the Sea Convention, which deals with the multiple uses of the oceans and also sets forth the basic framework for managing marine pollution.