Beyond Rio? The evolution of international environmental law. (includes related articles on Canada's position on biodiversity treaties) (Cover Story)

Environmental degradation and other threats to sustainability are now clearly global problems and many of them require global responses. So far, from an environmental protection perspective, most of these responses could be called disappointing. Accordingly, the 1992 United Nations Conference on Environment and Development in Rio de Janeiro is widely regarded among environmentalists as a failure that consumed much energy and delivered little substance.(1)

Judged against the pressing needs for immediate global action, the Rio conference and other such international initiatives have indeed been inadequate. Nevertheless, it would be unwise to give up on such approaches and premature to dismiss Rio as a failure merely because it did not yield conventions with specific environmental protection targets.

It is difficult to imagine success in global environmental protection without effective international law. Dissatisfaction with the accomplishments of international environmental protection efforts should be taken as reason to look more carefully at the challenges to be faced and the tools available for facing them.

Certainly the challenges are formidable. Development of effective mechanisms of international environmental law must overcome the fundamental tension between the unity of ecosystems and the fragmentation of an international legal order built upon the rights and obligations of sovereign states. Progress is inevitably slow. Nonetheless, the past decade has seen considerable expansion and innovation in the use of international environmental law mechanisms, beginning with customary international law and proceeding creatively with various forms of international agreements and non-binding "soft law".

Customary law

Customary law evolves from the consistent practice of states accompanied by their conviction that they are legally bound to adhere to this practice. Customary international environmental law has its roots in the concept of international neighbourhood law, which developed as a response to the conflicting interests of sovereign states.(2) The idea of state sovereignty is central to the international legal order. Initially, environmental problems were simply defined in terms of interferences with the interests of other states. Rules were based on the idea that no state may use its territory, or allow the use of it, in a way that causes serious damage to the territory of another state.(3)

Over the years other customary rules have evolved. Generally, states are subject to "procedural" duties, which derive from an obligation to co-operate in matters of international environmental protection, and include the duty to warn, notify, inform or consult.(4) Unfortunately, all these obligations are connected to the threshold of serious transboundary damage. Serious damage must occur before such rules can be invoked. Only in the context of shared resources has another concept evolved: the equitable use of resources.(5) Originally applied to transboundary water systems, the idea is that states must share common resources fairly with neighbouring states.

There are a variety of limitations to the effectiveness of these rules of traditional international environmental law. Conceptually, the rules are often general and vague. Notions such as "serious damage" and "equitable share" are poorly defined, making it difficult to determine when a violation has occurred. It is easy for states to cite "scientific uncertainty" and "lack of proof" to escape responsibility while still claiming to uphold the letter of the law.(6)

This situation is exacerbated by the increasing complexity of environmental problems. Even where there is reasonable scientific agreement about the overall seriousness of global problems such as ozone layer depletion and climate change, the multiplicity of sources, effects and other relevant factors makes it virtually impossible to determine the responsibilities of individual states. In most cases it is at best difficult to satisfy the ideals of scientific certainty, clearly responsible parties and well-identified victims that the current international legal order demands. As a result, customary international rules are perhaps best seen as general guidelines that outline proper behaviour but cannot provide the carefully crafted solutions essential to addressing major global environmental problems.

Existing customary norms are also limited by their bias toward the territorial interests of states. For example, the duty not to cause transboundary damage applies to areas beyond the limits of national jurisdiction, but the term "areas" has a geographical connotation.(7) This neglects global issues such as ozone layer depletion and global warming. The only way to provide protection on these issues is to apply the rules indirectly, for example when ozone loss or climate change adversely affects a state's territory. Current international law generally fails to recognize the idea of a global "commons". No state may defend areas or environmental resources beyond the limits of national jurisdiction against even serious damage, unless injury to the "commons" happens to coincide with injury to sovereign interests.

A related problem is that states are reluctant to accept an obligation to preserve certain resources which, while within their territorial jurisdiction, are of importance to other nations or the international community as a whole. A classic example of this is rainforest preservation. Extending the idea of an obligation to protect such resources would present a challenge to deeply held notions of territorial sovereignty, which nations are not ready to tolerate. Developing countries in particular assert their sovereign rights against what they see as "eco-imperialism".

In addition to the "spatial" gaps thus left by customary law, there is also a "temporal" gap of future generations in cases where there is a time lag between human activities and the subsequent negative impacts, or when activities have irreversible impacts.

The conceptual shortcomings of the customary international legal system can be explained, in large part, by the fact that states, as the subjects of international law, are also the law makers, enforcers and adjudicators. As a result, their interests significantly shape the content of rules. With the exception of some cases dealing with localized transboundary problems, states have not pursued pollution incidents, for example through arbitration, to an extent that would have permitted the formation of more specific or further reaching rules. Obviously, the more complex environmental problems become, the more solutions implicate the economic and sovereign spheres of states. States are unwilling to create precedents for fear of undermining control over their affairs and interests.(8) The evolution of …