Trail Smelter's (Semi) Precautionary Legacy

Abstract

Although almost every discussion of state responsibility begins with its talismanic invocation, time has not been kind to the Trail Smelter arbitration. Its primary contributions to international law have been the statement that: no State has the right to use or permit the use of its territory in such a manner as to cause [environmental] injury . . . in or to the territory of another, and its requirement that Canada pay the United States compensation for damages. While these Trail Smelter principles have become customary international environmental law, the arbitration itself is often viewed as a quaint remnant of a bygone world. Many scholars view Trail Smelter's marginalization as inevitable in light of international law's evolution from a state-to-state realm to one of multi-lateral, consensus-based actions. Others have suggested that the arbitration's impact is blunted by the fact that harm was not contested before the Arbitral Tribunal. This unique combination of characteristics leads many to conclude that Trail Smelter has little relevance for resolving the thorny transboundary environmental challenges that beset our ever-globalizing world. I think the case has much to teach modern international environmental law, but for somewhat unconventional reasons. This chapter explores one of the arbitration's least considered facets - the decisional process itself. Hampered by a lack of scientific evidence, the Trail Smelter Tribunal crafted an adaptive decisional structure in order to fulfill its charge to be just to all parties while resolving a conflict over pollution flowing across the Canadian border and causing harm in Washington State. The Tribunal's innovative and far-reaching solution, which I am calling (semi)precautionary, was to craft an interim regime from the available but incomplete information, with a clear understanding that the interim period would be used to develop more information. The newly-developed information was then used to create a permanent regime designed to minimize harms while permitting the smelter to continue operations. This structure - using preliminary measures to prevent harm while information sufficient to create a permanent regime fair to all parties is developed - is the Trail Smelter arbitration's (semi)precautionary legacy. Regardless of the critiques of the arbitration's holdings or its normative relevance, this (semi)precautionary legacy resonates profoundly in modern international environmental law. For example, this early case presaged much of the contemporary debate about appropriate regulation, like that surrounding genetically modified organisms (GMOs). Viewing this controversy through Trail Smelter's (semi)precautionary lens might reveal an appropriate middle ground between the competing claims for regulatory legitimacy made by advocates and opponents of the precautionary principle.