Introduction

Environmental and health risks are today a subject of great debate and concern in many countries, as well as at the global level. Risks of climate change, ozone depletion, the spread of disease and loss of species, among many others, have become central issues of policy and legal development preoccupying national governments and international organisations. The language of ‘risk’ is used in discussing these issues because, in many cases, available information is inadequate or incomplete. Enough is known to suspect or predict that a threat exists, but the full outcomes for human health and the environment, including for future generations, may not be well understood. This uncertainty, together with the complexity of the ecological systems and processes at issue, encourages a proliferation of plausible perspectives on risk problems and the best way to manage them. In this context, the regulatory and adjudicative systems of international law may be turned to as a forum for mediating between different risk perspectives and, indeed, for determining whether risks exist that should be the subject of legal intervention.

Where international legal disputes arise over the nature and extent of health and environmental risks – such as the 2006 World Trade Organization (WTO) dispute involving genetically modified organisms (GMOs) – typically an enormous amount of scientific material is gathered in order to substantiate (and contest) risk claims. In the GMO case, for instance, the WTO panel involved consulted six independent experts on scientific and technical matters, who produced reports running to hundreds of pages.