More than two centuries ago, the industrial revolution introduced an age of unprecedented growth in production, consumption, and resource use. The global community has experienced major changes as a result of the unfolding and globalization of that revolution.
The next major global revolution is now under way, mainly driven by innovations in information technology and increased mobility. Accelerated industrialization, economic and cultural globalization, technological innovation, new world political orders, and the communication revolution are apparent everywhere. Liberalized trade, global markets, and capital flows are opening new avenues for the circulation of materials and products. The revolution in telecommunication is leading to unprecedented access to knowledge. The expansion and increase in the economic dominance of transnational corporations affects everyone's life. For many people, these changes mean a broadening of personal horizons, new hope of a more prosperous future, and the opportunity to become part of a global village-with all the perceived benefits that offers. Such changes in society occur subtly and over time. Often they go unnoticed in the daytoday life of many. These developments will, however, lead to a vastly different future in the decades ahead.
Many of the changes are positive, and progress is being made. Nevertheless, the benefits of economic globalization and technological innovations have bypassed the vast majority of the poor in many countries. The gap between rich and poor is increasing, both between countries and within them. The impact of new technologies on employment is still uncertain. In some parts of the world, strong manifestations of cultural or religious identity are resulting in friction and even fragmentation of society. Environmental degradation still continues unabated in many parts of the world, and adequate control over excessive urban expansion is absent or inadequate in many areas. Marginalization of groups within society and an increase in conflicts, poverty, and massive migration-these are all signs that global development is uneven (Raskin et al., 1996).
Against this background of major changes in the world and the global efforts to address them, environmental assessment is changing too. Monitoring progress towards sustainable development and assessing the state of the environment are no longer just static reporting activities. They involve co-operative and frequent interactions of policy-makers and scientists working together to achieve orderly progress towards the implementation of Agenda 21, the blueprint for action adopted in 1992 at the United Nations Conference on Environment and Development in Rio de Janeiro.
Assessments that aim to support sustainable development can no longer report on the environment in isolation. Rather, environmental issues have to be seen as parts of larger systems, closely coupled to socio-economic developments and strongly influenced by political and institutional structures. The current trend is thus towards integrated analyses, including the evaluation of alternative policy options to provide an improved knowledge base for action, political accountability, and public participation.
Evidence of this new approach is found in the international assessments done on ozone layer depletion, climate change, acidification, biodiversity, land degradation, toxic wastes, and land-based sources of pollution. These studies have supported and still support international negotiations and decision-making. The adoption and the implementation of major global environmental conventions in recent years have relied on such scientific assessments, which involved hundreds of experts, analyses of the latest information and research results, scientific consensus, and translation of the consensus view into policy-relevant action documents.
In addition to these well-publicized assessments, some 200 multilateral agreements target regional and global action to protect the environment (UNEP, 1993; Bergesen and Parmann, 1994; CIESIN, 1996). This multitude of agreements illustrates the inherent complexity of environmental issues and of the mechanisms to deal with them. The complexities also arise from the persistence of changes and their impacts and from the fact that fundamental socio-economic and institutional aspects of life underlie every environmental problem.
The regional or global nature of environmental problems further complicates the assessment and formulation of effective responses. Even though the contribution of a single country to an environmental problem may seem insignificant taken on its own, the global total of individual contributions can result in degradation that is larger than the sum of the parts. By the same token, unilateral actions to deal with such problems will be less than optimally effective. Finally, different regions and nations have varying perspectives and priorities on the urgency of many environmental issues. These complexities make the production of comprehensive, policy-relevant assessments a challenging task.