R. E. Munn’s research while affiliated with University of Toronto and other places

Six atmospheric ‘issues’ are currently being assessed by scientists, modellers and policy analysts in Canada: climate change; stratospheric ozone depletion (including UV-B radiation increases); acidic deposition; smog (e.g. ground-level ozone episodes); suspended particulate matter; and hazardous air pollutants. This paper provides a brief historical review of how these particular issues came to the forefront internationally and in Canada. Then the characteristics of the issues are described, revealing the wide range of space and time scales involved, as well as the several different ecological systems and socioeconomic sectors affected. Historically each air issue has been treated as a separate problem — from root causes, through the atmospheric processes involved, through the impacts on the biosphere and society, and finally to the design of policies to slow down or eliminate unwanted impacts. In recent years, however, recognition has been growing that the six air issues are interrelated through complex feedbacks, lags and synergisms. For example, replacing CFCs may slow down stratospheric ozone depletion, but the replacement gases may contribute to climate warming. The lesson to be learned by both scientists and policy analysts is therefore that strategies for dealing with a particular issue may not be optimal for the whole. Two examples are given to illustrate the point. (1) With respect to policies to reduce greenhouse gas emissions, the warming potentials of all such gases should be assessed, and the effects of proposed strategies on the other five air issues should also be included. (2) With respect to regional land-use planning, a long-term perspective (decades) should be taken, and the effects of global and regional atmospheric change on the region should be included in the assessment. Because the future is difficult and often impossible to predict, an adaptive strategy is recommended in which options are kept open, and the assessment document is revisited periodically (at 2–5-year intervals).

Integrated assessments (IAs) and integrated assessment models (IAMs) arerecent responses to the inter-disciplinary challenges provided by complexglobal environmental issues such as atmospheric change. This paper discussesan array of integrated assessments, providing an overview of the role of IAsas bridges or foundations for epistemic communities. Formal as well associal, political, and ethical issues are presented. As well as a definition of anIA and an IAM, different forms and approaches of current or proposed IAsare reviewed. Particular stress is laid on the need to maintain the integrity ofthe diverse components of an IA. Finally, reference is made to the need tounderstand the underlying ethical and normative concerns that have promotedthe current interest in IA.

The rise of global science in the last 30 years has paralleled a shift in the role of science and scientists from pure advisors of how to put the cornucopia of scientific and technological advance to work, to a more ambivalent role, again foreshadowed by the concerns of scientists about the control of atomic devices. This new role is one in which, among other things, the long-term implications or complex outcomes of certain acti vities need to be considered. This ’early warning’ role was — and is — difficult and ambivalent for many scientists, since uncertainty is pivotal towards scientific endeavour. Furthermore, since public involvement and understanding are now seen as essential to creating a climate of support for science, scientists have had to enter into public fora, and learn to redescribe their often complex activities for a wider audience.

Over the past 25 years, increasing numbers of public interest groups concerned with the environment have emerged locally, nationally, regionally and internationally. At the 1992 Rio Conference, over 1400 non-governmental organizations (NGOs) were officially accredited and represented. These had mandates in the area of the environment, development, or both. Their influence on public opinion and on the political will of decisionmakers is felt by many to be considerable. Quite often of course, NGOs represent differing points of view, e.g., those wishing to stress poverty and development concerns vs. those wishing to protect the environment. It should also be noted that since Rio, there has been a substantial increase in the number and power of Southern NGOs.

Historically, science played a minor role in national affairs, until perhaps the rise of the industrial state and the exigencies of modern warfare promoted science and its technological offshoots into becoming a major participant. The Second World War in particular dramatically showed how scientific and technological advances could affect, and even turn the tide of battles. The more obvious of these were advances in radar, airplanes, and the development of atomic weapons; but there were important roles played by, for example, increased sophistication in meteorological prediction. Symbolic of this new-found importance was the creation of the role of the science advisor to government, as well as Ministries of Science and Technology. This importance of science to government was reciprocated through vastly increased commitments of developed-country governments to funding science, either through internal government research or through universities.