Environmental Foresight and Models: A Manifesto. .

Beck M B (Ed). 2002. Oxford: Elsevier Science. US$120.00. ISBN 0-080-44086-X (hardback) 473 pages.

Reviewed by: Shivanand Balram, Department of Geography, Simon Fraser University, 8888 University Drive, Bumaby, B.C., Canada V5A 1S6

Models provide an abridged but effective representation of the real world. Through the filter of environmental models we examine and explore the complexity of natural processes across space and time. Usually these models are subjected to variations in their building blocks and the impact on the model output is compared against reality to determine the exactness of the representation. How these models are constructed and the consequences of that construction for the model outputs have been well researched and reported in the literature.

But as environmental changes become more global and the evolution dynamics more long-term, there is an increasing chance that the behaviour of the environment may become dramatically different from that observed in the past. It is these structural changes in the behaviour of the environment and their implications for the way we conceptualise and develop our models that are the focus of Environmental Foresight and Models: A Manifesto. The book represents the declaration of the International Task Force on Forecasting Environmental Change (1993-1998) that was assembled to address the issue of structural change and the extent to which models can be trusted in predicting environmental change. The book consists of nineteen chapters arranged into four logical Parts (The Manifesto, Case Histories, The Approach, Epilogue). This volume in the Developments in Environmental Modelling Series (22) has left few stones unturned in examining structural changes, environmental behaviour, and model development.

The book begins at Part I by immediately outlining the central questions to be addressed:

* "What system of 'radar' might we design to detect threats to the environment lying just beyond the 'horizon'?"

* "Are the seeds of structural change identifiable within the record of the recent past?"

* "Do we have an appropriate model development approach for dealing with structural change in environmental behaviour?"

The answer to these, the book suggests, must come from an amalgamated paradigm of model development that considers assessments of possible future patterns of environmental behaviour based on present beliefs, and then reconciling these with time-varying model parameters that enable these futures to be reached. In this way the observations of the past can be interpreted in light of the predicted future behaviour. Model coefficients, model characteristics, and formal statements of future system behaviour become key factors in this new multi-perspective model development process. Elaboration and justification are provided using convincing but terse arguments that expose the non-pluralistic core of current model development approaches. In this regard the book makes a case for the synergistic role of the social and cultural milieu in pluralistic settings when environmental models are developed. Policy-makers and the public become a greater factor in contributing to the understanding and forecasting of environmental behaviour.

In Part II, lessons learned from case histories in three key global application areas, water quality, acidic atmospheric deposition, and ozone depletion, are used to illustrate the need for a new way of constructing and learning from environmental models. Part Ill expands on the Manifesto by outlining specific methods and techniques that can facilitate the understanding of structural change. Attention is also directed to ways of addressing uncertainty and the "enduring tension between low-order and high-order models' (page xiv) as processes move between geographic scales. The Epilogue (Part IV) presents a concise summary of the main arguments.

Reading this book is difficult, mostly because of the academic style of writing and the breadth and complexity of the issues covered. But those who persist towards completion will be rewarded with much food for thought on dealing with current modelling challenges. However, there may still be a few issues that were not adequately stressed in the arguments. For example, the role of systems thinking and its value in facilitating the aims of the Manifesto, and ways of representing dynamic spatio-temporal environmental processes (with geographical information systems, for example) needed a bit more elaboration and integration into the discussion. Despite these minor omissions, advanced students, professionals, and academic researchers involved with modelling environmental systems will find this book valuable reading.