The use of word-based models to describe the development of UK acid rain policy in the 1980s

Understanding how environmental policy decisions were reached in the past might help predict policy development in the future. This paper evaluates how well two existing frameworks for decision analysis fit acid rain policy development of the UK Central Electricity Generating Board (CEGB) in the 1980s. Decision tree analysis assumes a rational approach to decision-making and overlooks the dynamic nature of the decision making process. Trudgill's model identifies barriers to policy development, but it is not possible to identify which are most important. Both concentrate on the role of scientific uncertainty in the acid rain debate. An alternative approach is presented which identifies all possible influencing factors and assesses their relative influence. Whilst confirming the importance of the resolution of scientific uncertainty in this case study, it identifies a number of alternative pressure sources, including independent scientific review, rises in SO₂ emissions, European environmental legislation, and influences within the Government. In all three models, ascribing predictive values to all possible options is a major problem. All models are limited in their ability to describe complex and dynamic environmental problems, and hence have limited predictive powers. Decision tree analysis and Trudgill's barriers model identify how scientific uncertainty is dealt with within organisations, whilst the influencing factors approach puts decisions in a broader, political framework.