Chapter Six The SAS Approach: Combining Qualitative and Quantitative Knowledge in Environmental Scenarios

This chapter discusses the pros and cons of qualitative and quantitative scenarios and the way they fulfill the different requirements of scenario developers and users and some ideas are presented for producing more scientifically sound scenarios.

Abstract

This chapter discusses the pros and cons of qualitative and quantitative scenarios and the way they fulfill the different requirements of scenario developers and users. It also describes major international scenario exercises in which combined scenarios have been used. This international experience is distilled into a general procedure for combining qualitative and quantitative scenarios called the "story and simulation" (SAS) approach. In the chapter, the successes and drawbacks of this approach are pointed out and some ideas are presented for producing more scientifically sound scenarios. The qualitative storylines provide an understandable vehicle for communicating the messages of the scenarios and can express the more complex dimensions and interconnectedness of environmental problems. The quantitative scenarios provide a consistency check to the different assumptions of the qualitative scenarios and the numerical data often needed in environmental studies. To capitalize on their advantages, qualitative and quantitative scenarios have been combined in recent international scenario exercises.