Figure 5: Illustrative patterns of the changes over time of key scenario assumptions The interfacing and changes in these key driving forces, as used in the narratives in this chapter, are assumed to take the patterns reflected in Figure 5. The narratives presented in the subsequent sections are based on these patterns of change in the main driving forces.

In order to provide a holistic storyline, the regional and sub-regional narratives have been integrated for some issues while stand-alone sections have been reserved for issues more directly relevant to specific sub-regions. The four regional narratives focus on transboundary aspects and ecosystems at subregional and regional levels, and discuss the implications of policy choices for meeting the MDG targets by 2025. The analysis is undertaken in the context of the Opportunity Framework (see Introduction). The policy lessons from the scenarios are closely related to the future state of the environment as presented in Section 2: Environment State-and-Trends: 20-Year Retrospective.