Global Environment Outlook 3 (GEO 3)

3 2 1

OUTLOOK 2002–32

Drawing on the experience and work of other scenario initiatives, including those of the Global Scenario Group (Raskin and Kemp-Benedict 2002), a set of four scenarios has been developed for GEO-3 . The Markets First scenario envisages a world in which market-driven developments converge on the values and expectations that prevail in industrialized countries; In a Policy First world, strong actions are undertaken by governments in an attempt to reach specific social and environmental goals; The Security First scenario assumes a world of great disparities, where inequality and conflict prevail, brought about by socio-economic and environmental stresses; and Sustainability First pictures a world in which a new development paradigm emerges in response to the challenge of sustainability, supported by new, more equitable values and institutions. For each of these scenarios, an overall narrative — ‘A tale of four futures’ — describes the future in the next 30 years in a predominantly qualitative manner, providing both regional and global perspectives. The stories of the four scenarios are followed by a more detailed examination of their environmental implications, drawing on quantitative data derived from a number of analytical tools — and with a regional focus intended to highlight particular concerns in the different regions. A brief comparison of qualitative and quantitative approaches is provided in the box. For more details of the GEO-3 scenario analysis, see the technical annex to this chapter (page 398).

Narratives or numbers?

Scenarios can be told in many ways. The two most common methods used in scenario analysis have been descriptive, written narratives (qualitative scenarios) and tables and figures incorporating numerical data, often generated by sophisticated computer models (quantitative scenarios). Both approaches have strengths and weaknesses and their relative worth has been much debated. Qualitative scenarios can explore relationships and trends for which few or no numerical data are available, including shocks and discontinuities. They can more easily incorporate human motivations, values and behaviour and create images that capture the imagination of those for whom they are intended. Quantitative scenarios can provide greater rigour, precision and consistency. Their assumptions are explicit and their conclusions can be traced back to the assumptions. The effects of changes in assumptions can be easily checked, pointing to important uncertainties. They can provide order-of-magnitude estimates of past, present and future trends in, for example, population growth, economic growth or resource use.

In GEO-3, qualitative narratives take centre stage with the quantitative tools playing a supporting role.

The chapter concludes with ‘Lessons from the future’, a discussion of important lessons arising from the scenario analysis for future environmentally relevant policy development. Before embarking on the journey through these four possible futures, however, it is useful to know the key assumptions made in constructing them and how these act as driving forces behind the scenarios. These assumptions are therefore outlined in the next section.