Scenario narratives and their implementation in the IMAGE/TIMER model

A1 Scenario

A2 Scenario

B1 Scenario

B2 Scenario

Summary

The objective of the IMAGE 2.2 model is to explore the long-term dynamics of global environmental change, in particular, dynamics related to climate change. This requires an image of how the world system could evolve. Future greenhouse gas emissions, for instance, are the result of complex interacting demographic, techno-economic, socio-cultural and political forces. Scenarios are alternative images of how the future might unfold. They form an appropriate tool in analyzing how driving forces may influence future emissions and in assessing the associated uncertainties.

Recently, the Intergovernmental Panel on Climate Change (IPCC) published a set of new scenarios in the Special Report on Emissions Scenarios (SRES) (IPCC, 2000). These scenarios are based on a thorough review of the literature, the development of narrative 'storylines' and the quantification of these storylines using six different integrated models from different countries. These storylines were constructed on two axes, i.e. the degree of globalization versus regionalization, and the degree of orientation on material versus social and ecological values. The four clusters were given simple names:

The storylines describe developments in many different social, economic, technological, environmental and policy dimensions. The storylines do not have a particular order, but they are listed alphabetically and numerically.

The scenarios could cover a wide range of futures, but not all possible futures. Specifically:

• The two axis do not pretend to be complete; such important aspects as governance and technology are either absent or implicit. Neither should any of these future worlds be interpreted as a blueprint of some probability or desirability. Some regions of the world will evolve in one direction, influencing the evolution of other regions. The scenarios will relate possible stories if certain regions, values and mechanisms become more dominant than others.
• Neither should the four scenario clusters be seen as a stable endpoint. They interact dynamically: if the forces characterizing one of them become dominant, counterforces will emerge and push on in other, new, directions. For instance, advocates of liberalization and privatization in accordance with the free-market ideology may be so successful that the resulting inequity and overexploitation will strengthen environmentalist and fundamentalist forces.
• So-called 'disaster' scenarios are not included.
• None of the scenarios include new explicit climate policies.

This USS represents the IMAGE 2.2 elaboration of the SRES storylines. Contrary to the original SRES scenarios, the scenarios on this USS do not focus solely on emissions, but also describe the possible environmental impacts of these scenarios . It should, however, be clear that the scenarios on this USS represent only one of the many possible elaborations of the SRES scenarios. In this respect, they reflect the authors' interpretations and valuation of only a part of past and present events, behaviours and structures.