Appendix IV: Six Modeling Approaches

The SRES Terms of Reference call for a multi-model approach for developing emissions scenarios (see Appendix I). In all, six different modeling approaches were used to generate the 40 SRES scenarios. These six models are representative of the approaches to emissions scenario modeling and the different integrated assessment frameworks used in the scenario literature and include both macro-economic (so-called top-down) and systems-engineering (so-called bottom-up) models. Some modeling teams developed scenarios to reflect all four storylines, while some presented scenarios for fewer storylines. Chapter 4 lists all the SRES scenarios, by modeling group and by scenario family. The six modeling approaches include:

• Asian Pacific Integrated Model (AIM) from the National Institute of Environmental Studies in Japan (Morita et al., 1994);
• Atmospheric Stabilization Framework Model (ASF) from ICF Consulting in the USA (Lashof and Tirpak, 1990; Pepper et al., 1992, 1998; Sankovski et al., 2000);
• Integrated Model to Assess the Greenhouse Effect (IMAGE) from the National Institute for Public Health and Environmental Hygiene (RIVM) (Alcamo et al., 1998; de Vries et al., 1994, 1999, 2000), used in connection with the Dutch Bureau for Economic Policy Analysis (CPB) WorldScan model (de Jong and Zalm, 1991), the Netherlands;
• Multiregional Approach for Resource and Industry Allocation (MARIA) from the Science University of Tokyo in Japan (Mori and Takahashi, 1999; Mori, 2000);
• Model for Energy Supply Strategy Alternatives and their General Environmental Impact (MESSAGE) from the International Institute of Applied Systems Analysis (IIASA) in Austria (Messner and Strubegger, 1995; Riahi and Roehrl, 2000); and the
• Mini Climate Assessment Model (MiniCAM) from the Pacific Northwest National Laboratory (PNNL) in the USA (Edmonds et al., 1994, 1996a, 1996b).

IV.1. Asian Pacific Integrated Model

The Asian Pacific Integrated Model (AIM) is a large-scale computer simulation model for scenario analyses of greenhouse gas (GHG) emissions and the impacts of global warming in the Asian-Pacific region. This model is being developed mainly to examine global warming response measures in the region, but it is linked to a world model so that it is possible to make global estimates. AIM comprises three main models - the GHG emission model (AIM/emission), the global climate change model (AIM/climate), and the climate change impact model (AIM/impact).

The AIM-based quantification was conducted as an Asian collaborative project using a new linked version of the AIM/emission model, which covers the world but has a more detailed structure for the Asian-Pacific region than for other regions. The new linked version couples bottom-up models and top-down models (Figure IV-1).

IPCC Homepage