Emissions Scenarios - IPCC

336 Six Modeling Approaches
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 topdown)
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:
IV.l.
• Asian Pacific Integrated Model (AIM) from the
National Institute of Environmental Studies in Japan
(Morita etal., 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 Pubtic Health
and Environmental Hygiene (RIVM) (Alcamo et al,
1998; de Vries et ai, 1994, 1999, 2000), used in
connection with the Dutch Bureau for Economic Policy
Analysis (СРВ) 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 Altematives and
their General Environmental Impact (MESSAGE) from
the Intemational Institute of Applied Systems Analysis
(IIASA) in Austria (Messner and Stmbegger, 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).
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 Unked 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 cUmate 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 lirdicd 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).
The bottom-up models were prepared using the original AIM
bottom-up components, which can reproduce detailed
processes of energy consumption, industrial production, landuse
changes, and waste management as well as technology
development and social demand changes. However, two kinds
of top-down models were prepared for this quantification:
An energy-economic model based on the revised
Edmonds-Reilly-Barns (ERB) Model, which can
estimate interactions between energy sectors and
economic sectors.
• An original land equilibrium model that can reproduce
interactions between land-use changes and economic
sectors.
The original AIM bottom-up components were integrated with
these two top-down models through a newly developed linkage
module. This new stracture maximizes the ability to simulate a
variety of inputs at a variety of levels, and to calculate future
GHG emissions in a relatively full-range analysis.
The AIM model has nine regions for the energy-economic
model and 17 regions for the bottom-up and land equilibrium
models (see Table IV-1). Its time horizon is from 1990 to
2100. Before 2030, h uses 5-year time steps, but then jumps
to 2050, 2075, and 2100. The GHGs and related gases
include:
• Carbon dioxide (CO2), methane (CH^), nitrous oxide
(N2O), carbon monoxide (CO), non-methane volatile
organic compounds (NMVOCs), nitrogen oxides
(N0,^), and sulfur dioxide (SOj) etnissions from energy
combustion-production processes.
CO, from deforestation.
CH^ and N2O from agricultural production.
• NMVOCs and SOj from biomass combustion.
• CO2, CH4, N2O, N0^, CO, NMVOCs. and SOj
emissions from industrial processes, waste
management, and land-use changes.
More detailed information can be obtained by referring to the
web site: www-cger.nies.go.jp/ipcc/aim/
The ASF energy model consists of four end-use sectors
(residential, commercial, industrial, and transportation). These
sectors consume liquid fuels, solid fuels, gaseous fuels, and
electricity. An electricity generation sector converts liquid
fuels, solid fuels, gaseous fuels, nuclear energy, hydro energy,
and solar energy into electricity. A synfuels sector converts
coal and/or biomass into either a liquid or gaseous fuel. There
is no direct consumption of solar energy or biomass by the enduse
sectors.