Model scope and methods - MESSAGE-GLOBIOM
| Corresponding documentation | |
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| Model information | |
| Model link | |
| Institution | International Institute for Applied Systems Analysis (IIASA), Austria, http://data.ene.iiasa.ac.at. |
| Solution concept | General equilibrium (closed economy) |
| Solution method | Optimization |
| Anticipation | |
MESSAGEix represents the core of the IIASA IAM framework <xr id="fig:MESSAGE-GLOBIOM_iiasaiam"></xr> and its main task is to optimize the energy system so that it can satisfy specified energy demand at the lowest cost. MESSAGEix carries out this optimization in an iterative setup with MACRO, which provides estimates of the macro-economic demand response that results from energy system and services costs computed by MESSAGEix. For the six commercial end-use demand categories depicted in MESSAGEix (see Demand of MESSAGE-GLOBIOM), MACRO adjusts useful energy demand based on demand prices until the two models have reached equilibrium (see Macro-economy section of MESSAGE-GLOBIOM). It thus reflects price-induced energy efficiency improvements that can occur when energy prices change. MESSAGEix can represent different energy- and climate-related policies.
GLOBIOM provides MESSAGEix with information on land use and its implications, like the availability and cost of bio-energy, and availability and cost of emission mitigation in the AFOLU (Agriculture, Forestry and Land Use) sector (see Land-use of MESSAGE-GLOBIOM). To reduce computational costs, MESSAGEix iteratively queries a GLOBIOM emulator which can provide possible land-use outcomes during the optimization process instead of requiring the GLOBIOM model to be rerun continuously. Only once the iteration between MESSAGEix and MACRO has converged, the resulting bioenergy demands along with corresponding carbon prices are used for a concluding online analysis with the full-fledged GLOBIOM model. This ensures full consistency in the modelled results from MESSAGEix and GLOBIOM, and also allows the production of a more extensive set of reporting variables.
Air pollution implications of the energy system are computed in MESSAGEix by applying technology-specific pollution coefficients from GAINS (see Pollutants and non-GHG forcing agents for MESSAGE-GLOBIOM and Air pollution and health of MESSAGE-GLOBIOM).
In general, cumulative global GHG emissions from all sectors are constrained at different levels to reach the forcing levels (cf. right-hand side <xr id="fig:MESSAGE-GLOBIOM_iiasaiam"></xr>). The climate constraints are thus taken up in the coupled MESSAGE-GLOBIOM optimization, and the resulting carbon price is fed back to the full-fledged GLOBIOM model for full consistency. Finally, the combined results for land use, energy, and industrial emissions from MESSAGE and GLOBIOM are merged and fed into MAGICC (see Climate of MESSAGE-GLOBIOM), a global carbon-cycle and climate model, which then provides estimates of the climate implications in terms of atmospheric concentrations, radiative forcing, and global-mean temperature increase. Importantly, climate impacts and impacts of the carbon cycle are currently not accounted for in the IIASA IAM framework. The entire framework is linked to an online database infrastructure which allows straightforward visualisation, analysis, comparison and dissemination of results (Fricko et al., 2016 MSG-GLB_fricko_marker_2016).
