Overview

The Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model is an Integrated Assessment Model (IAM) allowing the identification of emission control strategies achieving given targets on air quality and greenhouse gas emissions at least costs, thereby revealing important synergies and trade-offs between these policy areas.

In its function as the Centre for Integrated Assessment Modelling (CIAM), IIASA has extensively been using the GAINS model to inform the negotiations under the Convention on Long-range Transboundary Air Pollution (CLRTAP) for e.g. the revision of the Gothenburg Protocol. Other relevant policy applications include the EU Thematic Strategy on Air Pollution and the Air Policy review as well as negotiations under the United Nations Framework Convention on Climate Change (UNFCCC), for which a special version of GAINS has been developed to compare greenhouse gas mitigation efforts among the Annex-I countries.

In practice, GAINS quantifies the technical and economic interactions between mitigation measures for ten air pollutants and six GHGs based on data from international energy and industrial statistics, emission inventories and on data supplied by countries themselves. Such an approach allows analyzing different air pollution policy packages, including the estimation of emissions, costs for air pollution control measures as well as the health or environmental impacts from various endpoints.

To that extent, the GAINS model also features an optimization routine deriving the most cost-effective combination of mitigation measures or the one minimizing emissions following given policy targets (e.g., current legislation, maximum feasible reduction).