Methodology

This paper presents the motivation for choosing the particular methods used in our study. After this, we describe, in aggregate terms, how the IIASA-ECS scenarios were built. The description of the scenario building includes an overview of the development of the global E3 (energy-economy-environment) system in the course of the 20th century. We then proceed to give, in non-technical language, a macroscopic description of models and concepts used for the scenario formulation. Together with the models we also describe, in general terms, how the so-called 'driving forces' define scenarios. This way, we give readers an idea of the respective importance of the variables that shape scenarios and, at the same time, an approximate idea about the sensitivity of the results.