Methodical Challenges of Prognostic Lifecycle Assessment - an Exemplary Study of ICT's Environmental Impact in Germany 2030

This paper covers methodological aspects of predictive lifecycle assessment (LCA). Forecasts on the future environmental impact of information and communication technology (ICT) are required, among other things, for the planning of industrial policy measures such as IT infrastructure expansion or for legislative measures to achieve climate policy goals. Companies are also interested in trend analysis of the environmental impact of ICT. Predictive LCA, which not only looks at individual products but also looks at the absolute environmental impact of entire product groups on the market, requires a lot of data. In the context of ICT, for example, the forecasts for the development of data traffic and the volume of stored data are used as basic information for determining trends. However, these forecasts are only a small part of the data needed. For example, realistic product stock models as well as technology development models are crucial. In order to assess the manufacturing phase of ICT equipment, the future development of integrated circuit (IC) and printed circuit board (PCB) production needs to be considered and adequately modelled. Furthermore, the carbon intensity of future electricity generation has a substantial impact. But there is also the question of considering an appropriate set of environmental impact categories in addition to global warming potential. The authors analyse the considerations underlying the modelling. Using the example of ICT in data centers, the methodical approach to creating complex and linked lifecycle inventories (LCI) is explained. Finally, the methodical approach and concluding results of the study are critically analysed and future measures to optimize this type of predictive LCA are identified.