Most economic models struggle to incorporate biophysical relationships between materials, energy and emissions, in order to
appropriately deal with biophysical constraints of supply (and possibly also demand). After the incorporation of biophysical
constraints, some functions produced surprising or even highly implausible results. These results have been checked against
expert judgement of plausibility, some biophysical assumptions have been refomulated or removed to secure consistency, and
some economic functions have been adjusted to take care of adequacy and plausibility of outcomes and model specifications.
A number of efforts were made to check the consistency of economic modelling outcomes with some fundamental functional interdependencies
on the biophysical level and against the biophysical scenarios presented in earlier papers. This usually required extensive
communication between research teams and the re-formulation of certain parameters, relationships and semi-empirical assumptions.
Methodologically, such interdisciplinary cross-checking is a novel and time-consuming exercise. This process highlights the
limitations of existing economic models to incorporate certain biophysical functional interdependencies, and vice versa the
still very limited ability of biophysical models to explore ranges of flexibility imposed upon changing economic assumptions.
Furthermore this ongoing collaboration showed that the specification of the baseline scenario and the semi-empirical assumptions
about efficiency gains as well as developments of factor productivity and technical change are highly influential on the results
of each scenario. Therefore a "realistic" specification and critical reflection of the actual feasability of certain baseline
trajectories is deemed necessary.
Forschungsbereich:Umwelt, Landwirtschaft und Energie