Felix Müller, Christian Lehmann
The efficient and sustainable use of natural resources is one of the principal economic, social and
environmental challenges of our times. Germany has enormous material assets in the form of anthropogenic
material stocks as part of buildings, infrastructure and other durable goods. These assets
constitute a valuable reservoir of secondary resources. Without domestic mining activities for
any non-ferrous metal, Germany changes gradually to an “extractive economy” by extensive recovery
from secondary materials. Notwithstanding, many challenges remain to be overcome, e.g. substance
and product diversity and technology change, international trade flows, dissipation, contamination
and downcycling, in order to ascertain the potential of secondary raw materials. Hence, it is
key to the future high quality and non-detrimental management of secondary raw materials in general
– and nonferrous metals in particular – to apply a holistic, dynamic and proactive approach
which takes into account dynamics and discrepancies in time, place and across the multitude of
stakeholders who are involved along value chains.
The German Federal Environment Agency initiated a series of major projects on the “Mapping of
anthropogenic stocks in Germany”, in order to promote urban mining as a strategy to implement the
circular economy. The series is not only supposed to provide systematically compiled knowledge on
the composition of the current stock and its dynamics of change but also a forecast model for secondary
raw materials. For this purpose, a database was being developed and combined with a calculable
material flow network. The resulting system DyMAS (Dynamic Modeling of Anthropogenic
Stocks) is meant to represent an ever increasing inventory of goods and materials respecting their
specific dynamics. It aims to widen the knowledge base and evidence for decision making in the
circular economy by drawing attention to future recycling potentials. Moreover, it is being used to
share knowledge on the urban metabolism along the value chains, to implement a beneficial policy
framework in a timely manner and to improve an effective material flow management in the long
run. Besides, the modeling is backed by instructive indicator based approaches to monitor and report
the actual resource savings in terms of virgin raw materials and energy.
The presentation will provide insight into the state and perspectives of anthropogenic stock and
flow modeling in Germany, elucidating the rationale and terminology of major approaches and the
context of the urban mining, circular economy and resource efficiency policy framework. Particularly,
key results and lessons learnt for non-ferrous metals will be highlighted.