This contribution presents the state of the art of economy-wide material flow accounting. Starting from a brief recollection of the intellectual and policy history of this approach, we outline system definition, key methodological assumptions, and derived indicators. The next section makes an effort to establish data reliability and uncertainty for a number of existing multinational (European and global) material flow accounting (MFA) data compilations and discusses sources of inconsistencies and variations for some indicators and trends. The results show that the methodology has reached a certain maturity: Coefficients of variation between databases lie in the range of 10% to 20%, and correlations between databases across countries amount to an average R2 of 0.95. After discussing some of the research frontiers for further methodological development, we conclude that the material flow accounting framework and the data generated have reached a maturity that warrants material flow indicators to complement traditional economic and demographic information in providing a sound basis for discussing national and international policies for sustainable resource use.
The global land area required to meet the German consumption of agricultural products for food and non-food use was quantified, and the related greenhouse gas (GHG) emissions, particularly those induced by land-use changes in tropical countries, were estimated. Two comprehensive business-as-usual scenarios describe the development corridor of biomass for non-food use in terms of energetic and non-energetic purposes. In terms of land use, Germany was already a net importer of agricultural land in 2004, and the net additional land required by 2030 is estimated to comprise 2.5–3.4 Mha. This is mainly due to biofuel demand driven by current policy targets. Meeting the required biodiesel import demand would result in an additional GWP of 23–37 Tg of CO2 equivalents through direct and indirect land-use changes. Alternative scenario elements outline the potential options for reducing Germany's land requirement, which reflect future global per capita availability.
Resource flows constitute the materials basis of the economy. At the same time, they carry and induce an environmental burden associated with resource extraction and the subsequent material flows and stocks, which finally end up as waste and emissions. A reduction of this material throughput and the related impacts would require a reduction of resource inputs. And breaking the link between resource consumption and economicgrowth would require an increase in resource productivity. Material flow analysis (MFA) can be used to quantify resource flows and indicate resource productivity. In this article, we study the available empirical evidence on the actual (de-)linkage of material resource use and economic growth. We compare resource use with respect to total material requirement (TMR) and direct material input (DMI) for 11 and 26 countries, respectively, and the European Union (EU-15). The dynamics of TMR, as well as of the main components are analysed in relation to economic growth in order to show whether there is a decoupling (relative or absolute) from GDP and a change of the metabolic structure in the course of economicdevelopment. DMI/cap so far only decoupled from GDP/cap in relative terms; that is, in most countries, it reached a rather constant level but - with the exception of Czech Republic - showed no absolute decline yet. TMR/cap was reduced in two high-income countries and one low-income country due to political influence. Changes in TMR were more influenced by hidden flows (HF) than by DMI. We analyse the dynamics of the structure and composition of TMR in the course of economic development. In general, the economic development of industrial countries was accompanied by a shift from domestic to foreign resource extraction. Different relations can be discovered for the share of biomass, fossil fuel resources, construction resources and metals and industrial minerals.
Rationale for and interpretation of economy-wide materials flow analysis and derived indicators
(2003)
Economy-wide material flow analysis (MFA) and derived indicators have been developed to monitor and assess the metabolic performance of economies, that is, with respect to the internal economic flows and the exchange of materials with the environment and with other economies. Indicators such as direct material input (DMI) and direct material consumption (DMC) measure material use related to either production or consumption. Domestic hidden flows (HF) account for unused domestic extraction, and foreign HF represent the upstream primary resource requirements of the imports. DMI and domestic and foreign HF account for the total material requirement (TMR) of an economy. Subtracting the exports and their HF provides the total material consumption (TMC). DMI and TMR are used to measure the (de-) coupling of resource use and economic growth, providing the basis for resource efficiency indicators. Accounting for TMR allows detection of shifts from domestic to foreign resource requirements. Net addition to stock (NAS) measures the physical growth of an economy. It indicates the distance from flow equilibrium of inputs and outputs that may be regarded as a necessary condition of a sustainable mature metabolism. We discuss the extent to which MFA-based indicators can also be used to assess the environmental performance. For that purpose we consider different impacts of material flows, and different scales and perspectives of the analysis, and distinguish between turnover-based indicators of generic environmental pressure and impact-based indicators of specific environmental pressure. Indicators such as TMR and TMC are regarded as generic pressure indicators that may not be used to indicate specific environmental impacts. The TMR of industrial countries is discussed with respect to the question of whether volume and composition may be regarded as unsustainable.
It is not the scarcity of resources that constitutes environmental problems, but their use, the physical throughput of our economies. Material flows are a proxy for the totality of the unspecific environmental risks from human activities. As a strategic goal, an increase of the life-cycle-wide resource productivity by a factor 10 is suggested, including the materials bought and sold and the not-valued materials: we have to take into account the product itself and its "ecological rucksack". Material flows are best measured at the input side of the economy, where their number as well as the number of entry gates is limited. Thus here regulation and economic incentives can work more efficiently and less bureaucratically than today. The material intensity of products and services can be expressed as MIPS, the material input per unit of service, and as TMR, the total material requirement on the macro level, an important element in physical input–output tables.
Material flows induced by national economies can be regarded as indirect pressure indicators for environmental degradation. Economy-wide material flow analysis and indicators have been designed to monitor material and energy flows at the macroeconomic level and to provide indicators, which could contribute to management of resourceuse and output emission flows from both economic, environmental and broader sustainability points of view. These indicators can serve various purposes including monitoring the material basis of national economies and related environmental pressures, assessment of the material and resource productivity and monitoring the implications of trade and globalisation.
The main part of this paper compares the material and resourceuse of the Czech Republic, Germany and the EU-15 by means of DMI and TMR indicators over the period of 1991–2004 (1991–2000 for EU-15). At the aggregate level both indicators in all three economies do not show any clear decreasing or increasing trends over the period considered. This means that environmental pressure related to use of materials for production and consumption purposes remains rather stable. All the economies however, recorded an increase in the efficiency of transforming the material/resource inputs into economic output. The analysis further revealed that most of the dynamics of DMI and TMR in the Czech Republic tended towards a higher similarity with Germany and the EU-15. In the future, further decreases in DMI as well as in TMR of fossils fuels might be expected in the Czech Republic, which could be counteracted by increase in DMI and TMR of metal ores/metal resources and non-metallic minerals/non-metallic resources. The future development of total DMI, TMR and material/resource intensity in both the Czech Republic and Germany will depend on further shifts to less material intensive industries and services and on increasing material efficiency in production and consumption of particular products. This is not only a technological, but also a social challenge, as there are barriers in current mode of governance and in shaping of current economic and social systems to do so.