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   Consumption and Production Patterns

Total Material Requirement


Consumption and Production Patterns


  1. Indicator

(a)     Name: Total Material Requirement (TMR)

(b)     Brief Definition: Total Material Requirement is a compound indicator reflecting  all of the  physical materials that are mobilized each year to support an economy, including “hidden”, non-economic materials such as mineral overburden, processing waste and soil erosion. The TMR includes an aggregate indicator and disaggregated sub-indicators by resource sector.

(c)          Unit of Measurement: Metric tonnes per year

(d)         Placement in the CSD Indicator Set: The indicator is part of the set of indicators of consumption and production patterns.  It is not included in the general CSD indicator set.  

2. Policy Relevance

(a)          Purpose: This compound indicator measures the total materials mobilized to support an economy.  It can be used to analyze material efficiency and physical environmental disruption. 

(b)     Relevance to Sustainable/Unsustainable Development: A measure of the material required to support an economy is useful, especially if measured regularly and consistently over time to identify trends in material intensity. The indicator should be combined with economic measures (e.g. TMR per unit GDP) to track changes in material intensity and thus tendencies toward dematerialization of an economy (or the reverse).  TMR per unit GDP would also  provide a tool to compare a country’s material economy with those of other countries for a greater understanding of common as well as unique patterns. Measurement of level and trends in material requirements would allow better identification both of priorities for policy intervention as well as points of leverage for that intervention.  Measurement of total material flows requires the creation of a set of physical accounts that illuminate activities that impact the environment, their relative sizes, and leakages (such as pollution or toxins embodied in products or emitted in processes that might otherwise be unaccounted for).  These physical accounts could also be part of a set of Agreen national accounts.@  

(c)     International Conventions and Agreements: None. The OECD is in the process of establish an informal Forum, where interested countries may exchanged information on definitions, methodologies and data issues, in order to facilitate the development of national physical accounts. 

(d)         International Targets / Recommended Standards: There are no known international targets.  Some non-governmental organizations have recommended a target of a factor of ten reduction in the material intensity of industrialized economies, which would demonstrate an increase in eco-efficiency, as expressed by such measures as TMR per unit GDP and ensure sufficient resources for the material needs of developing countries and movement toward a cleaner environment for all.  Some European countries have established long-term national targets for energy and material efficiency, together with indicators for measuring progress, which is likely to stimulate demand for the collection of material flow statistics.  

(e)     Linkages to Other Indicators: This indicator is linked to other physical indicators dealing with pollution, land use, water use, and national financial indicators.  

3. Methodological Description

(a)        Underlying Definitions and Concepts: The Total Material Requirement is as comprehensive as possible in accounting for all physical material flows that support national economies, excluding only air, water, and agricultural tillage. Flows include those from mining (including overburden and gangue), construction (including earth moving), agriculture (including crop residues), forestry (including ancillary clearing and residues), soil erosion, energy, manufacturing and every other sector that requires the mobilization of materials from the environment for its operation. For purposes of this macro indicator of national behavior, truly minor flows can be excluded (e.g. diamond collecting in the United States) although nationally important flows must be included -- even if of trivial importance in many other countries (e.g., from gold mining.).  

In addition to an aggregate TMR, the indicator should be disaggregated into components corresponding to broad sectors of activity: fossil fuels, metals, other minerals, construction, infrastructure, renewable resources and semi-manufactures. In each of these areas, total material flows should be disaggregated into economic commodities and non-economic hidden flows.  

In principle, flows are only counted once during a given year -- even if during that year the materials are shifted about several times.  While dredging and excavation are covered  -- whether used for extraction of raw materials, infrastructure development, or construction -- each country will be confronted with unique data and modeling problems in estimating these flows.  Dredging in the United States, for example, is well documented, in Germany less so. 

In principle, imported raw materials are included, with the data on their mass and on the mass of the associated hidden flows included in the TMR for the importing country, even for hidden flows that remained in the country of origin.  The indirect material flows associated with those imports (e.g., energy expended, metal in earth moving machinery) are not included.  Imports of metals pose especially difficult problems since they may be imported as crude ore, several grades of concentrated ores, or as refined metal.  In the latter case, a certain proportion (currently undocumented and therefore unknown) might be recycled, with much lower hidden flows than primary metal.  Each important metal may need to be treated differently. However, as more countries develop sets of national physical accounts, the inclusion of hidden flows associated with imported materials in the accounts of the importing country could lead to double counting, if those flows are also counted in the physical accounts of the exporting country. Development of the TMR indicator for any country should take this into account when drawing system boundaries.  Flows from renewable resources are, in principle, treated similarly to those from non-renewable sources.  The primary hidden flow associated with agricultural and forestry activities, soil erosion, is categorized separately. Otherwise, hidden flows are not distinguished or disaggregated from commodities.  Material flows from agricultural and forestry should include the dry weight of all major crops and their associated non-salable above-ground harvested biomass.  Thus, a tree, for example, is counted as the mass of roundwood, and the associated limbs, leaves, and stumpage.  Livestock, fish, and other animal biomass are counted only if they are fed from non-agricultural feeds.  Thus fish harvested from wild stock are counted -- fish raised in aquaculture are not.  Livestock produced primarily from grazing are counted, those raised on grain are not.

Domestic semi-manufactures, such as Portland cement, are not counted, although the minerals used to make them are. .  Foreign semi-manufactures, such as Portland cement, are counted as imported along with the rucksacks associated with them.  Foreign finished goods are counted alone (primarily due to lack of data on the materials embodied in those goods and their associated rucksacks. 

Recycled materials (e.g. scrap metal and paper) are counted as finished goods if imported but not counted if domestically produced.  Data on foreign imports are usually available as the value of the import, defined by standard industrial codes (SIC), and are difficult to convert to physical quantities of materials.   

Exports were not deducted.  Materials that were ultimately exported were, nonetheless essential to the support of the economy and were, therefore, as much a basis for an industrial economy as purely domestic flows. It should be noted that the inclusion of imported goods together with their associated hidden flows in the country of origin, and the non-deduction of exports and their hidden flows, results in some double counting on the international level. International aggregates of TMR will therefore overstate total material flows. 

(b)               Measurement Methods:

  B Sources of data for calculating TMR vary considerably from country to country.  Sources for imported goods include financial data on trade and tonnes landed at ports.  Sources for minerals and energy can often be obtained from Ministries, industry organizations, and even individual companies and academic literature.   

It is inevitable that estimates based on expert opinion, economic costs, and industry practice will be used until the statistical infrastructure exists to provide better measures of the physical mass of materials mobilized to support the economy. 

  B Hidden flows in particular usually require indirect methods for their estimation.  Overburden from mining might be modeled based on an average mine or from information on costs or area impacted.  Gangue can be estimated from the average Agrade@ of ore from a country=s mines, or from some illustrative example.  

  B Time series require, as much as possible, common definitions and data collection methods.  Often definitions subtly change over time or the time series changes from estimated to measured. 

(c)        Limitations of the Indicator: The Total Material Requirement is not a measure of the impact of economic activity on the environment.  Measuring all materials in mass units gives them all equal weight.  Yet dredging might have an important local environmental impact and would be important in an analysis of the local impact of material flows.  The burning of coal might have an important global environmental impact and would be important in any analysis of the global impacts of material flow B in which local dredging would be ignored.  The construction of this indicator does, however, provide the underlying physical accounts that will allow analysis of impacts, using those flows important to the impact in question and using appropriate weights.  Someone interested in the impact of mining, for example, might concentrate on overburden removed and the toxicity of metals mined.  

Over time it is likely that additional B nationally relevant B indicators will be derived from the underlying data and that method and data will be refined.  

(d)        Status of the Methodology:  

(e)        Alternative Definitions / Indicators: The Total Material Requirement may be more useful when shown on a per capita or per unit GDP basis.  Time series are especially useful.  

4. Assessment of Data

(a)          Data Needed to Compile the Indicator:  Data on all material inputs into an economy, including minerals, fossil fuels, earth movement, dredging, and harvesting of renewable resources through agriculture, animal husbandry, and forestry.  

(b)         National and International Data Availability: Data for the construction of this indicators comes from a variety of sources.  To date TMR has been published only for the United States, Germany, Japan, and the Netherlands. Material flow studies are also underway, or completed, in Finland, Australia, Sweden, Norway, Italy, and Brazil. The UK, Chile, and China are also beginning work on physical accounts. Data for the construction of the indicator is in part available from the UN Statistical Office on energy consumption and production, and data is often available by country on imports of raw materials, semi-manufactures, and finished goods.  No one source provides all the data needed for the construction of this indicator.  

(c)    Data References:  See sections 3(b) and 4(b) above.  

5. Agencies Involved in the Development of the Indicator

Lead Agency:  

World Resources Institute (WRI)

10 G Street N.E. Suite 800, Washington D.C. 20002, U.S.A.

Other Organizations:

Wuppertal Institute (WI)

Postfach 100480, Doppersberg 19, D-42103, Wuppertal, Germany


National Institute for Environmental Studies (NIES)

16-2 Onogawa, Tsukuba, Ibaraki 305-0053, Japan


Centre of Environmental Science (CML), Leiden University

Van Steenisgebouw, Einsteinweg 2, 2300 RA, Leiden, The Netherlands


Institute for Interdisciplinary Studies of Austrian Universities (IFF), Department of Social Ecology

Schottenfeldgasse 29, A-1070 Vienna, Austria


6. References

(a)                Readings:

A. Adriaanse et al. 1997. "Resource Flows: The Material Basis of Industrial Economies". Washington D.C. World Resources Institute.  

E. Matthews et al. 2000. "The Weight of Nations: Material Outflows from Industrial Economies". Washington D.C. World Resources Institute.

(a)          Internet sites:  

As mentioned above.



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24 March 2003