Supply versus use designs of environmental extensions in input–output analysis: Conceptual and empirical implications for the case of energy

Input–output analysis is one of the central methodological pillars of industrial ecology. However, the literature that discusses different structures of environmental extensions (EEs), that is, the scope of physical flows and their attribution to sectors in the monetary input–output table (MIOT), remains fragmented. This article investigates the conceptual and empirical implications of applying two different but frequently used designs of EEs, using the case of energy accounting, where one represents energy supply while the other energy use in the economy. We derive both extensions from an official energy supply–use dataset and apply them to the same single‐region input–output (SRIO) model of Austria, thereby isolating the effect that stems from the decision for the extension design. We also crosscheck the SRIO results with energy footprints from the global multi‐regional input–output (GMRIO) dataset EXIOBASE. Our results show that the ranking of footprints of final demand categories (e.g., household and export) is sensitive to the extension design and that product‐level results can vary by several orders of magnitude. The GMRIO‐based comparison further reveals that for a few countries the supply‐extension result can be twice the size of the use‐extension footprint (e.g., Australia and Norway). We propose a graph approach to provide a generalized framework to disclosing the design of EEs. We discuss the conceptual differences between the two extension designs by applying analogies to hybrid life‐cycle assessment and conclude that our findings are relevant for monitoring of energy efficiency and emission reduction targets and corporate footprint accounting.     

Economy‐wide Material Flow Indicators on a Sectoral Level and Strategies for Decreasing Material Inputs of Sectors

The article presents a method for the calculation of selected economy‐wide material flow indicators (namely, direct material input [DMI] and raw material input [RMI]) for economic sectors. Whereas sectoral DMI was calculated using direct data from statistics, we applied a concept of total flows and a hybrid input‐output life cycle assessment method to calculate sectoral RMI. We calculated the indicators for the Czech Republic for 2000–2011. We argue that DMI of economic sectors can be used for policies aiming at decreasing the direct input of extracted raw materials, and imported raw materials and products, whereas sectoral RMI can be better used for justifying support for or weakening the role of individual sectors within the economy. High‐input material flows are associated in the Czech Republic with the extractive industries (agriculture and forestry, the mining of fossil fuels [FFs], other types of mining, and quarrying), with several manufacturing industries (manufacturing of beverages, basic metals, motor vehicles or electricity, and gas and steam supply) and with construction. Viable options for reducing inputs of agricultural biomass include changes in people's diet toward a lower amount of animal‐based food and a decrease in the wasting of food. For FFs, one should think of changing the structure of total primary energy supply toward cleaner gaseous and renewable energy sources, innovations in transportation systems, and improvements in overall energy efficiency. For metal ores, viable options include technological changes leading to smaller and lighter products, as well as consistent recycling and use of secondary metals.     

Structural Decomposition Analysis of Raw Material Consumption

The aim of this article is to quantify the drivers for the changes in raw material consumption (domestic material consumption expressed in the form of all materials extracted and used in the production phase) in terms of technology, which refers to the concept of sustainable production; the product structure of final demand, which refers to the concept of sustainable consumption; and the volume of final demand, which is related to economic growth. We also aim to determine to what extent the technological development and a shift in product structure of the final demand compensate for the growth in final consumption volume. Therefore, we apply structural decomposition analysis (SDA) to the change in raw material consumption (RMC) of the Czech Republic between 2000 and 2007. To present the study in a broader context, we also show other material flow indicators for the Czech Republic for 2000 and 2007. Our findings of SDA show that final demand structure has a very limited effect on the change in material flows. The rapid change in final demand volume was not compensated for crude oil, metal ores, construction materials, food crops, and timber. For the material category of non‐iron metal ores, even the change in technology contributes to an increase in material flows. The largest relative increases are reported for non‐iron metal ores (38%) and construction materials (30%). The main changes in material flows related to the Czech Republic are driven by exports and enabled by imports, the main source of these increased material flows. This emphasizes the increasing role of international trade.     

经济系统物质流分析研究述评

作为研究经济系统物质代谢的重要方法,经济系统物质流分析方法近年来在资源与环境管理领域得到了广泛的应用,理论发展非常迅速。对经济系统物质流分析进行了系统综述,以期为更深入的理论研究提供参考。系统回顾了经济系统物质流分析的发展历史,介绍了其核算框架和指标体系。重点对经济系统物质流分析的研究现状进行了总结和述评,研究表明:(1)在经济系统物质流分析指标的核算研究方面:国家层面的核算研究多、方法较为成熟,而区域层面的核算研究尚未形成成熟的核算框架;针对直接流指标的核算研究多,而包含间接流或隐藏流的综合指标的核算方法研究不足;(2)在经济系统物质流分析指标的变化原因研究方面,目前的研究较少,研究方法包括分解分析法和回归分析法:前者多基于IPAT方程的直接分解法,难以考察经济系统内部的结构和技术的变化对经济系统物质流分析指标的影响,而后者则在所识别的经济系统物质流分析指标的影响因素方面具有较大差异。提出了经济系统物质流分析的未来研究方向。     

Mapping first to final uses for rare earth elements,globally and in the United States

Estimating the material flows of rare earth elements (REEs) is essential to understanding which industries are most vulnerable to potential REE supply disruptions which, in turn, may inform policy recommendations aimed at reducing the supply risk. However, the REEs are a group of mineral commodities characterized by highly uncertain estimates of supply and demand due to the REE market's complexity, opacity, and small size. In this study, a streamlined methodology was applied to map mineral commodity first-use to final-use applications and to estimate total requirements at the national level based on available industrial data for final-use finished goods. This analysis examines REEs both as a group and individually, showing that total US requirements are between 15% and 16.5% of world requirements for the year 2015, the latest year with the most complete information available. The findings shed light on US industrial capabilities by revealing the discrepancy between the types of REEs that go into US raw material consumption and those that are contained in embedded consumption. For instance, given the United States’ large oil refining industry, US raw material consumption of lanthanum is quite high. In contrast, US raw material consumption of neodymium is relatively low, whereas embedded demand is comparatively high. This reflects the lack of industrial capacity to process REE concentrates into magnet material combined with the US's high imports of products that contain rare earth permanent magnets.     

The future in and of criticality assessments

In recent literature, the concept of criticality aspires to provide a multifaceted risk assessment of resource supply shortage. However, most existing methodologies for the criticality assessment of raw materials are restricted to a fixed temporal and spatial reference system. They provide a snapshot in time of the equilibrium between supply and demand/economic importance and do not account for temporal changes of their indicators. The static character of criticality assessments limits the use of criticality methodologies to short‐term policy making of raw materials. In the current paper, we argue for an enhancement of the criticality framework to account for three key dynamic characteristics, namely changes of social, technical, and economic features; consideration of the spatial dimension in site‐specific assessments; and impact of changing governance frameworks. We illustrate how these issues were addressed in studies outside of the field of criticality and identify the dynamic parameters that influence resource supply and demand based on a review of studies that belong to the general field of resource supply and demand. The parameters are grouped in seven categories: extraction, social, economic, technical, policy, market dynamics, and environmental. We explore how these parameters were considered in the reviewed studies and propose ways and specific examples of addressing the dynamic effects in the criticality indicators. Furthermore, we discuss the current work on future scenarios to provide reference points for indicator benchmarks. The insights and guidelines derived from the review and our recommendations for future research set the foundations for an enhanced dynamic and site‐specific criticality assessment framework.     

Consumption‐based Material Flow Accounting

In 2007, imports accounted for approximately 34% of the material input (domestic extraction and imports) into the Austrian economy and almost 60% of the GDP stemmed from exports. Upstream material inputs into the production of traded goods, however, are not yet included in the standard framework of material flow accounting (MFA). We have reviewed different approaches accounting for these upstream material inputs, or raw material equivalents (RME), positioning them in a wider debate about consumption‐based perspectives in environmental accounting. For the period 1995–2007, we calculated annual RME of Austria's trade and consumption applying a hybrid approach. For exports and competitive imports, we used an environmentally extended input‐output model of the Austrian economy, based on annual supply and use tables and MFA data. For noncompetitive imports, coefficients for upstream material inputs were extracted from life cycle inventories. The RME of Austria's imports and exports were approximately three times larger than the trade flows themselves. In 2007, Austria's raw material consumption was 30 million tonnes or 15% higher than its domestic material consumption. We discuss the material composition of these flows and their temporal dynamics. Our results demonstrate the need for a consumption‐based perspective in MFA to provide robust indicators for dematerialization and resource efficiency analysis of open economies.     

Material Flow Indicators in the Czech Republic in Light of the Accession to the European Union

This article deals with the economy‐wide material flows in the Czech Republic in 1990–2006. It presents in brief the overall trends of the material flow indicators in 1990–2002. The major part of the article is focused on the years 2002–2006, which immediately preceded and followed the accession of the Czech Republic to the European Union in 2004. It is shown that this accession had quite a significant impact on the volume and character of the material flows of the Czech Republic. The accession was beneficial from an economic point of view, as it allowed for an increased supply of materials needed for economic growth. Furthermore, it was accompanied by an improvement in the efficiency of material transformation into economic output. From an environmental and broader sustainability point of view, however, this accession brought about some controversial outcomes. There was a significant increase in the net export of environmental pressure, on one hand, and an increase in net additions to the physical stock of the economy, on the other. Although the former is controversial from the viewpoint of equity in sharing area and resources, the latter places an additional burden on future generations because all physical stocks will turn into waste and emissions at some point, when their life span expires.     

A Material History of Australia

This article presents an analysis of the material history of Australia in the period 1975–2005. The values of economy‐wide indicators of material flow roughly trebled since 1975, and we identify the drivers of this change through structural decomposition analysis. The purpose of this work is to delve beneath the top‐level trends in material flow growth to investigate the structural changes in the economy that have been driving this growth. The major positive drivers of this change were the level of exports, export mix, industrial structure, affluence, and population. Only improvements in material intensity offered retardation of growth in material flow. Other structural components had only small effects at the aggregate level. At a more detailed level, however, the importance of the mineral sectors became apparent. Improvements in mining techniques have reduced material requirements, but increased consumption within the economy and increased exports have offset these reductions. The full roll out of material flow accounting through Australian society and business and a systematic response to its implications will require change in the national growth focus of the last two generations, with serious consideration needed to reverse the current volume‐focused growth of the economy and also to recast neoliberal and globalized trade policies that have dominated the globe for the past decades.     

The Raw Material Equivalents of International Trade

This article aims at estimating the raw material equivalents (RMEs)—the upstream used material flows required along the production chain—of imports and exports for some Latin American countries: Brazil, Chile, Colombia, Ecuador, and Mexico. Furthermore, the United States is included in the analysis as a reference for a high‐income economy. The RME concept and the empirical evidence are articulated by use of an input?output methodology. Results are set out for the year 2003 for each of the countries and in time series for the years 1977, 1986, 1996, and 2003 in the case of Chile. The findings show not only the physical dimensions behind direct material traded but also how the previous exporter (importer) position of a country (based on standard material flow analysis indicators) deteriorates, alleviates, or changes. Implications for material consumption indicators, such as direct material consumption (DMC) and raw material consumption (RMC), are also drawn. The results suggest basing the discussion of material flows on a broader set of indicators to obtain a more comprehensive picture of the implications of international trade and its impacts on the environment.     

Unified Materials Information System (UMIS): An Integrated Material Stocks and Flows Data Structure

Modern society depends on the use of many diverse materials. Effectively managing these materials is becoming increasingly important and complex, from the analysis of supply chains, to quantifying their environmental impacts, to understanding future resource availability. Material stocks and flows data enable such analyses, but currently exist mainly as discrete packages, with highly varied type, scope, and structure. These factors constitute a powerful barrier to holistic integration and thus universal analysis of existing and yet to be published material stocks and flows data. We present the Unified Materials Information System (UMIS) to overcome this barrier by enabling material stocks and flows data to be comprehensively integrated across space, time, materials, and data type independent of their disaggregation, without loss of information, and avoiding double counting. UMIS can therefore be applied to structure diverse material stocks and flows data and their metadata across material systems analysis methods such as material flow analysis (MFA), input‐output analysis, and life cycle assessment. UMIS uniquely labels and visualizes processes and flows in UMIS diagrams; therefore, material stocks and flows data visualized in UMIS diagrams can be individually referenced in databases and computational models. Applications of UMIS to restructure existing material stocks and flows data represented by block flow diagrams, system dynamics diagrams, Sankey diagrams, matrices, and derived using the economy‐wide MFA classification system are presented to exemplify use. UMIS advances the capabilities with which complex quantitative material systems analysis, archiving, and computation of material stocks and flows data can be performed.     

Can S-LCA methodology support responsible sourcing of raw materials in EU policy context?

Purpose

Access, affordability and sustainability of raw material supply chains are crucial to the sustainable development of the European Union (EU) for both society and economy. The study investigates whether and how the social life cycle assessment (S-LCA) methodology can support responsible sourcing of raw materials in Europe. The potential of social indicators already available in an S-LCA database is tested for the development of new metrics to monitor social risks in raw material industries at EU policy level.

Methods

The Product Social Impact Life Cycle Assessment (PSILCA) database was identified as a data and indicators source to assess social risks in raw material industries in EU-28 and extra-EU countries. Six raw material country sectors in the scope of the European policy on raw materials were identified and aggregated among those available in PSILCA. The selection of indicators for the assessment was based on the RACER (Relevance, Acceptance, Credibility, Ease, Robustness) analysis, leading to the proposal of 9 social impact categories. An S-LCA of the selected raw material industries was, thus, performed for the EU-28 region, followed by a contribution analysis to detect direct and indirect impacts and investigate related supply chains. Finally, the social performance of raw material sectors in EU-28 was compared with that of six extra-EU countries.

Results and discussion

Considering the overall social risks in raw material industries, “Corruption”, “Fair salary”, “Health and safety” and “Freedom of association and collective bargaining” emerged as the most significant categories both in EU and extra-EU. EU-28 shows an above-average performance where the only exception is represented by the mining and quarrying sector. An investigation of the most contributing processes to social impact categories for EU-28 led to the identification of important risks originating in the supply chain and in extra-EU areas. Therefore, the S-LCA methodology confirmed the potential of a life cycle perspective to detect burdens shifting and trade-offs. However, only a limited view on the sectoral social performance could be obtained from the research due to a lack of social data.

Conclusions

The S-LCA methodology and indicators appear appropriate to perform an initial social sustainability screening, thus enabling the identification of hotspots in raw material supply chains and the prioritization of areas of action in EU policies. Further methodological developments in the S-LCA field are necessary to make the approach proposed in the paper fully adequate to support EU policies on raw materials.

     

Use of Physical Supply and Use Tables for Calculation of Economy‐Wide Material Flow Indicators

The study described in this article presents the first‐ever physical supply and use tables (PSUTs) based on the recently published methodological standard for the System of Environmental‐Economic Accounting (SEEA). The tables were compiled for the Czech Republic for 2014. The compilation procedure followed was described in detail so that it can serve as a source of inspiration and a benchmark for other researchers and/or statisticians. The major shortcoming of the PSUTs is that not all needed data were readily available in physical units and required estimations based on proxies. Some parts of the tables are therefore burdened with a degree of uncertainty. In order to address the price inhomogeneity of sectoral prices for commodity outputs, imports, and exports, which tends to be typical for monetary supply and use tables (MSUTs), the PSUTs and MSUTs were further used for the calculation of raw material equivalents of import, exports, and raw material input (RMI) and raw material consumption (RMC) indicators. A comparison of results showed that the total indicators do not differ that much: the largest difference of 5% was recorded for raw material equivalents of exports, while RMC, for instance, remained nearly the same. However, we still argue for the use of PSUTs for the calculation of raw material equivalents, as changes in total volume of the indicators were accompanied with changes in their material structure. This can have significant consequences for the assessment of environmental impacts related to material consumption, as environmental impacts are very material specific.     

Methodology and Indicators of Economy‐wide Material Flow Accounting

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.     

Material flow analysis (MFA) of an eco-economic system:a case study of Wujin District,Changzhou,China

The economic and ecological aspects of a social system are coherently linked and can be examined by its material and energy flows.In this study,we used the material flow analysis (MFA) to model the material input and output of the Wujin District of Changzhou City,Jiangsu Province in China.It was revealed that:(1) total material input and material input per capita increased with economic development,while the total material out-put and material output per capita decreased consistently;(2) except for water,the total material input continued to increase.Input of solid materials grew faster than that of gaseous materials,while the total material output declined.The gas output accounted for the largest pro-portion of the output resulting in primary environmental pollution as burned fossil fuel; (3) water use in agriculture continued with an increasing trend while that in industrial and residential sectors decreased per capita.The total wastewater discharge and wastewater discharge per capita decreased with a faster decreasing rate of residential was-tewater discharge followed by industrial wastewater dis-charge; (4) material input per unit GDP fluctuated and material output per unit GDP decreased.A decreasing trend in both water use and wastewater discharge per unit GDP was disclosed.These results suggest that the effi-ciency of resource use in the Wujin District has improved.This weakened the direct link between economic develop-ment and environmental deterioration.Additionally,we discussed the harmonic development between environ-ment and economy.Potential limitations of MFA's application were also discussed.It is suggested that effec-tive measures should be taken for the enforcement of cir-cular economic strategies and the construction of a resource-saving economy     

Model collaboration for the improved assessment of biomass supply,demand, and impacts

Existing assessments of biomass supply and demand and their impacts face various types of limitations and uncertainties, partly due to the type of tools and methods applied (e.g., partial representation of sectors, lack of geographical details, and aggregated representation of technologies involved). Improved collaboration between existing modeling approaches may provide new, more comprehensive insights, especially into issues that involve multiple economic sectors, different temporal and spatial scales, or various impact categories. Model collaboration consists of aligning and harmonizing input data and scenarios, model comparison and/or model linkage. Improved collaboration between existing modeling approaches can help assess (i) the causes of differences and similarities in model output, which is important for interpreting the results for policy‐making and (ii) the linkages, feedbacks, and trade‐offs between different systems and impacts (e.g., economic and natural), which is key to a more comprehensive understanding of the impacts of biomass supply and demand. But, full consistency or integration in assumptions, structure, solution algorithms, dynamics and feedbacks can be difficult to achieve. And, if it is done, it frequently implies a trade‐off in terms of resolution (spatial, temporal, and structural) and/or computation. Three key research areas are selected to illustrate how model collaboration can provide additional ways for tackling some of the shortcomings and uncertainties in the assessment of biomass supply and demand and their impacts. These research areas are livestock production, agricultural residues, and greenhouse gas emissions from land‐use change. Describing how model collaboration might look like in these examples, we show how improved model collaboration can strengthen our ability to project biomass supply, demand, and impacts. This in turn can aid in improving the information for policy‐makers and in taking better‐informed decisions.     

Key sectors in greenhouse gas emissions in Spain: An alternative input–output analysis

We develop an alternative input–output approach and apply it to the determination of key sectors in emissions. This methodology allows us to assess and classify the different productive sectors according to their greenhouse gas emissions and the role that they play in the productive structure, as well as the participation of their output in the total volume of production. In contrast with previous approaches, we do not focus on the responsibility of final demand, but on the responsibility of the total production of each sector. We apply our methodology to the 2014 input–output table for Spain provided by the World Input–Output Database (2016). The results show that the sectors that induce more emissions from other sectors are manufacture of food products, wholesale and retail trade, and construction. Those that are pulled to emit coincide with those that are relevant for their own final demand, being the most important electricity and gas provision, agriculture, and transportation. The classification obtained allows to orient the design of greenhouse gas emission mitigation policies for the different sectors.     

Estimation of Life Cycle Material Costs of Cadmium Telluride– and Copper Indium Gallium Diselenide–Photovoltaic Absorber Materials based on Life Cycle Material Flows

Chalcogenide and chalcopyrite photovoltaic (PV) technologies are highly suitable for solar energy conversion because of their high efficiency, long‐term stable performance, and low‐cost production. However, the absorber materials that are used, such as indium, gallium, and tellurium, are regarded as critical, and their limited availability can hinder market expansion. Therefore, we assess how material efficiency measures along the PV module's life cycle can reduce the net material demand of the absorber materials and thus the material costs. In order to estimate the material flows, we developed a closed‐loop model for the life cycle representing the phases module production, module collection, module recycling, and refinement. In order to reflect the variety and uncertainty in each phase, we compose three different efficiency scenarios by varying material efficiency measures on process and product levels. For each scenario, we compute the life cycle material costs based on the computed material flows. The results show that, in the long term, the material demand can be reduced down to one fourth of the required feedstock for module manufacturing; that is, three fourths of the absorber material stays in the life cycle in a very efficient scenario. Thus, total material costs along the life cycle could be significantly reduced, because the costs for material recycling are lower than the costs for “new” technical‐grade material. This reduction in life cycle material costs means that cadmium telluride– and copper indium gallium diselenide–PV can still be financially viable even if the price of the absorber materials increases significantly. Hence those technologies will still be competitive against crystalline silicon PV in the mid to long term.     

The Energy Structure of the Canadian Economy

We developed a model of a national economy in which the phenomena of supply, demand, economic growth, and international trade are represented in terms of energy flows. In examining the structure of the economy, we distinguish between the energy embodied in capital assets used in the production and distribution of energy and that embodied in capital assets and goods that consume energy. Sources used to quantify the energy flows include: end‐use energy data by economic sector; International Energy Agency–style national energy balances, and national input‐output tables. As an example, the Canadian economy for 2008 produced 16.97 exajoules (EJ) of energy, which after net export of 6.16 EJ and other adjustments left a total primary energy consumption of 10.61 EJ. The energy supply and distribution sectors used close to 32% (3.36 EJ) of total primary consumption. Analysis of primary energy consumption shows that 25.14% was embodied in household consumption, 22.85% was consumed directly by households, 7.88% was embodied in government services, and 34.07% was embodied in exports. Of significance to economic growth, 7.14% was embodied in capital in energy demanding sectors, 1.25% in energy consuming personal assets, and 1.52% in supply sector capital. The energy return on energy investment was relatively constant, averaging 5.14 between 1990 and 2008. Capital investments required to decouple the Canadian economy from its dependence on fossil fuels are discerned.