ALBERT

Description: Environmental impacts of the provision of wood energy have been analyzed through life cycle assessment (LCA) techniques for many years. Systems for the generation of heat, power, and combined heat and power (CHP) differ, and methodological choices for LCA can vary greatly, leading to inconsistent findings. We analyzed factors that promote these findings by conducting a systematic review and meta-analysis of existing LCA studies for wood energy services. The systematic review investigated crucial methodological and systemic factors, such as system boundaries, allocation, transportation, and technologies, for transformation and conversion of North American and European LCA studies. Meta-Analysis was performed on published results in the impact category global warming (GW). A total of 30 studies with 97 systems were incorporated. The studies exhibit great differences in their systemic and methodological choices, as well as their functional units, technologies, and resulting outcomes. A total of 44 systems for the generation of power, with a median impact on GW of 0.169 kilograms (kg) of carbon dioxide equivalents (CO 2 -eq) per kilowatt-hour (kWh el ), were identified. Results for the biomass fraction only show a median impact on GW of 0.098 kg CO 2 -eq * kWh el −1 . A total of 31 systems producing heat exhibited a median impact on GW of 0.040 kg CO 2 -eq * kWh th −1 . With a median impact on GW of 0.066 kg CO 2 -eq * kWh el+th −1 , CHP systems show the greatest variability among all analyzed wood energy services. To facilitate comparisons, we propose a methodological approach for the description of system boundaries, the basis for calculations, and reporting of findings.

Description: For half a century, system scientists have relied on urban metabolism (UM) as a pragmatic framework to support the needed transition toward sustainable urban development. It has been suggested that information and communication technology (ICT) and, more specifically, smart cities can be leveraged in this transition. Given the recent advances in smart cities, smart urban metabolism (SUM) is considered a technology-enabled evolution of the UM framework, overcoming some of its current limitations. Most significantly, the SUM framework works at high temporal (up to real-time) and spatial (down to household/individual) resolutions. This article presents the first implementation of SUM in the Smart City Stockholm Royal Seaport R&D project; it further analyzes barriers and discusses the potential long-term implications of the findings. Four key performance indicators (KPIs) are generated in real time based on the integration of heterogeneous, real-time data sources. These are kilowatt-hours per square meter, carbon dioxide equivalents per capita, kilowatt-hours of primary energy per capita, and share of renewables percentage. These KPIs are fed back on three levels (household, building, and district) on four interfaces, developed for different audiences. The most challenging barrier identified was accessing and integrating siloed data from the different data owners (utilities, building owners, and so forth). It is hard to overcome unless a significant value is perceived. A number of long-term opportunities were described in the SUM context; among those, it is envisioned that SUM could enable a new understanding of the causalities that govern urbanism and allow citizens and city officials to receive feedback on the system consequences of their choices.

Description: A hybrid approach combining life cycle assessment and input-output analysis was used to demonstrate the economic and environmental benefits of current and future improvements in agricultural and industrial technologies for ethanol production in Brazilian biorefineries. In this article, three main scenarios were evaluated: first-generation ethanol production with the average current technology; the improved current technology; and the integration of improved first- and second-generation ethanol production. For the improved first-generation scenario, a US$1 million increase in ethanol demand can give rise to US$2.5 million of total economic activity in the Brazilian economy when direct and indirect purchases of inputs are considered. This value is slightly higher than the economic activity (US$1.8 million) for an energy equivalent amount of gasoline. The integration of first- and second-generation technologies significantly reduces the total greenhouse gas emissions of ethanol production: 14.6 versus 86.4 grams of carbon dioxide equivalent per megajoule (g CO 2 -eq/MJ) for gasoline. Moreover, emissions of ethanol can be negative (–10.5 g CO 2 -eq/MJ) when the system boundary is expanded to account for surplus bioelectricity by displacement of natural gas thermal electricity generation considering electricity produced in first-generation optimized biorefineries.

Description: Extended producer responsibility (EPR) legislation in the United States, which currently only exists on the state level, now includes three mattress EPR acts, which intend to shift the financial and operational burden of mattress end-of-life (EOL) management away from local and state government. It is important to keep in mind, however, that the original objective behind EPR is to reduce the environmental life cycle impacts of products. This article therefore quantifies the greenhouse gas (GHG) savings potential of mattress and boxspring recycling and reuse in the United States and also discusses labor implications and mattress design issues. We find that all three acts are unlikely to generate redesign incentives, but are expected to dramatically increase mattress collection and recycling. The collection and recycling of all 35 million EOL mattress and boxspring units estimated to reach the end of their lives in the United States every year would generate in the order of 10,000 jobs and GHG savings between 1 and 1.5 million metric tonnes.

Description: Based on the standards, International Organization for Standardization (ISO) 14040/44 and EN 15804, a cradle-to-gate analysis with an end-of-life scenario was carried out to provide a sector-representative environmental product declaration (EPD) for wooden interior doors according to the new standard, EN 15804. Methodological challenges caused by the complexity of the product system and the objective of representativeness are discussed. Primary inventory data were collected at 19 door production sites and covers 87% of the total German door production. The life cycle assessment was conducted using generic data for wooden materials, which is in line with EN 15804 derived from the ÖkoHolzBauDat project. Additionally, generic data from GaBi Professional and ecoinvent databases were used. Besides the estimation of fossil carbon dioxide emissions, the biogenic carbon content of the wooden biomass was taken into account. The highest environmental impacts originate from manufacturing the semifinished wood products and fittings in the prechains. A sensitivity analysis reveals uncertainties up to 17% in the EPD results. These can be attributed to the use of the partly inadequate linear scaling of the life cycle inventory by a factor of 1.57 to fit the required size of the functional unit given by the relevant product category rules. The consideration of biogenic carbon embodied in the wooden biomass leads to very high manufacturer-specific deviations to the averaged global warming potential results when cradle-to-gate stages are considered only.

Description: State-of-the-art technologies that implement theindustrial ecology concept only make it to the market if environmental gains and economic benefits are significant. Therefore, the article investigates, in an interdisciplinary way, two innovative technologies that valorize stainless steel (SS) slags as block masonry (bricks): carbonation and thermo-alkali-activation. The technical, environmental, and economic features of three SS bricks—solid bricks, perforated bricks, and lightweight aerated blocks—are compared to commercially available construction materials. Although the produced bricks meet industrial standards, technical challenges, such as optimization of alkali addition and use of metal molds, should be dealt with before upscaling to industrial production. A cradle-to-gate life cycle assessment that aggregates the results of the various impact categories shows that the environmental impact of solid and perforated SS bricks is lower than the impact of conventional clay-baked bricks owing to the avoidance of additives for slag stabilization and energy consumption for sintering clay. The impact of aerated SS bricks was found to be similar to the commercially available aerated blocks. More specifically, the carbon dioxide uptake from carbonation reduces the overall environmental impact, whereas use of alkalis increases the impact. A strengths weaknesses opportunity threats analysis highlights the economic advantages of SS bricks originating from lower energy requirements, reduced dependence on primary resources, and improved metal recovery from slag. However, in order to apply the innovative technologies at industrial scale, challenges related to processing conditions, feedstock variability, and potential competition from existing brick suppliers have to be overcome.

Description: The present Peru's metabolic profile study poses the specific question, What are the long-term national energy system implications of the recent government-supported growth of the mining sector? The question is addressed by analyzing interactions between human economic activity (in hours) and electricity input flows (in joules) in the mining sector of the Peruvian economy in 2000 and 2010, with a projection for 2020. The methodology is based on the multi-scale integrated analysis of societal and ecosystem metabolism (MuSIASEM), which is an application of Georgescu-Roegen's bioeconomics approach. Empirical results found for the national economy show: (1) the massive increase in size of the energy system, which is explained by exploitation of the Camisea natural gas (NG) reserves, and (2) the potential for establishing a carbon lock-in in the electricity sector, owing to increasing construction of electricity plants based on NG as their primary energy source. Empirical results specific to the mining sector indicate: (1) the extremely high electricity metabolic rate of the mining sector (61.6 megajoules per hour in 2010), which was found to be 11 times the rate of electricity used per hour of human activity in the building and manufacturing sector in Peru, and (b) the potential increases in the proportion of electricity used in the mining sector (flow share), which could jeopardize the availability of high-quality primary energy supplies for the rest of society. In light of these implications, it is argued that the Peruvian government's strong support for growth of the mining sector may have to be reconsidered.

Description: The construction industry is an important contributor to urban economic development and consumes large volumes of building material that are stocked in cities over long periods. Those stocked spaces store valuable materials that may be available for recovery in the future. Thus quantifying the urban building stock is important for managing construction materials across the building life cycle. This article develops a new approach to urban building material stock analysis (MSA) using land-use heuristics. Our objective is to characterize buildings to understand materials stocked in place by: (1) developing, validating, and testing a new method for characterizing building stock by land-use type and (2) quantifying building stock and determining material fractions. We conduct a spatial MSA to quantify materials within a 2.6-square-kilometer section of Philadelphia from 2004 to 2012. Data were collected for buildings classified by land-use type from many sources to create maps of material stock and spatial material intensity. In the spatial MSA, the land-use type that returned the largest footprint (by percentage) and greatest (number) of buildings were civic/institutional (42%; 147) and residential (23%; 275), respectively. The model was validated for total floor space and the absolute overall error (n = 46; 20%) in 2004 and (n = 47; 24%) in 2012. Typically, commercial and residential land-use types returned the lowest overall error and weighted error. We present a promising alternative method for characterizing buildings in urban MSA that leverages multiple tools (geographical information systems [GIS], design codes, and building models) and test the method in historic Philadelphia.

Description: In this article, we apply an additive two-stage data envelopment analysis estimator on a panel of 20 countries with advanced economies for the time period 1990–2011 in order to create a composite sustainability efficiency index. We use a window-based approach in order to study the countries over the years. The sustainability efficiency index is decomposed into production efficiency and eco-efficiency indicators. The results reveal inequalities among the examined countries between the two stages. The eco-efficiency stage is characterized by large inequalities among countries and significantly lower efficiency scores than the overall sustainability efficiency and the production efficiency. Finally, it is reported that a country's high production efficiency level does not ensure a high eco-efficiency performance.

Description: The growth in Austria's raw material consumption (RMC) or material footprint is driven by changes in consumption and production. In using the tool of structural decomposition analysis and applying it to Austrian RMC between 1995 and 2007, three specific drivers (technology, composition, and volume of final demand) are identified and quantified. The overall growth of Austrian RMC across the period of time under investigation shows that neither improved production or consumption efficiency nor reduction of consumption alone can lead to absolute material savings. The “rebound effect” has been used to describe how efficiency gains can be offset by growth in overall consumption, putting “degrowth” on the agenda of sustainability sciences and political movements. Absolute decoupling, that is, simultaneous growth in gross domestic product (GDP) and reduction of RMC, can only be achieved if reductions in final demand volume as a driver of material use are not offset by increases as a result of the changing final demand mix and/or technology effect (and vice versa). The Austrian case study provides very little evidence for such developments having occurred simultaneously during the period of time under investigation. In order for economic degrowth to contribute to lower material use and thus greater environmental protection, it must occur not only quantitatively, but also qualitatively in production and consumption structures.

Description: Material flow analysis (MFA) has been an effective tool to identify the scale of physical activity, the allocation of materials across economic sectors for different purposes, and to identify inefficiencies in production systems or in urban contexts. However, MFA relies on ignoring the social drivers of those flows to be able to perform its calculations. In many cases therefore, it remains detached from the processes (e.g., urban) that underpin them. This becomes a problem when the purpose of research is to inform the design of detailed recycling schemes, for which micro-level practice knowledge on how material flows are mediated by human agency is needed. The aim of this article is to demonstrate how a particular social science approach, namely, infrastructure studies (IS), can be combined with MFA to enhance the latter's potential as a decision support tool. To achieve a successful combination between IS and MFA, the object of inquiry must be carefully defined to function as a ‘boundary object,’ which allows academic approaches to work together without the need for consensus. This approach is illustrated with a case study example in urban mining research that assesses the hibernating stock of subsurface urban infrastructure in Norrköping, Sweden. It provides an example of how a well-calibrated MFA and a complementary social science approach can provide hands-on advice for private as well as public actors in a local and place-specific context. The article aims to advance the integration of social science and the study of the physical economy to contribute to the emerging field of social industrial ecology.

Description: Determining the relevance and importance of a technosphere process or a cluster of processes in relation to the rest of the industrial network can provide insights into the sustainability of supply chains: those that need to be optimized or controlled/safeguarded. Network analysis (NA) can offer a broad framework of indicators to tackle this problem. In this article, we present a detailed analysis of a life cycle inventory (LCI) model from an NA perspective. Specifically, the network is represented as a directed graph and the “emergy” numeraire is used as the weight associated with the arcs of the network. The case study of a technological system for drinking water production is presented. We investigate the topological and structural characteristics of the network representation of this system and compare properties of its weighted and unweighted network, as well as the importance of nodes (i.e., life cycle unit processes). By identifying a number of advantages and limitations linked to the modeling complexity of such emergy-LCI networks, we classify the LCI technosphere network of our case study as a complex network belonging to the scale-free network family. The salient feature of this network family is represented by the presence of “hubs”: nodes that connect with many other nodes. Hub failures may imply relevant changes, decreases, or even breaks in the connectedness with other smaller hubs and nodes of the network. Hence, by identifying node centralities, we can rank and interpret the relevance of each node for its special role in the life cycle network.

Description: The article analyzes and discusses the environmental and natural resource impacts, benefits, and greenhouse gas (GHG) mitigation potential associated with a long-term transition to more energy-efficient pyrometallurgical smelting technologies for the production of refined copper. Using generic data from the KGHM Polska Miedź S.A, Glogow I and II smelting facilities in Poland, this study employs life cycle assessment (LCA) to compare the environmental impacts of shaft and flash furnace-based smelting technologies. Additionally, this analysis accounts for likely technological changes in the more energy-efficient flash furnace smelting technologies and electricity generation from 2030 to 2050 to forecast the long-term impacts of copper production. Life cycle impact assessment results for copper production are characterized using the ReCiPe 2008 midpoint method. LCA results show that, for most impact categories, the flash-based technology can achieve significantly lower environmental impacts than a shaft furnace (i.e., to produce 1 ton of copper in 2010 generates, on average, a 24% lower overall impact). For climate change, transitioning from shaft furnace-based copper production to more efficient flash furnace technology leads to decreasing GHG emissions of 29% in 2010, 50% in 2030, and 56% in 2050.

Description: In this article, we track how consumption in the United States, a highly developed “core” country, triggers value added and carbon inequalities around the globe. We consider these two sources of inequality for all commodities and services consumed in the United States, and then for three specific sectors, these being electronics, motor vehicles, and wearing apparel. Our findings show how the production of commodities for U.S. consumption tends to reify inequalities between countries. Larger shares of value added (in comparison to shares of carbon emissions) are generally experienced by more-developed, more-integrated countries, whereas the opposite tendency is experienced in less-developed, less-integrated regions. We note how these between-country differences can depend on the product chains that are analyzed. Our article makes use of a novel combination of social network analysis and multiregional input-output analysis to better capture some intuitive ideas of global trade and its consequences.

Description: Wheat is an important commodity in Europe. With a production of 133 million tonnes per year and annual import and export accounting for 6.3 and 5.3 billion US$, respectively, wheat is the most important cereal in Europe. Wheat cultivation further feeds into a wide variety of products ranging from bread, over imitation meat, to biofuels and bio-based materials. Therefore, it is desirable to have a synthetic life cycle assessment (LCA) of the impacts of an average kilogram (kg) of wheat produced in Europe. This article aims to provide such a synthesis using two strategies. In the first strategy, we give an overview of published LCA impacts of wheat production. A second strategy is a meta-analysis in which a re-evaluation is made of 20 available life cycle inventories representing cases in 11 different European countries. Based on the production shares of these countries in the total European production, weighted average impacts are calculated. These weighted averages of the re-evaluated inventories show that an average kg of wheat grain produced in Europe demands 3.25 megajoules of nonrenewable, fossil energy, emits 0.61 to 0.65 kg carbon dioxide equivalents, triggers terrestrial acidification of 4.94 to 6.51 grams (g) sulphur dioxide equivalents, freshwater eutrophication of 0.08 to 0.09 g phosphorous equivalents, marine eutrophication of 4.97 to 7.60 g nitrogen equivalents, and occupies 1.63 square meter years of agricultural land. The re-evaluation of studies results in similar impacts as the mere reviewing of energy demands and global warming potentials. Given the many applications of wheat, the presented meta-analysis is interesting to evaluate the average and range of environmental performance of wheat production in Europe, but is also useful as an input in assessing impacts of wheat-based products.

Description: The formation of effective policies to reduce emissions from goods movement should consider local and remote life cycle effects as well as barriers for mode shifting. Using uni- and multimodal freight movements by truck, rail, and ocean-going vessel (OGV) associated with California, a life cycle assessment (LCA) is developed to estimate the local and remote emissions that occur from freight activity inside and associated with the state. Long-run average per tonne-kilometer results show that OGVs emit the fewest emissions, followed by rail, then trucks, and that the inclusion of life cycle processes can increase impacts by up to 32% for energy and greenhouse gas (GHG) emissions and 4,200% for conventional air pollutants. Efforts to reduce emissions through mode shifting should recognize that infrastructure and market configurations may be inimical to mode substitution. A uni- and multimodal shipping emissions assessment is developed for intrastate and California-associated freight movements to illustrate the life cycle impacts of typical trips for certain types of goods. When targeting GHG reductions in California, it should be recognized that heavy-duty trucks are responsible for 99% of intrastate goods movement emissions. An assessment of future freight truck technology improvements is performed to estimate the effectiveness of strategies to meet 2050 GHG reduction goals. Whereas aggressive improvements in fuel economy coupled with alternative vehicles and fuels can significantly reduce GHG emissions, to meet 2050 goals will likely require zero carbon emission vehicle technology. The value of using LCA in GHG reduction policy for transportation systems is explored.

Description: Cyclical industrial networks are becoming highly desirable for their efficient use of resources and capital. Progress toward this ideal can be enhanced by mimicking the structure of naturally sustainable ecological food webs (FWs). The structures of cyclic industrial networks, sometimes known as eco-industrial parks (EIPs), are compared to FWs using a variety of important structural ecological parameters. This comparison uses a comprehensive data set of 144 FWs that provides a more ecologically correct understanding of how FWs are organized than previous efforts. In conjunction, an expanded data set of 48 EIPs gives new insights into similarities and differences between the two network types. The new information shows that, at best, current EIPs are most similar to those FWs that lack the components that create a biologically desirable cyclical structure. We propose that FWs collected from 1993 onward should be used in comparisons with EIPs, given that these networks are much more likely to include important network functions that directly affect the structure. We also propose that the metrics used in an ecological analysis of EIPs be calculated from an FW matrix, as opposed to a community matrix, which, to this point, has been widely used. These new insights into the design of ecologically inspired industrial networks clarify the path toward superior material and energy cycling for environmental and financial success.

Description: Conservation of mass and energy are essential to physical accounting, just as price and market balances are essential to economic accounting. These principles guide data collection and inventory compilation in industrial ecology. The resulting balanced surveys, however, can rarely be used directly for life cycle assessment (LCA) or environmentally extended input-output (EEIO) analysis; some modeling is necessary to recast coproductions by multifunctional activities as monofunctional unit processes (a.k.a. Leontief production functions or technical “recipes”). This modeling is done with allocations in LCA and constructs in input-output. In this article, we ask how these models respect or perturb the balances of the original inventory. Which allocations or constructs, applied to what type of data set, have the potential to simultaneously respect its multiple physical, financial, and market balances? Our analysis builds upon the recent harmonization of allocations and constructs and the ongoing development of multilayered supply and use inventory tables. We derive the necessary and sufficient conditions for balanced models, investigate the role of data aggregation, and clarify these models' relation to system expansion. We find that none of the modeling families in LCA and EEIO are balanced in general, but special data characteristics can allow for the respect of multiple balances. An analysis of these special cases allows for clear guidance for data compilation and methods integration.

Description: Sustainable building rooftop technologies, such as white roofs, green roofs, and photovoltaic(s) (PV) panels, are becoming increasingly implemented as a result of their associated environmental benefits. Studies of these rooftop technologies are often located in hot climates and do not assess their full environmental consequences. Further, current studies tend to focus on one technology and often do not evaluate the full range of technology options using a systematic framework with common assumptions and boundaries. This article evaluates the environmental performance on a life cycle basis of white roofs, green roofs, and roof-mounted PV in the cold Canadian climate. Solar PV demonstrates the highest environmental performance in all impact categories considered (see complete list in Results section) and is the preferred option from an environmental perspective. Green roofs result in beneficial environmental impacts, although much less significant than those obtained with PV, and are the only rooftop technology that reduces both heating and cooling energy use. The environmental performance of white roofs in cold climates is strongly affected by the heating penalty (i.e., the increase in heating energy use resulting from the high solar reflectance). Although white roofs have been proven an outstanding option in warmer climates, in cold climates, net negative environmental impacts lead to white roof technology not being recommended for general applications in cold climates. A sensitivity analysis shows that the conclusions in this study provide robust insights across Canada and cold climates in general.

Description: This study explored the impacts of electricity allocation protocols on the life cycle greenhouse gas (GHG) emissions of electricity consumption. The selection of appropriate electricity allocation protocols, methodologies that assign pools of electricity generators to electricity consumers, has not been well standardized. This can lead to very different environmental profiles of similar, electricity-intensive processes. In an effort to better represent the interconnected nature of the U.S. electrical grid, we propose two new protocols that utilize inter-regional trade information and localized emission factors to combine generating pools that are sub- or supersets of one another. This new nested approach increases the likelihood of capturing important inter-regional electricity trading and the appropriate assignment of generator emissions to consumers of local and regional electricity. We applied the new and existing protocols to the U.S. primary aluminum industry, an industry whose environmental impact is heavily tied to its electricity consumption. Our analysis found GHG emission factors that were dramatically different than those reported in previous literature. We calculated production-weighted average emission factors of 19.0 and 19.9 kilograms carbon dioxide equivalent per kilogram of primary aluminum ingot produced when using our two nested electricity allocation protocols. Previous studies reported values of 10.5 and 11.0, at least 42% lower than those found by our study.

Description: We investigate the extent to which Japanese people can change their consumption and the corresponding environmental impact. We propose a new analytical framework with a rebound matrix that captures the monetary flow from potential savings to their respending (referred to as rebound). A questionnaire is used to derive the matrix. On average, respondents spent 3.4 million Yen annually, resulting in 12.4 tons of carbon dioxide (CO 2 ) emissions in their daily lives. The survey results suggest that acceptable spending reductions would correspond to a CO 2 emissions reduction of nearly 6%. However, the CO 2 emissions would increase by nearly the same amount when the respondents respend their savable money (rebound CO 2 emissions). The annual CO 2 emissions and the annually reducible CO 2 emissions both increase with the increase in annual expenditure. Consequently, the net CO 2 emissions also increase with the increase in annual expenditure. The rebound spending is approximated using the rebound matrix. Finally, it is suggested that the net CO 2 emissions can be reduced through lifestyle changes whereby spending on energy items is reduced and the resulting savings are spent on telecommunication, clothes, shoes, education, and housing.

Description: Reductions in the greenhouse gas (GHG) intensity of passenger and freight transportation are possible through adoption of fuel-saving technologies, demand switching between modes, and large-scale electrification of fleets, in addition to other actions. In this study, future scenarios to 2030 and 2050 are the basis for assessment of GHG reduction potentials for major passenger and freight modes (automobiles, buses, trains, aircraft, and oceangoing vessels) across eight regions of the world. New fuel-saving technologies can significantly reduce the life-cycle GHG footprint of both passenger and freight vehicles, but not uniformly worldwide. Countries outside of the Organization for Economic Cooperation and Development (OECD) lag behind OECD countries in GHG reduction potentials for all modes but oceangoing vessels owing to a combination of slower adoption of fuel-saving technologies and a slower decarbonization of electricity generation and other processes. The reduction of GHG intensity will occur more slowly for freight modes than for passenger modes. However, improved fuel efficiency has negative feedbacks to the effectiveness of mode-switching and alternative fuel adoption policies through 2050 because improvements in the fuel efficiency of vehicles alone may cause the marginal benefits of GHG abatement policies to diminish over time. This trend may be reversed if alternative fuel pathways decarbonize at faster rates than conventional transportation fuels. The largest opportunities for GHG reductions occur in non-OECD countries. Given the many factors that distinguish transportation systems between developed and developing nations (e.g., availability of new technologies, the financial ability to acquire them, and policies to incentivize their adoption), many benefits could be gained through interregional cooperation.

Description: The fear that human consumption is causing climate change, biodiversity loss, and mineral scarcity has recently prompted interest in reuse because of the intuitive belief that it reduces new production and waste. The environmental impacts of reuse have, however, received little attention—the benefits typically assumed rather than understood—and consequently the overall effects remain unclear. In this article, we structure the current work on the topic, reviewing the potential benefits and pitfalls described in the literature and providing a framework for future research. Many products’ use-phase energy requirements are decreasing. The relative importance of the embodied impacts from initial production is therefore growing and the prominence of reuse as an abatement strategy is likely to increase in the future. Many examples are found in the literature of beneficial reuse of standardized, unpowered products and components, and repairing an item is always found to be less energy intensive than new production. However, reusing a product does not guarantee an environmental benefit. Attention must be paid to restoring and upgrading old product efficiencies, minimizing overspecification in the new application, and considering whether more efficient, new products exist that would be more suitable. Cheap, reused goods can allow many consumers access to products they would otherwise have been unable to afford. Though socially valuable, these sales, which may help minimize landfill in the short term, can represent additional consumption rather than a net environmental benefit compared to the status quo.

Description: Refurbishing products, which are increasingly sold in business-to-consumer markets, is a key strategy to reduce waste. Nevertheless, research finds that consumers’ willingness to pay (WTP) for refurbished products is low. Strategies for a higher WTP are needed in order to grow consumer markets for refurbished products. Eco-certification of refurbished products may be a key strategy here. Drawing on the consumer WTP literature concerning “green” products, we investigate the impact of independent eco-certificates. Our analysis is based on a survey of 231 potential customers. The results suggest that, across various product categories, the WTP for products with refurbished components is significantly lower. Adding an eco-certificate tends to return the WTP toward the virgin product level. We show that consumers with proenvironmental attitudes particularly exhibit green buying behavior. Our findings indicate that eco-certification is often worthwhile because it enhances the business rationale for producing products with refurbished components.

Description: Greenhouse gas (GHG) emissions from energy use in the water sector in China have not received the same attention as emissions from other sectors, but interest in this area is growing. This study uses 2011 data to investigate GHG emissions from electricity use for urban water supply in China. The objective is to measure the climate cobenefit of water conservation, compare China with other areas on a number of emissions indicators, and assist in development of policy that promotes low-emission water supply. Per capita and per unit GHG emissions for water supplied to urban areas in China in 2011 were 24.5 kilograms carbon dioxide equivalent (kg CO 2 -eq) per capita per year and 0.213 kg CO 2 -eq per cubic meter, respectively. Comparison of provinces within China revealed that GHG emissions for urban water supply as a percentage of total province-wide emissions from electricity use correlate directly with the rate of leakage and water loss within the water distribution system. This highlights controlling leakage as a possible means of reducing the contribution of urban water supply to GHG emissions. An inverse correlation was established between GHG emissions per unit water and average per capita daily water use, which implies that water demand tends to be higher when per unit emissions are lower. China's high emission factor for electricity generation inflates emissions for urban water supply. Shifting from emissions-intensive electricity sources is crucial to reducing emissions in the water supply sector.

Description: Plant-derived renewable resources have the potential to enable the simultaneous generation of high-value-added products, such as foods, with energy, such as electricity and thermal power. Much of the heat cogenerated from renewables in power plants has been discarded because of the geographical and temporal gaps in heat supply and demand. In this study, we aim to devise an effective industrial symbiosis (IS) for a regional combined heating and power (CHP) plant utilizing local renewable resources. For the actual region of IS, the island of Tanegashima in Japan was adopted, where sugarcane is planted as a base industry. Through a thermodynamic analysis of the energy flows in a sugar mill, it was demonstrated that large amounts of heat were discarded from the sugar mill, even though the quality of heat was high enough for power generation or other energy demand. This is partly because some of the renewables have been regarded as wastes in the production of foods or other high-value-added products. At the same time, scenarios were defined and analyzed on the integrated use of locally available lignocellulosic biomass to increase the operation ratio of an existing bagasse-based CHP system. Through both periods with and without sugar production, additional heat and power can be made available by decreasing the energy loss and through IS.

Description: The building sector is a major contributor to energy consumption, greenhouse gas (GHG) emissions, and depletion of natural resources. In developed countries, existing buildings represent the majority of the stock, their low-carbon refurbishment hence being one of the most sensible ways to mitigate GHG emissions and reduce environmental impacts of the construction sector. This article has investigated and established the GHG and non-GHG life cycle impacts of several double skin façade (DSF) configurations for office refurbishments by means of a parametric comparative life cycle assessment against up-to-standard single skin façade (SSF) refurbishment solutions. Two different methods were used to assess both GHG emissions and other environmental impacts. Results show that if, on the one hand, most of the DSF configurations assessed actually reduce GHG emissions compared to SSFs over their life cycle—thus supporting a wider adoption of DSFs for low-carbon refurbishments—on the other hand, there exist non-negligible ecological and environmental impacts that the DSF generates, specifically in terms of some materials of the structure and their final disposal. Research attention is thus needed regarding the environmental impacts of the materials used for DSFs and not only in minimizing the energy consumption of the operational phase.

Description: A wide spectrum of accounting frameworks and models is available to describe socioeconomic metabolism (SEM). Despite the common system of study, a large variety of terms and representations of that system are used by different models. This makes it difficult for practitioners to compare and choose a model or model combination that is fit for purpose. To facilitate model comparison, we analyze the system structure of material flow analysis (MFA); life cycle assessment (LCA); supply and use tables (SUTs); Leontief, Ghosh, and waste input-output analysis; integrated assessment models; and computable general equilibrium models. We show that the typical system structure of MFA and LCA is a directed graph. For the other models and some MFA and LCA studies, the system structure is a bipartite directed graph. We demonstrate that bipartite directed graphs and SUTs are equivalent representations of SEM. We show that the system structures of the models above are special cases of a general system structure, which models SEM as a bipartite graph . The general system structure includes industries, markets, the final use phase, products, waste, production factors, resources, and emissions. From the general system structure, we derive an accounting framework in the form of a generalized SUT. The general system structure facilitates the development of clear and unambiguous terminology across models. It helps to identify rules for the correct accounting of waste flows and stock changes. It facilitates model comparison and can serve as a blueprint for a model-independent database of SEM.

Description: Artificial lighting has allowed the decoupling of human activities from natural daylight hours. Electricity utilized for artificial lighting accounts for 18.8% of U.S. electricity consumption. Compact fluorescent lamp (CFL) and light-emitting diode (LED) options are more efficient and have longer lifetimes than conventional incandescent bulbs, but the question remains about the actual energy savings likely to be realized through more efficient lighting delivery systems. This uncertainty influences the rate of adoption and use of efficient lighting technology (and thus the extent and time lags of efficiency gains). Once adopted, gains in efficiency can lead to rebound effects that eliminate these gains and, paradoxically, lock society into increased use of energy. In this study, an agent-based model and complex systems approach is used to understand how available information and perceptions of different lighting options influence adoption and use, and the potential impact of the rebound effect to reduce the energy savings of energy-efficient lighting options in a residential setting. Individual households and their decisions are modeled to create overall population-level consumption data. The multifunctionality of LED lighting may cause consumers to use significantly more light, creating the potential for both rebound and backfire to occur. The results indicate that the adoption of CFL and LED lighting will decrease residential energy consumption if consumers continue to use the same amount or slightly more light; however, when an expansion of lit spaces is included or a large increase in lighting usage occurs, energy consumption will increase and, over time, reduce or completely erode energy savings.

Description: The aim of this work is to reconstruct the main economy-wide/material flow accounting indicators for the Spanish economy between 1860 and 2010. The main results indicate that from 1960 onward, the country saw a very rapid industrial transition based on the domestic extraction of quarry products and the import of fossil fuels and manufactured goods. Direct material consumption rose from 58.7 million tonnes (Mt) in 1860 to 570.2 Mt in 2010. In per capita terms, it rose from 2.76 tonnes per capita per year (t/cap/yr) to 11.61 t/cap/year. Of the decennial years studied in this article, a peak of 15.23 t/cap/yr occurs in the year 2000; the subsequent fall is explained by the crisis of 2008. Until 1930, Spain was a net exporter of resources, but since that year, and especially since 1960, it began to depend heavily on overseas resources. The physical trade balance per inhabitant in Spain was –0.01 t/cap/year in 1860 and today it is 2.45 t/cap/year. This process also reveals the change in consumption patterns, which became increasingly dependent on abiotic resources. In 1860, 98.1% of resources consumed was biomass, whereas today the figure is 16.2%. In all events, this article shows how, although the great transformation did not occur until 1960, before that date the country saw significant qualitative transformation, which did not involve relevant changes in the mobilization of resources.

Description: Artificial lighting is a major source of electricity demand globally. As the demand for lighting services grows over the next 40 years, especially in developing countries, efficient light-source technologies such as light-emitting diodes (LEDs) can reduce the energy consumed for lighting services and therefore its environmental impacts. LED technologies in both residential and commercial/industrial applications are expected to see dramatic improvements in luminous efficacy over the coming decades, potentially leading to more environmentally benign lighting. A scenario-based, integrated hybrid life cycle assessment quantifies and confirms the environmental benefits of deploying efficient light sources in all global regions through 2050, with electricity generation following the International Energy Agency's (IEA) BLUE Map scenario for limiting climate change to 2 degrees Celsius. Data used for previous assessments of light sources is updated and harmonized to reflect recent and expected future improvements in luminous efficacy and materials efficiency for LED lamps and luminaires. The aggregate life cycle greenhouse gas (GHG) emissions of global light provision can be reduced by more than a factor of 7 owing to decarbonization of electricity generation, increased adoption of efficient light sources, and future advances in LED technology. Estimates of the technological capability and market penetration of efficient light sources show that by 2050, a 2.5 to 2.9 times growth in the global demand for lighting services can be accommodated while still meeting IEA GHG mitigation goals and increasing metal depletion just 20% above 2010 estimates.

Description: Cities are thought to be associated with most of humanity's consumption of natural resources and impacts on the environment. Cities not only constitute major centers of economic activity, knowledge, innovation, and governance—they are also said to be linked to approximately 70% to 80% of global carbon dioxide emissions. This makes cities primary agents of change in a resource- and carbon-constraint world. In order to set meaningful targets, design successful policies, and implement effective mitigation strategies, it is important that greenhouse gas (GHG) emissions accounting for cities is accurate, comparable, comprehensive, and complete. Despite recent developments in the standardization of city GHG accounting, there is still a lack of consistent guidelines regarding out-of-boundary emissions, thus hampering efforts to identify mitigation priorities and responsibilities. We introduce a new conceptual framework—based on environmental input-output analysis—that allows for a consistent and complete reconciliation of direct and indirect GHG emissions from a city. The “city carbon map” shows local, regional, national, and global origins and destinations of flows of embodied emissions. We test the carbon map concept by applying it to the greater metropolitan area of Melbourne, Australia. We discuss the results and limitations of the approach in the light of possible mitigation strategies and policies by different urban stakeholders.

Description: The extraction, transformation, use, and disposal of materials can be represented by directed, weighted networks, known in the material flow analysis (MFA) community as Sankey or flow diagrams. However, the construction of such networks is dependent on data that are often scarce, conflicting, or do not directly map onto a Sankey diagram. By formalizing the forms of data entry, a nonlinear constrained optimization program for data estimation and reconciliation can be formulated for reconciling data sets for MFA problems where data are scarce, in conflict, do not directly map onto a Sankey diagram, and are of variable quality. This method is demonstrated by reanalyzing an existing MFA of global steel flows, and the resulting analytical solution measurably improves upon their manual solution.

Description: This article assesses the impact of economic integration on Tanzania's sociometabolic profile for the years 1970–2011, which witnessed an opening and further integration of Tanzania's economy through increased trade and foreign investment, through a time-series economy-wide material flows analysis (EW-MFA). The EW-MFA results show that contrary to the trade patterns of many developing countries, increased economic integration has resulted in Tanzania becoming a net importer of resources across all material categories when measured by the physical trade balance indicator. Additionally, the article discusses the conceptual and empirical challenges of measuring ecologically unequal exchange with EW-MFAs for developing countries whose export profiles are dominated by lightweight, high-value precious stones and metals. It also assesses the degree to which the Tanzanian economy has undergone dematerialization over the past 40 years of economic integration.

Description: The production of waste creates both direct and indirect environmental impacts. A range of strategies are available to reduce the generation of waste by industry and households, and to select waste treatment approaches that minimize environmental harm. However, evaluating these strategies requires reliable and detailed data on waste production and treatment. Unfortunately, published Australian waste data are typically highly aggregated, published by a variety of entities in different formats, and do not form a complete time-series. We demonstrate a technique for constructing a multi-regional waste supply-use (MRWSU) framework for Australia using information from numerous waste data sources. This is the first MRWSU framework to be constructed (to the authors' knowledge) and the first sub-national waste input-output framework to be constructed for Australia. We construct the framework using the Industrial Ecology Virtual Laboratory (IELab), a cloud-hosted computational platform for building Australian multi-regional input-output tables. The structure of the framework complies with the System of Environmental-Economic Accounting (SEEA). We demonstrate the use of the MRWSU framework by calculating waste footprints that enumerate the full supply chain waste production for Australian consumers.

Description: One of the key drivers that influence building energy consumption is the demand for space heating. Particularly in countries with cold climates and a large stock of residential buildings with central heating, building energy management systems (BEMS) are an option to reduce energy consumption and greenhouse gas (GHG) emissions. These systems can be combined with existing space heating technologies and other efficiency measures, such as building insulation. They are ideal for retrofitting purposes owing to their low up-front costs. A prospective life cycle assessment model is used to analyze the environmental impacts of the technology today, in 2030, and in 2050. This allows for a first-ever, order-of-magnitude assessment of the environmental impacts of BEMS over their life cycle. The assessment is based on manufacturer information and generic life cycle inventory data for electronic components. Future impacts are based on changes in electricity generation following the International Energy Agency's 2 degree and 6 degree scenarios, and are used to assess the contribution of BEMS to global energy and GHG saving goals. Results show substantially lower life cycle GHG emissions and higher savings of environmental impacts per kilowatt-hour of heating when compared to natural gas or electric heating. Potential net emissions savings range from approximately 0.4 kilograms carbon dioxide equivalent (kg CO 2 -eq) when avoiding natural gas heating to over 1 kg CO 2 -eq when avoiding electric heating in regions with GHG-intensive electricity generation. At present, BEMS can avoid at least 40 times the GHG emissions that they require for production and use, when deployed in regions with cold climates.

Description: Environmental remediation activities often require the management of large volumes of water and the consumption of significant amounts of local natural resources, including energy and fossil fuels. Traditionally, proposed remedial approaches for a specific cleanup scenario are evaluated by overall project implementation cost, time frame of the cleanup, and effectiveness to meet cleanup goals. A new paradigm shift, referred to as sustainable remediation, has influenced the remediation industry to consider environmental, social, and economic impacts from cleanup activities. An environmental footprint analysis is the most common method to evaluate environmental implications of cleanup approaches. Presently, these footprint tools do not associate the environmental implications with global impacts. In this article, the method has been extended to integrate the social cost of carbon emissions to quantify global impacts. The case study site is a former aircraft parts manufacturing facility that caused chlorinated solvent contamination in soil and groundwater beneath the building. A groundwater pump-and-treat system was initially installed, followed by its gradual phase-out with concurrent phase in of in situ bioremediation. The case study evaluates the monetized societal benefits from quantifying carbon emission impacts of the proposed cleanup approaches and alternative scenarios. Our results suggest that societal impacts based on monetized carbon emissions can be reduced by 27% by optimizing the remediation processes. The sensitivity analysis results elucidate how variation in carbon prices and social discount rates can influence cleanup decisions for remediation projects.

Description: We analyze the environmental impact of household consumption in terms of the material, water, and land-use requirements, as well as greenhouse gas (GHG) emissions, associated with the production and use of products and services consumed by these households. Using the new EXIOBASE 2.2 multiregional input-output database, which describes the world economy at the detail of 43 countries, five rest-of-the-world regions, and 200 product sectors, we are able to trace the origin of the products consumed by households and represent global supply chains for 2007. We highlight the importance of environmental pressure arising from households with their consumption contributing to more than 60% of global GHG emissions and between 50% and 80% of total land, material, and water use. The footprints are unevenly distributed across regions, with wealthier countries generating the most significant impacts per capita. Elasticities suggest a robust and significant relationship between households’ expenditure and their environmental impacts, driven by a rising demand of nonprimary consumption items. Mobility, shelter, and food are the most important consumption categories across the environmental footprints. Globally, food accounts for 48% and 70% of household impacts on land and water resources, respectively, with consumption of meat, dairy, and processed food rising fast with income. Shelter and mobility stand out with high carbon and material intensity, whereas the significance of services for footprints relates to the large amount of household expenditure associated with them.

Description: The complexity of data and methods in industrial ecology (IE) keeps growing, and the demand for comprehensive and interdisciplinary assessments increases. To keep up with this development, the field needs a data infrastructure that allows researchers to annotate, store, retrieve, combine, and exchange data at low cost, without loss of information, and across disciplines and model frameworks. A consensus-building debate about how to describe the common object of study, socioeconomic metabolism (SEM), is necessary for the development of practical data structures and databases. We review the definitions of basic concepts to describe SEM in IE and related fields such as integrated assessment modeling. We find that many definitions are not compatible, are implicit, and are sometimes lacking. To resolve the conflicts and inconsistencies within the current definitions, we propose a hierarchical system of terms and definitions, a practical ontology , for describing objects, their properties, and events in SEM. We propose a typology of object properties and use sets to group objects into a hierarchical, mutually exclusive, and collectively exhaustive (H-MECE) classification. This grouping leads to a general definition of stocks . We show that a MECE representation of events necessarily requires two complementary concepts: processes and flows , for which we propose general definitions based on sets. Using these definitions, we show that the system structure of any interdisciplinary model of SEM can be formulated as a directed graph . We propose guidelines for semantic data annotation and database design, which can help to turn the vision of a powerful data infrastructure for SEM research into reality.

Description: China's mineral resource consumption has gone through multiple increases since 1980, resulting in the inadequacy of important strategic resources and a high level of external dependence. Some developed countries have already reduced primary resources consumption through urban mining. Can China also break through the bottleneck of the resource shortage and continue its economic and social development through strengthening of urban mining? This article selected copper (Cu), aluminum (Al), lead (Pb), and iron (Fe) as case studies and established predictive models for metal demand, recycling, and stock, based on stock analysis, material flow analysis, and a life distribution model, and then analyzed the metabolism of the four resources and compared the environmental effects of three scenarios. The study indicates that the urban mining potential of Cu, Fe, Al, and Pb will attain 8.1, 711.6, 37.0, and 12.1 million tonnes, respectively, in 2040. Compared with 2010, the substitution rate (secondary metals substituting primary metals) of Cu and Fe increase by 25.4% and 59.9%, whereas external dependence decreases by 30.8% and 25.7%. However, substitution is not obvious regarding Al and Pb. The low resource scenario decreases resources use, which will reduce external dependence in the short term, whereas the strengthened recovery scenario increases resource recovery and has a larger effect in reducing external dependence in the long term. So, in line with urban mining in the future, China should change its environment and resource strategy, further strengthen layout and construction of urban mining demonstration bases, and encourage the use of recyclable resources to provide a better foundation for urban mining.

Description: World food production has increased substantially in the past century, thanks mostly to the increase in the use of oil as input in the production processes. This growing use of fossil fuels has negative effects, both on the environment and the production costs. Fishing is a fuel consuming food production activity, and its energy efficiency performance has worsened over time. World-wide fisheries are also suffering from overexploitation, which contributes to the poor efficiency performance, adding more pressure and criticism on this economic activity. In this paper we analyzed the energy efficiency performance of more than 20,000 European Union (EU) fishing vessels for the period 2002–2008, using the edible energy return on investment (EROI) indicator. The vessels analyzed, grouped in 49 different fleets, represented 25% of the vessels and 33% of the landings of the EU fishing sector. These EU fishing fleets’ average EROI for 2008 was 0.11, which translates to an energy content of the fuel burned that is 9 times greater than the edible energy content of the catch. Hence, the significance of this study arises from the use of time-series data on a relevant part of the EU fleet that showed stable or even slight improvements on the EROI over time. Moreover, results showed that the energy efficiency of the different fleets varied significantly (from 0.02 to 1.12), mainly depending on the fishing gear and the vessel length. The performance of the most efficient fleets, such as large pelagic trawlers and seiners, was comparable to many agricultural production activities. The plausible drivers behind these trends are further considered.

Description: The environmental characterization of the charging infrastructure required to operate electric vehicles (EVs) is usually overlooked in the literature. Only rudimentary life cycle inventories of EV charging facilities are available. This lack of information is especially noticeable in environmental studies of the environmental performance of electric two-wheelers (E2Ws), none of which have included an analysis of charging facilities, even though they constitute the most successful electric-drive market in the world. This article focuses on characterizing the life cycle of the global warming potential (GWP) and primary energy demand (PED) of two conventional charging facility designs that are widely implemented for charging E2Ws in public spaces. The relative environmental relevance of charging facilities per kilowatt-hour (kWh) supplied to E2Ws is determined by considering a range of use scenarios (variability in the service ratio) and the effect of upgrading the electricity mix to include more renewable energy sources. Savings of over 3 metric tons (tonnes) of carbon dioxide equivalent emissions and 56 equivalent gigajoules can be achieved by implementing an optimized charging facility design. The internalization of the relative environmental burden from the charging facility per kWh supplied to E2Ws can increase the GWP of E2Ws’ use phase from 1% to 20% and the PED from 1% to 13%. Although the article focuses on one particular case scenario, the research is intended to provide complementary criteria for further research on the life cycle management of electric mobility systems. Thus, a series of factors that can influence the environmental performance of EV charging networks at the macro scale are discussed.

Description: COVER FIGURE: Word cloud made from the titles, abstracts, and keywords of the articles, columns, and forums published in this special issue on Advances in Complex Adaptive Systems and Industrial Ecology. The word cloud was created using the tool at www.werdle.net . Credit: Ming Xu, Hannah Lifset.

Description: This study examines the life cycle energy demand and greenhouse gas (GHG) emissions associated with substituting natural cellulose and kenaf in place of glass fibers in automotive components. Specifically, a 30 wt% glass-fiber composite component weighing 3 kilograms (kg) was compared to a 30 wt% cellulose fiber composite component (2.65 kg) and 40 wt% kenaf fiber composite component (2.79 kg) for six cars, crossovers, and sport utility vehicles. The use-phase fuel consumption of the baseline and substitute components, with and without powertrain resizing, were determined using a mass-induced fuel consumption model based on U.S. Environmental Protection Agency test records. For all vehicles, compared to the baseline glass fiber component, using the cellulose composite material reduced life cycle energy demand by 9.2% with powertrain resizing (7.2% without) and reduced life cycle GHG emissions by 18.6% with powertrain resizing (16.3% without), whereas the kenaf composite component reduced energy demand by 6.0% with powertrain resizing (4.8% without) and GHG emissions by 10.7% with powertrain resizing (9.2% without). For both natural fiber components, the majority of the life cycle energy savings is realized in the use-phase fuel consumption as a result of the reduced weight of the component.

Description: In order to fully comprehend the socioeconomic metabolic (SEM) dynamics and material balance of nations, long-term accounting of economy-wide material stock is necessary in parallel to material flow accounts. Nevertheless, material stock accounts have been scarce, isolated, and mostly focused either on single materials, short time spans, or small regions. This study has two objectives: (1) review the state of the art of material stock research in the SEM discourse and (2) present a project to map, in a high level of detail, the in-use construction material stocks of Japan and its 47 prefectures from the 1940s until the present era. This project documents the two major depositories of material stock: buildings and infrastructure. We describe the challenges and benefits of utilizing a bottom-up approach, in order to promote its usage in material stock studies. The resulting database presents the accumulation of stock over time, as well as visually displaying the spatial distribution of the stock using geographical information systems (GIS), which, we argue, is an essential aspect of material stock analysis in the context of socioeconomic metabolism research.

Description: There is a growing concern over the security and sustainable supply of raw material among businesses and governments of developed, material-intensive countries. This has led to the development of a systematic analysis of risk incorporated with raw materials usage, often referred as criticality assessment. In principle, this concept is based on the material flow approach. The potential role of life cycle assessment (LCA) to integrate resource criticality through broadening its scope into the life cycle sustainability assessment (LCSA) framework has been discussed within the LCA communities for some time. In this article, we aim at answering the question of how to proceed toward integration of the geopolitical aspect of resource criticality into the LCSA framework. The article focuses on the assessment of the geopolitical supply risk of 14 resources imported to the seven major advanced economies and the five most relevant emerging countries. Unlike a few previous studies, we propose a new method of calculation for the geopolitical supply risk, which is differentiated by countries based on the import patterns instead of a global production distribution. Our results suggest that rare earth elements, such as tungsten, antimony, and beryllium, generally pose high geopolitical supply risk. Results from the Monte Carlo simulation allow consideration of data uncertainties for result interpretation. Issues concerning the consideration of the full supply chain are exemplarily discussed for cobalt. Our research broadens the scope of LCA from only environmental performance to a resource supply-risk assessment tool that includes accessibility owing to political instability and market concentration under the LCSA framework.

Description: This study provides a global substance flow analysis for gallium (Ga), germanium (Ge), and indium (In) for 2011, quantifying the amount of metal lost during extraction, beneficiation/smelting/refining, manufacturing of intermediate products, and the amount embodied in end-use products. Thus far, studies illustrating their cradle to end-use life cycle on a global scale are either missing or outdated, and thus opportunities to increase their supply remain unknown and/or not quantified. The results illustrate the losses and inefficiencies stages, thereby identifying potential additional supply by process improvement, recovery, and recycling. Results show that there are significant opportunities to meet future demand of Ga and Ge by concentrating recovery efforts in the extraction and beneficiation/smelting/refining stages. Further, 1.4% Ga, 0.7% Ge, and 54% In of the theoretical available amount in the attractor ores are extracted to meet the primary refined demand in 2011. Of the 9,065 tonnes (t) of Ga embodied in the Bayer liquor (from aluminum production), only 263 t are refined. This is owing to low capacities of Ga refining, combined with a refining efficiency of 60%. Ge presents a similar case for the same reasons, in which only 43 t of Ge of the 7,636 t of Ge available from zinc leach residue are refined. Meeting future In demand, on the other hand, will require greater efforts in increasing end-of-life recycling. Process efficiencies for Ga (46%), Ge (56%), and In (78%) demonstrate further potential. We quantify the flows into use by distinguishing among dissipative and nondissipative end uses, as well as the recyclable fraction for each metal for 2011.

Description: This article develops a modeling approach for estimating emissions (e.g., carbon dioxide) from nuclear, coal, natural gas, and hydropower generators in reaction to short-term changes to electricity demand. The modeling approach accounts for a set of operating constraints (OCs), including scheduled maintenance, forced outage, spinning reserves, fuel switching, seasonal output capacities, and seasonal hydro resource availability. It is found that these OCs are important to achieve reasonable estimates of electricity production by fuel type as well as associated emissions. This conclusion follows from an analysis of electric power generation by networks of power plants in Texas and New York in 2004 and 2005. The inputs to the model with operating constraints (OC model) developed in this article include hourly electricity demand, fuel costs, a list of power plants in the network, their basic generation characteristics, and the set of OCs developed in this article. Given these inputs, the OC model estimates the hourly amount of electricity generation by each power plant in the network, which leads to estimates of marginal resource consumption and emissions. Our central result is that historical annual and monthly generation by fuel type and efficiency are well estimated by the OC model and that the exclusion of OCs leads to poor estimates. This work can be combined with emerging work on wind and solar generation to provide a complete picture of contemporary grid dispatch and associated emissions.

Description: The identification of potential by-product exchanges is are areimportant for fostering industrial symbiosis. To discover these potential exchanges, this article extends the analysis of local industrial symbiosis to a national scale. A waste input-output table, which is a material flow accounting tool, was compiled and used as a database to examine the existing exchanges of by-products. The supplies and demands of industrial wastes or by-products were compared to highlight their potential use for promoting higher exchange flows. The analysis of the linkages indicated that the majority of each of the by-products were reused by the few industries that had the technology and operational capacity for reuse. This finding is useful for determining which industries are good candidates for promoting further industrial symbiosis (IS). Based on a nation-wide analysis that considered the industrial characteristics of Taiwan comprehensively, 23 types of major by-products with greater reuse flows and 216 potential exchange patterns were identified between the industries. In addition, three types of eco-industrial networks were characterized as follows according to their dominant types: (1) fossil fuel, metal, and mineral-dominated; (2) agricultural and synthetic material-dominated; and (3) ICT and chemical industry-dominated eco-industrial networks. This analysis highlights the resource exchange potentials and provides information to new firms for networking with existing businesses.

Description: Urban metabolism provides a framework to understand resource flows into cities and waste flows out. Its potential has been hampered by the lack of good disaggregated data. This article presents energy-use findings for the residential sector for the city of Los Angeles based on census-block–level aggregation of address-level electricity use obtained from the Los Angeles Department of Water and Power. City or county billing data by customer class over time can enable empirical tracking of energy conservation and efficiency programs by different customer classes, and matched to census information and county tax assessor data about building vintage, size, and type can provide information important for rate setting, for example, or energy conservation and efficiency program investments. We report on median electricity demand and corresponding greenhouse gas emissions and expenditures at three geographical aggregations: city council district (15 in total); neighborhood (114 in total); and census block group (2,538 in total). We find that the ratio of median annual demand between highest- and lowest-tier users is 26 at the census-block group level, but only 2.2 at the city council district level, demonstrating that spatial aggregation significantly masks the degree of variation that may be observed. We also show how such data can enable the description of energy to develop energy disclosure thresholds that reflect a city's morphology. In contrast to New York City's 50,000-square-foot reporting threshold, to capture half of Los Angeles’ electricity consumption, the threshold for reporting would have to be 5,000 square feet.

Description: Secure access to energy and food are two of the challenges facing the Northeast region of the United States. Traditional biofuel feedstocks, such as corn and oil seed, are able to satisfy energy requirements. However, they compete with food production for desirable land and water resources and, in any case, are not likely to exploit the region's current comparative advantages. This study investigates a potential solution to the energy security problem in the Northeast: biofuel from advanced feedstock in the form of net forest growth and woody wastes, of which the region has abundant endowments. The federal government has committed to requiring 79.5 billion liters (BL) of advanced biofuel production annually by 2022. We evaluate both the physical capacity for its production and its cost competitiveness using an input-output model of consumption, production, and trade in the 13-state region. The model minimizes resource use required to satisfy given consumer demand using alternative technological options and subject to resource constraints. We compile data from the technical literature quantifying state-level biofuel feedstock endowments and the technological requirements for cellulosic ethanol production. We find that exploiting the region's endowment of cellulosic feedstock requires either making the price of biofuels competitive with gasoline through subsidies or restricting imports of gasoline. Based on this initial investigation, we conclude that the region can produce significant amounts of advanced biofuel, up to 20.28 BL of cellulosic ethanol per year, which could displace nearly 12.5% of the gasoline that is now devoted to motorized transport in the region.

Description: Evaluating metal criticality is a topic that addresses future metals supply and that has inspired research in corporations, academic institutions, and governments. In this article, we apply a comprehensive criticality methodology to seven specialty metals—scandium (Sc), strontium (Sr), antimony (Sb), barium (Ba), mercury (Hg), thallium (Tl), and bismuth (Bi)—at the national and global levels for 2008. The results are presented along with uncertainty estimates in a three-dimensional “criticality space” comprised of supply risk (SR), vulnerability to supply restriction (VSR), and environmental implications (EI) axes. The SR score is the highest for antimony over the medium term (i.e., 5 to 10 years), followed very closely by bismuth and thallium; for the long term (i.e., a few decades), the highest SR is for thallium, followed very closely by antimony. Strontium and barium, followed very closely by mercury, have the lowest SR over the medium term, and mercury has the lowest SR over the long term. Mercury has the highest EI score. For VSR, thallium is the most vulnerable at both the national level (for the United States) and global level, followed by strontium at both levels. In general, specialty metals are found to possess a unique mix of sparse data, toxicity concerns (in some cases), and inadequate or nonexistent substitutes for a number of specialized uses, a situation that would seem to demand increased effort in acquiring the information needed to characterize specialty metal criticality with more rigor and transparency than is currently possible.

Description: Current life cycle assessment (LCA) interpretation practices typically emphasize hotspot identification and improvement assessment. However, these interpretation practices fail in the context of a decision-driven comparative LCA where the goal is to select the best option from a set of dissimilar alternatives. Interpretation of comparative LCA results requires understanding of the trade-offs between alternatives—instances in which one alternative performs better or worse than another—to identify the environmental implications of a specific decision. In this case, analysis must elucidate relative trade-offs between decision alternatives, rather than absolute description of the alternatives individually. Here, typical practices fail. This article introduces a probability distribution-based approach to assess the significance of performance differences among alternatives that allows LCA practitioners to focus analyses on those aspects most influential to the decision, identify the areas that would benefit the most from data refinement given the level of uncertainty, and complement existing hotspot analyses. In a case study of a comparative LCA of five photovoltaic technologies, findings show that thin-film cadmium telluride and amorphous silicon cell panels are most likely to perform better than other alternatives. Additionally, the impact categories highlighted by the new approach are different than those highlighted by typical external normalization practices, suggesting that a decision-driven approach to interpretation would redirect environmental research efforts.

Description: This article examines the dynamic relationship between the consumption of goods and services, technological efficiency, and associated resource use, as described by the theory of Jevons’ Paradox (JP). A theory is presented about what causes JP, in which resource efficiency savings are eventually overtaken by increases in consumption to produce a net increase in resource use and therefore environmental impacts. An application of the theory was carried out using system dynamics, modeling carbon dioxide equivalent (CO 2 -eq) emissions from private road transport in the UK between 1970 and 2010. The model results indicate the approximate impact of JP within the historical period: a rise in travel consumption of approximately one half and a rise in CO 2 -eq emissions of approximately one third. The model was used to estimate whether the European Union (EU) goal of a 40% drop in CO 2 -eq emissions by 2030 is achievable in the road transport sector, by adding interventions, and the results indicate that higher increases in fleet efficiency than are currently forecast, costlier travel, and a reduction in travel consumption would all be required. The theory and model presented in this article highlight the need to implement a system of interventions that can influence the strength and direction of each of the feedback loops within the system being intervened with, if CO 2 -eq emissions are to be more reliably reduced than they are at present. Further, because the system is constantly evolving, intervening with it requires a responsive, holistic approach, while maintaining focus on a long-term goal.

Description: The sustainable production and supply of raw materials (“nonenergy raw materials”) and primary energy carriers (“energy raw materials”) is a core element of many policies. The natural resource base for their production and supply, and the access thereto, are limited. Moreover, raw material supply is high on environmental and social impact agendas as well. A broad, quantitative framework that supports decision makers is recommended so as to make use of raw materials and primary energy carriers more sustainably. First, this article proposes a holistic classification of raw materials and primary energy carriers. This is an essential prerequisite for developing an integrated sustainability assessment framework (ISAF). Indeed, frequently, only a subset of raw materials and primary energy carriers are considered in terms of their source, sector, or final application. Here, 85 raw materials and 30 primary energy carriers overall are identified and grouped into seven and five subgroups, respectively. Next, this article proposes a quantitative ISAF for the production and supply of raw materials and primary energy carriers, covering all the sustainability pillars. With the goal of comprehensiveness, the proposed ISAF integrates sustainability issues that have been covered and modeled in quite different quantitative frameworks: ecosystem services; classical life cycle assessment (LCA); social LCA; resource criticality assessment; and particular international concerns (e.g., conflict minerals assessment). The resulting four areas of concerns (i.e., environmental, technical, economic, and social/societal) are grouped into ten specific sustainability concerns. Finally, these concerns are quantified through 15 indicators, enabling the quantitative sustainability assessment of the production and supply of raw materials and primary energy carriers.

Description: Steam is an important utility that is required in nearly all industrial process chains and hence needs to be modeled in life cycle assessment studies. Industrial steam systems are often very complex, with different steam flows varying in pressure and temperature and being transported over different distances. This should be accounted for when calculating the energy requirements related to steam supply. In this article, we constructed a generic model that allows estimating final energy requirements (i.e., gate-to-gate energy required to generate the steam) of various types of single-fuel steam systems without turbines (i.e., open and closed cycles) with or without flash steam and expressed per tonne (t) of steam supplied to a process (before heat exchange) or per gigajoule (GJ) heat delivered within the process (after heat exchange, i.e., as useful energy). The model focuses on steam provided for covering process heat requirements and hence excludes cogeneration schemes with steam turbines. Based on the final energy requirements estimated with our generic model, primary energy requirements and environmental impacts can be calculated for various circumstances. Depending on the conditions chosen, final energy requirements for natural gas–fueled systems, as estimated in this study, are 2.71 to 3.44 GJ/t produced steam or 1.33 to 1.78 GJ/GJ delivered heat.

Description: Concerns about the future availability and continuity of metal supplies have triggered research efforts to define and assess metal criticality. In this study, we apply a comprehensive methodology to the elements of the geological zinc, tin, and lead family: zinc (Zn); germanium (Ge); cadmium (Cd); indium (In); tin (Sn); and lead (Pb). Zn, Sn, and Pb have played important roles in various technological sectors for centuries, whereas Ge, Cd, and In are by-product metals that are increasingly utilized in emerging and strategic technologies. Criticality assessments are made on national (i.e., the United States) and global levels for 2008. The results are presented with uncertainty estimates in three-dimensional “criticality space,” comprised of supply risk (SR), environmental implications, and vulnerability to supply restriction (VSR) axes. SR is the highest for In for both the medium (i.e., five to ten years) and long term (i.e., a few decades). Pb and Zn have the lowest SR for the medium term and Pb the lowest SR for the long term. In and Ge production have the highest environmental burdens, mainly as a result of emissions from Zn smelting and subsequent metals purification and recovery from Zn leaching residues. VSR is highest for Pb at the global and national levels.

Description: Information and communication technology (ICT) is providing new ways to access media content. ICT has environmental benefits and burdens. The overall goal of the present study was to assess the environmental impacts of production and consumption of magazines read on tablets from a life cycle perspective. Important goals were to identify the activities giving rise to the main impacts and the key factors influencing the overall environmental impacts. Data gaps and uncertainties were also addressed. The results are compared against those for the print edition of the magazine in a separate article (part 2). The methodology used in the study was life cycle assessment. The environmental impacts assessed included climate change, cumulative energy/exergy demand, metal depletion, photochemical oxidant formation, particulate matter formation, terrestrial acidification, freshwater/marine eutrophication, fossil depletion, human toxicity, and ecotoxicity. The results indicate that content production can be the major contributor to environmental impacts if readers are few (as for the emerging version of the magazine studied). Assuming more readers (more mature version) or a larger file size for the tablet magazine, electronic storage and distribution may be the major contributor. Thus, in contrast to previous studies on electronic media, which reported a dominant impact of the use phase, this study found a higher impact for content production (emerging version) and electronic storage and distribution (mature version). However, with inefficient, low overall use of the tablet with a mature version of the tablet magazine, the greatest impact was shown to come from the reading activity (i.e., the use phase). In conclusion, the relative impacts of the tablet magazine would decrease considerably with high numbers of readers, their efficient use of the tablet (i.e., for many purposes over a long life of the device), and a smaller magazine file.

Description: Within this article, I investigate a number of the conceptual issues that arise when attempting to translate Herman Daly's definition of a steady-state economy (SSE) into a set of national biophysical indicators. Although Daly's definition gives a high-level view of what would be held steady in an SSE, it also leaves many questions unanswered. How should stocks and flows be aggregated? What is the role of international trade? How should nonrenewable resources be treated? And where does natural capital fit in? To help answer these questions, I relate Daly's definition to key concepts and terminology from material and energy flow accounting. I explore topics such as aggregation, international trade, the relevance of throughput, and hidden flows. I conclude that a set of biophysical accounts for an SSE should include three types of indicators (stocks, flows, and scale), track how stocks and flows are changing over a 5- to 10-year period, use aggregated data that measure the quantity of resource use (rather than its quality), measure both total and nonrenewable resource use, adopt a consumption-based approach, include hidden flows, and exclude indicators that measure characteristics of the stock of natural capital (with the notable exception of indicators that measure the regenerative and assimilative capacities of ecosystems).

Description: In pursuit of more sustainable development of industry, China has been actively developing eco-industrial parks (EIPs) for more than a decade. However, the environmental value of these EIPs remains largely unverified. This study aimed to evaluate the environmental performance of national EIPs in China using data envelopment analysis. Eco-efficiency and environmental performance indices were used to represent the static and dynamic environmental performance of EIPs, respectively. An environmental performance index was formed by combining measures of eco-efficiency in a dynamic setting with the sequential Malmquist index approach. We obtained three main empirical findings. First, 34 national EIPs exhibited a cumulative environmental performance improvement of 89.4% from 2007 to 2010, which is primarily the result of eco-efficiency change rather than environmental technical change. Second, compared with the trial EIPs, the demonstration EIPs had a higher average eco-efficiency (0.611 vs. 0.446 in 2010) and experienced greater average environmental performance improvement (129% vs. 60%). Third, the EIPs retrofitted from high-tech industrial development zones exhibited much higher average eco-efficiency (0.798 vs. 0.440 in 2010) than those retrofitted from economic and technical development zones. The key measures supporting the performance improvement and policy implications for the development of EIPs are also discussed.

Description: The ongoing globalization process strengthens the connections between different geographic regions through trade. Biomass products, such as food, fiber, or bioenergy, are increasingly traded globally, thereby leading to telecouplings between distant, seemingly unrelated regions. For example, restrictions for agricultural production or changes in bioenergy demand in Europe or the United States might contribute to deforestation in Latin America or Sub-Saharan Africa. One approach to analyze trade-related land-use effects of the global socioeconomic biomass metabolism is the “embodied human appropriation of net primary production” or eHANPP. eHANPP accounts allocate to any product the entire amount of the human appropriation of net primary production (HANPP) that emerges throughout its supply chain. This allows consumption-based accounts to move beyond simple area-demand approaches by taking differences in natural productivity as well as in land-use intensity into account, both across land-use types as well as across world regions. In this article, we discuss the eHANPP related to the European Union's (EU) consumption of biomass products in the period 1986–2007, based on a consistent global trade data set derived from bilateral data. We find a considerable dependency of the EU on the appropriation of biological productivity outside its own boundaries, with increasing reliance on Latin America as a main supplier. By using the EU as an illustrative example, we demonstrate the usefulness of eHANPP for assessing land-use impacts caused by nations’ socioeconomic activities and conclude that the eHANPP approach can provide useful information to better manage ecosystems globally in the face of an increasingly interconnected world.

Description: Material flow analysis (MFA) is a widely applied tool to investigate resource and recycling systems of metals and minerals. Owing to data limitations and restricted system understanding, MFA results are inherently uncertain. To demonstrate the systematic implementation of uncertainty analysis in MFA, two mathematical concepts for the quantification of uncertainties were applied to Austrian palladium (Pd) resource flows and evaluated: (1) uncertainty ranges expressed by fuzzy sets and (2) uncertainty ranges defined by normal distributions given as mean values and standard deviations. Whereas normal distributions represent the traditional approach for quantifying uncertainties in MFA, fuzzy sets may offer additional benefits in relation to uncertainty quantification in cases of scarce information. With respect to the Pd case study, the fuzzy representation of uncertain quantities is more consistent with the actual data availability in cases of incomplete databases, and fuzzy sets serve to highlight the effect of uncertainty on resource efficiency indicators derived from the MFA results. For both approaches, data reconciliation procedures offer the potential to reduce uncertainty and evaluate the plausibility of the model results. With respect to Pd resource management, improved formal collection of end-of-life (EOL) consumer products is identified as a key factor in increasing the recycling efficiency. In particular, the partial export of EOL vehicles represents a substantial loss of Pd from the Austrian resource system, whereas approximately 70% of the Pd in the EOL consumer products is recovered in waste management. In conclusion, systematic uncertainty analysis is an integral part of MFA required to provide robust decision support in resource management.

Description: This study aims to assess the environmental impacts of canned sardines in olive oil, by considering fishing, processing, and packaging, using life cycle assessment (LCA) methodology. The case study concerns a product of a canning factory based in Portugal and packed in aluminum cans. It is the first LCA of a processed seafood product made with the traditional canning method. The production of both cans and olive oil are the most important process in the considered impact categories. The production of olives contributes to the high environmental load of olive oil, related to cultivation and harvesting phases. The production of aluminum cans is the most significant process for all impact categories, except ozone depletion potential and eutrophication potential, resulting from the high energy demand and the extraction of raw materials. To compare to other sardine products consumed in Portugal, such as frozen and fresh sardines, transport to the wholesaler and store was added. The environmental cost of canned sardines is almost seven times higher per kilogram of edible product. The main action to optimize the environmental performance of canned sardines is therefore to replace the packaging and diminish the olive oil losses as much as possible. Greenhouse gas emissions are reduced by half when plastic packaging is considered rather than aluminum. Frozen and fresh sardines represent much lower environmental impacts than canned sardines. Nevertheless, when other sardine products are not possible, it becomes feasible to use sardines for human consumption, preventing them from being wasted or used suboptimally as feed.

Description: Material stocks are an important part of the social metabolism. Owing to long service lifetimes of stocks, they not only shape resource flows during construction, but also during use, maintenance, and at the end of their useful lifetime. This makes them an important topic for sustainable development. In this work, a model of stocks and flows for nonmetallic minerals in residential buildings, roads, and railways in the EU25, from 2004 to 2009 is presented. The changing material composition of the stock is modeled using a typology of 72 residential buildings, four road and two railway types, throughout the EU25. This allows for estimating the amounts of materials in in-use stocks of residential buildings and transportation networks, as well as input and output flows. We compare the magnitude of material demands for expansion versus those for maintenance of existing stock. Then, recycling potentials are quantitatively explored by comparing the magnitude of estimated input, waste, and recycling flows from 2004 to 2009 and in a business-as-usual scenario for 2020. Thereby, we assess the potential impacts of the European Waste Framework Directive, which strives for a significant increase in recycling. We find that in the EU25, consisting of highly industrialized countries, a large share of material inputs are directed at maintaining existing stocks. Proper management of existing transportation networks and residential buildings is therefore crucial for the future size of flows of nonmetallic minerals.

Description: Photovoltaic (PV) waste is expected to significantly increase. However, legislation on producer responsibility for the collection and recovery of PV panels is limited to the European Union (EU) Waste Electrical and Electronic Equipment Directive Recast, which lays down design, collection, and recovery measures. Academic knowledge of closed-loop supply chains (CLSCs) for PV panels is scarce. We analyze the supply chain using multiple cases involving the main stakeholders in the design, production, collection, and recovery of PV panels. Our article answers two research questions: How does the PV supply chain operate, and what are critical factors affecting the reverse supply chain management of used panels? Our research seeks to fill the gap in the CLSC literature on PV panels, as well as to identify barriers and enablers for PV panel design, collection, and recycling.

Description: Industrial symbiosis (IS) has been identified as a strategy for promoting industrial sustainability. IS has been defined as the development of close working agreements between industrial and other organizations that, through the innovative reuse, recycling, or sharing of resources, leads to resource efficiency. Key to IS are innovation and social network development. This article critically reviews IS literature and concludes that, to inform proactive strategies for promoting IS, the understanding of the social processes leading to resource innovation needs to be improved. Industrial ecologists generally believe that close geographical proximity and trust are essential to the development of IS. This article argues, however, that there is a need to learn more about the meaning of, need for, and specific role of geographical proximity and trust in IS and, additionally, that other potentially important social factors have remained underexplored. To move IS research forward, this article suggests to engage with research in economic geography on the concept of ‘proximity,’ which draws attention to the ways in which geographical, cognitive, institutional, social, and organizational distances between actors might affect innovation. Arguably, the analytically distinct, but flexible, dimensions of proximity can be useful to explore how and why IS develops. The resulting qualitative knowledge would form a basis for researching whether general patterns for IS development exist and, more important, could inform public and private strategies that indicate which actions could be taken, as well as when and in what way to promote resource synergies and sustainable industrial development.

Description: Industrial ecology (IE) is a maturing scientific discipline. The field is becoming more data and computation intensive, which requires IE researchers to develop scientific software to tackle novel research questions. We review the current state of software programming and use in our field and find challenges regarding transparency, reproducibility, reusability, and ease of collaboration. Our response to that problem is fourfold: First, we propose how existing general principles for the development of good scientific software could be implemented in IE and related fields. Second, we argue that collaborating on open source software could make IE research more productive and increase its quality, and we present guidelines for the development and distribution of such software. Third, we call for stricter requirements regarding general access to the source code used to produce research results and scientific claims published in the IE literature. Fourth, we describe a set of open source modules for standard IE modeling tasks that represent our first attempt at turning our recommendations into practice. We introduce a Python toolbox for IE that includes the life cycle assessment (LCA) framework Brightway2, the ecospold2matrix module that parses unallocated data in ecospold format, the pySUT and pymrio modules for building and analyzing multiregion input-output models and supply and use tables, and the dynamic_stock_model class for dynamic stock modeling. Widespread use of open access software can, at the same time, increase quality, transparency, and reproducibility of IE research.

Description: Metabolism is a key concept in industrial ecology (IE). Industrial metabolism (IM) is widely used but seldom discussed, and the rare contributions discussing the concept show divergent views, so the debate is still open. Building on recent contributions that broaden the scope of the epistemological debate, the goal of the present discussion is to go beyond the general statement of IM as a biological analogy in IE. The aim is to infer a definition by a thorough deduction so as to further the debate or even federate the community. An etymological analysis demonstrates the eligibility of standpoints other than biological analogy. Moreover, an analysis of the biological characteristics of a metabolism to be emulated may question the pertinence of the currently employed biological analogy. Here, I propose an alternative view based on the present analysis results and in line with modern ecological precepts, whereby IM is considered as an actual phenomenon. According to the definition derived from the analysis—human-mediated matter change for sustaining a productive system's economic activity—IM should be considered as a subset of a complex system of interconnected transformative processes across all scales of life: the metabolic network. The consequences and promising future orientations that may result from adopting such a shift in definition are succinctly explored.

Description: Material flow analysis (MFA) is a tool for research and decision support in environmental policy and management. In order to promote the use of MFA at different spatial scales, a quantification of the uncertainty in nationwide, regional, and urban MFA methodologies is provided. In particular, the impact of the input data quality on the main MFA indicators is analyzed and the sources and extent of uncertainties for different spatial scales are listed. The types, origin, and extent of the errors are described in detail and several imputation methods are explained and evaluated. By introducing a novel approach to account measurement errors in data sets with “very few details on the measurement errors,” this article aims at contributing to the development of a standardized method to account for the uncertainty in MFA studies. This study uses the time series of MFA data for 1996–2011 at three spatial scales—nationwide (Sweden), regional (the Stockholm Region), and metropolitan (Stockholm, Gothenburg, and Malmo)—to determine how propagation of measurement errors affects the MFA results. The following MFA indicators were studied: direct material input; domestic processed output; and domestic material consumption. Generally, availability decreased as the spatial scale was lowered, whereas data errors increased. In the specific case of Sweden, the data on freight transport by rail and on waste produced by economic activities at the regional and metropolitan level should be improved.

Description: This article reviews, categorizes, and evaluates the objectives, means, and results of the application of material flow analysis (MFA) in waste management. It identifies those areas where MFA methodologies are most successful in supporting waste management decisions. The focus of this review is on the distinction between MFA on the level of goods and on the level of substances. Based on 83 reviewed studies, potentials, strengths, and weaknesses are investigated for the two levels of MFA when applied for analysis, evaluation, and improvement of waste management systems. The differences are discussed in view of effectiveness, applicability, and data availability. The results show that MFA on the level of goods are instrumental for understanding how waste management systems function, facilitating the connections of stakeholders, authorities, and waste management companies. The substance level is essential to assess qualitative aspects regarding resources and environment. Knowledge about the transformation, transport, and storage of valuable and hazardous substances forms the base for identifying both resource potentials and risks for human health and the environment. The results of this review encourage the application of MFA on both levels of goods and substances for decision making in waste management. Because of the mass balance principle, this combination has proven to be a powerful tool for comprehensively assessing if a chosen system reaches designated waste management goals.

Description: Water accounting is an unresolved issue in metabolism studies. Through epistemological analysis, we show that the problem resides in the conceptualization of social metabolism. Social metabolism has its origins in the analysis of societal energetics, which has led to an exclusive focus on society and a representation based on linear throughputs at a single scale. Whereas fossil energy resources constitute a mere stock flow for society, water constitutes a set of both funds and flows essential for the maintenance of the internal organization and stability of society and ecosystems. This means that societies and ecosystems need water for different reasons. Consequently, the analysis of water requires the simultaneous adoption of multiple narratives and scales. The development of hydrology toward a socio-eco-hydrology (SE-hydrology) deals with this multidimensionality, but lacks a conceptualization of the coupled human-water system useful to integrate the assessment of water processes at different rates and scales. We propose a conceptual framework, based on the multiscale integrated analysis of societal and ecosystem metabolism approach, that combines the perspectives of SE-hydrology and social metabolism. This framework describes society and the embedding ecosystem as two distinct levels of the same hierarchical system (i.e., the socioecological system), expressing two distinct, but tightly interconnected, metabolic patterns (societal and ecosystem) at different spatiotemporal scales. Using food grain production in Punjab as an example, we show that this framework can accommodate the multiple interpretations of social metabolism found in different scientific fields.

Description: Commodity trade networks exhibit certain patterns in the configuration of material flows that are similar to natural ecological networks. This article develops and explores an ecological information-based approach to examine the ecology of commodity trade networks. We demonstrate that commodity trade networks show a pattern of commonality when viewed through the introduced ecological information-based metrics. Specifically, we show how the network metrics of effective connectivity and effective number of roles can convey boundaries where commodity trade networks are robust. Further, the temporal trends of these metrics suggest the existence of multiple basins of attractions and provide clues on the dynamics of resilience of these networks over time.

Description: The focus when analyzing the environmental requirements and impacts of the economic system is usually placed on production activities. But all production is associated with final consumption, and recently many studies have also been dedicated to final consumption. This article comprehensively reviews the biophysical assessment of households from the point of view of materials and energy required and emissions and wastes resulting from household consumption patterns. Although the aggregation bias and methodological variability make comparisons difficult, some patterns can be recognized. Results show that for many Organization for Economic Cooperation and Development (OECD) and a few developing countries, household metabolism has been mainly assessed from the energetic perspective, stressing household responsibility for emissions of greenhouse effect gases and climate change. Few studies deal with other emissions and wastes. There is a lack of information about material requirements, too. Environmental input-output (I-O) analysis and life cycle assessment are the methods usually employed, together with the use of economic, environmental, and expenditure information. Information about direct inputs and outputs is complemented with data on the environmental requirements associated with the consumption of goods and services. Multiregional I-O techniques have been used to capture upstream requirements in an attempt to avoid errors owing to truncation and domestic technology assumptions. Housing, food, and mobility are the most important consumption categories, but the shares of these categories in the requirements are different according to environmental, socioeconomic, and demographic factors. Finally, challenges for further research are discussed based on the need for new methodological developments, as well as the potential of the metabolic narrative to elaborate information relevant to sustainable consumption policies.

Description: Yttrium tends to occur in the same ore deposits as the lanthanides and exhibits similar chemical properties as rare earth elements. Yttrium sources are typically concentrated in China, and there are concerns about supply security. Yttrium is used in small, but essential, quantities in a variety of advanced industrial sectors, for example, in phosphors, advanced ceramics, optical glasses, and batteries. In terms of resource security, it is important to verify the domestic yttrium consumption trends. In order to characterize the domestic yttrium consumption trends in Japan, we tracked the historical yttrium consumption patterns from 2001 to 2011 by applying the bottom-up approach and illustrated the recent domestic yttrium flow by using a substance flow analysis. The results showed that the total yttrium consumption has remained steady over 10 years, from 1,124 tonnes (t) in 2001 to 967 t in 2011. Recent consumption in 2011 was driven primarily by the use of yttrium in fluorescent lamps (462 t), nickel metal hydride batteries (185 t), and optic glasses (149 t).

Description: Distributed energy sources, such as self-power generation, steam boilers, and combined heat and power production (CHP), are operated to manage the supply of energy by optimizing the costs of meeting the demand for electricity and heat. This article was written in conjunction with reports by the United Nations Environment Program's International Resource Panel that quantifies and compares the environmental and natural resource impacts and benefits of using demand-side efficient technologies for greenhouse gas mitigation scenarios from now until 2050. In this article, we examine the potential of using distributed energy sources in future energy systems. First, we reviewed the existing research into several energy technologies, especially into cogeneration systems for CHP, using a bibliometric analysis. The current energy supply/demand in the demand-side sectors in Japan is also reviewed using available statistical data, and an investigation into the energy requirements of industrial manufacturers was performed. After systematizing the results of our review on progress in current research, a scenario analysis was conducted on the potential of distributed energy sources to clarify the contribution of the various technology options. A mismatch between the quality of energy produced, especially heat, or any benefits arising from scale from other energy technologies, can decrease the incentive to implement distributed energy technologies. As a requirement of a regional energy system design and management, distributed energy sources should be considered so that the appropriate technology options can be adopted for the desired energy supply in the demand-side sector. The possibility exists to replace conventional single-generation technologies, such as boilers or power generators, with multigeneration technologies. A change in the grid power mix is one of the most sensitive parameters affecting the performance of cogeneration technologies.

Description: This article employs panel data from 28 Chinese provinces over the period 1999–2011 to analyze the effects of industrial waste reuse (IWR) on carbon emissions. The extant studies mainly consider the direct effects that individual firms garner from IWR while ignoring other possible indirect effects in a more macroscopic context. Considering this research void, this article examines the potential indirect effects of IWR on carbon emissions through economic growth as the mediator. The results show that the direct effect of IWR on carbon emissions is negative and significant, but the positive indirect effect, through economic growth, is present. From the perspective of total effect, IWR is beneficial for both economic growth and carbon emission reduction (CER). However, the benefits for CER are mitigated when the economy is less developed, because the emission reduction could be compromised through the indirect effect of economic growth. Nevertheless, the indirect effect on compensating carbon emission is decreased with an increase in the economic growth. When the growth reaches a higher level, the indirect effect of IWR will alter to contribute to CER. The turning point in China is around 7,000 to 9,000 renminbi gross domestic product (GDP) per capita in 1999 constant price.

Description: The construction of a nation-wide high-speed rail (HSR) network has emerged as a hugely expensive and ambitious infrastructure project in China. As of December 2012, some 8,800 kilometers (km) of double-track HSR lines came into service in the country, accounting for 40% of the total HSR length in the world. The network is expected to expand to 34,000 km or longer in around two decades. As the first HSR system specially built and operated in an economically developing country, it helps integrate the sprawling economy and lift the quality of life of the increasing urban population. China's experiences in HSR are expected to be of value to other countries aiming to adopt bullet train systems, especially those at a similar level of industrialization and urbanization. This work specifically examines material stocks and flows associated with the HSR infrastructure construction in China. A major distinction from the construction of HSR tracks in Europe is that nearly 70% of the HSR tracks in China are laid upon bridges or inside tunnels, which are structures that demand great amounts of raw materials. The entire network, once completed by 2030, will cumulatively require 83 to 137 million tonnes (Mt) of steel and 560 to 920 Mt of cement. This is still a small share of China's use of material resources. Nonetheless, the massive application of the steel- and cement-intensive structures deserves consideration when assessing the environmental performance of HSR over its entire life cycle.