Electric vehicles (EVs) coupled with low‐carbon electricity sources offer the potential for reducing greenhouse gas emissions and exposure to tailpipe emissions from personal transportation. In considering these benefits, it is important to address concerns of problem‐shifting. In addition, while many studies have focused on the use phase in comparing transportation options, vehicle production is also significant when comparing conventional and EVs. We develop and provide a transparent life cycle inventory of conventional and electric vehicles and apply our inventory to assess conventional and EVs over a range of impact categories. We find that EVs powered by the present European electricity mix offer a 10% to 24% decrease in global warming potential (GWP) relative to conventional diesel or gasoline vehicles assuming lifetimes of 150,000 km. However, EVs exhibit the potential for significant increases in human toxicity, freshwater eco‐toxicity, freshwater eutrophication, and metal depletion impacts, largely emanating from the vehicle supply chain. Results are sensitive to assumptions regarding electricity source, use phase energy consumption, vehicle lifetime, and battery replacement schedules. Because production impacts are more significant for EVs than conventional vehicles, assuming a vehicle lifetime of 200,000 km exaggerates the GWP benefits of EVs to 27% to 29% relative to gasoline vehicles or 17% to 20% relative to diesel. An assumption of 100,000 km decreases the benefit of EVs to 9% to 14% with respect to gasoline vehicles and results in impacts indistinguishable from those of a diesel vehicle. Improving the environmental profile of EVs requires engagement around reducing vehicle production supply chain impacts and promoting clean electricity sources in decision making regarding electricity infrastructure.
It is increasingly recognized that the growing metabolism of society is approaching limitations both with respect to sources for resource inputs and sinks for waste and emission outflows. The circular economy (CE) is a simple, but convincing, strategy, which aims at reducing both input of virgin materials and output of wastes by closing economic and ecological loops of resource flows. This article applies a sociometabolic approach to assess the circularity of global material flows. All societal material flows globally and in the European Union (EU‐27) are traced from extraction to disposal and presented for main material groups for 2005. Our estimate shows that while globally roughly 4 gigatonnes per year (Gt/yr) of waste materials are recycled, this flow is of moderate size compared to 62 Gt/yr of processed materials and outputs of 41 Gt/yr. The low degree of circularity has two main reasons: First, 44% of processed materials are used to provide energy and are thus not available for recycling. Second, socioeconomic stocks are still growing at a high rate with net additions to stocks of 17 Gt/yr. Despite having considerably higher end‐of‐life recycling rates in the EU, the overall degree of circularity is low for similar reasons. Our results indicate that strategies targeting the output side (end of pipe) are limited given present proportions of flows, whereas a shift to renewable energy, a significant reduction of societal stock growth, and decisive eco‐design are required to advance toward a CE.
In this article, we use Hirsch and Levin's notion of umbrella concepts as an analytical lens, in order to articulate the valuable catalytic function the circular economy (CE) concept could perform in the waste and resource management debate. We realize this goal by anchoring the CE concept in this broader debate through a narrative approach. This leads to the insight that whereas the various resource strategies grouped under the CE's banner are not new individually, the concept offers a new framing of these strategies by drawing attention to their capacity of prolonging resource use as well as to the relationship between these strategies. As such, the CE offers a new perspective on waste and resource management and provides a new cognitive unit and discursive space for debate. We conclude by discussing research opportunities for the industrial ecology (IE) community relating to the concept's theoretical development and its implementation. Specifically, we pose that reinvigorating and growing the social science aspects of IE is required for both. After all, it is in understanding and facilitating the collective implementation of any idea, also the CE concept, that the potential lies for shaping our material future.
Aggregation of environmental pressures into a single environmental damage index is a major challenge of eco-efficiency measurement. This article examines how the data envelopment analysis (DEA) method can be adapted for this purpose. DEA accounts for substitution possibilities between different natural resources and emissions and does not require subjective judgment about the weights. Although DEA does not require subjective or normative judgment, soft weight restrictions can be incorporated into the framework. The proposed approach is illustrated by an application to assessing eco-efficiency of road transportation in the three largest towns of eastern Finland.
Environmentally extended multiregional input‐output (EE MRIO) tables have emerged as a key framework to provide a comprehensive description of the global economy and analyze its effects on the environment. Of the available EE MRIO databases, EXIOBASE stands out as a database compatible with the System of Environmental‐Economic Accounting (SEEA) with a high sectorial detail matched with multiple social and environmental satellite accounts. In this paper, we present the latest developments realized with EXIOBASE 3—a time series of EE MRIO tables ranging from 1995 to 2011 for 44 countries (28 EU member plus 16 major economies) and five rest of the world regions. EXIOBASE 3 builds upon the previous versions of EXIOBASE by using rectangular supply‐use tables (SUTs) in a 163 industry by 200 products classification as the main building blocks. In order to capture structural changes, economic developments, as reported by national statistical agencies, were imposed on the available, disaggregated SUTs from EXIOBASE 2. These initial estimates were further refined by incorporating detailed data on energy, agricultural production, resource extraction, and bilateral trade. EXIOBASE 3 inherits the high level of environmental stressor detail from its precursor, with further improvement in the level of detail for resource extraction. To account for the expansion of the European Union (EU), EXIOBASE 3 was developed with the full EU28 country set (including the new member state Croatia). EXIOBASE 3 provides a unique tool for analyzing the dynamics of environmental pressures of economic activities over time.
Life cycle assessment (LCA) is generally described as a tool for environmental decision making. Results from attributional LCA (ALCA), the most commonly used LCA method, often are presented in a way that suggests that policy decisions based on these results will yield the quantitative benefits estimated by ALCA. For example, ALCAs of biofuels are routinely used to suggest that the implementation of one alternative (say, a biofuel) will cause an X% change in greenhouse gas emissions, compared with a baseline (typically gasoline). However, because of several simplifications inherent in ALCA, the method, in fact, is not predictive of real‐world impacts on climate change, and hence the usual quantitative interpretation of ALCA results is not valid. A conceptually superior approach, consequential LCA (CLCA), avoids many of the limitations of ALCA, but because it is meant to model actual changes in the real world, CLCA results are scenario dependent and uncertain. These limitations mean that even the best practical CLCAs cannot produce definitive quantitative estimates of actual environmental outcomes. Both forms of LCA, however, can yield valuable insights about potential environmental effects, and CLCA can support robust decision making. By openly recognizing the limitations and understanding the appropriate uses of LCA as discussed here, practitioners and researchers can help policy makers implement policies that are less likely to have perverse effects and more likely to lead to effective environmental policies, including climate mitigation strategies.
The so‐called circular economy—the concept of closing material loops to preserve products, parts, and materials in the industrial system and extract their maximum utility—has recently started gaining momentum. The idea of substituting lower‐impact secondary production for environmentally intensive primary production gives the circular economy a strong intuitive environmental appeal. However, proponents of the circular economy have tended to look at the world purely as an engineering system and have overlooked the economic part of the circular economy . Recent research has started to question the core of the circular economy—namely, whether closing material and product loops does, in fact, prevent primary production. In this article, we argue that circular economy activities can increase overall production, which can partially or fully offset their benefits. Because there is a strong parallel in this respect to energy efficiency rebound, we have termed this effect “circular economy rebound.” Circular economy rebound occurs when circular economy activities, which have lower per‐unit‐production impacts, also cause increased levels of production, reducing their benefit. We describe the mechanisms that cause circular economy rebound, which include the limited ability of secondary products to substitute for primary products, and price effects. We then offer some potential strategies for avoiding circular economy rebound. However, these strategies are unlikely to be attractive to for‐profit firms, so we caution that simply encouraging private firms to find profitable opportunities in the circular economy is likely to cause rebound and lower or eliminate the potential environmental benefits.
The recycling of metals is widely viewed as a fruitful sustainability strategy, but little information is available on the degree to which recycling is actually taking place. This article provides an overview on the current knowledge of recycling rates for 60 metals. We propose various recycling metrics, discuss relevant aspects of recycling processes, and present current estimates on global end‐of‐life recycling rates (EOL‐RR; i.e., the percentage of a metal in discards that is actually recycled), recycled content (RC), and old scrap ratios (OSRs; i.e., the share of old scrap in the total scrap flow). Because of increases in metal use over time and long metal in‐use lifetimes, many RC values are low and will remain so for the foreseeable future. Because of relatively low efficiencies in the collection and processing of most discarded products, inherent limitations in recycling processes, and the fact that primary material is often relatively abundant and low‐cost (which thereby keeps down the price of scrap), many EOL‐RRs are very low: Only for 18 metals (silver, aluminum, gold, cobalt, chromium, copper, iron, manganese, niobium, nickel, lead, palladium, platinum, rhenium, rhodium, tin, titanium, and zinc) is the EOL‐RR above 50% at present. Only for niobium, lead, and ruthenium is the RC above 50%, although 16 metals are in the 25% to 50% range. Thirteen metals have an OSR greater than 50%. These estimates may be used in considerations of whether recycling efficiencies can be improved; which metric could best encourage improved effectiveness in recycling; and an improved understanding of the dependence of recycling on economics, technology, and other factors.
Eco‐efficiency is an instrument for sustainability analysis, indicating an empirical relation in economic activities between environmental cost or value and environmental impact. This empirical relation can be matched against normative considerations as to how much environmental quality or improvement society would like to offer in exchange for economic welfare, or what the trade‐off between the economy and the environment should be if society is to realize a certain level of environmental quality. Its relevance lies in the fact that relations between economy and environment are not self‐evident, not at a micro level and not at the macro level resulting from micro‐level decisions for society as a whole. Clarifying the why and what of eco‐efficiency is a first step toward decision support on these two aspects of sustainability. With the main analytic framework established, filling in the actual economic and environmental relations requires further choices in modeling. Also, the integration of different environmental effects into a single score requires a clear definition of approach, because several partly overlapping methods exist. Some scaling problems accompany the specification of numerator and denominator, which need a solution and some standardization before eco‐efficiency analysis can become more widely used. With a method established, the final decision is how to embed it in practical decision making. In getting the details of eco‐efficiency better specified, its strengths, but also its weaknesses and limitations, need to be indicated more clearly.
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.
This contribution presents the state of the art of economy‐wide material flow accounting. Starting from a brief recollection of the intellectual and policy history of this approach, we outline system definition, key methodological assumptions, and derived indicators. The next section makes an effort to establish data reliability and uncertainty for a number of existing multinational (European and global) material flow accounting (MFA) data compilations and discusses sources of inconsistencies and variations for some indicators and trends. The results show that the methodology has reached a certain maturity: Coefficients of variation between databases lie in the range of 10% to 20%, and correlations between databases across countries amount to an average R 2 of 0.95. After discussing some of the research frontiers for further methodological development, we conclude that the material flow accounting framework and the data generated have reached a maturity that warrants material flow indicators to complement traditional economic and demographic information in providing a sound basis for discussing national and international policies for sustainable resource use.
There is disagreement on whether the supply of lithium is adequate to support a future global fleet of electric vehicles. We report a comprehensive analysis of the global lithium resources and compare it to an assessment of global lithium demand from 2010 to 2100 that assumes rapid and widespread adoption of electric vehicles. Recent estimates of global lithium resources have reached very different conclusions. We compiled data on 103 deposits containing lithium, with an emphasis on the 32 deposits that have a lithium resource of more than 100,000 tonnes each. For each deposit, data were compiled on its location, geologic type, dimensions, and content of lithium as well as current status of production where appropriate. Lithium demand was estimated under the assumption of two different growth scenarios for electric vehicles and other current battery and nonbattery applications. The global lithium resource is estimated to be about 39 Mt (million tonnes), whereas the highest demand scenario does not exceed 20 Mt for the period 2010 to 2100. We conclude that even with a rapid and widespread adoption of electric vehicles powered by lithium-ion batteries, lithium resources are sufficient to support demand until at least the end of this century.
Dietary behavioral choices have a strong effect on the environmental impact associated with the food system. Here, we consider the greenhouse gas (GHG) emissions associated with production of food that is lost at the retail and consumer level, as well as the potential effects on GHG emissions of a shift to dietary recommendations. Calculations are based on the U.S. Department of Agriculture's (USDA) food availability data set and literature meta‐analysis of emission factors for various food types. Food losses contribute 1.4 kilograms (kg) carbon dioxide equivalents (CO 2 ‐eq) capita −1 day −1 (28%) to the overall carbon footprint of the average U.S. diet; in total, this is equivalent to the emissions of 33 million average passenger vehicles annually. Whereas beef accounts for only 4% of the retail food supply by weight, it represents 36% of the diet‐related GHG emissions. An iso‐caloric shift from the current average U.S. diet to USDA dietary recommendations could result in a 12% increase in diet‐related GHG emissions, whereas a shift that includes a decrease in caloric intake, based on the needs of the population (assuming moderate activity), results in a small (1%) decrease in diet‐related GHG emissions. These findings emphasize the need to consider environmental costs of food production in formulating recommended food patterns.
The idea of a circular economy (CE) has become prominent in both European and Chinese policy making. Chinese and European perspectives on a CE share a common conceptual basis and exhibit many similar concerns in seeking to enhance resource efficiency. Yet they also differ, and this article explores differences in the focus of CE policy in China and Europe. We present evidence on the differing understandings of the CE concept in Chinese and European policy discourse, drawing on qualitative and quantitative analysis of policy documents, media articles, and academic publications. We show that the Chinese perspective on the CE is broad, incorporating pollution and other issues alongside waste and resource concerns, and it is framed as a response to the environmental challenges created by rapid growth and industrialization. In contrast, Europe's conception of the CE has a narrower environmental scope, focusing more narrowly on waste and resources and opportunities for business. We then examine similarities and differences in the focus of policy activity in the two regions and in the indicators used to measure progress. We show differences in the treatment of issues of scale and place and different priorities across value chains (from design to manufacture, consumption, and waste management). We suggest some reasons for the divergent policy articulation of the CE concept and suggest lessons that each region can learn from the other.
In a circular economy (CE), the economic and environmental value of materials is preserved for as long as possible by keeping them in the economic system, either by lengthening the life of the products formed from them or by looping them back in the system to be reused. The notion of waste no longer exists in a CE, because products and materials are, in principle, reused and cycled indefinitely. Taking this description as a starting point, the article asks which guiding principles, design strategies, and methods are required for circular product design and to what extent these differ from the principles, strategies, and methods of eco‐design. The article argues that there is a fundamental distinction to be made between eco‐design and circular product design and proceeds to develop, based on an extensive literature review, a set of new concepts and definitions, starting from a redefinition of product lifetime and introducing new terms such as presource and recovery horizon . The article then takes Walter Stahel's Inertia Principle as the guiding principle in circular product design and develops a typology of approaches for Design for Product Integrity, with a focus on tangible durable consumer products. The newly developed typology contributes to a deeper understanding of the CE as a concept and informs the discussion on the role of product design in a CE.
Electric vehicles (EVs) have no tailpipe emissions, but the production of their batteries leads to environmental burdens. In order to avoid problem shifting, a life cycle perspective should be applied in the environmental assessment of traction batteries. The aim of this study was to provide a transparent inventory for a lithium‐ion nickel‐cobalt‐manganese traction battery based on primary data and to report its cradle‐to‐gate impacts. The study was carried out as a process‐based attributional life cycle assessment. The environmental impacts were analyzed using midpoint indicators. The global warming potential of the 26.6 kilowatt‐hour (kWh), 253‐kilogram battery pack was found to be 4.6 tonnes of carbon dioxide equivalents. Regardless of impact category, the production impacts of the battery were caused mainly by the production chains of battery cell manufacture, positive electrode paste, and negative current collector. The robustness of the study was tested through sensitivity analysis, and results were compared with preceding studies. Sensitivity analysis indicated that the most effective approach to reducing climate change emissions would be to produce the battery cells with electricity from a cleaner energy mix. On a per‐kWh basis, cradle‐to‐gate greenhouse gas emissions of the battery were within the range of those reported in preceding studies. Contribution and structural path analysis allowed for identification of the most impact‐intensive processes and value chains. This article provides an inventory based mainly on primary data, which can easily be adapted to subsequent EV studies, and offers an improved understanding of environmental burdens pertaining to lithium‐ion traction batteries.
Data from urban metabolism studies from eight metropolitan regions across five continents, conducted in various years since 1965, are assembled in consistent units and compared. Together with studies of water, materials, energy, and nutrient flows from additional cities, the comparison provides insights into the changing metabolism of cities. Most cities studied exhibit increasing per capita metabolism with respect to water, wastewater, energy, and materials, although one city showed increasing efficiency for energy and water over the 1990s. Changes in solid waste streams and air pollutant emissions are mixed. The review also identifies metabolic processes that threaten the sustainability of cities. These include altered ground water levels, exhaustion of local materials, accumulation of toxic materials, summer heat islands, and irregular accumulation of nutrients. Beyond concerns over the sheer magnitudes of resource flows into cities, an understanding of these accumulation or storage processes in the urban metabolism is critical. Growth , which is inherently part of metabolism, causes changes in water stored in urban aquifers, materials in the building stock, heat stored in the urban canopy layer, and potentially useful nutrients in urban waste dumps. Practical reasons exist for understanding urban metabolism. The vitality of cities depends on spatial relationships with surrounding hinterlands and global resource webs. Increasing metabolism implies greater loss of farmland, forests, and species diversity; plus more traffic and more pollution. Urban policy makers should consider to what extent their nearest resources are close to exhaustion and, if necessary, appropriate strategies to slow exploitation. It is apparent from this review that metabolism data have been established for only a few cities worldwide, and interpretation issues exist due to lack of common conventions. Further urban metabolism studies are required.