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During the 20th century, the United States went from being the largest producer and user of lithium to being heavily reliant on imports from Asia, particularly lithium-ion batteries. To explore different futures for U.S. lithium, we here generate four scenarios─including COVID-19 implications─that model lithium use for its main applications: electric and hybrid vehicles, stationary energy storage systems, and small electronics. We find that the "Sustainable Future" scenario requires the highest amount of lithium (cumulatively 1281 Gg in the period 2020-2050, peak inflow in 2040 at 53 Gg); in contrast, "Fossil Fuel Everything" requires only 500 Gg and peaks in 2050 at 26 Gg. COVID-19 implications appear to be negligible in the long run. The future electrification of the U.S. vehicle fleet and energy storage systems will depend upon a reliable and resilient international supply chain of lithium chemicals and/or batteries as well as vigorous recycling efforts.

This study analyses how carbon footprints of electric vehicles (EVs) in China vary across regions and how they may evolve with power decarbonisation. It is understood that carbon footprints of battery electric vehicles (BEVs) depend largely on electricity mixes, but few studies have quantified their interregional divergence and future changes in China. Using THEMIS model as an integrated LCA framework, together with future electricity mixes from MESEIC, a cost optimisation model for the power sector, we calculate current and future carbon footprints of passenger vehicles in China. Results show that, carbon footprints of BEVs across all the 6 regions will drop from 265-419 gCO2e/km in 2017 to 116-383 gCO2e/km in 2050, or 141-266 gCO2e/km, with stringent carbon constraints applied to the power sector. The interregional divergence of BEV carbon footprints will shrink by 20% in the latter scenario. Under carbon constraints, BEV carbon footprints in East, Central, Northwest, and South will have their best-case reduction potentials, by 55%, 55%, 46%, and 5% respectively. Stringent carbon constraints lead to increased share of coal-based generation in North and Northeast, whose most favourable reduction potentials will be 42%, and 69%, respectively, when no carbon constraints exist.

In the search for low-carbon energy carriers, there is renewed interest in hydrogen. However, it remains highly uncertain to what extent hydrogen may be deployed in a future energy system, and at what cost. We improve on the state-of-the-art integrated assessment model GCAM and run several scenarios in which the global energy system reaches carbon neutrality by deploying different mitigation technology portfolios, including hydrogen, direct electrification, and negative emission technologies. Across a range of scenarios we confirm that hydrogen is an important mitigation technology for 'difficult-to-electrify' sectors such as cement, fertilizer, chemical, and iron and steel production, international shipping and heavy freight truck transport. Crucially however, we find that deploying hydrogen can reduce mid-century mitigation costs by 15-23%, compared to counterpart scenarios without hydrogen availability. Our findings can guide optimal investment decisions for effective climate change mitigation.

Ammonia has been proposed as a shipping fuel, yet potential adverse side–effects are poorly understood. We argue that if nitrogen releases from ammonia are not tightly controlled, the scale of the demands of maritime transport are such that the global nitrogen cycle could be substantially altered.

Material production accounts for 23% of all greenhouse gas emissions. More efficient use of materials—through decoupling of services that support human well‐being from material use—is imperative as other emission mitigation options are expensive. An interdisciplinary scientific assessment of material efficiency and its links to service provision, material cycle management, and climate policy is needed to identify effective strategies and help design the policy framework required for their implementation. We present the resource efficiency–climate change (RECC) mitigation framework, a first step toward such a comprehensive assessment. RECC is based on dynamic material flow analysis and links the services provided (individual motorized transport and shelter) to the operation of in‐use stocks of products (passenger vehicles and residential buildings), to their expansion and maintenance, and to their material cycles to model mitigation strategies and analyze trade‐offs for environmental impacts along the products’ life cycle. A key innovation of RECC is the upscaling of product archetypes with different degrees of material and energy efficiency, which are simulated with engineering tools. We utilize RECC with augmented storylines of the shared socioeconomic pathways to describe future service demand and associated material requirements. Ten material efficiency strategies at different stages of the material cycle can be assessed by ramping up their implementation rates to the identified technical potentials. RECC provides scenario results for the life cycle impacts of ambitious service–material decoupling concurrent with energy system decarbonization, giving detailed insights on the RECC mitigation nexus to policy‐makers worldwide.

The expansion of road networks in emerging economies such as China causes significant greenhouse gas (GHG) emissions. This development is conflicting with China's commitment to achieve carbon neutrality. Thus, there is a need to better understand life cycle emissions of road infrastructure and opportunities to mitigate these emissions. Existing impact studies of roads in developing countries do not address recycled materials, improved pavement maintenance, or pavement-vehicle interaction and electric vehicle (EV) adoption. Combining firsthand information from Chinese road construction engineers with publicly available data, this paper estimates a comprehensive account of GHG emissions of the road pavement network to be constructed in the next ten years in the Shandong province in Northern China. Further, we estimate the potential of GHG emission reductions achievable under three scenario sets: maintenance optimization, alternative pavement material replacement, and EV adoption. Results show that the life cycle GHG emissions of highways and Class 1-4 roads to be constructed in the next 10 years amount to 147 Mt CO2-eq. Considering the use phase in our model reveals that it is the dominant stage in terms of emissions, largely due to pavement-vehicle interaction. Vehicle electrification can only moderately mitigate these emissions. Other stages, such as materials production and road maintenance and rehabilitation, contribute substantially to GHG emissions as well, highlighting the importance of optimizing the management of these stages. Surprisingly, longer, not shorter maintenance intervals, yield significant emission reductions. Another counter-intuitive finding is that thicker and more material-intensive pavement surfaces cause lower emissions overall. Taken together, optimal maintenance and rehabilitation schedules, alternative material use, and vehicle electrification provide GHG reduction potentials of 11%, 4%-16% and 2%-6%, respectively.

Each year businesses, governments, and homeowners in the United States invest around one fifth of gross domestic product into the creation of capital assets such as buildings, machinery, and software to enable production and consumption. Use of capital is typically included to some extent in environmental life cycle assessments of goods and services but is not incorporated into most environmentally extended input‐output (EEIO) models, including the US Environmental Protection Agency's USEEIO. Capital assets are typically created in years prior to their use, so a challenge lies in distributing the impacts of their creation over time. In this work, a highly detailed capital flow matrix approach is followed to distribute the use of fixed capital assets to consuming industries. Data from the US Bureau of Economic Analysis's Fixed Asset Accounts is merged with its Industry Accounts data by the creation of concordance tables. Public highways and streets are partially reallocated to industries operating vehicles. The resulting capital use matrix is later combined into a modified USEEIO. “Housing” is found to be the largest consumer of fixed assets, followed by general government, fossil fuel extraction, and financial industries involved in leasing. Construction, vehicles, and machinery are mostly used by industries in the form of fixed assets. The types of fixed assets used by industries are consistent with expectations: housing is dominated by structures, transport by equipment, and information industries by intellectual property products.

Large-scale electric vehicle adoption can greatly reduce emissions from vehicle tailpipes. However, analysts have cautioned that it can come with increased indirect emissions from electricity and battery production that are not commonly regulated by transport policies. We combine integrated energy modeling and life cycle assessment to compare optimal policy scenarios that price emissions at the tailpipe only, versus both tailpipe and indirect emissions. Surprisingly, scenarios that also price indirect emissions exhibit higher, rather than reduced, sales of electric vehicles, while yielding lower cumulative tailpipe and indirect emissions. Expected technological change ensures that emissions from electricity and battery production are more than offset by reduced emissions of gasoline production. Given continued decarbonization of electricity supply, results show that a large-scale adoption of electric vehicles is able to reduce CO2 emissions through more channels than previously expected. Further, carbon pricing of stationary sources will also favor electric vehicles.

With the expected rapid growth of renewable electricity generation, charging plug-in hybrid electric vehicles (PHEVs) from the grid promise ever higher reductions in CO2 emissions. Previous analyses have found that the share that PHEVs are driven in electric mode can differ substantially depending on region, battery size, and trip purpose. Here, we provide a first fleet-wide emissions mitigation potential of US-based PHEV drivers adopting high or low shares of electric driving. Specifically, we illustrate scenarios of different combinations of PHEV uptake, renewable electricity generation shares, and PHEV fueling behavior. Across 21 analyzed scenarios, annual greenhouse gas (GHG) emissions of the light-duty vehicle (LDV) fleet could differ by an average of 21% (5-43% range) in 2050 depending alone on the fueling behavior of PHEV drivers. This behavior could further determine the discharge of about 1.3 (0.7-1.9) Gt CO2 (or roughly one year of current emissions) over the next three decades, significantly influencing the feasibility of reaching an 80% emission reduction target for the LDV sector. Governments can nudge PHEV drivers toward environmentally favorable fueling behavior. We discuss several options for nudging, including charging infrastructure availability, battery design, and consumer education.

Material production now accounts for 23% of global greenhouse gas (GHG) emissions. Resource efficiency and circular economy policies promise emission reductions through reducing material use, but their potential contribution to climate change mitigation has not yet been quantified. Here we present a high-resolution approach for tracking material flows and energy use of products throughout their life cycles, focusing on passenger vehicles and residential buildings. We estimate future changes in material flows and operational energy use due to increased yields, light-weight designs, material substitution, increased service efficiency, extended service life, and increased reuse and recycling. Together, these material efficiency strategies can reduce cumulative global GHG emissions until 2060 by 16-39 Gt CO2e (passenger vehicles) and 28-72 Gt CO2e (residential buildings), depending on climate policy assumptions. The use of wood and more intensive use are promising strategies in residential buildings. Ride sharing and car sharing are best for residential buildings.

This chapter explores how the interdisciplinary field of industrial ecology, a blend of environmental science, social science, engineering, and management, can help deliver sustainable development goals (SDGs). As a systems science, industrial ecology provides a source of knowledge that can guide sustainable manufacturing, waste and pollution reduction, and offer a framework for extending the life of physical goods in a circular economy. The chapter focuses on four industrial ecology approaches: material stock and flow analysis, life-cycle assessment, input-output analysis, and industrial symbiosis, offering descriptions and case examples that relate to specific SDGs and targets. Although these approaches are relevant to a broad range of SDG targets, the authors focus on those pertaining to responsible and efficient use of water and energy (SDG6 and target 7.3), economic growth (SDG8), reducing inequalities (SDG10), transportation (target 11.2), production and consumption systems (SDG12 and targets 2.4 and 9.4), and climate action (SDG13). Industrial ecology approaches are also beneficial to rapidly industrializing countries, where improvements in economic performance and the environment must be carefully balanced. Finally, by tracking flows of material and energy, industrial ecology promotes resource efficiency and provides a strong basis for making sustainable production and consumption decisions.

This is the preprint of the peer-reviewed article in the Journal of Industrial Ecology: https://onlinelibrary.wiley.com/doi/10.1111/jiec.13122 Scenario-based assessments are a useful tool to explore unknown futures and inform decision makers and the public of the consequences of different courses of action. Scenario developments in Industrial Ecology have focused on disparate components of the socioeconomic metabolism and case studies, and few efforts of comprehensive and cumulative scenario formulation are documented. Many important, empirically derived relationships between material cycles, end-use services, and energy use are relevant to global scenario modeling efforts, e.g., of integrated assessment models (IAMs), which do not routinely describe material cycles or the life-cycle impacts of various technology shifts. These inconsistent depictions of material cycles and their environmental impacts hinder the assessment of sustainable development strategies such as demand-side sufficiency, material efficiency, and energy efficiency. We developed three highly detailed scenarios covering 20 global regions to 2060 for the service provisioning of dwelling area and personal transport grounded in salient building and vehicle operation parameters. Our scenarios are based on, and interface with, the Low Energy Demand (LED) and Shared Socioeconomic Pathways (SSP1 and SSP2) narratives. The results comprise scenario-, region-, and period-specific narratives and corresponding parameter values, including per-capita floor space and vehicle stocks, building and vehicle archetype mixes, passenger-km, vehicle-km, vehicle occupancy rates, and implementation potentials of nine material efficiency strategies. The explicit storyline extension approach presented here is an alternative to the aggregate GDP-driven or historical trend extrapolations of service or energy demands. We describe the scenario formulation processes, resulting parameters, their applications, and offer an outlook for prospective sustainability models.

Material production accounts for 23% of all greenhouse gas emissions. More efficient use of materials – through decoupling of services that support human wellbeing from material use – is imperative as other emissions mitigation options are expensive. An interdisciplinary scientific assessment of material efficiency and its links to service provision, material cycle management, and climate policy is needed to identify effective strategies and help design the policy framework required for their implementation. We present RECC, the Resource Efficiency-Climate Change mitigation framework, a first step towards such a comprehensive assessment. RECC is based on dynamic material flow analysis and links the services provided (individual motorized transport and dwelling) to the operation of in-use stocks (passenger vehicles and residential buildings), to the expansion and maintenance of these stocks to their material cycles (major materials like steel and cement), and to energy use and climate impacts. A key innovation of RECC is the up-scaling of detailed descriptions of future product archetypes with different degrees of material and energy efficiency, which are simulated with engineering tools.We utilize RECC with augmented storylines of the shared socioeconomic pathways (SSP) to describe future service demand and associated material requirements. Ten material efficiency strategies at different stages of the material cycle can be assessed by ramping up their implementation rates to the identified technical potentials. RECC provides scenario results for the life cycle impacts of ambitious service-material decoupling concurrent with energy system decarbonization, giving detailed insights on the resource efficiency-climate change mitigation nexus to policy makers worldwide.

Recent life cycle assessments confirmed the greenhouse gas emission reduction potential of renewable electricity and electric vehicle technologies. However, each technology is usually assessed separately and not within a consistent macro-economic, multi-sectoral framework. Here we present a multi-regional input-output based hybrid approach with integrated scenarios to facilitate the carbon footprint assessment of all direct and indirect effects of a transition to low-emission transportation and electricity generation technologies in Australia. The work takes into account on-road energy consumption values that are more realistic than official drive-cycle energy consumption figures used in previous work. Accounting for these factors as well as for Australia’s grid electricity, which heavily relies on coal power, electric vehicles are found to have a higher carbon footprint than conventional vehicles, whereas hybrid electric vehicles have the lowest. This means that – from a carbon footprint perspective – powertrain electrification is beneficial only to a certain degree at the current stage. This situation can be changed by increasing shares of renewable electricity in the grid. In our best-case scenario, where renewable energy accounts for 96% of the electricity mix in 2050, electric vehicle carbon footprints can be cut by 66% by 2050 relative to 2009. In the business-as-usual scenario (36% renewable electricity share by 2050), electric vehicles can reach a 56% reduction if fossil fuel power plants significantly increase their efficiencies and use carbon capture and storage technologies.

As one quarter of global energy use serves the production of materials, the more efficient use of these materials presents a significant opportunity for the mitigation of greenhouse gas (GHG) emissions. With the renewed interest of policy makers in the circular economy, material efficiency (ME) strategies such as light-weighting and downsizing of and lifetime extension for products, reuse and recycling of materials, and appropriate material choice are being promoted. Yet, the emissions savings from ME remain poorly understood, owing in part to the multitude of material uses and diversity of circumstances and in part to a lack of analytical effort. We have reviewed emissions reductions from ME strategies applied to buildings, cars, and electronics. We find that there can be a systematic trade-off between material use in the production of buildings, vehicles, and appliances and energy use in their operation, requiring a careful life cycle assessment of ME strategies. We find that the largest potential emission reductions quantified in the literature result from more intensive use of and lifetime extension for buildings and the light-weighting and reduced size of vehicles. Replacing metals and concrete with timber in construction can result in significant GHG benefits, but trade-offs and limitations to the potential supply of timber need to be recognized. Repair and remanufacturing of products can also result in emission reductions, which have been quantified only on a case-by-case basis and are difficult to generalize. The recovery of steel, aluminum, and copper from building demolition waste and the end-of-life vehicles and appliances already results in the recycling of base metals, which achieves significant emission reductions. Higher collection rates, sorting efficiencies, and the alloy-specific sorting of metals to preserve the function of alloying elements while avoiding the contamination of base metals are important steps to further reduce emissions.

Despite considerable mitigation efforts, global emissions from the electricity sector continued to grow in recent years. In Australia, the electricity sector is the largest CO 2 -emitting industry, contributing 35% of the country's total greenhouse gas emissions. The Australian government targets an 80% reduction of greenhouse gas emissions by 2050 relative to 2010. With a large variety and quantity of renewable energy resources, it is technically feasible and seems indispensable that Australia's electricity sector be largely decarbonised by 2050 in order to achieve this target. In this paper, scenario-based hybrid Life-Cycle Assessment is applied to calculate the economy-wide carbon footprints of seven electricity generation technologies in scenarios with differing renewable electricity penetration. This work is the first to apply a full life-cycle approach to scenario analysis of electricity generation in Australia. The findings are at the higher end of previously reported carbon footprint intensity ranges and above median values. However, even when taking into account indirect emissions along the technologies' life-cycles, the results indicate that the employment of different renewable energy technologies can potentially save a considerable fraction of Australia's greenhouse gas emissions. This makes renewables an essential option for climate change mitigation.

This study contributes to better understanding the interregional variability in vehicle carbon footprints and presents a case study of China’s electric vehicle (EV) charging infrastructure promotion plan (EVSE2020). Based on an integrated hybrid life-cycle assessment (LCA) with new regional electricity mixes and the Thermal Emission Imaging System (THEMIS) model with local inventories, the carbon footprints of battery electric vehicles (BEVs) and internal combustion engine vehicles (ICEVs) are calculated for all size segments. For the A-class segment, the most popular size segment, the results show that the carbon footprint of ICEVs is approximately 250.6 gCO2e/km. The BEV carbon footprint under a nationwide electricity mix is 217.6 gCO2e/km and ranges between 104.4 (Yunnan) and 265.7 (Shandong) gCO2e/km. These results can be explained by the proportion of coal in provincial electricity consumption mixes (10% to 90%). Out of the 31 provinces in mainland China, A-class BEVs driven in 26 provinces will reduce life-cycle greenhouse gas (GHG) emissions compared to ICEVs. In addition, the maximum BEV carbon footprint exceeds the minimum by 79%–121% owing to size segments, which is much higher than that for ICEVs, 59%. The interprovincial variability in vehicle carbon footprints calls for modifications to the interregional priority assignments in the EVSE2020 plan, which currently focuses on air pollution control and economic status. After incorporating explicit considerations of climate mitigation, this study recommends raising the level of priority of three provinces in Central and Southwest China (Sichuan, Chongqing, and Hubei) in the EVSE2020 plan. For provinces with a high share of coal-based electricity, the development of BEVs of small size segments (A00/A0) should be encouraged.