Integrated earth system dynamic modeling for life cycle impact assessment of ecosystem services

Integration of life cycle assessment and system dynamics modeling for environmental scenario analysis: A systematic review

System dynamics (SD) is widely recognized as a tool for simulating spatial and temporal dynamics in life cycle assessment (LCA) studies of the product system. However, there is no agreement on how SD and LCA could be applied effectively together in a consistent way. To address this gap, this research conducted a systematic literature review, analyzing 54 scientific articles published worldwide between 2010 and 2023, to explore the joint application of LCA with SD. The study aimed to answer three research questions: (1) What can be considered an integration of LCA and SD? (2) How can SD and LCA be effectively integrated? and (3)What are the advantages and constraints of this integration? The results highlighted the popularity of LCA and SD as impact assessment tools for sustainable design, each with its own strengths and limitations. Two primary integration types were identified when LCA was jointly applied with SD: (1) inclusion of the life cycle inventory and characterization factors in an SD model, and (2) inclusion of SD model results in an LCA. In the second type of integration, SD models the components of the technical system, and its outcomes served as input for scenario analysis, providing temporal and potentially spatial inventory data for the LCA model. The integrated approach offers a comprehensive understanding of product sustainability, aids decision-making, and enhances stakeholder engagement. The study also identifies knowledge gaps in the joint application of SD and LCA for environmental scenario analysis, suggesting the incorporation of optimization tools and strategy guidance for policy makers.

Simulation study on carbon emission of China's freight system under the target of carbon peaking

The development of Chinese society needs the support of a perfect and efficient freight transport system. Nonetheless, China's freight system is facing a major challenge in reducing carbon emissions. Hence, firstly, this paper explores three major internal drivers of carbon emissions by analyzing the current situation in China's freight system: proportion of railway freight (PORF), railway electrification level (REL) and electric truck penetration (ETP). Secondly, the system dynamics (SDs) model is used to simulate the carbon emission system of freight transportation in China. Thirdly, this paper sets 13 scenarios of carbon peaking to explore the paths of carbon peaking before 2030 under the three levels of development of ETP oriented freight system. The results indicate that when PORF, REL, and ETP reach 23.96% of total freight volume, 83.7% of rail freight, and 11% of truck freight in 2030 respectively, China's freight system has the most optimistic scenario of carbon peaking. Meanwhile, the time of carbon peaking is 2024, and the peak value is 0.842 billion tons. When PORF, REL, and ETP reach 15.96% of total freight volume, 63.7% of rail freight, and 3% of truck freight in 2030 respectively, China's freight system has the worst scenario of carbon peaking. Meanwhile, the time of carbon peaking is 2029, and the peak value is 1.016 billion tons. Also, it is proved that improving PORF, REL, and ETP is an effective way to achieve green and sustainable development of China's freight industry.

Towards a comprehensive sustainability methodology to assess anthropogenic impacts on ecosystems: Review of the integration of Life Cycle Assessment, Environmental Risk Assessment and Ecosystem Services Assessment

Nowadays, a variety of methodologies are available to assess local, regional and global impacts of human activities on ecosystems, which include Life Cycle Assessment (LCA), Environmental Risk Assessment (ERA) and Ecosystem Services Assessment (ESA). However, none can individually assess both the positive and negative impacts of human activities at different geographical scales in a comprehensive manner. In order to overcome the shortcomings of each methodology and develop more holistic assessments, the integration of these methodologies is essential. Several studies have attempted to integrate these methodologies either conceptually or through applied case studies. To understand why, how and to what extent these methodologies have been integrated, a total of 110 relevant publications were reviewed. The analysis of the case studies showed that the integration can occur at different positions along the cause-effect chain and from this, a classification scheme was proposed to characterize the different integration approaches. Three categories of integration are distinguished: post-analysis, integration through the combination of results, and integration through the complementation of a driving method. The literature review highlights that the most recurrent type of integration is the latter. While the integration through the complementation of a driving method is more realistic and accurate compared to the other two categories, its development is more complex and a higher data requirement could be needed. In addition to this, there is always the risk of double-counting for all the approaches. None of the integration approaches can be categorized as a full integration, but this is not necessarily needed to have a comprehensive assessment. The most essential aspect is to select the appropriate components from each methodology that can cover both the environmental and socioeconomic costs and benefits of human activities on the ecosystems.

Life Cycle Assessment of Bridges Using Bayesian Networks and Fuzzy Mathematics

At present, reducing the impact of the construction industry on the environment is the key to achieving sustainable development. Countries all over the world are using software systems for bridge environmental impact assessment. However, due to the complexity and discreteness of environmental factors in the construction industry, they are difficult to update and determine quickly, and there is a phenomenon of data missing in the database. Most of the lost data are optimized by Monte Carlo simulation, which greatly reduces the reliability and accuracy of the research results. This paper uses Bayesian advanced fuzzy mathematics theory to solve this problem. In the research, a Bayesian fuzzy mathematics evaluation and a multi-level sensitivity priority discrimination model are established, and the weights and membership degrees of influencing factors were defined to achieve comprehensive coverage of influencing factors. With the support of theoretical modelling, software analysis and fuzzy mathematics theory are used to comprehensively evaluate all the influencing factors of the five influencing stages in the entire life cycle of the bridge structure. The results show that the material manufacturing, maintenance, and operation of the bridge still produce environmental pollution; the main source of the emissions exceeds 53% of the total emissions. The effective impact factor reaches 3.01. At the end of the article, a big data sensitivity model was established. Through big data innovation and optimization analysis, traffic pollution emissions were reduced by 330 tonnes. Modeling of the comprehensive research model; application; clearly confirms the effectiveness and practicality of the Bayesian network fuzzy number comprehensive evaluation model in dealing with uncertain factors in the evaluation of the sustainable development of the construction industry. The research results have made important contributions to the realization of the sustainable development goals of the construction industry.

Addressing temporal considerations in life cycle assessment

In life cycle assessment (LCA), temporal considerations are usually lost during the life cycle inventory calculation, resulting in an aggregated "snapshot" of potential impacts. Disregarding such temporal considerations has previously been underlined as an important source of uncertainty, but a growing number of approaches have been developed to tackle this issue. Nevertheless, their adoption by LCA practitioners is still uncommon, which raises concerns about the representativeness of current LCA results. Furthermore, a lack of consistency can be observed in the used terms for discussions on temporal considerations. The purpose of this review is thus to search for common ground and to identify the current implementation challenges while also proposing development pathways. This paper introduces a glossary of the most frequently used terms related to temporal considerations in LCA to build a common understanding of key concepts and to facilitate discussions. A review is also performed on current solutions for temporal considerations in different LCA phases (goal and scope definition, life cycle inventory analysis and life cycle impact assessment), analysing each temporal consideration for its relevant conceptual developments in LCA and its level of operationalisation. We then present a potential stepwise approach and development pathways to address the current challenges of implementation for dynamic LCA (DLCA). Three key focal areas for integrating temporal considerations within the LCA framework are discussed: i) define the temporal scope over which temporal distributions of emissions are occurring, ii) use calendar-specific information to model systems and associated impacts, and iii) select the appropriate level of temporal resolution to describe the variations of flows and characterisation factors. Addressing more temporal considerations within a DLCA framework is expected to reduce uncertainties and increase the representativeness of results, but possible trade-offs between additional data collection efforts and the increased value of results from DLCAs should be kept in mind.

Bridge Carbon Emissions and Driving Factors Based on a Life-Cycle Assessment Case Study: Cable-Stayed Bridge over Hun He River in Liaoning, China

Due to the rapid growth of the construction industry’s global environmental impact, especially the environmental impact contribution of bridge structures, it is necessary to study the detailed environmental impact of bridges at each stage of the full life cycle, which can provide optimal data support for sustainable development analysis. In this work, the environmental impact case of a three-tower cable-stayed bridge was analyzed through openLCA software, and more than 23,680 groups of data were analyzed using Markov chain and other research methods. It was concluded that the cable-stayed bridge contributed the most to the global warming potential value, which was mainly concentrated in the operation and maintenance phases. The conclusion shows that controlling the exhaust pollution of passing vehicles and improving the durability of building materials were the key to reducing carbon contribution and are also important directions for future research.

Ecosystem Services and Economic Assessment of Land Uses in Urban and Periurban Areas

This work quantified ecosystem services (ES) and the geographic gross product (GGP) at municipal level in the Metropolitan Region of Buenos Aires (MRBA), Argentina. The ES offer and GGP were evaluated for each land use (extensive agriculture EA, intensive agriculture IA, urban and periurban agriculture UPA, green areas GA, urban use URB), expressed as a percentage (%), at the municipality level. Municipalities with a greater URB percentage (<70) presented an elevated ES offer from GA. In periurban municipalities EA contributed to ES offer more than other vegetated land uses (IA, GA, and UPA). Urban municipalities presented 20% more GGP than periurban municipalities. The GGP was negatively associated with total ES offer (-0.34) and ES offer from EA (-0.46). The identification and quantification of ES and GGP is relevant for achieving an adequate landscape planning and a sustainable environmental and economic use of urban systems.

An improved life cycle impact assessment principle for assessing the impact of land use on ecosystem services

In order to consider the effects of land use, and the land cover changes it causes, on ecosystem services in life cycle assessment (LCA), a new methodology is proposed and applied to calculate midpoint and endpoint characterization factors. To do this, a cause-effect chain was established in line with conceptual models of ecosystem services to describe the impacts of land use and related land cover changes. A high-resolution, spatially explicit and temporally dynamic modeling framework that integrates land use and ecosystem services models was developed and used as an impact characterization model to simulate that cause-effect chain. Characterization factors (CFs) were calculated and regionalized at the scales of Luxembourg and its municipalities, taken as a case to show the advantages of the modeling approach. More specifically, the calculated CFs enable the impact assessment of six land cover types on six ecosystem functions and two final ecosystem services. A mapping and comparison exercise of these CFs allowed us to identify spatial trade-offs and synergies between ecosystem services due to possible land cover changes. Ultimately, the proposed methodology can offer a solution to overcome a number of methodological limitations that still exist in the characterization of impacts on ecosystem services in LCA, implying a rethinking of the modeling of land use in life cycle inventory.

Towards integrating the ecosystem services cascade framework within the Life Cycle Assessment (LCA) cause-effect methodology

The assessment of ecosystem services (ES) is covered in a fragmented manner by environmental decision support tools that provide information about the potential environmental impacts of supply chains and their products, such as the well-known Life Cycle Assessment (LCA) methodology. Within the flagship project of the Life Cycle Initiative (hosted by UN Environment), aiming at global guidance for life cycle impact assessment (LCIA) indicators, a dedicated subtask force was constituted to consolidate the evaluation of ES in LCA. As one of the outcomes of this subtask force, this paper describes the progress towards consensus building in the LCA domain concerning the assessment of anthropogenic impacts on ecosystems and their associated services for human well-being. To this end, the traditional LCIA structure, which represents the cause-effect chain from stressor to impacts and damages, is re-casted and expanded using the lens of the ES 'cascade model'. This links changes in ecosystem structure and function to changes in human well-being, while LCIA links the effect of changes on ecosystems due to human impacts (e.g. land use change, eutrophication, freshwater depletion) to the increase or decrease in the quality and/or quantity of supplied ES. The proposed cascade modelling framework complements traditional LCIA with information about the externalities associated with the supply and demand of ES, for which the overall cost-benefit result might be either negative (i.e. detrimental impact on the ES provision) or positive (i.e. increase of ES provision). In so doing, the framework introduces into traditional LCIA the notion of "benefit" (in the form of ES supply flows and ecosystems' capacity to generate services) which balances the quantified environmental intervention flows and related impacts (in the form of ES demands) that are typically considered in LCA. Recommendations are eventually provided to further address current gaps in the analysis of ES within the LCA methodology.

Exploring Expedient Protected Area for Ecosystem Services: Decision-Making Method with a New Algorithm

From the point of view of ecological environment protection, the concepts of biodiversity, carbon sequestration, water production and culture have been selected to evaluate the ecosystem services of Guanzhong-Tianshui Economic Zone. A multi-criterion decision-making method is applied to select the expedient protected area of the study area, which can provide abundant natural resources and a basis for the maintenance of ecological balance. In this paper, by setting up different risk values and weights to calculate OWA (ordered weighted averaging) operator, the scenario of the expedient protected area with the highest tradeoff value is selected. This study analyzes and evaluates ecosystem services in the study area by combining natural and human factors, and the OWA operator is used to balance the trade-offs between different ecosystem services, as well as select the expedient protected areas, which provides a reference for improving ecosystem services in the study area.

Setting conservation priorities based on ecosystem services - A case study of the Guanzhong-Tianshui Economic Region

Economic development and the increased human demand for natural resources have seriously damaged many ecosystems. Nature reserves are areas with good natural conditions, abundant natural resources and healthy ecosystems that have been established for protection and management. This paper introduces cultural ecosystem services into the selection criteria for priority conservation areas. Both natural and human factors are considered, making it possible to protect both ecological and cultural services in reserves. In this paper, (1) the cultural ecosystem services of the Guanzhong-Tianshui Economic Region were estimated and quantified using questionnaires and the SolVES application; (2) the supplying services (water yield) and regulating services (net primary productivity (NPP), soil conservation) were calculated, and several ecosystem services were valued by models combining human and cultural data; and (3) multiple scenarios were considered, and a priority conservation area with NPP, soil conservation, water yield, aesthetic value and recreation protection efficiencies of 1.315, 2.458, 1.018, 1.414, and 1.079, respectively was selected by comparing the protection efficiencies of the different areas in each scenario to achieve the highest value for the various ecosystem services in the study area. The results provide decision support for the environmental protection of the Guanzhong-Tianshui Economic Region.

Ecosystem Services in Life Cycle Assessment: A novel conceptual framework for soil

Ecosystem Services (ES) are the direct and indirect contributions of ecosystems to human well-being, which include provision of food and water, regulation of flood and erosion processes, soil formation and non-material benefits such as recreation. The integration of ES impact modeling in Life Cycle Assessment (LCA) still has limitations regarding the typology embodied and some conceptual errors in not actually evaluating the benefits provided by ES. In this context, soil is an important resource and provides a wide diversity of ES. Therefore, this article aims to: (i) Review the evolution of ES assessment in LCA and the current methods used to study the biophysical aspects of ES; (ii) Compare the ES cascade model and LCA environmental mechanism for land use impacts; and (iii) Improve and synthesize a new conceptual framework for soil-ES assessment in LCA studies. Results show that the cascade model provides a useful framework for operationalizing ES assessment and should integrate LCA. Thus, this study proposes a new conceptual framework for soil-ES including the main soil processes, functions, services, benefits and values. Each of these cascade model steps is aligned with LCA terminology in order to match the usual midpoint or endpoint levels of modeling. Future works should focus on new indicators to measure the supply of ES and their benefit to humans as well as indicators to their value.

Integrate carbon dynamic models in analyzing carbon sequestration impact of forest biomass harvest

Biomass is an attractive natural energy resource for mitigating climate change. However, the loss of carbon sequestration as an ecosystem service due to biomass harvest has not been considered in previous studies. To assess the impact of biomass harvest on carbon sequestration, carbon dynamics in the forests and the atmosphere were integrated. The impact of forest biomass harvests on carbon sequestration was assessed based on the difference between carbon sequestration after harvest and carbon sequestration without harvest. A Chapman-Richards function and the forest vegetation simulator (FVS) were used to simulate the growth of a forest stand. The carbon dynamics in the atmosphere were simulated by the Bern2.5CC carbon cycle model. Characterization factors of the impact were calculated in three time horizons: 20-, 100- and 500-year. According to the simulations, postponement of harvest and low harvest intensity could prolong the compensation period. The annual impact on carbon sequestration was mostly negative over a short time and became positive in the end of compensation period. The highest characteristic factors of the impact on carbon sequestration were found in rotation length of 100years with the time horizon of 500-year in the Chapman-Richards simulation and in the lowest harvest intensity with the time horizon of 500-year in the FVS simulation. Based on the results, increasing growth rate, postponing harvest, reducing harvest intensity and increasing length of time horizon could reduce the impact of forest harvest on carbon sequestration. The method proposed in this study is more proper to assess the impact on carbon sequestration, and it has much wider applications in forest management practice.

Ecosystem services response to urbanization in metropolitan areas: Thresholds identification

Ecosystem service is the key comprehensive indicator for measuring the ecological effects of urbanization. Although various studies have found a causal relationship between urbanization and ecosystem services degradation, the linear or non-linear characteristics are still unclear, especially identifying the impact thresholds in this relationship. This study quantified four ecosystem services (i.e. soil conservation, carbon sequestration and oxygen production, water yield, and food production) and total ecosystem services (TES), and then identified multiple advantageous area of ecosystem services in the peri-urban area of Beijing City. Using piecewise linear regression, the response of TES to urbanization (i.e., population density, GDP density, and construction land proportion) and its thresholds were detected. The results showed that, the TES was high in the north and west and low in the southeast, and there were seven multiple advantageous areas (distributed in the new urban development zone and ecological conservation zone), one single advantageous area (distributed in the ecological conservation zone), and six disadvantageous areas (mainly distributed in the urban function extended zone). TES response to population and economic urbanization each had a threshold (229personkm^-2 and 107.15millionyuankm^-2, respectively), above which TES decreased rapidly with intensifying urbanization. However, there was a negative linear relationship between land urbanization and TES, which indicated that the impact of land urbanization on ecosystem services was more direct and effective than that of population and economic urbanization. It was also found that the negative impact of urbanization on TES was highest in the urban function extended zone, followed in descending order by that in the new urban development zone and ecological conservation zone. According to the detected relationships between urbanization and TES, the economic and population urbanization should be strengthened accompanied by slowing or even reducing land urbanization, so as to achieve urban ecological sustainability with less ecosystem services degradation.

Climate regulation, energy provisioning and water purification: Quantifying ecosystem service delivery of bioenergy willow grown on riparian buffer zones using life cycle assessment

Whilst life cycle assessment (LCA) boundaries are expanded to account for negative indirect consequences of bioenergy such as indirect land use change (ILUC), ecosystem services such as water purification sometimes delivered by perennial bioenergy crops are typically neglected in LCA studies. Consequential LCA was applied to evaluate the significance of nutrient interception and retention on the environmental balance of unfertilised energy willow planted on 50-m riparian buffer strips and drainage filtration zones in the Skåne region of Sweden. Excluding possible ILUC effects and considering oil heat substitution, strategically planted filter willow can achieve net global warming potential (GWP) and eutrophication potential (EP) savings of up to 11.9 Mg CO₂e and 47 kg PO₄e ha^-1 year^-1, respectively, compared with a GWP saving of 14.8 Mg CO₂e ha^-1 year^-1 and an EP increase of 7 kg PO₄e ha^-1 year^-1 for fertilised willow. Planting willow on appropriate buffer and filter zones throughout Skåne could avoid 626 Mg year^-1 PO₄e nutrient loading to waters.

Assessing and Enhancing Environmental Sustainability: A Conceptual Review

While sustainability is an essential concept to ensure the future of humanity and the integrity of the resources and ecosystems on which we depend, identifying a comprehensive yet realistic way to assess and enhance sustainability may be one of the most difficult challenges of our time. We review the primary environmental sustainability assessment approaches, categorizing them as either being design-based or those that employ computational frameworks and/or indicators. We also briefly review approaches used for assessing economic and social sustainability because sustainability necessitates integrating environmental, economic, and social elements. We identify the collective limitations of the existing assessment approaches, showing that there is not a consistent definition of sustainability, that the approaches are generally not comprehensive and are subject to unintended consequences, that there is little to no connection between bottom-up and top-down approaches, and that the field of sustainability is largely fragmented, with a range of academic disciplines and professional organizations pursuing similar goals, but without much formal coordination. We conclude by emphasizing the need for a comprehensive definition of sustainability (that integrates environmental, economic, and social aspects) with a unified system-of-systems approach that is causal, modular, tiered, and scalable, as well as new educational and organizational structures to improve systems-level interdisciplinary integration.

Environmental impact assessment and monetary ecosystem service valuation of an ecosystem under different future environmental change and management scenarios; a case study of a Scots pine forest

For a sustainable future, we must sustainably manage not only the human/industrial system but also ecosystems. To achieve the latter goal, we need to predict the responses of ecosystems and their provided services to management practices under changing environmental conditions via ecosystem models and use tools to compare the estimated provided services between the different scenarios. However, scientific articles have covered a limited amount of estimated ecosystem services and have used tools to aggregate services that contain a significant amount of subjective aspects and that represent the final result in a non-tangible unit such as 'points'. To resolve these matters, this study quantifies the environmental impact (on human health, natural systems and natural resources) in physical units and uses an ecosystem service valuation based on monetary values (including ecosystem disservices with associated negative monetary values). More specifically, the paper also focuses on the assessment of ecosystem services related to pollutant removal/generation flows, accounting for the inflow of eutrophying nitrogen (N) when assessing the effect of N leached to groundwater. Regarding water use/provisioning, evapotranspiration is alternatively considered a disservice because it implies a loss of (potential) groundwater. These approaches and improvements, relevant to all ecosystems, are demonstrated using a Scots pine stand from 2010 to 2089 for a combination of three environmental change and three management scenarios. The environmental change scenarios considered interannual climate variability trends and included alterations in temperature, precipitation, nitrogen deposition, wind speed, Particulate matter (PM) concentration and CO2 concentration. The addressed flows/ecosystem services, including disservices, are as follows: particulate matter removal, freshwater loss, CO2 sequestration, wood production, NOx emissions, NH3 uptake and nitrogen pollution/removal. The monetary ecosystem service valuation yields a total average estimate of 361-1242 euro ha(-1) yr(-1). PM2.5 (<2.5 μm) removal is the key service, with a projected value of 622-1172 euro ha(-1) yr(-1). Concerning environmental impact assessment, with net CO2 uptake being the most relevant contributing flow, a loss prevention of 0.014-0.029 healthy life years ha(-1) yr(-1) is calculated for the respective flows. Both assessment methods favor the use of the least intensive management scenario due to its resulting higher CO2 sequestration and PM removal, which are the most important services of the considered ones.

Assessment of Life Cycle Impacts on Ecosystem Services: Promise, Problems, and Prospects

The analysis of ecosystem services (ES) is becoming a key-factor to implement policies on sustainable technologies. Accordingly, life cycle impact assessment (LCIA) methods are more and more oriented toward the development of harmonized characterization models to address impacts on ES. However, such efforts are relatively recent and have not reached full consensus yet. We investigate here on the transdisciplinary pillars related to the modeling of LCIA on ES by conducting a critical review and comparison of the state-of-the-art in both LCIA and ES domains. We observe that current LCIA practices to assess impacts on "ES provision" suffer from incompleteness in modeling the cause-effect chains; the multifunctionality of ecosystems is omitted; and the "flow" nature of ES is not considered. Furthermore, ES modeling in LCIA is limited by its static calculation framework, and the valuation of ES also experiences some limitations. The conceptualization of land use (changes) as the main impact driver on ES, and the corresponding approaches to retrieve characterization factors, eventually embody several methodological shortcomings, such as the lack of time-dependency and interrelationships between elements in the cause-effect chains. We conclude that future LCIA modeling of ES could benefit from the harmonization with existing integrated multiscale dynamic integrated approaches.

Challenge clusters facing LCA in environmental decision-making-what we can learn from biofuels

PURPOSE

Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy's sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers.

METHODS

The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policy-facing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy.

RESULTS AND DISCUSSION

The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance.

CONCLUSIONS

The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large.