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

Recent Developments and Challenges in Projecting the Impact of Crop Productivity Growth on Biodiversity Considering Market-Mediated Effects

The effect of an increase in crop productivity (output per unit of inputs) on biodiversity is hitherto poorly understood. This is because increased productivity of a crop in particular regions leads to increased profit that can encourage expansion of its cultivated area causing land use change and ultimately biodiversity loss, a phenomenon also known as "Jevons paradox" or the "rebound effect". Modeling such consequences in an interconnected and globalized world considering such rebound effects is challenging. Here, we discuss the use of computable general equilibrium (CGE) and other economic models in combination with ecological models to project consequences of crop productivity improvements for biodiversity globally. While these economic models have the advantage of taking into account market-mediated responses, resource constraints, endogenous price responses, and dynamic bilateral patterns of trade, there remain a number of important research and data gaps in these models which must be addressed to improve their performance in assessment of the link between local crop productivity changes and global biodiversity. To this end, we call for breaking the silos and building interdisciplinary networks across the globe to facilitate data sharing and knowledge exchange in order to improve global-to-local-to-global analysis of land, biodiversity, and ecosystem sustainability.

Micro- and nanoplastics in soil: Linking sources to damage on soil ecosystem services in life cycle assessment

Soil ecosystems are crucial for providing vital ecosystem services (ES), and are increasingly pressured by the intensification and expansion of human activities, leading to potentially harmful consequences for their related ES provision. Micro- and nanoplastics (MNPs), associated with releases from various human activities, have become prevalent in various soil ecosystems and pose a global threat. Life Cycle Assessment (LCA), a tool for evaluating environmental performance of product and technology life cycles, has yet to adequately include MNPs-related damage to soil ES, owing to factors like uncertainties in MNPs environmental fate and ecotoxicological effects, and characterizing related damage on soil species loss, functional diversity, and ES. This study aims to address this gap by providing as a first step an overview of the current understanding of MNPs in soil ecosystems and proposing a conceptual approach to link MNPs impacts to soil ES damage. We find that MNPs pervade soil ecosystems worldwide, introduced through various pathways, including wastewater discharge, urban runoff, atmospheric deposition, and degradation of larger plastic debris. MNPs can inflict a range of ecotoxicity effects on soil species, including physical harm, chemical toxicity, and pollutants bioaccumulation. Methods to translate these impacts into damage on ES are under development and typically focus on discrete, yet not fully integrated aspects along the impact-to-damage pathway. We propose a conceptual framework for linking different MNPs effects on soil organisms to damage on soil species loss, functional diversity loss and loss of ES, and elaborate on each link. Proposed underlying approaches include the Threshold Indicator Taxa Analysis (TITAN) for translating ecotoxicological effects associated with MNPs into quantitative measures of soil species diversity damage; trait-based approaches for linking soil species loss to functional diversity loss; and ecological networks and Bayesian Belief Networks for linking functional diversity loss to soil ES damage. With the proposed conceptual framework, our study constitutes a starting point for including the characterization of MNPs-related damage on soil ES in LCA.

Development of an LCA characterization factor to account UHI local effect on terrestrial ecosystems damage category: Evaluation of European Bombus and Onthophagus genera heat-stress mortality

Life Cycle Assessment as currently implemented fails in detecting and measuring the interactions between urban climate and built environment, specifically the urban heat island, providing potentially misleading results. The present study offers an advancement in Life Cycle Assessment methodology, and specifically in ReCiPe2016 method, by (a) suggesting the implementation of the Local Warming Potential midpoint impact category where the variation of urban temperature converges; (b) developing a new characterization factor through the definition of damage pathways to assess the effect of urban heat island on terrestrial ecosystems damage category, specifically on European Bombus and Onthophagus genera; (c) defining local endpoint damage categories where environmental local impacts can be addressed. The developed characterization factor has been applied to the case study of an urban area in Rome, Italy. The results show that the evaluation of the effects of urban overheating on local terrestrial ecosystems is meaningful and may support urban decision-makers who want to holistically assess urban plans.

Characterization Factors to Assess Land Use Impacts on Pollinator Abundance in Life Cycle Assessment

While wild pollinators play a key role in global food production, their assessment is currently missing from the most commonly used environmental impact assessment method, Life Cycle Assessment (LCA). This is mainly due to constraints in data availability and compatibility with LCA inventories. To target this gap, relative pollinator abundance estimates were obtained with the use of a Delphi assessment, during which 25 experts, covering 16 nationalities and 45 countries of expertise, provided scores for low, typical, and high expected abundance associated with 24 land use categories. Based on these estimates, this study presents a set of globally generic characterization factors (CFs) that allows translating land use into relative impacts to wild pollinator abundance. The associated uncertainty of the CFs is presented along with an illustrative case to demonstrate the applicability in LCA studies. The CFs based on estimates that reached consensus during the Delphi assessment are recommended as readily applicable and allow key differences among land use types to be distinguished. The resulting CFs are proposed as the first step for incorporating pollinator impacts in LCA studies, exemplifying the use of expert elicitation methods as a useful tool to fill data gaps that constrain the characterization of key environmental impacts.

Linking freshwater ecotoxicity to damage on ecosystem services in life cycle assessment

Freshwater ecosystems provide major benefits to human wellbeing-so-called ecosystem services (ES)-but are currently threatened among others by ecotoxicological pressure from chemicals reaching the environment. There is an increased motivation to incorporate ES in quantification tools that support decision-making, such as life cycle assessment (LCA). However, mechanistic models and frameworks that can systematically translate ecotoxicity effect data from chemical tests into eventual damage on species diversity, functional diversity, and ES in the field are still missing. While current approaches focus on translating predicted ecotoxicity impacts to damage in terms of species loss, no approaches are available in LCA and other comparative assessment frameworks for linking ecotoxicity to damage on ecosystem functioning or ES. To overcome this challenge, we propose a way forward based on evaluating available approaches to characterize damage of chemical pollution on freshwater ES. We first outline an overall framework for linking freshwater ecotoxicity effects to damage on related ES in compliance with the boundary conditions of quantitative, comparative assessments. Second, within the proposed framework, we present possible approaches for stepwise linking ecotoxicity effects to species loss, functional diversity loss, and damage on ES. Finally, we discuss strengths, limitations, and data availability of possible approaches for each step. Although most approaches for directly deriving damage on ES from either species loss or damage to functional diversity have not been operationalized, there are some promising ways forward. The Threshold Indicator Taxa ANalysis (TITAN) seems suitable to translate predicted ecotoxicity effects to a metric of quantitative damage on species diversity. A Trait Probability Density Framework (TPD) approach that incorporates various functional diversity components and functional groups could be adapted to link species loss to functional diversity loss. An Ecological Production Function (EPF) approach seems most promising for further linking functional diversity loss to damage on ES flows for human wellbeing. However, in order to integrate the entire pathway from predicted freshwater ecotoxicity to damage on ES into LCA and other comparative frameworks, the approaches adopted for each step need to be harmonized in terms of assumptions, boundary conditions and consistent interfaces with each other.

Life cycle assessment of microalgal biorefinery: A state-of-the-art review

Microalgal biorefineries represent an opportunity to economically and environmentally justify the production of bioproducts. The generation of bioproducts within a biorefinery system must quantitatively demonstrate its viability in displacing traditional fossil-based refineries. To this end, several works have conducted life cycle analyses on microalgal biorefineries and have shown technological bottlenecks due to energy-intensive processes. This state-of-the-art review covers different studies that examined microalgal biorefineries through life cycle assessments and has identified strategic technologies for the sustainable production of microalgal biofuels through biorefineries. Different metrics were introduced to supplement life cycle assessment studies for the sustainable production of microalgal biofuel. Challenges in the comparison of various life cycle assessment studies were identified, and the future design choices for microalgal biorefineries were established.

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.

Global Assessment of Agricultural Productivity Losses from Soil Compaction and Water Erosion

To guide us toward a sustainable future, the impacts of human activities on natural resources need to be understood and quantified. In this study on global agriculture, we use a Life Cycle Assessment framework to estimate potential long-term soil productivity losses caused by soil compaction and water erosion due to agricultural crop production. We combine several data sets to model spatially resolved Life Cycle Inventory information at the global level and multiply results with characterization factors from a previous publication. The global picture shows a compaction-stressed "Global North" and an erosion-stressed "Global South", with some countries and regions in between, for example, China and parts of South America. Results show that both compaction and water erosion impacts matter at the global level and that overall potential long-term productivity losses of 10-20% can be expected, with high relative impacts on low input production systems. These losses might limit long-term agricultural productivity and lead to additional land use change. Our work adds to and extends the discussion of global assessments of soil degradation. Furthermore, we prove the suggested framework to be applicable and useful for Life Cycle Assessments and other studies and provide results that can be used in such global assessments.

Life cycle assessment (LCA): informing the development of a sustainable circular bioeconomy?

The role of life cycle assessment (LCA) in informing the development of a sustainable and circular bioeconomy is discussed. We analyse the critical challenges remaining in using LCA and propose improvements needed to resolve future development challenges. Biobased systems are often complex combinations of technologies and practices that are geographically dispersed over long distances and with heterogeneous and uncertain sets of indicators and impacts. Recent studies have provided methodological suggestions on how LCA can be improved for evaluating the sustainability of biobased systems with a new focus on emerging systems, helping to identify environmental and social opportunities prior to large R&D investments. However, accessing economies of scale and improved conversion efficiencies while maintaining compatibility across broad ranges of sustainability indicators and public acceptability remain key challenges for the bioeconomy. LCA can inform, but not by itself resolve this complex dimension of sustainability. Future policy interventions that aim to promote the bioeconomy and support strategic value chains will benefit from the systematic use of LCA. However, the LCA community needs to develop the mechanisms and tools needed to generate agreement and coordinate the standards and incentives that will underpin a successful biobased transition. Systematic stakeholder engagement and the use of multidisciplinary analysis in combination with LCA are essential components of emergent LCA methods. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.

Global process-based characterization factors of soil carbon depletion for life cycle impact assessment

Regionalization of land use (LU) impact in life cycle assessment (LCA) has gained relevance in recent years. Most regionalized models are statistical, using highly aggregated spatial units and LU classes (e.g. one unique LU class for cropland). Process-based modelling is a powerful characterization tool but so far has never been applied globally for all LU classes. Here, we propose a new set of spatially detailed characterization factors (CFs) for soil organic carbon (SOC) depletion. We used SOC dynamic curves and attainable SOC stocks from a process-based model for more than 17,000 world regions and 81 LU classes. Those classes include 63 agricultural (depending on 4 types of management/production), and 16 forest sub-classes, and 1 grassland and 1 urban class. We matched the CFs to LU elementary flows used by LCA databases at country-level. Results show that CFs are highly dependent on the LU sub-class and management practices. For example, transformation into cropland in general leads to the highest SOC depletion but SOC gains are possible with specific crops.

Creating ecosystem services assessment models incorporating land use impacts based on soil quality

Life cycle assessment (LCA) is a widely applied approach used to evaluate the environmental impacts of a product or service across its life cycle stages; however, the impacts of land use on ecosystem services are less addressed in most LCA studies. This study, therefore, aims to improve the LCA model by incorporating a new impact category of land use on ecosystem services at both midpoint and endpoint levels in the existing ReCiPe2016 impact assessment method. The impacts of land use in the LCA model included land occupation and land transformation. The soil quality-based indicator, soil organic carbon (SOC), was adopted to quantify the soil quality change in ecosystem services caused by land use. A site with contaminated soils was adopted to validate the proposed impact assessment approach and to compare the results of various remediation practices. Our results revealed that the characterization factors (CFs) varied with the type of land use intervention, with land occupation of settlements presenting the highest CFs and land occupation of forest presenting the most negative CFs and thus benefitting ecosystem services. These results were well reflected in the case study, while the type of land intervention was the key factor determining the impact level. The results suggested that long-term occupation, high contamination levels, and high material or energy use contributed to relatively higher impacts of land use on ecosystem services. The proposed approach enables the quantification of land use impacts on ecosystem services as expressed in monetary loss or benefit at the endpoint resource level. The impact assessment results indicated that the in situ bioremediation scenario contributed relatively higher impacts ($12,667 USD) than the excavation and thermal treatment scenario ($-37 USD). These monetary assessment results are informative and are expected to be used in the decision-making process towards achieving beneficial environmental outcomes.

Biodiversity Assessment of Value Chains: State of the Art and Emerging Challenges

The consumption of materials and products is one of the drivers of biodiversity loss, which in turn affects ecosystem functioning and has socio-economic consequences worldwide. Life cycle assessment (LCA) is a reference methodology for appraising the environmental impacts of products along their value chains. Currently, a generally accepted life cycle impact assessment (LCIA) framework for assessing biodiversity impacts is lacking. The existing LCIA models present weaknesses in terms of the impact drivers considered, geographical coverage, as well as the indicators and metrics adopted. Sound ecological indicators and metrics need to be integrated in order to better assess the impacts of value chains on biodiversity on a global, regional, and local scale. This review analyses studies which, using a life cycle perspective, assess the impacts of products' and services' value chains on biodiversity. We identify and discuss promising synergies between the studies which look beyond the life cycle context, and apply other biodiversity metrics. Our results highlight that the existing metrics of biodiversity impact assessment in LCA are poor at capturing the complexities of biodiversity. There are operational models at the midpoint level that expand on the assessed dimensions of biodiversity (e.g., ecosystem structure), and the drivers of biodiversity loss (e.g., assessment of species exploitation), but efforts are required to fully include these models in the LCA framework. In the business domain, many initiatives are developing frameworks to assess impacts on biodiversity. Many approaches make use of LCIA methods and input-output databases. However, these are generally coupled with other biodiversity metrics. This shows that the current LCA framework is not yet sufficient to support decision-making based on different sets of biodiversity indicators. Ecosystem accounting may provide important ecological information for both the inventory and the impact assessment stages of LCA, helping to disentangle the relationship between biodiversity and ecosystem services. Looking beyond the LCA domain can lead us to new ways of advancing the coverage of biodiversity impacts, in a way that increases the relevance of LCA across a wider range of areas. Future work should assess the indicators provided in various policy contexts.

A review of LCA assessments of forest-based bioeconomy products and processes under an ecosystem services perspective

The emergence of politically driven bioeconomy strategies worldwide calls for considering the ecological issues associated with bio-based products. Traditionally, life cycle analysis (LCA) approaches are key tools used to assess impacts through product life cycles, but they present limitations regarding the accounting of multiple ecosystem service-related issues, at both the land-use and supply chain levels. Based on a systematic review of empirical articles, this study provides insights on using LCA assessments to account for ecosystem service-related impacts in the context of bioeconomy activities. We address the following research questions: what is the state of the art of the literature performing LCA assessments of forest-based bioeconomy activities, including the temporal distribution, the geographic areas and products/processes at study, and the approaches and methods used? 2. Which impacts and related midpoints are considered by the reviewed studies and what types of ecosystem service- related information do they bear? Out of over 600 articles found through the Scopus search, 155 were deemed relevant for the review. The literature focuses on North-America and Europe. Most of the articles assessed the environmental impact of lower-value biomass uses. Climate change was assessed in over 90% of the studies, while issues related to ozone, eutrophication, human toxicity, resource depletion, acidification, and environmental toxicity were assessed in 40% to 60% of the studies. While the impact categories accounted for in the reviewed LCA studies bear information relevant to certain provisioning and regulating services, several ecosystem services (especially cultural ones) remain unaccounted for. The implications of our study are relevant for professionals working in the ecosystem services, circular bioeconomy, and/or LCA communities.

An Integrated Approach to Determining the Capacity of Ecosystems to Supply Ecosystem Services into Life Cycle Assessment for a Carbon Capture System

In the life cycle assessment (LCA) method, it is not possible to carry out an integrated sustainability analysis because the quantification of the biophysical capacity of the ecosystems to supply ecosystem services is not taken into account. This paper considers a methodological proposal connecting the flow demand of a process or system product from the technosphere and the feasibility of the ecosystem to supply based on the sink capacity. The ecosystem metabolism as an analytical framework and data from a case study of an LCA of combined heat and power (CHP) plant with and without post-combustion carbon capture (PCC) technology in Mexico were applied. Three scenarios, including water and energy depletion and climate change impact, are presented to show the types of results obtained when the process effect of operation is scaled to one year. The impact of the water–energy–carbon nexus over the natural infrastructure or ecological fund in LCA is analyzed. Further, the feasibility of the biomass energy with carbon capture and storage (BECCS) from this result for Mexico is discussed. On the supply side, in the three different scenarios, the CHP plant requires between 323.4 and 516 ha to supply the required oil as stock flow and 46–134 ha to supply the required freshwater. On the sink side, 52–5,096,511 ha is necessary to sequester the total CO2 emissions. Overall, the CHP plant generates 1.9–28.8 MW/ha of electricity to fulfill its function. The CHP with PCC is the option with fewer ecosystem services required.

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.

Bio-Based Production Systems: Why Environmental Assessment Needs to Include Supporting Systems

The transition to a bio-based economy is expected to deliver substantial environmental and economic benefits. However, bio-based production systems still come with significant environmental challenges, and there is a need for assessment methods that are adapted for the specific characteristics of these systems. In this review, we investigated how the environmental aspects of bio-based production systems differ from those of non-renewable systems, what requirements these differences impose when assessing their sustainability, and to what extent mainstream assessment methods fulfil these requirements. One unique characteristic of bio-based production is the need to maintain the regenerative capacity of the system. The necessary conditions for maintaining regenerative capacity are often provided through direct or indirect interactions between the production system and surrounding “supporting” systems. Thus, in the environmental assessment, impact categories affected in both the primary production system and the supporting systems need to be included, and impact models tailored to the specific context of the study should be used. Development in this direction requires efforts to broaden the system boundaries of conventional environmental assessments, to increase the level of spatial and temporal differentiation, and to improve our understanding of how local uniqueness and temporal dynamics affect the performance of the investigated system.

Accounting for land use, biodiversity and ecosystem services in life cycle assessment: Impacts of breakfast cereals

This study considers the life cycle impacts of land use on biodiversity and ecosystem services associated with the production of a ubiquitous food type: breakfast cereals. For biodiversity, the impacts on five taxonomic groups have been assessed: mammals, birds, vascular plants, amphibians and reptiles. For ecosystem services, the potential loss in the following ecosystem services of soil has been considered: biotic production, erosion resistance, groundwater regeneration, infiltration and physicochemical filtration. The findings indicate that the main hotspot for the biodiversity loss is cocoa cultivation for all taxonomic groups, with a contribution of 27-67%. Cocoa is also a major contributor (35%) to the loss of biotic production, while rice is the largest contributor to erosion (34%), reduction in groundwater replenishment (43%) and physiochemical filtration (23%). Corn is the main cause of the infiltration reduction, accounting for 44% of the impact. Unlike the biodiversity impacts, which are almost entirely caused by agricultural activities, non-agricultural land use occurring in other life cycle stages (transport, packaging and manufacturing), has significant contribution to the reductions in groundwater replenishment and infiltration. The impacts on ecosystem services are almost entirely driven by land occupation, while the biodiversity impacts are caused by both land use change and occupation. The identification of cocoa as the main hotspot is unexpected as it is used only in very small quantities (<5% by mass) in breakfast cereals. Its high contribution to the impacts is partly due to the land use change in the ecoregion of the Eastern Guinean forests, which are home to a relatively large number of endemic species. The paper also discusses the limitations of the impact assessment methods for evaluating the biodiversity and ecosystem services and highlights the need for further development of indicators and methods to assess the land use impacts in life cycle assessment.

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.

Consolidating Regionalized Global Characterization Factors for Soil Organic Carbon Depletion Due to Land Occupation and Transformation

Land occupation and transformation change soil organic carbon (SOC) stocks, which are a priority indicator for biotic production potential (BPP) in life cycle impact assessment (LCIA). SOC is a potential umbrella indicator for land use-related impacts, but global LCIA characterization models have never been sufficiently regionalized. Regeneration times required for the calculation of transformation impacts are unknown and can only be estimated through expert judgment or using additional assumptions. In this paper, we calculate global midpoint characterization factors (CF) for SOC depletion following land use and land use change using data from the European Soil Data Center with a resolution of 30 arc second. We used three possible calculation procedures to determine regeneration times: (1) estimations based on literature; (2) equal regeneration duration for all land uses; (3) equal regeneration rates for all land uses. We then propose an innovative approach for LCIA that combines all CFs in this paper as well as prior models using a spatial consolidation approach to arrive at a single set of CFs. We show that this procedure combines the strengths of each individual model and dilutes their shortcomings, and recommend the use of these consolidated CFs rather than individual sets of factors. For endpoints, we applied a nutrient replacement method using fertilizer input to compensate for organic matter depletion and obtained monetary CFs for SOC-related damages caused by land use on BPP.

LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative

Increasing needs for decision support and advances in scientific knowledge within life cycle assessment (LCA) led to substantial efforts to provide global guidance on environmental life cycle impact assessment (LCIA) indicators under the auspices of the UNEP-SETAC Life Cycle Initiative. As part of these efforts, a dedicated task force focused on addressing several LCIA cross-cutting issues as aspects spanning several impact categories, including spatiotemporal aspects, reference states, normalization and weighting, and uncertainty assessment. Here, findings of the cross-cutting issues task force are presented along with an update of the existing UNEP-SETAC LCIA emission-to-damage framework. Specific recommendations are provided with respect to metrics for human health (Disability Adjusted Life Years, DALY) and ecosystem quality (Potentially Disappeared Fraction of species, PDF). Additionally, we stress the importance of transparent reporting of characterization models, reference states, and assumptions, in order to facilitate cross-comparison between chosen methods and indicators. We recommend developing spatially regionalized characterization models, whenever the nature of impacts shows spatial variability and related spatial data are available. Standard formats should be used for reporting spatially differentiated models, and choices regarding spatiotemporal scales should be clearly communicated. For normalization, we recommend using external normalization references. Over the next two years, the task force will continue its effort with a focus on providing guidance for LCA practitioners on how to use the UNEP-SETAC LCIA framework as well as for method developers on how to consistently extend and further improve this framework.