Stefanie Hellweg
Biographic Data
| ID | 6546701 |
|---|---|
| NAME | Stefanie Hellweg |
| GIVEN NAMES | Stefanie |
| FAMILY NAME | Hellweg |
| SIGNATURE | HELLWEG S |
| AFFILIATIONS | ETH Zurich |
| ORCID | 0000-0001-6376-9878 |
| VERIFIED | Yes |
| TOTAL WORKS | 39 |
| TOTAL CITATIONS | 18 |
| AUTHOR COUNT | 39 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2005 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 3 |
Efficient and representative door-to-door travel time estimation for planning and policy
Travel times for many individual origin–destination pairs can be estimated without relying on detailed transport simulations by using commercial mapping services or by combining open-source routing engines with open street network data. While the former are more accurate, the latter are more scalable and economical. Neither option typically accounts for the time it takes to get to and unlock a vehicle or find parking. Here, we present a data-driv…
Spatiotemporal mapping of Swiss exterior wall material stock using a large language model and architectural history
Building material stock studies are essential for advancing the circular economy in construction. However, existing models often lack both accuracy and scalability. While machine learning has demonstrated significant potential to enhance predictive accuracy, its adoption has been hindered by a shortage of high‐quality training data. In this study, we introduce a novel methodology leveraging a large language model to extract previously untapped bu…
Assessing decarbonization strategies and industrial symbiosis in the chemical and waste‐to‐energy sector
Swiss waste‐to‐energy (WtE) plants are required to capture their CO 2 emissions by 2050 to meet the net‐zero climate target, with options for underground storage (carbon capture and storage [CCS]) or utilization (carbon capture and utilization [CCU]). This opens up a synergistic opportunity for the petrochemical industry to utilize the captured CO 2 as a feedstock, potentially helping both sectors reduce their carbon footprints. We conducted a pr…
Global sensitivity analysis of correlated uncertainties in life cycle assessment
Recent advances in research have made global sensitivity analysis of very large and highly linear life cycle assessment systems feasible. In this paper, we build on these developments to include sensitivity analysis of correlated parameters and nonlinear models. We augment numerical uncertainty propagation with Monte Carlo simulations (i) to include propagation of uncertainty from uncertain variables in parameterized inventory datasets; (ii) to a…
Spatial optimization of industrial symbiosis for heat supply of agricultural greenhouses
Despite the many benefits of greenhouses, it is challenging to meet their heating demand, as greenhouses belong to the most energy‐intensive production systems in the agriculture sector. Industrial symbiosis can bring an effective solution by utilizing waste heat from other industries to meet the greenhouse heat demand. This study proposes an optimization framework by which optimum symbiotic relationships can be identified. For this aim, the spat…
Biodiversity impacts of recent land-use change driven by increases in agri-food imports
Land-use change such as the conversion of natural habitat to agricultural land has been a major driver of global biodiversity loss, prompting efforts at biodiversity restoration. However, restoration measures in certain areas can shift the detrimental biodiversity impacts elsewhere through the outsourcing of agri-food supply chains to biodiverse regions. This study examines the link between biodiversity impacts from land-use change and shifts in …
Potentials and limits of mechanical plastic recycling
Plastics consumption continues to steeply increase worldwide, while resultant waste is currently mostly landfilled, discarded to the environment, or incinerated. This significantly contributes to global warming and causes negative health and ecosystem effects. Increasing the circularity of plastics can reduce these impacts. This study investigated to which extent plastics' circularity can be increased by mechanical recycling. For this purpose, fu…
Combining industrial ecology tools to assess potential greenhouse gas reductions of a circular economy: Method development and application to Switzerland
Industrial ecology (IE) methodologies, such as input/output or material flow analysis and life cycle assessment (LCA), are often used for the environmental evaluation of circular economy strategies. Up to now, an approach that utilizes these methods in a systematic, integrated framework for a holistic assessment of a geographic region's sustainable circular economy potential has been lacking. The approach developed in this study (IE4CE approach) …
Turning trash into treasure: An approach to the environmental assessment of waste prevention and its application to clothing and furniture in Switzerland
According to the waste hierarchy, waste prevention is environmentally superior to recycling or recovery, hence its inclusion in government policy. The assessment and prioritization of waste prevention strategies are impeded, inter alia, by ambiguous definitions and the lack of a sound environmental assessment method. In this study, a systematic approach to the environmental assessment of waste prevention activities (WPAs), covering the whole life…
Improved sustainability assessment of the G20’s supply chains of materials, fuels, and food
Transparency in global value chains of materials, fuels, and food is critical for the implementation of sustainability policies. Such policies should be led by the G20, who represent more than 80% of global material, fuel, and food consumption. Multi-regional input–output analysis plays an important role for consumption-based assessment, including supply chains and their environmental impacts. However, previous accounting schemes were unable to f…
Methodology and optimization tool for a personalized low environmental impact and healthful diet specific to country and season
To remain within the limits of the planetary boundaries and address increasing disease rates due to poor eating habits, there needs to be a major shift in dietary patterns. The composition of an optimal diet changes depending on location, season, and personalized dietary needs. We develop a methodology to build a 500+ food item, nutrient, and environmental impact database specific to a given country and month, which includes several life cycle st…
Symbiosis opportunities between food and energy system: The potential of manure‐based biogas as heating source for greenhouse production
The concept of symbiosis, a mutually beneficial relationship, can be applied to food and energy systems. Greenhouse systems and biogas plants are interesting technologies for food–energy symbiosis, because both are usually based in rural areas and offer opportunities for the exchange of materials (e.g., biomass waste from the greenhouse as input to biogas plants) and energy (heat from biogas co‐generation for heating greenhouses). In this paper, …
Growing environmental footprint of plastics driven by coal combustion
Research on the environmental impacts from the global value chain of plastics has typically focused on the disposal phase, considered most harmful to the environment and human health. However, the production of plastics is also responsible for substantial environmental, health and socioeconomic impacts. We show that the carbon and particulate-matter-related health footprint of plastics has doubled since 1995, due mainly to growth in plastics prod…
Bending the curve of terrestrial biodiversity needs an integrated strategy
Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity3; however, just feeding the growing human population will make this a challenge4. Here we use an ensemble of land-use and biodiversity models to assess whether—and how—humanity can reverse the declines in terrestrial biodive…
Lc‐impact: A regionalized life cycle damage assessment method
Life cycle impact assessment (LCIA) is a lively field of research, and data and models are continuously improved in terms of impact pathways covered, reliability, and spatial detail. However, many of these advancements are scattered throughout the scientific literature, making it difficult for practitioners to apply the new models. Here, we present the LC-IMPACT method that provides characterization factors at the damage level for 11 impact categ…
Machine learning based modeling of households: A regionalized bottom‐up approach to investigate consumption‐induced environmental impacts
As major drivers of economy, households induce a large share of worldwide environmental impacts. The variability of local consumption patterns and associated environmental impacts needs to be quantified as an important starting point to devise targeted measures aimed at reducing household environmental footprints. The goal of this article is the development and appraisal of a comprehensive regionalized bottom‐up model that assesses realistic envi…
Tracking Construction Material over Space and Time: Prospective and Geo‐referenced Modeling of Building Stocks and Construction Material Flows
Construction material plays an increasingly important role in the environmental impacts of buildings. In order to investigate impacts of materials on a building level, we present a bottom‐up building stock model that uses three‐dimensional and geo‐referenced building data to determine volumetric information of material stocks in Swiss residential buildings. We used a probabilistic modeling approach to calculate future material flows for the indiv…
Noise footprint from personal land‐based mobility
A large part of the world population is exposed to noise levels that are unhealthy. Yet noise is often neglected when impact assessment studies are conducted and when policy interventions are designed. In this study, we provide a way to calculate the noise footprint of citizens directly determined by their use of private and public transport on land. The study combines the results of the large transport simulation model MATSim applied to Switzerl…
Global emission hotspots of coal power generation
Greenhouse Gas Emissions Quantification and Reduction Efforts in a Rural Municipality
The present article aims to determine the current carbon footprint (CF) of Zernez, a Swiss mountain village, and to identify reduction potentials of greenhouse gas (GHG) emissions. For this purpose, material and energy flows were assessed mainly based on detailed household surveys, interviews, and energy bills, but also by means of other information sources, for example, national statistics, traffic censuses, and literature values. To set up the …
Do We Have the Right Performance Indicators for the Circular Economy: Insight into the Swiss Waste Management System
A material flow analysis of the 2012 Swiss waste management system is presented, highlighting the material content available from waste. Half of municipal solid waste (MSW) is materially recycled and the other half thermally treated with energy recovery. A key component of an industrial ecosystem is increasing the resource efficiency through circulating materials. Recycling rates (RRs), an indicator for the circulating behavior of materials, are …
Let's Be Clear(er) about Substitution: A Reporting Framework to Account for Product Displacement in Life Cycle Assessment
The multifunctional character of resource recovery in waste management systems is commonly addressed through system expansion/substitution in life cycle assessment (LCA). Avoided burdens credited based on expected displacement of other product systems can dominate the overall results, making the underlying assumptions particularly important for the interpretation and recommendations. Substitution modeling, however, is often poorly motivated or in…
Influence of Input‐Scrap Quality on the Environmental Impact of Secondary Steel Production
In electric arc furnaces (EAFs), different grades of steel scrap are combined to produce the targeted carbon steel quality. The goal of this study is to assess the influence of scrap quality on the recycling process and on the final product by investigating the effect of the scrap mix composition, and other inputs, for example, preheating energy, on the electricity demand of the melting process. A large industrial data set (empirical data set of …
Assessing Space Heating Demandon a Regional Level: Evaluation of a Bottom‐Up Model in the Scope of a Case Study
The residential sector constitutes a major energy consumer, particularly on account of its needs for space heating. Offering a high leverage potential, this sector is a suitable starting point for greenhouse gas mitigation policies. By providing predictions of the energy demand of building stocks, bottom‐up building energy models represent a first step toward deriving strategies for abatement of detrimental effects related to housing energy use. …
Life Cycle Impacts and Benefits of Wood along the Value Chain: The Case of Switzerland
Sustainable use of wood may contribute to coping with energy and material resource challenges. The goal of this study is to increase knowledge of the environmental effects of wood use by analyzing the complete value chain of all wooden goods produced or consumed in Switzerland. We start from a material flow analysis of current wood use in Switzerland. Environmental impacts related to the material flows are evaluated using life cycle assessment–ba…
Growing environmental footprint of plastics driven by coal combustion
Research on the environmental impacts from the global value chain of plastics has typically focused on the disposal phase, considered most harmful to the environment and human health. However, the production of plastics is also responsible for substantial environmental, health and socioeconomic impacts. We show that the carbon and particulate-matter-related health footprint of plastics has doubled since 1995, due mainly to growth in plastics prod…
Ecological footprint accounting in the life cycle assessment of products
Biodiversity impacts of recent land-use change driven by increases in agri-food imports
Land-use change such as the conversion of natural habitat to agricultural land has been a major driver of global biodiversity loss, prompting efforts at biodiversity restoration. However, restoration measures in certain areas can shift the detrimental biodiversity impacts elsewhere through the outsourcing of agri-food supply chains to biodiverse regions. This study examines the link between biodiversity impacts from land-use change and shifts in …
Global emission hotspots of coal power generation
The ecoinvent Database: Overview and Methodological Framework (7 pp)
Assessing the Eco‐efficiency of End‐of‐Pipe Technologies with the Environmental Cost Efficiency Indicator
The concept of eco‐efficiency is increasingly being applied to judge the combined environmental and economic performance of product systems, processes, and/or companies. Ecoefficiency is often defined as the ratio of economic value added to environmental impact added. This definition is not appropriate for end‐of‐pipe treatment technologies because these technologies aim at improving the environmental performance of technical processes at the cos…
Environmental Assessment of Waste‐Solvent Treatment Options
The software tool ecosolvent is presented that allows for comparative environmental assessment of treatment technologies for specific, user‐defined, waste‐solvent mixtures. The tool is composed of models for waste‐solvent distillation as well as for thermal treatment in hazardous waste‐solvent incinerators and cement kilns. It was designed with a tiered structure in order to allow for a high flexibility regarding informational needs. The life‐cyc…
Ecological footprint accounting in the life cycle assessment of products
Environmental Assessment of Waste‐Solvent Treatment Options: Part II: General Rules of Thumb and Specific Recommendations
A comparison of various waste‐solvent treatment technologies, such as distillation (rectification) and incineration in hazardous‐waste‐solvent incinerators and cement kilns, is presented for 45 solvents with respect to the environmental life‐cycle impact. The environmental impact was calculated with the ecosolvent tool that was previously described in Part I of this work. A comprehensive sensitivity analysis was performed, and uncertainties were …
Assessing the Environmental Impacts of Freshwater Consumption in LCA
A method for assessing the environmental impacts of freshwater consumption was developed. This method considers damages to three areas of protection: human health, ecosystem quality, and resources. The method can be used within most existing life-cycle impact assessment (LCIA) methods. The relative importance of water consumption was analyzed by integrating the method into the Eco-indicator-99 LCIA method. The relative impact of water consumption…
Recent developments in Life Cycle Assessment
The Environmental Importance of Energy Use in Chemical Production
Assessing the Environmental Impact of Water Consumption by Energy Crops Grown in Spain
The environmental impact of the water consumption of four typical crop rotations grown in Spain, including energy crops, was analyzed and compared against Spanish agricultural and natural reference situations. The life cycle assessment (LCA) methodology was used for the assessment of the potential environmental impact of blue water (withdrawal from water bodies) and green water (uptake of soil moisture) consumption. The latter has so far been dis…
Life Cycle Assessment Model for the Use of Alternative Resources in Ironmaking
The iron and steel industry represents an important case for industrial ecology due to its ability to accept waste‐derived inputs and due to the generation of useful by‐products. With the objective of supporting environmentally conscious decisions regarding resource use and waste management, a life cycle assessment (LCA) tool for ironmaking was developed. The tool combines mass flow‐based process models with an LCA database to assess the use of a…
Emerging approaches, challenges and opportunities in life cycle assessment
In the modern economy, international value chains—production, use, and disposal of goods—have global environmental impacts. Life Cycle Assessment (LCA) aims to track these impacts and assess them from a systems perspective, identifying strategies for improvement without burden shifting. We review recent developments in LCA, including existing and emerging applications aimed at supporting environmentally informed decisions in policy-making, produc…
Scaling Relationships in Life Cycle Assessment: The Case of Heat Production from Biomass and Heat Pumps
Life cycle assessment (LCA) studies include a vast amount of different products. Often, extrapolations are necessary to obtain the life cycle inventory of a specific product. This article provides quantitative scaling factors with power (heat output) for product properties and life cycle impact assessment results of heat pump and biomass furnace technologies. Included in the study are 508 heat pumps and furnaces with differences in power over thr…
Life Cycle Environmental and Natural Resource Implications of Energy Efficiency Technologies
Pay the farmer, or buy the land?—Cost-effectiveness of payments for ecosystem services versus land purchases or easements in Central Kenya
Do We Have the Right Performance Indicators for the Circular Economy: Insight into the Swiss Waste Management System
A material flow analysis of the 2012 Swiss waste management system is presented, highlighting the material content available from waste. Half of municipal solid waste (MSW) is materially recycled and the other half thermally treated with energy recovery. A key component of an industrial ecosystem is increasing the resource efficiency through circulating materials. Recycling rates (RRs), an indicator for the circulating behavior of materials, are …
Let's Be Clear(er) about Substitution: A Reporting Framework to Account for Product Displacement in Life Cycle Assessment
The multifunctional character of resource recovery in waste management systems is commonly addressed through system expansion/substitution in life cycle assessment (LCA). Avoided burdens credited based on expected displacement of other product systems can dominate the overall results, making the underlying assumptions particularly important for the interpretation and recommendations. Substitution modeling, however, is often poorly motivated or in…
Influence of Input‐Scrap Quality on the Environmental Impact of Secondary Steel Production
In electric arc furnaces (EAFs), different grades of steel scrap are combined to produce the targeted carbon steel quality. The goal of this study is to assess the influence of scrap quality on the recycling process and on the final product by investigating the effect of the scrap mix composition, and other inputs, for example, preheating energy, on the electricity demand of the melting process. A large industrial data set (empirical data set of …
Assessing Space Heating Demandon a Regional Level: Evaluation of a Bottom‐Up Model in the Scope of a Case Study
The residential sector constitutes a major energy consumer, particularly on account of its needs for space heating. Offering a high leverage potential, this sector is a suitable starting point for greenhouse gas mitigation policies. By providing predictions of the energy demand of building stocks, bottom‐up building energy models represent a first step toward deriving strategies for abatement of detrimental effects related to housing energy use. …
Life Cycle Impacts and Benefits of Wood along the Value Chain: The Case of Switzerland
Sustainable use of wood may contribute to coping with energy and material resource challenges. The goal of this study is to increase knowledge of the environmental effects of wood use by analyzing the complete value chain of all wooden goods produced or consumed in Switzerland. We start from a material flow analysis of current wood use in Switzerland. Environmental impacts related to the material flows are evaluated using life cycle assessment–ba…
Greenhouse Gas Emissions Quantification and Reduction Efforts in a Rural Municipality
The present article aims to determine the current carbon footprint (CF) of Zernez, a Swiss mountain village, and to identify reduction potentials of greenhouse gas (GHG) emissions. For this purpose, material and energy flows were assessed mainly based on detailed household surveys, interviews, and energy bills, but also by means of other information sources, for example, national statistics, traffic censuses, and literature values. To set up the …
Tracking Construction Material over Space and Time: Prospective and Geo‐referenced Modeling of Building Stocks and Construction Material Flows
Construction material plays an increasingly important role in the environmental impacts of buildings. In order to investigate impacts of materials on a building level, we present a bottom‐up building stock model that uses three‐dimensional and geo‐referenced building data to determine volumetric information of material stocks in Swiss residential buildings. We used a probabilistic modeling approach to calculate future material flows for the indiv…
Noise footprint from personal land‐based mobility
A large part of the world population is exposed to noise levels that are unhealthy. Yet noise is often neglected when impact assessment studies are conducted and when policy interventions are designed. In this study, we provide a way to calculate the noise footprint of citizens directly determined by their use of private and public transport on land. The study combines the results of the large transport simulation model MATSim applied to Switzerl…
Global emission hotspots of coal power generation
Bending the curve of terrestrial biodiversity needs an integrated strategy
Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity3; however, just feeding the growing human population will make this a challenge4. Here we use an ensemble of land-use and biodiversity models to assess whether—and how—humanity can reverse the declines in terrestrial biodive…
Lc‐impact: A regionalized life cycle damage assessment method
Life cycle impact assessment (LCIA) is a lively field of research, and data and models are continuously improved in terms of impact pathways covered, reliability, and spatial detail. However, many of these advancements are scattered throughout the scientific literature, making it difficult for practitioners to apply the new models. Here, we present the LC-IMPACT method that provides characterization factors at the damage level for 11 impact categ…
Environmental Science (27 works) · Economics (25 works) · Environmental Impact and Sustainability (25 works) · Engineering (24 works) · Life-cycle assessment (19 works) · Ecology (17 works) · Waste management (17 works) · Computer Science (16 works) · Business (15 works) · Environmental economics (15 works)