Comparing urban food system characteristics and actions in US and Indian cities from a multi‐environmental impact perspective: Toward a streamlined approach

Food action plans in many global cities articulate interest in multiple objectives including reducing in‐ and trans‐boundary environmental impacts (water, land, greenhouse gas (GHG)). However, there exist few standardized analytical tools to compare food system characteristics and actions across cities and countries to assess trade‐offs between multiple objectives (i.e., health, equity) with environmental outcomes. This paper demonstrates a streamlined model applied for analysis of four cities with varying characteristics across the United States and India, to quantify system‐wide water, energy/GHG, and land impacts associated with multiple food system actions to address health, equity, and environment. Baseline diet analysis finds key differences between countries in terms of meat consumption (Delhi 4; Pondicherry 16; United States 59, kg/capita/year), and environmental impact of processing of the average diet (21%, 19%, <1%, <1% of community‐wide GHG‐emissions for New York, Minneapolis, Delhi, and Pondicherry). Analysis of supply chains finds city average distance (food‐miles) varies (Delhi 420; Pondicherry 200; United States average 1,640 km/t‐food) and the sensitivity of GHG emissions of food demand to spatial variability of energy intensity of irrigation is greater in Indian than US cities. Analysis also finds greater pre‐consumer waste in India versus larger post‐consumer accumulations in the United States. Despite these differences in food system characteristics, food waste management and diet change consistently emerge as key strategies. Among diet scenarios, all vegetarian diets are not found equal in terms of environmental benefit, with the US Government's recommended vegetarian diet resulting in less benefit than other more focused targeted diet changes.     

Life Cycle Energy Assessment of Alternative Water Supply Systems (9 pp)

Goal, Scope and Background This paper discusses the merging of methodological aspects of two known methods into a hybrid on an application basis. Water shortages are imminent due to scarce supply and increasing demand in many parts of the world. In California, this is caused primarily by population growth. As readily available water is depleted, alternatives that may have larger energy and resource requirements and, therefore, environmental impacts must be considered. In order to develop a more environmentally responsible and sustainable water supply system, these environmental implications should be incorporated into planning decisions. Methods Comprehensive accounting for environmental effects requires life cycle assessment (LCA), a systematic account of resource use and environmental emissions caused by extracting raw materials, manufacturing, constructing, operating, maintaining, and decommissioning the water infrastructure. In this study, a hybrid LCA approach, combining elements of process-based and economic input-output-based LCA was used to compare three supply alternatives: importing, recycling, and desalinating water. For all three options, energy use and air emissions associated with energy generation, vehicle and equipment operation, and material production were quantified for life-cycle phases and water supply functions (supply, treatment, and distribution). The Water-Energy Sustainability Tool was developed to inform water planning decisions. It was used to evaluate the systems of a Northern and a Southern California water utility. Results and Discussion The results showed that for the two case study utilities desalination had 2–5 times larger energy demand and caused 2–18 times more emissions than importation or recycling, due primarily to the energy-intensity of the treatment process. The operation life-cycle phase created the most energy consumption with 56% to 90% for all sources and case studies. For each water source, a different life-cycle phase dominated energy consumption. For imported water, supply contributed 56% and 86% of the results for each case study; for desalination, treatment accounted for approximately 85%; for recycled water, distribution dominated with 61% and 74% of energy use. The study calculated external costs of air pollution from all three water supply systems. These costs are borne by society, but not paid by producers. The external costs were found to be 6% of desalinated water production costs for both case studies, 8% of imported water production costs in Southern California, and 1–2% for the recycled water systems and for the Northern California utility's imported water system. Conclusion Recycling water was found to be more energy intensive in Northern than in Southern California, but the results for imported water were similar. While the energy demand of water recycling was found to be larger than importation in Northern California, the two alternatives were competitive in Southern California. For all alternatives in both case studies, the energy consumed by system operation dominated the results, but maintenance was also found to be significant. Energy production was found to be the largest contributor in all water provision systems, followed by materials production. The assessment of external costs revealed that the environmental effects of energy and air emissions caused by infrastructure is measurable, and in some cases, significant relative to the economic cost of water. Recommendation and Perspective This paper advocates the necessity of LCA in water planning, and discusses the applicability of the described model to water utilities.     

Trade‐offs across productivity,GHG intensity,and pollutant loads from second‐generation sorghum bioenergy

Greenhouse gas (GHG) intensity is frequently used to assess the mitigation potential of biofuels; however, failure to quantify other environmental impacts may result in unintended consequences, effectively shifting the environmental burden of fuel production rather than reducing it. We modeled production of E₈₅, a gasoline/ethanol blend, from forage sorghum (Sorghum bicolor cv. photoperiod LS) grown, processed, and consumed in California's Imperial Valley in order to evaluate the influence of nitrogen (N) management on well‐to‐wheel (WTW) environmental impacts from cellulosic ethanol. We simulated 25 N management scenarios varying application rate, application method, and N source. Life cycle environmental impacts were characterized using the EPA's criteria for emissions affecting the environment and human health. Our results suggest efficient use of N is an important pathway for minimizing WTW emissions on an energy yield basis. Simulations in which N was injected had the highest nitrogen use efficiency. Even at rates as high as 450 kg N ha^?1, injected N simulations generated a yield response sufficient to outweigh accompanying increases in most N‐induced emissions on an energy yield basis. Thus, within the biofuel life cycle, trade‐offs across productivity, GHG intensity, and pollutant loads may be possible to avoid at regional to global scales. However, trade‐offs were seemingly unavoidable when impacts from E₈₅ were compared to those of conventional gasoline. The GHG intensity of sorghum‐derived E₈₅ ranged from 29 to 44 g CO₂ eq MJ^?1, roughly 1/3 to 1/2 that of gasoline. Conversely, emissions contributing to local air and water pollution tended to be substantially higher in the E₈₅ life cycle. These adverse impacts were strongly influenced by N management and could be partially mitigated by efficient application of N fertilizers. Together, our results emphasize the importance of minimizing on‐farm emissions in maximizing both the environmental benefits and profitability of biofuels.     

Environmental assessment of sewage effluent disinfection system: electron beam, ultraviolet, and ozone using life cycle assessment

Purpose

This study assesses the impacts of three different disinfection processes of sewage effluent, namely the electron beam (E-beam), ultraviolet (UV), and ozone systems, on the environment by using life cycle assessment (LCA).

Methods

The LCA employed was the comparative LCA which consists of three parts according to life cycle stages. Electricity consumption was the reference flow that can yield 99% disinfection efficiency for microorganisms present in a 1?×?10⁵?m³?day^?1 sewage treatment plant effluent over 20?years.

Results

The comparison of the LCA results indicated that the environmental impact of the UV disinfection system was the lowest, followed by the E-beam and ozone disinfection systems. The key issues of the E-beam, UV, and ozone disinfection systems are electricity consumption and SF₆ usage, electricity consumption and UV lamp, and electricity consumption and liquid oxygen feeding system, respectively.

Conclusions

Electricity consumption is the key input parameter that determines the LCA results.     

Strategies and Practices for Sustainable Use of Water in Industrial Papermaking Processes

The problem of water use in industrial sectors is analyzed in the context of sustainability, and the manufacturing process as one of the most important water consumers is scrutinized. Some practices of water conservation and reduction of water consumption, as well as the implementation of advanced treatment processes for wastewater recycling are considered under the general aspect of process integration and control in order to minimize environmental discharges. Reduction of effluents in papermaking processes are discussed as well as preventative approaches. It is emphasized that four groups of methods can be applied in order to minimize water consumption: process changes, water reuse, regeneration reuse and regeneration recycling. Minimizing the water consumption and thus reducing the hydraulic load may help to improve effluent treatment, reduce operating costs and, when subsequent disposal is to sewers, minimize effluent disposal charges. The data presented show that initially producing less effluents will reduce the demands on the effluent treatment plant and thus save both money and efforts. Separation techniques for minimizing effluents and effluent loads are presented, as well as potential practices to ensure a sustainable use of water, grouped as short term and long term measures. Prevention measures for water consumption in a Romanian paper mill are considered and discussed in relation with best available techniques (BAT), taking into account both economical and environmental benefits.     

Dry Matter Losses and Methane Emissions During Wood Chip Storage: the Impact on Full Life Cycle Greenhouse Gas Savings of Short Rotation Coppice Willow for Heat

A life cycle assessment (LCA) approach was used to examine the greenhouse gas (GHG) emissions and energy balance of short rotation coppice (SRC) willow for heat production. The modelled supply chain includes cutting multiplication, site establishment, maintenance, harvesting, storage, transport and combustion. The relative impacts of dry matter losses and methane emissions from chip storage were examined from a LCA perspective, comparing the GHG emissions from the SRC supply chain with those of natural gas for heat generation. The results show that SRC generally provides very high GHG emission savings of over 90 %. The LCA model estimates that a 1, 10 and 20 % loss of dry matter during storage causes a 1, 6 and 11 % increase in GHG emissions per MWh. The GHG emission results are extremely sensitive to emissions of methane from the wood chip stack: If 1 % of the carbon within the stack undergoes anaerobic decomposition to methane, then the GHG emissions per MWh are tripled. There are some uncertainties in the LCA results, regarding the true formation of methane in wood chip stacks, non-CO₂ emissions from combustion, N₂O emissions from leaf fall and the extent of carbon sequestered under the crop, and these all contribute a large proportion of the life cycle GHG emissions from cultivation of the crop.     

Determination of GHG contributions by subsystems in the oil palm supply chain using the LCA approach

Purpose  

With increasing attention on sustainable development, the environmental and social relevance of palm oil production are now important trade issues. The life cycle assessment (LCA) study of Malaysian oil palm products from mineral soils including palm biodiesel was aimed to provide baseline information on the environmental performance of the industry for drawing up policies pertaining to the sustainable production. The share of greenhouse gas (GHG) contribution by the various subsystems in the oil palm supply chain is considered here.     

Life Cycle Assessment of End‐of‐Life Management Options for Construction and Demolition Debris

A life cycle assessment (LCA) of various end‐of‐life management options for construction and demolition (C&D) debris was conducted using the U.S. Environmental Protection Agency's Municipal Solid Waste Decision Support Tool. A comparative LCA evaluated seven different management scenarios using the annual production of C&D debris in New Hampshire as the functional unit. Each scenario encompassed C&D debris transport, processing, separation, and recycling, as well as varying end‐of‐life management options for the C&D debris (e.g., combustion to generate electricity versus landfilling for the wood debris stream and recycling versus landfilling for the nonwood debris stream) and different bases for the electricity generation offsets (e.g., the northeastern U.S. power grid versus coal‐fired power generation). A sensitivity analysis was also conducted by varying the energy content of the C&D wood debris and by examining the impact of basing the energy offsets on electricity generated from various fossil fuels. The results include impacts for greenhouse gas (GHG) emissions, criteria air pollutants, ancillary solid waste production, and organic and inorganic constituents in water emissions. Scenarios with nonwood C&D debris recycling coupled with combustion of C&D wood debris to generate electricity had lower impacts than other scenarios. The nonwood C&D debris recycling scenarios where C&D wood debris was landfilled resulted in less overall impact than the scenarios where all C&D debris was landfilled. The lowest impact scenario included nonwood C&D debris recycling with local combustion of the C&D wood debris to generate electricity, providing a net gain in energy production of more than 7 trillion British thermal units (BTU) per year and a 130,000 tons per year reduction in GHG emissions. The sensitivity analysis revealed that for energy consumption, the model is sensitive to the energy content of the C&D wood debris but insensitive to the basis for the energy offset, and the opposite is true for GHG emissions.     

The impacts of Japanese food losses and food waste on global natural resources and greenhouse gas emissions

Japan depends heavily on imports for its food supply. Since 2000, the food self‐sufficiency ratio has remained approximately 40% on a caloric basis. Japanese food wastage (i.e., food losses and food waste) is estimated to have been 6.42 million tonnes (50 kg per capita of wastage) in 2012. These values indicate that food wastage leads to wasted natural resources and excessive greenhouse gas (GHG) emissions both in Japan and in countries that export to Japan. This study estimates Japanese food wastage by food item to evaluate impacts on land and water resources and global GHG emissions during the processing, distribution, and consumption phases of the food supply chain while also considering the feed crops needed for livestock production. Despite uncertainties due to data limitations, in 2012, 1.23 million hectares of harvested land were used to produce food that was eventually wasted, and 413 million m³ of water resources were wasted due to Japanese food wastage in agricultural production. Furthermore, unnecessary GHG emissions were 3.51 million tonnes of CO₂ eq. in agricultural production and 0.49 million tonnes of CO₂ eq. in international transportation. The outcomes of the present study can be used to develop countermeasures to food wastage in industrializing Asian countries where food imports are projected to increase and food wastage issues in the consumption stage are expected to become as serious as they currently are in Japan.     

An integrative modeling framework to evaluate the productivity and sustainability of biofuel crop production systems

The potential expansion of biofuel production raises food, energy, and environmental challenges that require careful assessment of the impact of biofuel production on greenhouse gas (GHG) emissions, soil erosion, nutrient loading, and water quality. In this study, we describe a spatially explicit integrative modeling framework (SEIMF) to understand and quantify the environmental impacts of different biomass cropping systems. This SEIMF consists of three major components: (1) a geographic information system (GIS)‐based data analysis system to define spatial modeling units with resolution of 56 m to address spatial variability, (2) the biophysical and biogeochemical model Environmental Policy Integrated Climate (EPIC) applied in a spatially‐explicit way to predict biomass yield, GHG emissions, and other environmental impacts of different biofuel crops production systems, and (3) an evolutionary multiobjective optimization algorithm for exploring the trade‐offs between biofuel energy production and unintended ecosystem‐service responses. Simple examples illustrate the major functions of the SEIMF when applied to a nine‐county Regional Intensive Modeling Area (RIMA) in SW Michigan to (1) simulate biofuel crop production, (2) compare impacts of management practices and local ecosystem settings, and (3) optimize the spatial configuration of different biofuel production systems by balancing energy production and other ecosystem‐service variables. Potential applications of the SEIMF to support life cycle analysis and provide information on biodiversity evaluation and marginal‐land identification are also discussed. The SEIMF developed in this study is expected to provide a useful tool for scientists and decision makers to understand sustainability issues associated with the production of biofuels at local, regional, and national scales.     

Benchmarking environmental performance of electric insulator supply chain in India using life cycle assessment

Purpose

This study aims at finding the environmental impacts generated by an electric disk insulator supply chain, used for the distribution of electricity by an open wire system, through a case study. This study also aims at benchmarking the environmental impacts of an electric insulator manufacturing process by taking ideal condition of zero waste as reference.

Methods

Cradle-to-grave life cycle assessment (LCA) has been carried out by following the guidelines provided in ISO 14040 series standards and using Umberto NXT software. ReCiPe endpoint and ReCiPe midpoint impact assessment methodologies have been used to calculate environmental impacts under various categories. The primary data has been collected from a medium-scale manufacturer of electric disk insulators located at Bikaner in north-west India. The secondary data has been taken from ecoinvent 3.0 database and literature. The environmental impacts using endpoint assessment (ecosystem quality, human health, and resources) and midpoint assessment (climate change, fossil depletion, human toxicity, metal depletion, ozone depletion, terrestrial acidification, and water depletion) categories have been computed. Finally, the results are compared and benchmarked against the ideal zero waste condition using three different production scenarios. The limitation of this study is that the data has been collected only from one manufacturer and its supply chain.

Results and discussion

It has been found that the use of steel, electricity, and fuel; transportation of product; and disposal of water generate high environmental impacts in the supply chain. It has also been found that in the electric disk insulator supply chain, the raw material extraction phase has the highest environmental impacts followed by manufacturing, disposal, transportation, and installation phases. This study has also found that benchmark scenario “B” (zero waste condition) is environmentally more efficient in comparison to scenario “A” (actual recycling condition) and scenario “C” (maximum waste condition).

Conclusions

This study has identified that raw materials, resources, and processes in the supply chain of an electric disk insulator manufacturing unit are responsible for the environmental damage. The various manufacturing processes and installation of the electric disk insulators are similar for all manufacturers except the machinery efficiency and the generated waste. This study provides environmental impacts associated with an electric disk insulator manufacturing process under zero waste or ideal conditions (scenario B). These results are used as a benchmark to compare environmental performance of electric disk insulator supply chain operating under actual conditions.

     

Life cycle analysis of biochemical cellulosic ethanol under multiple scenarios

Cellulosic ethanol is widely believed to offer substantial environmental advantages over petroleum fuels and grain‐based ethanol, particularly in reducing greenhouse gas emissions from transportation. The environmental impacts of biofuels are largely caused by precombustion activities, feedstock production and conversion facility operations. Life cycle analysis (LCA) is required to understand these impacts. This article describes a field‐to‐blending terminal LCA of cellulosic ethanol produced by biochemical conversion (hydrolysis and fermentation) using corn stover or switchgrass as feedstock. This LCA develops unique models for most elements of the biofuel production process and assigns environmental impact to different phases of production. More than 30 scenarios are evaluated, reflecting a range of feedstock, technology and scale options for near‐term and future facilities. Cellulosic ethanol, as modeled here, has the potential to significantly reduce greenhouse gas (GHG) emissions compared to petroleum‐based liquid transportation fuels, though substantial uncertainty exists. Most of the conservative scenarios estimate GHG emissions of approximately 45–60 g carbon dioxide equivalent per MJ of delivered fuel (g CO₂e MJ^?1) without credit for coproducts, and 20–30 g CO₂e MJ^?1 when coproducts are considered. Under most scenarios, feedstock production, grinding and transport dominate the total GHG footprint. The most optimistic scenarios include sequestration of carbon in soil and have GHG emissions below zero g CO₂e MJ^?1, while the most pessimistic have life‐cycle GHG emissions higher than petroleum gasoline. Soil carbon changes are the greatest source of uncertainty, dominating all other sources of GHG emissions at the upper bound of their uncertainty. Many LCAs of biofuels are narrowly constrained to GHG emissions and energy; however, these narrow assessments may miss important environmental impacts. To ensure a more holistic assessment of environmental performance, a complete life cycle inventory, with over 1100 tracked material and energy flows for each scenario is provided in the online supplementary material for this article.     

Life cycle environmental and economic impact of a food waste recycling-farming system: a case study of organic vegetable farming in Japan

Purpose

Bio-based recycling systems and agricultural production using recycled materials are often evaluated separately. This study performs an environmental and socio-economic life cycle assessment (LCA) of a food waste treatment and spinach farming system in Japan. The environmental and economic tradeoffs of introducing a recycling system and the net environmental benefit of the substitution of market fertilizer considering operation changes are also examined.

Methods

Three scenarios were developed and compared. In the conventional (CV) scenario, food waste is collected, incinerated, and disposed of in landfill, and the farmer uses market organic fertilizer. The on-site composting (OC) scenario processes food waste using an on-site garbage disposer and transports compost to a nearby spinach farmer. Food waste in the centralized composting (CC) scenario is transported to a centralized composting facility and resultant compost is sent to the farm. Primary data were obtained from field experiments and interviews. Non-greenhouse gas (GHG) emissions from the field and nitrogen leaching to water systems were simulated using the denitrification–decomposition (DNDC) model.

The environmental LCA targeted climate change, eutrophication, and waste landfill. An input–output analysis estimated socio-economic indicators, namely gross added value and employment inducement effect.

Results and discussion

The scenario with the lowest impact is the CC scenario. Climate change and eutrophication impacts are highest in the OC scenario and waste landfill impacts are most significant in the CV scenario. The weighted impact by LIME2 can be reduced by 47% in the CC scenario and 17% in the OC scenario due to the recycling of food waste instead of dumping in the landfill. The difference in socio-economic indicators between the scenarios was relatively small, although the CV scenario encouraged more employment. The substitution effect of composting, as well as the environmental impact reduction of replacing market organic fertilizer with compost, will result in 28.7% of the avoided impacts in GHG emissions.

Conclusions

Both composting scenarios are feasible from an environmental and socio-economic perspective when compared with conventional organic production, although there is a tradeoff between waste landfill and GHG emissions for the on-site composting system. However, the OC scenario needs to save electricity to improve its environmental competitiveness with the CV scenario. When considering the substitution effect of composting, it is recommended to take into account that agricultural operation also changes.

     

ONE TWO WE—life cycle management in canteens together with suppliers,customers and guests

Purpose

Private food consumption accounts for 30 % of total environmental impacts caused by the final consumption of Swiss households. The private expenses for gastronomy and hotels account for another 6 %. Therefore, it is necessary to investigate and better understand the environmental impacts of food consumption and the possibilities for a reduction of these impacts. This was the starting point for the collaboration between the canteen operator SV Group, the life cycle assessment (LCA) consultancy ESU-services, the energy supplier ewz and the World Wide Fund for Nature (WWF) in Switzerland focusing on food consumption in canteens.

Methods

In a first step, an LCA study was used to analyse the environmental impacts of about 20 million meals served in 240 canteens in 2011. LCA data for 160 food items were linked to the food amounts of about 10,000 articles purchased in this year. This was supplemented by data on canteen operation and resulted in a full organisational LCA.

Results and discussion

The impacts of food purchases are about four times higher than the direct impacts due to the operation of the canteens. The most important product groups are meat and dairy products. Improvement potentials have been identified within 14 different themes by the project group. They include measures in the canteen operation (e.g. reduction of food waste or energy-efficient appliances); measures in the supply chain, e.g. a reduction of vegetables grown in heated greenhouses; or the abandonment of air-transported products. But also dietary choices such as a reduction of the average amount of meat per meal are considered as an option. The results and recommendations of the detailed LCA as well as information by other partners have been used by the SV Group to develop the programme ONE TWO WE. It assists the customers (companies who commission the operation of canteens in their premises) to reach improved levels of environmental performance. The programme aims for a 20 % cut on GHG emissions after full implementation in the participating canteens.

Conclusions

The programme started successfully with many customers positively convinced by the proposed changes in the provision of canteen meals. An initial reduction of greenhouse gas emissions compared to the baseline was achieved. This LCA study is a good example for the value of calculating a full organisational environmental footprint for a company in the gastronomy sector and for using the results of such a study to bring down the overall environmental impacts.

     

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 disregarded in LCA. To account for green water, two approaches have been applied: the first accounts for the difference in green water demand of the crops and a reference situation. The second is a green water scarcity index, which measures the fraction of the soil‐water plant consumption to the available green water. Our results show that, if the aim is to minimize the environmental impacts of water consumption, the energy crop rotations assessed in this study were most suitable in basins in the northeast of Spain. In contrast, the energy crops grown in basins in the southeast of Spain were associated with the greatest environmental impacts. Further research into the integration of quantitative green water assessment in LCA is crucial in studies of systems with a high dependence on green water resources.     

Overcoming climate change adaptation barriers: A study on food–energy–water impacts of the average American diet by demographic group

Effectively adapting to climate change involves overcoming social and ecological system barriers. The present study uses a three‐phase adaptation framework to propose adaptation strategies aimed at overcoming socioecological barriers of the food–energy–water (FEW) nexus. Cradle‐to‐farm‐gate land, greenhouse gas (GHG), and water impacts—that derive from food consumption in the United States—are analyzed and differentiated by major demographic groups (Black, Latinx, and White). Results indicate that the White demographic yields the highest per capita GHG (680 kg of CO₂ eq?year^?1) and water impacts (328,600 L?year^?1) from food consumption, whereas the Black demographic yields the highest per capita land impacts (1,770 m²?year^?1) from food consumption. Our findings suggest that obtaining data with the intention of building consensus across sociodemographic lines overcomes barriers in the understanding phase, leading to increased social receptivity for many planning and managing phase processes. Specifically, we find that identifying and developing leaders who possess the cognitive and interpersonal capacity to manage many variables and stakeholders is key to assessing and selecting adaptation options in the planning phase. We also propose using government programming to encourage environmentally friendly food purchasing behavior. Then, we discuss how our proposals could be used in adaptation feasibility and evaluation activities in the managing phase. In all, these findings facilitate the development of improved climate change adaptation and policy by satisfying the understanding phase of the climate change adaptation framework, establishing a cross‐disciplinary methodological approach to addressing socioecological problems, and providing useful FEW impact data for FEW nexus and climate change researchers.     

The assessment of the relevance of building components and life phases for the environmental profile of nearly zero-energy buildings: life cycle assessment of a multifamily building in Italy

Purpose

Since the construction sector is a considerable energy consumer and greenhouse gas (GHG) producer, the EU rules strive to build nearly zero-energy buildings, by reducing the operative energy and yearning for on-site energy production. This article underlines the necessity to go beyond the energy evaluations and move towards the environmental assessment in a life cycle perspective, by comparing the impacts due to building materials and energy production devices.

Methods

We compared the operational energy impacts and those of technologies and materials carrying out a life cycle assessment (LCA; ISO 14040, ISO 14044, EN 15643–2, EN 15978) on a nearly zero-energy building (ZEB), a residential complex with 61 apartments in four buildings, situated near Milan (Italy). We consider all life cycle phases, including production, transport, building site activities, use and maintenance; the materials inventory was filled out collecting data from invoices paid, building site reports, construction drawings and product data sheets. To make the assessment results comparable, we set a functional unit of 1 m² of net floor area in 1 year (1 m²y), upon a lifespan of 100 years. The environmental data were acquired from Ecoinvent 2.2.

Results and discussion

The results highlight the important role of the pre-use and maintenance phases in building life so that in a nearly ZEB, the environmental impacts linked to the use are no longer the major proportion: the pre-use phase accounts for 56 %, while the operative energy is only 31 % of the total. For this reason, if the environmental assessment of the case study was shrunk to the operational consumption, only one third of the impacts would be considered. The consumption of non-renewable resources after 100 years are 193,950 GJ (133.5 kWh/m²y); the GHG emissions are 15,300 t (37.8 kg of CO₂?eq/m²y). In the pre-use phase, structures have the major impacts (50 %) and the load of system components is unexpectedly high (12 %) due to the ambition of on-site energy production.

Conclusions

Paying attention to the operative energy consumption seems to address to only one third of the environmental impacts of buildings: the adoption of LCA as a tool to guide the design choices could help to identify the solution which ensures the lowest overall impact on the whole life, balancing the options of reducing the energy requirements, the on-site production from renewable sources and the limitation of the impacts due to building components (simpler and more durable).

     

LCA application to integrated waste management planning in Gipuzkoa (Spain)

Goal, Scope and Background  Gipuzkoa is a department of the Vasque Country (Spain) with a population of about 700,000 people. By the year 2000 approximately 85% of municipal solid waste in this area was managed by landfilling, and only 15% was recycled. Due to environmental law restrictions and landfill capacity being on its limit, a planning process was initiated by the authorities. LCA was used, from an environmental point of view, to assess 7 possible scenarios arising from the draft Plan for the 2016 time horizon. Main Features  In each scenario, 9 waste flows are analysed: rest waste, paper and cardboard, glass containers, light packaging, organic-green waste, as well as industrial/commercial wood, metals and plastics, and wastewater sludge. Waste treatments range from recycling to energy recovery and landfilling. Results  Recycling of the waste flows separated at the source (paper and cardboard, glass, light packaging, organic-green waste, wood packaging, metals and plastics) results in net environmental benefits caused by the substitution of primary materials, except in water consumption. These benefits are common to the 7 different scenarios analysed. However, some inefficiencies are detected, mainly the energy consumption in collection and transport of low density materials, and water consumption in plastic recycling. The remaining flows, mixed waste and wastewater sludge, are the ones causing the major environmental impacts, by means of incineration, landfilling of partially stabilised organic material, as well as thermal drying of sludge. With the characterisation results, none of the seven scenarios can be clearly identified as the most preferable, although, due to the high recycling rates expected by the Plan, net environmental benefits are achieved in 9 out of 10 impact categories in all scenarios when integrated waste management is assessed (the sum of the 9 flows of waste). Finally, there are no relevant differences between scenarios concerning the number of treatment plants considered. Nevertheless, only the effects on transportation impacts were assessed in the LCA, since the plant construction stage was excluded from the system boundaries. Conclusions  The results of the study show the environmental importance of material recycling in waste management, although the recycling schemes assessed can be improved in some aspects. It is also important to highlight the environmental impact of incineration and landfilling of waste, as well as thermal drying of sludge using fossil fuels. One of the main findings of applying LCA to integrated waste management in Gipuzkoa is the fact that the benefits of high recycling rates can compensate for the impacts of mixed waste and wastewater sludge. Recommendations and Outlook  Although none of the scenarios can be clearly identified as the one having the best environmental performance, the authorities in Gipuzkoa now have objective information about the future scenarios, and a multidisciplinary panel could be formed in order to weight the impacts if necessary. In our opinion, LCA was successfully applied in Gipuzkoa as an environmental tool for decision making.     

Regional water resource implications of bioethanol production in the Southeastern United States

The Energy Independence and Security Act (EISA) of 2007 mandates US production of 136 billion L of biofuel by 2022. This target implies an appropriation of regional primary production for dedicated feedstocks at scales that may dramatically affect water supply, exacerbate existing water quality challenges, and force undesirable environmental resource trade offs. Using a comparative life cycle approach, we assess energy balances and water resource implications for four dedicated ethanol feedstocks – corn, sugarcane, sweet sorghum, and southern pine – in two southeastern states, Florida and Georgia, which are a presumed epicenter for future biofuel production. Net energy benefit ratios for ethanol and coproducts range were 1.26 for corn, 1.94 for sweet sorghum, 2.51 for sugarcane, and 2.97 for southern pine. Corn also has high nitrogen (N) and water demand (11.2 kg GJ_net^?1 and 188 m³ GJ_net^?1, respectively) compared with other feedstocks, making it a poor choice for regional ethanol production. Southern pine, in contrast, has relatively low N demand (0.4 kg GJ_net^?1) and negligible irrigation needs. However, it has comparatively low gross productivity, which results in large land area per unit ethanol production (208 m² GJ_net^?1), and, by association, substantial indirect and incremental water use (51 m³ GJ_net^?1). Ultimately, all four feedstocks require substantial land (10.1, 3.1, 2.5, and 6.1 million ha for corn, sugarcane, sweet sorghum, and pine, respectively), annual N fertilization (3230, 574, 396, 109 million kg N) and annual total water (54 400, 20 840, 8840, and 14 970 million m³) resources when scaled up to meet EISA renewable fuel standards production goals. This production would, in turn, offset only 17.5% of regional gasoline consumption on a gross basis, and substantially less when evaluated on a net basis. Utilization of existing waste biomass sources may ameliorate these effects, but does not obviate the need for dedicated primary feedstock production. Careful scrutiny of environmental trade‐offs is necessary before embracing aggressive ethanol production mandates.     

Evaluation of water services system through LCA. A case study for Iasi City,Romania

Purpose

The main objective of this paper is to analyse through life cycle assessment (LCA), the entire water services system in Iasi City (Romania): a representative city for the problems faced by the water services sector in Romania. Furthermore, the study is aimed at demonstrating the usefulness of the LCA approach as a support instrument for water resources management.

Methods

The life cycle inventory (LCI) of the Iasi water system was organized considering the water system components, as well as their function related to the water use life cycle: before the tap system as production phase (water abstraction, transport, treatment and distribution) and after the tap section as post-use phase (wastewater collection, treatment and discharge). The foreground data describing the LCI processes were provided directly by the company operating the Iasi water system, while the data for the background processes were sourced or selected from Ecoinvent 2.0 database. The assessment considers the quantification of environmental impacts (according to the CML 2000 baseline and Ecological Scarcity 2006 methodologies) of water supply (abstraction, treatment and distribution) and wastewater disposal (collection and treatment) relative to 1 m³ of tap water.

Results and discussion

For this given system, the results have pointed out that the before the tap system generates higher impacts than the after tap system, mainly due to the energetic effort needed for water supply and the fairly high water losses in the distribution system. However, the after the tap system, specifically the discharge of treated wastewater is still responsible for many of the water-related impact such as Eutrophication (when using CML) or Emissions to surface waters (when using the Ecological Scarcity method). Apart from the LCA approach, this study presents several scenarios for the improvement of the environmental performance of the water services, such as: changing between water sources, improving the distribution system and upgrading the wastewater treatment plant.

Conclusions

This study has demonstrated the usefulness of LCA to describe, compare and predict the environmental performance of complex water services systems (and all its components). The results have provided a reference case for the environmental profile of Iasi city water system, and have enabled the identification of its improvement alternatives. Also, this study, which represents a premiere for Romania, has opened future research directions which may include the development perspectives of the Iasi water services system, as well as improvements of LCIA methodologies to better represent the local specific water-related impacts.