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Purpose: How to build in more environmentally sustainable manner? This issue is increasingly coming to the fore in construction sector, which is responsible for a relevant share of resource depletion, solid waste, and greenhouse gas (GHG) emissions. Carbon-reinforced concrete (CRC), as a disruptive innovation of composite building material, requires less resources and enables new forms — but does it make CRC more environmentally sustainable than steel-reinforced concrete (SRC)? This article aims to assess and compare the environmental impact of 45 material and production scenarios of a CRC with a SRC double wall. Methods: The life cycle assessment method (LCA) is used to assess environmental impacts. The functional unit is a double wall and the reference flows are 1 m3 for concrete and 1 kg for fiber. CML methodology is used for life cycle impact assessment (LCIA) in the software GaBi© ts 10.0. A sensitivity analysis focuses on electricity grid mixes, concrete mixes, and steel production scenarios. Results: The midpoint indicator climate change respective global warming potential (in kg CO2e) ranges between 453 kg CO2e and 754 kg CO2e per CRC double wall. A comparable SRC double wall results in emissions of 611–1239 kg CO2e. Even though less raw material is needed for CRC, it does not represent a clear advantage over SRC in terms of climate change. In a comparison, the production of steel (blast furnace vs. electric arc furnace vs. recycled steel) and the choice of cement type are of decisive relevance. For concrete mixes, a mixture of Portland cement and blast furnace slag (CEM III) is beneficial to pure Portland cement (CEM) I. For fiber production, styrene-butadiene rubber (SBR) has an advantage over epoxy resin (EP) impregnation and the use of renewable energy could reduce emissions of fiber production up to 60%. Conclusion: CRC requires less material (concrete cover) than SRC, however, exhibits comparable CO2e to SRC — depending on the production process of steel. In the future, fiber production and impregnation should be studied in detail. Since in terms of climate change neither wall (CRC vs. SRC) clearly performs better, the two other pillars of sustainability (economic and social, resulting in LCSA) and innovative building components must be focused on. [ABSTRACT FROM AUTHOR]

ISO 14044, clause 5.2 only requires that third-party reports "shall be made available to any third party to whom the communication is made" (ISO [2]). More broadly, it should be noted that sector-specific ISO standards, such as ISO 21930, cannot overrule generic ISO management standards. Since the above ambiguities appear to be reasonable interpretations of the current language in ISO 14044, they should be addressed and clarified by future ISO/TC207/SC5 Working Groups, e.g., when revising ISO/TS 14071:2014. 8. ISO/IEC Directives, Part 1 - Consolidated ISO Supplement - Procedures specific to ISO. [Extracted from the article]

There is an increasing need for the reduction of greenhouse gas (GHG) emissions within pavement management decisionmaking. Pavement maintenance activities, such as resurfacing, account for millions of tons of the GHG emissions annually in the United States. Optimizing pavement resurfacing activities allows for the potential to reduce the carbon footprint of pavement maintenance. A framework is proposed for estimating the relationship between GHG emissions from pavement resurfacing activities and pavement cracking-threshold policies, where cracking is the trigger distress. Cracking threshold is the maximum percentage cracking level a pavement is allowed to reach before an asphalt overlay is applied. The data set used in the case study was obtained from the Washington State Department of Transportation. The results show that for a planning horizon of 10 years, the optimal cracking thresholds for minimizing costs and GHG emissions are very close to each other. [ABSTRACT FROM AUTHOR]

The formation of effective policies to reduce emissions from goods movement should consider local and remote life cycle effects as well as barriers for mode shifting. Using uni- and multimodal freight movements by truck, rail, and ocean-going vessel (OGV) associated with California, a life cycle assessment (LCA) is developed to estimate the local and remote emissions that occur from freight activity inside and associated with the state. Long-run average per tonne-kilometer results show that OGVs emit the fewest emissions, followed by rail, then trucks, and that the inclusion of life cycle processes can increase impacts by up to 32% for energy and greenhouse gas (GHG) emissions and 4,200% for conventional air pollutants. Efforts to reduce emissions through mode shifting should recognize that infrastructure and market configurations may be inimical to mode substitution. A uni- and multimodal shipping emissions assessment is developed for intrastate and California-associated freight movements to illustrate the life cycle impacts of typical trips for certain types of goods. When targeting GHG reductions in California, it should be recognized that heavy-duty trucks are responsible for 99% of intrastate goods movement emissions. An assessment of future freight truck technology improvements is performed to estimate the effectiveness of strategies to meet 2050 GHG reduction goals. Whereas aggressive improvements in fuel economy coupled with alternative vehicles and fuels can significantly reduce GHG emissions, to meet 2050 goals will likely require zero carbon emission vehicle technology. The value of using LCA in GHG reduction policy for transportation systems is explored. [ABSTRACT FROM AUTHOR]

Reductions in the greenhouse gas (GHG) intensity of passenger and freight transportation are possible through adoption of fuel-saving technologies, demand switching between modes, and large-scale electrification of fleets, in addition to other actions. In this study, future scenarios to 2030 and 2050 are the basis for assessment of GHG reduction potentials for major passenger and freight modes (automobiles, buses, trains, aircraft, and oceangoing vessels) across eight regions of the world. New fuel-saving technologies can significantly reduce the life-cycle GHG footprint of both passenger and freight vehicles, but not uniformly worldwide. Countries outside of the Organization for Economic Cooperation and Development (OECD) lag behind OECD countries in GHG reduction potentials for all modes but oceangoing vessels owing to a combination of slower adoption of fuel-saving technologies and a slower decarbonization of electricity generation and other processes. The reduction of GHG intensity will occur more slowly for freight modes than for passenger modes. However, improved fuel efficiency has negative feedbacks to the effectiveness of mode-switching and alternative fuel adoption policies through 2050 because improvements in the fuel efficiency of vehicles alone may cause the marginal benefits of GHG abatement policies to diminish over time. This trend may be reversed if alternative fuel pathways decarbonize at faster rates than conventional transportation fuels. The largest opportunities for GHG reductions occur in non-OECD countries. Given the many factors that distinguish transportation systems between developed and developing nations (e.g., availability of new technologies, the financial ability to acquire them, and policies to incentivize their adoption), many benefits could be gained through interregional cooperation. [ABSTRACT FROM AUTHOR]

To meet greenhouse gas (GHG) emissions for the transportation sector, the United States is expected to expand infrastructure for producing and distributing lignocellulosic biofuels over the next decade. To compare the life-cycle GHG footprint of biofuels to the petroleum baseline, emissions associated with feedstock and fuel handling, storage, and transportation must be included. U.S.-specific life-cycle GHG emission factors were developed for each major distribution chain activity by applying a hybrid life-cycle assessment methodology to the construction, manufacturing, operation and maintenance of each component. A projection was then made for the fleet of infrastructure components necessary to distribute 21 billion gal. (79.5 billion L) of ethanol derived entirely from Miscanthus grass for comparison to the baseline petroleum system. Owing to geographic, physical, and chemical properties of biomass and alcohols, the distribution system for Miscanthus-based ethanol is more capital- and energy-intensive than petroleum per unit of fuel energy delivered and was estimated to be over five times more GHG-intensive than petroleum (i.e., 17-18 versus of consumed fuel, ignoring feedstock production and conversion). Lower life-cycle emissions could be attained by employing more efficient and durable equipment and vehicles; reducing material losses; minimizing feedstock delivery, biofuel delivery, and consumer refueling errand distances; and producing more energy-dense biofuels than ethanol. [ABSTRACT FROM AUTHOR]

Research has separately existed for life-cycle costs and environmental assessment of photovoltaic systems. This study provides a framework for the identification of the optimal set of residential photovoltaic system options in terms of costs and selected air emissions by assessing the life cycle of the product from manufacturing to disposal. Analyzed air emissions include carbon, nitrogen oxides, sulfur oxides, carbon monoxide, and particulate matter. The study focuses on general residential installations within the San Francisco Bay Area of California. Pareto frontiers are determined for costs and emissions, and the best options for suppliers are identified in each case, including sensitivity analysis of the installation planning horizon. Choosing multicrystalline silicon modules over thin film modules has the greatest impact on cost reduction. The electricity mix with which the modules are produced has the greatest impact on the emissions. [ABSTRACT FROM AUTHOR]

In recent decades, pavement management optimization has been designed with the objective of minimizing user and agency costs. However, recent analyses indicate that pavement management decisions also have significant impacts on life-cycle greenhouse gas (GHG) emissions. This study expands beyond minimization of life-cycle costs to also include GHG emissions. Previous work on the single-facility, continuous-state, continuous-time optimal pavement resurfacing problem is extended to solve the multicriteria optimization problem with the two objectives of minimizing costs and GHG emissions. Results indicate that there is a trade-off between costs and emissions when developing a pavement resurfacing policy, providing a range of GHG emissions reduction cost-effectiveness options. Case studies for an arterial and a major highway are presented to highlight the contrast between policy decisions for various pavement and vehicle technologies. [ABSTRACT FROM AUTHOR]

Research has separately existed for life-cycle costs and environmental assessment of photovoltaic systems. This study provides a framework for the identification of the optimal set of residential photovoltaic system options in terms of costs and selected air emissions by assessing the life cycle of the product from manufacturing to disposal. Analyzed air emissions include carbon, nitrogen oxides, sulfur oxides, carbon monoxide, and particulate matter. The study focuses on general residential installations within the San Francisco Bay Area of California. Pareto frontiers are determined for costs and emissions, and the best options for suppliers are identified in each case, including sensitivity analysis of the installation planning horizon. Choosing multicrystalline silicon modules over thin film modules has the greatest impact on cost reduction. The electricity mix with which the modules are produced has the greatest impact on the emissions. [ABSTRACT FROM AUTHOR]

The exploration of life-cycle energy use and environmental effects from U.S. water infrastructure has been limited in spite of the strong connection between energy and water use. This research presents a methodology for quantifying the life-cycle energy consumption and associated air emissions from water supply, treatment, and distribution. A decision-support tool, the Water-Energy Sustainability Tool (WEST), has been developed to aid such analysis. WEST calculates the environmental effects of material production, including the supply chain, material delivery and transportation, construction and maintenance equipment use, energy production, and sludge disposal. Deterministic and probabilistic results for a California case study utility are provided to show the tool's capabilities. Results indicate that producing a million liters of water consumes 5.4 GJ and produces 390 kg of CO2-equivalent greenhouse gases. Energy production is the most significant activity (50%), but material production, especially for treatment chemicals, is also important (37%). This case study is contrasted with two previously published case study utilities, and the reasons for the range of results are analyzed. The results demonstrate that estimating water supply's energy needs and emissions without a life-cycle lens can underestimate the total effects significantly. [ABSTRACT FROM AUTHOR]

Solid state drives (SSDs) show potential for environmental benefits over magnetic data storage due to their lower power consumption. To investigate this possibility, a life-cycle assessment (LCA) of NAND flash over five technology generations (150 nm, 120 nm, 90 nm, 65 nm, and 45 nm) is presented to quantify environmental impacts occurring in flash production and to view their trends over time. The inventory of resources and emissions in flash manufacturing, electricity generation, and some chemicals are based on process data, while that of fab infrastructure, water and the remaining chemicals are determined using economic input-output life-cycle assessment (EIO-LCA) or hybrid LCA. Over the past decade, impacts have fallen in all impact categories per gigabyte. Sensitivity analysis shows that the most influential factors over the life-cycle global warming potential (GWP) of flash memory are abatement of perfluorinated compounds and reduction of electricity-related emissions in manufacturing. A limited comparison between the life-cycle energy use and GWP of a 100 GB laptop SSD and hard disk drive shows higher impacts for SSD in many use phase scenarios. This comparison is not indicative for all impact categories, however, and is not conclusive due to differences in boundary and functional unit. [ABSTRACT FROM AUTHOR]

Background, Aims and Scope Telework is associated with a number of costs and benefits, including reduced company overhead costs, need for office and parking space, office energy consumption, increased productivity, reduced absenteeism, retention of specialized employees, reduction in transportation-related fuel consumption and air pollution, and many others. This paper applies a systems model to telework and nontelework scenarios to quantify direct energy and fuel costs and external costs related to air emissions from transportation, heating, cooling, lighting, and electronic and electrical equipment use both at the company and the home office, including rebound effects. Methods: E-COMMUTair, a scalable web-based tool created by the authors and designed to assess the air pollution effects of individual or company telework programs versus nontelework is employed along with Monte Carlo simulation and sensitivity analysis. E-COMlvIUTair is using the latest available U.S. energy use and air emission factors. The external costs of air emissions are estimated. The role of telecommuting frequency is emphasized, and differences between various states are explored. The paper identifies the drivers of external costs, and presents an example breakeven analysis focused on CO2 and key model parameters. Results and Discussion: Nonteleworks external costs are equal to or higher than teleworks costs for every model component, demonstrating that telework programs could provide benefits, including monetary benefits, to society. Transportation is the major contributor to the total costs, with home heating and cooling, and office cooling following. Most of the monetary costs associated with transportation are borne by individuals rather than society. Teleworking employees increase their home- related expenses but reduce their travel-related expenses, ending up with smaller total costs. Energy and fuel costs get reduced in the office space when telework programs are applied, resulting in benefits to companies. Energy and external costs decrease as telework frequency increases. When compared to not teleworking, 5-day telework scenarios on cooling days in California can have about 50-70% lower total costs. The probabilistic analysis confirms the results of the deterministic analysis. The sensitivity analysis reveals that for the nontelework scenario, transportation-related variables such as commuting distance and average number of passengers affect GO2, GO, and NO~ emissions, while for the telework part, frequency and the number of roundtrips are the most relevant. Conclusions: Both analyses show that telework programs have the potential to lower both energy and external costs creating a favorable bottom line for society, employees, and companies by decreasing tailpipe emissions, lowering transportation costs, and decreasing energy costs at the company office. However, important parameters such as telecommuting frequency, characteristics of the office and home space, climate patterns, and rebound effects that determine external costs along with the price of gasoline, electricity and natural gas in the state where the program is implemented can greatly influence the final results, and should be carefully examined. Recommendations and Perspectives: The effects of telework programs on peoples daily lives are complex and difficult to predict and quantify. The current analysis showed that significant financial benefits can be expected from telework programs, but as seen often in environmental policy-making, the details of implementation will make or break the success of a program. [ABSTRACT FROM AUTHOR]

Background, Aims and Scope. Life cycle assessment models typically use product-specific, plant-level or national aggregate data. However, many decisions by regional policy makers would be better informed by local or regional aggregate data. This research is in- tended to construct and apply a regional US economic input-output analysis-based life cycle assessment (REIO-LCA) model based upon publicly available datasets. The model uses Gross State Product (GSP) estimates to calculate regional economic multipliers and then link them to regional electricity and fuel use, and air emission factors. Target audiences are governmental decision makers, industry experts and researchers concerned with the regional economic and environmental effects of public and private decisions. Methods. A regional version of the existing US EIO-LCA model was developed using regional economic multipliers and state environmental data. The national model is based on the US 491 by 491 leconomic input-output model, and uses sectoral energy consumption and emission factors to approximate the environmental effects of production and services. The proportion of the regional value added (Gross State Product) to the national value added for each sector was used to develop economic multipliers to allocate the output of industries to individual states and multi-state regions. Inter-sectoral transaction matrices were constructed for eight regions. Regional environmental emission and resource use factors were formed based upon publicly available data of the US Environmental Protection Agency (EPA) and Department of Energy. The Toxics Release Inventory include facility location parameters, enabling the estimation of sectoral toxic emissions for the regions. The national electricity and fuel use, air pollutants (CO, NOR, PM10, SO2 and VOC) and greenhouse gas emissions used by the ElO-LCA model were proportioned based upon state totals for each sector. Results. A regional economic input-output model was created for US regions, and sectoral energy use and environmental emission factors were estimated for Pennsylvania, the Far West (Alaska, California, Hawaii, Nevada, Oregon and Washington) and the Mideast (Delaware, District of Columbia, Maryland, New Jersey, New York and Pennsylvania) economic areas. The use of the framework for regional IO-LCA model is demonstrated through two case studies. Discussion. As a validation exercise, the regional outputs of petroleum refineries were calculated using the regional input-output matrices and the outcomes were compared to the Energy Information Administrations (EIA) Petroleum State Profile data. The model results show that approximately 70% of the total national sectoral production takes place in three regions, i.e., South West, South East and Far West, which corresponds with the EIA statistics. The REIO-LCA model constructed for the Far West is used to conduct a second case study estimating the annual toxic air emissions of power plants in the region in 2003. The results are evaluated by comparison to data provided by the US EPA. The estimated pollutions do not differ significantly from those presented in the Toxics Release Inventory reports. Conclusions. The usefulness of IO LCA models can be improved through the incorporation of local economic and environmental characteristics. Wiht the lack of US regional sectoral data, the allocation of national industrial production to regions can provide a frame- work to create smaller scale JO models. The results of case studies support the assumption that the GSP multipliers may be used to allocate the sectoral production to the regions, and show that the frame- work IO LCA model provides a reasonable approximation of supply chain economic activities and environmental effects caused by production and services. Recommendations and Perspectives.… [ABSTRACT FROM AUTHOR]

Goal, Scope and Background. LEED (Leadership in Energy and Environmental Design) is a scoring system that evaluates the environmental friendliness of buildings. It is composed of 69 credits, each one providing a score of one (i.e., one point) if implemented. However, since each credit does not always provide the same type and magnitude of benefits for the environment, a higher rating is not always synonymous with lower impacts. The goal of this paper is to evaluate the actual extent of the benefits and burdens of LEED, identify the critical credits and develop a new scale that will correct these miscorrelations. Methods. The various LEED credits are qualitatively analysed. It is possible to quantify the actual outcomes and thus perform a lifecycle assessment (LCA) on 45 credits applied to an actual California office building. This allows comparing the benefits of the different credits among each other. Commuting of the employees is included in the system. The LCA is performed with the help of SimaPro 7, combining the ecoinvent 1.2 inventory database and the impact assessment methodology IMPACT 2002+ v2.1, adapted to North America. Impacts are evaluated for human health, ecosystems quality, climate change, and resource consumption. Impacts of the different credits are aggregated in one indicator to allow the design of a new scoring system that assigns to the different credits an amount of points (i.e., a score) that are related to the actual benefits. A school and a residential building are also modeled in order to perform a sensitivity study. Results and Discussion. Operation, especially employee commuting and electricity consumption, dominates the impacts associated with the building. It appears that waste generation have limited but not negligible impacts, whereas water consumption has small impacts. Since the building is situated in California, heating is not an important source of impacts. As a result, credits that provide the most environmental benefits are the ones geared toward increasing the fraction of green electricity, reducing energy consumption, reducing employee commuting, and increasing waste recycling, along with the ones favoring the reuse and recycling of the building structure. The ones targeting reduction of water and land use, and recycling content in the furniture appear to be less beneficial. The scores of the different LEED credits range from -128 to 606. Negative credits are due to credits that lead to more burdens than benefits, for example, the one requiring the construction of a multifloor parking lot (with a score of -128). The most beneficial credit (with a score of 606) is the one requiring that electricity comes from at least 50% green power. Conclusions and Outlook. Comparing the new scale with the observations on site shows that the LEED credits actually implemented are not always the most beneficial for the environment. This issue should be addressed in order to make LEED more efficient. The proposed rating system should help correct these discrepancies. The amount of reduction in employee commuting that the related credits really achieve, actual impacts of land and water use, along with the benefits of improved indoor air quality are among the main future challenges of the present study. [ABSTRACT FROM AUTHOR]

Construction of commercial buildings consumes significant amounts of energy and produces lots of emissions and waste. Where should environmental improvement efforts be focused during design and construction? The Construction Environmental Decision-Support Tool allows designers and industry practitioners to quantify energy use, emissions, and waste generation rates due to the construction phase of commercial buildings. A case study of the Bren School at the University of California, Santa Barbara, and several relevant construction scenarios are analyzed. When considering the complete building over its entire life cycle, the construction phase comprised 2% of energy consumption, 1% of CO2 emissions, 7% of CO emissions, 8% of NOx emissions, 8% of PM10 emissions, and 1% of SO2 emissions. This is due to the dominance of the long-term use phase (50 years) compared to a relatively short construction phase (2 years). Scaling up to the national level, however, construction impacts of projects are significant. In each of the categories studied (temporary materials, equipment and materials transportation, equipment use, waste generation), there are actions that can be taken by designers and builders to improve construction phase environmental effects. In structural frame construction, particular areas of concern include material and equipment selection and temporary material use. Energy use and air emissions are primarily due to equipment use, which accounts for at least 50% of most types of emissions. The major contributors are concrete mixer trucks, concrete pumps, cranes, and air compressors. A single feasible decision, such as using a concrete mixer truck with a 335 hp engine instead of one with a 565 hp engine (but having the same capacity) would reduce total construction energy demand by 12%, and the emissions of CO, NO2, PM10, SO2, CO2, and HC by 3, 12, 8, 10, 12, and 10%, respectively. The use of significantly older equipment can have a formidable effect on construction phase emissions. In general, equipment larger that 175 hp made prior to 1996 tends to have significantly greater emissions of HC, CO, and NO2 than more recent models. The majority of waste generated during construction of the structural frame consists of concrete and wood. [ABSTRACT FROM AUTHOR]

Goal, Scope and Background. This paper discusses the merging of methodological aspects of two known methods into a hybrid form applied to water supply systems. 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 com- pare 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 utilitys 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. [ABSTRACT FROM AUTHOR]

Goal, Scope and Background. This study provides a life-cycle inventory of air emissions (CO2, NOx, PM10, and CO) associated with the transportation of goods by road, rail, and air in the U.S. It includes the manufacturing, use, maintenance, and end-of-life (EOL) of vehicles, the construction, operation, maintenance, and EOL of transportation infrastructure, as well as oil exploration, fuel refining, and fuel distribution. Methods. The comparison is performed using hybrid life-cycle assessment (LCA), a combination of process-based LCA and economic input-output analysis-based LCA (EIO-LCA). Results are summed by means of a common functional unit of grams of air pollutant per ton-mile of freight activity. Results and Discussion. Results show that the vehicle use phase is responsible for approximately 70% of total emissions of CO2 for all three modes. This confirms that tailpipe emissions underestimate total emissions of freight transportation as infrastructure, pre-combustion, as well as vehicle manufacturing and EOL account for a sizeable share of total emissions. Depending on mode and pollutant, differences between tailpipe emissions and total systemwide emissions can range from only 4% for road transportations CO emissions to an almost tenfold difference for air transportations PM10 emissions. Conclusion. Rail freight has the lowest associated air emissions, followed by road and air transportation. Depending on the pollutant, rail is 50–94% less polluting than road. Air transportation is rated the least efficient in terms of air emissions, partly due to the fact that it carries low weight cargo. It emits 35 times more CO2 than rail and 18 times more than road transportation on a ton-mile basis. It is important to consider infrastructure, vehicle manufacturing, and pre-combustion processes, whose life-cycle share is likely to increase as new tailpipe emission standards are enforced. Recommendation and Outlook. Emission factors, fuel efficiency, and equipment utilization contribute the most to uncertainty in the results. Further studies are necessary to address all variables that influence these parameters, such as road grade, vehicle speed, and vehicle weight. A focus on regional variation, EOL processes, fuel refining processes, terminals, as well as more accurate infrastructure allocation between freight and passenger transportation would strengthen the model. [ABSTRACT FROM AUTHOR]

Telework has emerged as a possible solution to transportation-related air pollution problems. This paper analyzes, both deterministically and probabilistically, a California-based 1-day telework scenario, and explores how the mode of transportation and other parameters such as vehicle miles traveled, vehicle model, occupancy rate, telecommuting frequency, and season (heating or cooling) affect the air pollution effects of telework programs when energy consumption-related emissions due to heating, cooling, lighting, and the use of electronic and electrical equipment (in the home and company office) are accounted for. Among others, the study found that total telework-related CO2 emissions during the cooling season and SO2, NOx, and hydrocarbon emissions in both seasons appear to be lower than nontelework emissions for all modes of transportation (except for light rail with higher NOx emissions and urban transit buses with roughly equal NOx emissions in the heating season). Light rail also has higher telework N2O and CH4 emissions. However, given the uncertainties in the data, the differences may be negligible. Urban transit buses and commuter express buses were found to be associated with more telework than nontelework CO emissions in both seasons. For these two modes, telework PM10 emissions are higher in the cooling and about the same in the heating season than nontelework emissions. Natural gas-powered ferries have more telework PM10 emissions than nontelework emissions. The study also found that for low-frequency telework programs energy use impacts could overturn transportation-related emission reductions independent of the mode of transportation used. Avoiding more polluting modes of transportation, increasing occupancy rates, substituting longer commutes and especially increasing telecommuting frequency could counteract these negative effects. [ABSTRACT FROM AUTHOR]

Office buildings are thought to be significant sources of energy use and emissions in industrialized countries, but quantitative assessments of all of the phases of the service life of office buildings are still quite rare. In order to enable environmentally conscious design and management, this paper presents life-cycle assessments of newly constructed European and U.S. office buildings from materials production through construction, use, and maintenance to end-of-life treatment. The significant environmental aspects indicate the dominance of the use phase in the quantified environmental categories, but draw attention to the importance of embedded materials and expected maintenance investments throughout the assumed 50-year service life, especially for particulate matter emissions. The relevance of the materials, construction, maintenance, and end-of-life phases relative to the use of buildings is expected to increase considerably as functional obsolescence of office buildings becomes more rapid, and complete reconstruction and reconfiguration become more frequent. By quantifying the energy use and environmental emissions of each life-cycle phase in more detail, the elements that cause significant emissions can be identified and targeted for improvement. [ABSTRACT FROM AUTHOR]

In order to create an environmentally-conscious building, the environmental impacts of the entire service life must be known. Life-cycle assessment (LCA), which evaluates the impacts from all life-cycle phases, from “cradle to grave,” is the best method to achieve this goal. In this paper, LCA is used to quantify the energy use and the environmental emissions during the construction phase of two typical office buildings, one with a structural steel frame and one with a cast-in-place concrete frame, and then these are put in the perspective of the overall service life of each building. The concrete structural-frame construction has more associated energy use, CO2, CO, NO2, particulate matter, SO2, and hydrocarbon emissions due to more formwork used, larger transportation impacts due to a larger mass of materials, and longer equipment use due to the longer installation process. In contrast, the steel-frame construction has more volatile organic compound (VOC) and heavy metal (Cr, Ni, Mn) emissions due to the painting, torch cutting, and welding of the steel members. The energy use and the environmental emissions of the two buildings are comparable if the total impacts from materials’ manufacturing, construction, transportation, use, maintenance, and demolition are considered. Energy use and environmental emissions from office buildings can be reduced through a careful selection of embedded and temporary materials and construction equipment. [ABSTRACT FROM AUTHOR]

Environmental awareness is increasingly important to society, government, and industry, and there is a strong demand for sustainable development practices. The importance of supply chain management is critical, as it characterizes and influences the life cycles of all products. Within the major logistics trends, outsourcing has a significant potential to increase sustainability in the supply chain as third-party logistics providers (3PLs) focus on improving resource utilization and making processes more efficient. However, their motivation is largely economic, and an environmental perspective is rarely seen in 3PLs. As consumers demand greener alternatives and, subsequently, environmental regulatory measures are implemented, 3PLs will have to become more environmentally and socially aware in order to develop sustainability goals. This study compares two scenarios using life-cycle assessment (LCA): one where logistics functions are handled in-house, and an alternative scenario where such functions are outsourced to a 3PL. The impacts of logistics outsourcing on energy utilization, global warming potential, and fatalities are first quantified in the supply chain of an automobile. Even though vehicle operation, responsible for most of the impacts considered, is outside the domain of logistics functions, logistics outsourcing nonetheless has the potential to reduce energy use and global warming potential by 0.4–2% and fatalities by 0.8–3.3% throughout the entire life cycle of a typical automobile. Road and air transportation are found to account for most of the impacts in all selected metrics. Analyzing logistics outsourcing in the other sectors of the U.S. economy revealed the same trend as observed in the supply chain of an automobile. [ABSTRACT FROM AUTHOR]

No other industry in the United States uses more materials by weight than the construction industry. Because of its economic strength and societal importance, it is also a significant polluter and a target of growing stakeholder scrutiny. This review offers an extended, supply chain inclusive framework for the study of the construction industry that serves all the life-cycle stages of society's infrastructure systems, and it summarizes selected literature on the life-cycle environmental assessment of construction materials, designs, and processes. On the basis of identified knowledge gaps, a research agenda is discussed for lesser-studied questions in order to first understand and then eventually reduce the environmental impacts of construction materials, processes, and activities. [ABSTRACT FROM AUTHOR]

This paper quantifies the significant environmental aspects of a new high-end office building over 50 years of service life. A comprehensive environmental life-cycle assessment—including data quality assessment—was conducted to provide detailed information for establishing the causal connection between the different life-cycle elements and potential environmental impacts. The results show that most of the impacts are associated with electricity use and building materials manufacturing—in particular, electricity used in lighting, HVAC systems, and outlets; heat conduction through the structures; manufacturing and maintenance of steel; manufacturing of concrete and paint; water use and wastewater generation; and office waste management. Construction and demolition were found to have relatively insignificant impacts. The identified most significant aspects are quite predominant; 7% of all counted aspects cover over 50% of the life-cycle impacts. Practical applications of the study’s results could be in the environmentally conscious design and management of office buildings. [ABSTRACT FROM AUTHOR]

The Construction Institute’s Committee on Social and Environmental Concerns in Construction has examined 24 items of social and environmental concerns in construction that will have to be considered by those who are going to be involved in the reconstruction of the World Trade Center. These topics include the economic aspects of the reconstruction, the planning and design, the environmental issues, the transportation challenges, the contractual problems, the memorial, and the security requirements. During the drafting of this report, the Committee received assistance and guidance from the engineering staff of the Port Authority of New York and New Jersey. Some Committee members visited the World Trade Center site at Ground Zero during the preparation of the report. Also consulted by the Committee were some well-known, highly qualified engineers on various aspects of the report. These contributions from nonmembers of the Committee made the report richer. It is the intent of this report to serve as a starting point for planning and redevelopment. [ABSTRACT FROM AUTHOR]

Buildings use large amounts of materials and produce much waste. Some building materials are recycled, but most become waste. Extended Producer Responsibility (EPR) policies require producers to be responsible for their products after their useful life. The basic drivers of EPR are reduced pollution and resource and energy use over a product’s life cycle. For buildings, EPR provides an opportunity to divert additional waste away from landfills and into reuse and recycling. Energy shortages and pollution prevention are concerns at regional and global levels, while material shortages occur in some regions. EPR can be achieved through regulatory, economic, or information instruments. Product takeback (PTB) is a regulatory instrument that requires producers to take back products at the end of their useful life and reuse or recycle them. This paper finds that PTB policies are not feasible for entire buildings, but many building materials and components are candidates for reuse and recycling. Using recycled materials may save energy, reduce virgin material use, and prevent pollution. Economic instruments can also be used to promote EPR for buildings, while information instruments are not as effective. [ABSTRACT FROM AUTHOR]

The production of equipment and materials used for transportation facilities and services can have significant environmental effects. Considerable effort is expended to reduce such effects as efficiently and effectively as possible. In this paper, we estimate external environmental costs resulting from the production of common transportation equipment, materials, and services. These external cost estimates only include the effects from air emissions of conventional pollutants, including carbon monoxide, greenhouse gases (or global warming potential), volatile organics, sulfur dioxide, particulate matter, and nitrogen oxides. The estimates include all the direct and indirect supply chain emissions, such as electricity generation and mining. The cost estimates are uncertain and are likely to be underestimates of total external costs. However, the estimates should be useful for an initial assessment of the total social costs of transportation projects, and to indicate products and processes worthy of additional pollution prevention efforts. In particular, we find that additional external environmental costs may range from as low as 1% to as high as 45% for transportation services. External environmental costs of transportation equipment manufacturing range between 0.3 and 11%, while the external environmental costs of transportation construction and operation materials are estimated to vary between 1 and 100%. [ABSTRACT FROM AUTHOR]

Estimates the major commodity and service inputs, resource requirements and environmental emissions and wastes for four major United States construction sectors. Reduction of construction's environmental effects to promote sustainable development; US Department of Commerce's definition of construction sectors; Sectors' use of resources and rates of environmental emissions and wastes .

Bridge material selection has traditionally been based on engineering and economic criteria. With the increasing interest of the public, industry, and government in sustainable development, environmental assessment in construction is becoming more important. However, we need metrics and data on design alternatives for effective decision making. In this paper, we present results of a life cycle inventory analysis of steel and steel-reinforced concrete bridge girders, based on publicly available data. We find that for the initial construction of equivalent designs for a particular location, a steel-reinforced concrete bridge generally has lower environmental effects than a steel bridge. The expected design life of the two types of bridges is influenced by wear and tear, but also by obsolescence. The uncertainty in bridge design life and related data uncertainties make comparisons based on annualized environmental effects difficult. The steel bridges' beneficial reuse and recycling rates may result in lower annualized environmental effects. In particular applications, however, one material might be preferred over the other due to engineering, aesthetic, or economic criteria, regardless of overall environmental effects. [ABSTRACT FROM AUTHOR]