Policy implications of uncertainty in modeled life-cycle greenhouse gas emissions of biofuels

Biofuels have received legislative support recently in California's Low-Carbon Fuel Standard and the Federal Energy Independence and Security Act. Both present new fuel types, but neither provides methodological guidelines for dealing with the inherent uncertainty in evaluating their potential life-cycle greenhouse gas emissions. Emissions reductions are based on point estimates only. This work demonstrates the use of Monte Carlo simulation to estimate life-cycle emissions distributions from ethanol and butanol from corn or switchgrass. Life-cycle emissions distributions for each feedstock and fuel pairing modeled span an order of magnitude or more. Using a streamlined life-cycle assessment, corn ethanol emissions range from 50 to 250 g CO(2)e/MJ, for example, and each feedstock-fuel pathway studied shows some probability of greater emissions than a distribution for gasoline. Potential GHG emissions reductions from displacing fossil fuels with biofuels are difficult to forecast given this high degree of uncertainty in life-cycle emissions. This uncertainty is driven by the importance and uncertainty of indirect land use change emissions. Incorporating uncertainty in the decision making process can illuminate the risks of policy failure (e.g., increased emissions), and a calculated risk of failure due to uncertainty can be used to inform more appropriate reduction targets in future biofuel policies.     

Coupling multi-criteria decision analysis, life-cycle assessment, and risk assessment for emerging threats

Emerging environmental threats such as novel chemical compounds, biological agents, and nanomaterials present serious challenges to traditional models of risk analysis and regulatory risk management processes. Even a massive expansion of risk and life-cycle assessment research efforts is unlikely to keep pace with rapid technological change resulting in new and modified materials with changing properties. Therefore, it is essential to have a framework for interpreting available information in the context of high uncertainty and a strategy for prioritizing research efforts to reduce those uncertainties that are most critical. We discuss how integrating the three analytic approaches of risk assessment, life-cycle assessment, and multicriteria decision analysis into a framework permits understanding uncertainty and prioritizes needs for scientific research. Our approach is illustrated with two separate cases: nanomaterials and contaminated sediment remediation.     

A mixed-unit input-output model for environmental life-cycle assessment and material flow analysis

Materials flow analysis models have traditionally been used to track the production, use, and consumption of materials. Economic input-output modeling has been used for environmental systems analysis, with a primary benefit being the capability to estimate direct and indirect economic and environmental impacts across the entire supply chain of production in an economy. We combine these two types of models to create a mixed-unit input-output model that is able to bettertrack economic transactions and material flows throughout the economy associated with changes in production. A 13 by 13 economic input-output direct requirements matrix developed by the U.S. Bureau of Economic Analysis is augmented with material flow data derived from those published by the U.S. Geological Survey in the formulation of illustrative mixed-unit input-output models for lead and cadmium. The resulting model provides the capabilities of both material flow and input-output models, with detailed material tracking through entire supply chains in response to any monetary or material demand. Examples of these models are provided along with a discussion of uncertainty and extensions to these models.     

Variability assessment of groundwater exposure to pesticides and its consideration in life-cycle assessment

Pesticide leaching from agricultural fields to groundwater is an environmentally relevant and highly variable process. In the present paper, leaching scenarios typical in European agriculture are defined. These scenarios consider important sources of pesticide leaching variability, namely site factors, farming practice, and substance properties. The logic-tree method was used to structure these scenarios. For each scenario, leached fractions of pesticide applied in agriculture were calculated with data and models used in the registration process of the European Union (EU). Contributions of all parameters to variability were calculated for 11 pesticides. Substance properties (Koc and DT50,soil) contributed the mostto variability, followed by site, weather, season of application, crop, and macropore flow. The results of the variability assessment may be directly applied in policy making or they may be used in the environmental assessment of pesticides, e.g. with the life-cycle assessment (LCA) method. Several approaches are suggested for howthe variability assessment presented in this paper may be incorporated in LCA. The application of these approaches is illustrated by a case study on atrazine.     

Economic input-output life-cycle assessment of trade between Canada and the United States

With increasing trade liberalization, attempts at accounting for environmental impacts and energy use across the manufacturing supply chain are complicated by the predominance of internationally supplied resources and products. This is particularly true for Canada and the United States, the world's largest trading partners. We use an economic input-output life-cycle assessment (EIO-LCA) technique to estimate the economy-wide energy intensity and greenhouse gas (GHG) emissions intensity for 45 manufacturing and resource sectors in Canada and the United States. Overall, we find that U.S. manufacturing and resource industries are about 1.15 times as energy-intensive and 1.3 times as GHG-intensive as Canadian industries, with significant sector-specific discrepancies in energy and GHG intensity. This trend is mainly due to a greater direct reliance on fossil fuels for many U.S. industries, in addition to a highly fossil-fuel based electricity mix in the U.S. To account for these differences, we develop a 76 sector binational EIO-LCA model that implicitly considers trade in goods between Canada and the U.S. Our findings show that accounting for trade can significantly alter the results of life-cycle assessment studies, particularly for many Canadian manufacturing sectors, and the production/consumption of goods in one country often exerts significant energy- and GHG-influences on the other.     

Time horizon dependent characterization factors for acidification in life-cycle assessment based on forest plant species occurrence in Europe

This paper describes a new approach in life-cycle impact assessment to derive characterization factors for acidification in European forests. Time horizon dependent characterization factors for acidification were calculated, whereas before only steady-state factors were available. The characterization factors indicate the change in the potential occurrence of plant species due to a change in emission, and they consist of a fate and an effect factor. The fate factor combines the results of an atmospheric deposition model and a dynamic soil acidification model. The change in base saturation in soil due to an atmospheric emission change was derived for 20, 50, 100, and 500 year time horizons. The effect factor was based on a dose-response curve of the potential occurrence of plant species, derived from multiple regression equations per plant species. The results showed that characterization factors for acidification increase up to a factor of 13 from a 20 years to a 500 years time horizon. Characterization factors for ammonia are 4.0-4.3 times greater than those for nitrogen oxides (NO(x)), and characterization factors for sulfur dioxide are 1.4-2.0 times greater than those for NO(x). Aggregation of damage due to acidification with other impact categories on the European scale becomes feasible with the applied approach.     

Evaluating uncertainty in environmental life-cycle assessment. A case study comparing two insulation options for a Dutch one-family dwelling

The evaluation of uncertainty is relatively new in environmental life-cycle assessment (LCA). It provides useful information to assess the reliability of LCA-based decisions and to guide future research toward reducing uncertainty. Most uncertainty studies in LCA quantify only one type of uncertainty, i.e., uncertainty due to input data (parameter uncertainty). However, LCA outcomes can also be uncertain due to normative choices (scenario uncertainty) and the mathematical models involved (model uncertainty). The present paper outlines a new methodology that quantifies parameter, scenario, and model uncertainty simultaneously in environmental life-cycle assessment. The procedure is illustrated in a case study that compares two insulation options for a Dutch one-family dwelling. Parameter uncertainty was quantified by means of Monte Carlo simulation. Scenario and model uncertainty were quantified by resampling different decision scenarios and model formulations, respectively. Although scenario and model uncertainty were not quantified comprehensively, the results indicate that both types of uncertainty influence the case study outcomes. This stresses the importance of quantifying parameter, scenario, and model uncertainty simultaneously. The two insulation options studied were found to have significantly different impact scores for global warming, stratospheric ozone depletion, and eutrophication. The thickest insulation option has the lowest impact on global warming and eutrophication, and the highest impact on stratospheric ozone depletion.     

Meeting the challenges in the development of risk-benefit assessment of foods

BackgroundRisk-benefit assessment (RBA) of foods aims to assess the combined negative and positive health effects associated with food intake. RBAs integrate chemical and microbiological risk assessment with risk and benefit assessment in nutrition.Scope and ApproachBased on the past experiences and the methodological differences between the underlying research disciplines, this paper aims to describe the recent progress in RBAs, identifying the key challenges that need to be addressed for further development, and making suggestions for meeting these challenges.Key Findings and ConclusionsTen specific challenges are identified and discussed. They include the variety of different definitions and terminologies used in the underlying research disciplines, the differences between the “bottom-up” and the “top-down” approaches and the need for clear risk-benefit questions. The frequent lack of data and knowledge with their consequential uncertainties is considered, as well as the imbalance in the level of scientific evidence associated with health risks and benefits. The challenges that are consequential to the need of considering substitution issues are discussed, as are those related to the inclusion of microbiological hazards. Further challenges include the choice of the integrative health metrics and the potential scope of RBAs, which may go beyond the health effect. Finally, the need for more practical applications of RBA is stressed. Suggestions for meeting the identified challenges include an increased interdisciplinary consensus, reconsideration of methodological approaches and health metrics based on a categorisation of risk-benefit questions, and the performance of case studies to experience the feasibility of the proposed approaches.     

Critical review: life-cycle inventory procedures for long-term release of metals

Life-cycle assessment (LCA) is the method of inventorying, assessing, and interpreting environmental interventions caused by products and product systems through their life cycle. The ecotoxicity of metals has proven a challenge for LCA given metal characteristics such as reversibility of removal processes, speciation, and the effect on bioavailability and ecotoxic effect assessment. Our review focuses on the first part of the ecotoxic impact chain for metals, i.e., the release of metals from solid deposits. According to the principle of temporal justice, sustainability assessment tools such as LCA should accountfor emissions regardless of temporal location distribution. This is in LCA commonly interpreted as leaching until depletion of metals bound in solid wastes under the presumption that infinite time implies infinite weathering. This approach is risk conservative for metals and it hampers the use of LCA to assess remediation projects for soils and sediments contaminated by inorganic substances. We discuss metal significance and inventory issues in LCA, and review existing and proposed approachesto make LCA applicable to metal long-term emission.     

Next‐generation biofuels: a new challenge for yeast

Economic growth depends strongly on the availability and price of fuels. There are various reasons in different parts of the world for efforts to decrease the consumption of fossil fuels, but biofuels are one of the main solutions considered towards achieving this aim globally. As the major bioethanol producer, the yeast Saccharomyces cerevisiae has a central position among biofuel‐producing organisms. However, unprecedented challenges for yeast biotechnology lie ahead, as future biofuels will have to be produced on a large scale from sustainable feedstocks that do not interfere with food production, and which are generally not the traditional carbon source for S. cerevisiae. Additionally, the current trend in the development of biofuels is to synthesize molecules that can be used as drop‐in fuels for existing engines. Their properties should therefore be more similar to those of oil‐derived fuels than those of ethanol. Recent developments and challenges lying ahead for cost‐effective production of such designed biofuels, using S. cerevisiae‐based cell factories, are presented in this review. Copyright © 2015 John Wiley & Sons, Ltd.     

Brown and black grease suitability for incorporation into feeds and suitability for biofuels

Waste grease lipids used in animal feeds have been the cause of food recalls in Europe, where such materials were incorporated into animal feedstuffs. This resulted in unwanted residues in human food. The composition of such lipid sources has been lacking. Seventeen composite trap grease and isolated brown grease samples were analyzed. Analytes included nutrients, metals, and volatile organic compounds. Analytes were selected for relevance to wastewater treatment and resource reuse potential. Moisture averaged 89.4% and the pH was 3.8. The 5-day biological oxygen demand was 32,531 mg/liter, solids were 7.5%, and fats, oil, and grease were 48,970 mg/liter. Non-polychlorinated biphenyl volatile organic compounds were surveyed. In the 17 grease samples, 14 contained an average of 102.5 μg/liter chloroform; 11 samples contained acetone, averaging 369 μg/liter; 9 samples contained 2-butanone, with an average of 484 μg/liter; and 8 contained an average of 710 μg/liter methylene chloride and toluene at 311 μg/liter. The mean concentration of copper in 17 composite samples ranged from 15 to 239 mg/liter, iron averaged 314 mg/liter, lead means ranged from 2.5 to 24 mg/liter, and magnesium averaged 975 mg/liter. It is hypothesized that food preparation facility cleaning and chlorinated cleaning-disinfection agents combined with the organics in the low-pH environment of the traps produce potentially carcinogenic compounds. It is recommended that these waste grease materials be used as a feedstock for biofuel.     

A demand-centered, hybrid life-cycle methodology for city-scale greenhouse gas inventories

Greenhouse gas (GHG) accounting for individual cities is confounded by spatial scale and boundary effects that impact the allocation of regional material and energy flows. This paper develops a demand-centered, hybrid life-cycle-based methodology for conducting city-scale GHG inventories that incorporates (1) spatial allocation of surface and airline travel across colocated cities in larger metropolitan regions, and, (2) life-cycle assessment (LCA) to quantify the embodied energy of key urban materials--food, water, fuel, and concrete. The hybrid methodology enables cities to separately report the GHG impact associated with direct end-use of energy by cities (consistent with EPA and IPCC methods), as well as the impact of extra-boundary activities such as air travel and production of key urban materials (consistent with Scope 3 protocols recommended by the World Resources Institute). Application of this hybrid methodology to Denver, Colorado, yielded a more holistic GHG inventory that approaches a GHG footprint computation, with consistency of inclusions across spatial scale as well as convergence of city-scale per capita GHG emissions (approximately 25 mt CO2e/person/year) with state and national data. The method is shown to have significant policy impacts, and also demonstrates the utility of benchmarks in understanding energy use in various city sectors.     

2013威龙有机葡萄酒系列报导——4 威龙有机葡萄酒对接全渠道

在威龙葡萄酒股份有限公司推出有机葡萄酒时,业内有一种观点认为,威龙有机葡萄酒的整体价位抬升了一个档次,可能只适合在团购渠道销售。然而,威龙有机葡萄酒多年的快速发展证明,之前业内的这种观点是有失偏颇的。从2012年开始,威龙有机葡萄酒在中国掀起了有机风潮,在中国内地基本上完成了各个省、市的市场布局。     

Evaluation of life-cycle air emission factors of freight transportation

Life-cycle air emission factors associated with road, rail, and air transportation of freight in the United States are analyzed. All life-cycle phases of vehicles, infrastructure, and fuels are accounted for in a hybrid life-cycle assessment (LCA). It includes not only fuel combustion, but also emissions from vehicle manufacturing, maintenance, and end of life, infrastructure construction, operation, maintenance, and end of life, and petroleum exploration, refining, and fuel distribution. Results indicate that total life-cycle emissions of freight transportation modes are underestimated if only tailpipe emissions are accounted for. In the case of CO2 and NOx, tailpipe emissions underestimate total emissions by up to 38%, depending on the mode. Total life-cycle emissions of CO and SO2 are up to seven times higher than tailpipe emissions. Sensitivity analysis considers the effects of vehicle type, geography, and mode efficiency on the final results. Policy implications of this analysis are also discussed. For example, while it is widely assumed that currently proposed regulations will result in substantial reductions in emissions, we find that this is true for NOx, emissions, because fuel combustion is the main cause, and to a lesser extent for SO2, but not for PM10 emissions, which are significantly affected by the other life-cycle phases.     

慕思睡眠文化中国梦——2012—2013GIA全球家居创新奖巡礼

作为全球健康睡眠系统的首创者，慕思寝室用品有限公司专注于健康睡眠系统的研发、制造和营销。慕思倡导个性化“量身定制”与“体验式”消费，并致力于改善人类睡眠质量的产品与服务创新。     

喷墨油墨大观

喷墨印刷油墨（以下简称喷墨油墨）是喷墨印刷设备使用的油墨,是喷墨印刷中重要的耗材,直接决定了喷墨印刷质量的高低。但是具体到对喷墨涵墨的理解、对其与各种喷墨印刷方式的匹配（印刷适性）问题等,也许并不是那么容易回答。下面,就让笔者对此进行简要分析。抛砖引玉,以期一同探讨喷墨油墨的奥妙。     

Event report: SynBio Workshop (Paris 2012) – Risk assessment challenges of Synthetic Biology

In Europe and beyond, several advisory bodies have been monitoring the developments in the field of Synthetic Biology. Reports have been sent to national governments for information on the developments and possible regulatory and risk assessment questions raised by this field. To put the issues in a broader perspective, four national biosafety advisory bodies (the French High Council for Biotechnology, the German Central Committee on Biological Safety, the Netherlands Commission on Genetic Modification and the Belgian Scientific Institute of Public Health (Biosafety and Biotechnology Unit)) decided to join forces and organize an international scientific workshop to review some of the latest scientific insights and look into possible challenges in the risk assessment of Synthetic Biology. The SynBio Workshop (Paris 2012) – Risk assessment challenges of Synthetic Biology took place on the 12th of December 2012 and gathered scientists from biosafety advisory bodies from fifteen European countries, from the European Food Safety Authority as well as representatives of the European Commission, together with research scientists selected for their excellence in the field. The workshop was divided into two sessions: the first session gave an overview of four major fields in Synthetic Biology. The second session was set up for discussion with a scientific panel and the audience to identify and address relevant questions for risk assessment raised by recent and future developments of Synthetic Biology. An overview of the workshop and the discussion points put forward during the day are discussed in this document.