A model to estimate road transport emissions from the entire life cycle

Embodied GHG emissions of buildings – The hidden challenge for effective climate change mitigation

The body of life cycle assessment (LCA) literature is vast and has grown over the last decade at a dauntingly rapid rate. Many LCAs have been published on the same or very similar technologies or products, in some cases leading to hundreds of publications. One result is the impression among decision makers that LCAs are inconclusive, owing to perceived and real variability in published estimates of life cycle impacts. Despite the extensive available literature and policy need formore conclusive assessments, only modest attempts have been made to synthesize previous research. A significant challenge to doing so are differences in characteristics of the considered technologies and inconsistencies in methodological choices (e.g., system boundaries, coproduct allocation, and impact assessment methods) among the studies that hamper easy comparisons and related decision support. An emerging trend is meta-analysis of a set of results from LCAs, which has the potential to clarify the impacts of a particular technology, process, product, or material and produce more robust and policy-relevant results. Meta-analysis in this context is defined here as an analysis of a set of published LCA results to estimate a single or multiple impacts for a single technology or a technology category, either in a statisticalmore » sense (e.g., following the practice in the biomedical sciences) or by quantitative adjustment of the underlying studies to make them more methodologically consistent. One example of the latter approach was published in Science by Farrell and colleagues (2006) clarifying the net energy and greenhouse gas (GHG) emissions of ethanol, in which adjustments included the addition of coproduct credit, the addition and subtraction of processes within the system boundary, and a reconciliation of differences in the definition of net energy metrics. Such adjustments therefore provide an even playing field on which all studies can be considered and at the same time specify the conditions of the playing field itself. Understanding the conditions under which a meta-analysis was conducted is important for proper interpretation of both the magnitude and variability in results. This special supplemental issue of the Journal of Industrial Ecology includes 12 high-quality metaanalyses and critical reviews of LCAs that advance understanding of the life cycle environmental impacts of different technologies, processes, products, and materials. Also published are three contributions on methodology and related discussions of the role of meta-analysis in LCA. The goal of this special supplemental issue is to contribute to the state of the science in LCA beyond the core practice of producing independent studies on specific products or technologies by highlighting the ability of meta-analysis of LCAs to advance understanding in areas of extensive existing literature. The inspiration for the issue came from a series of meta-analyses of life cycle GHG emissions from electricity generation technologies based on research from the LCA Harmonization Project of the National Renewable Energy Laboratory (NREL), a laboratory of the U.S. Department of Energy, which also provided financial support for this special supplemental issue. (See the editorial from this special supplemental issue [Lifset 2012], which introduces this supplemental issue and discusses the origins, funding, peer review, and other aspects.) The first article on reporting considerations for meta-analyses/critical reviews for LCA is from Heath and Mann (2012), who describe the methods used and experience gained in NREL's LCA Harmonization Project, which produced six of the studies in this special supplemental issue. Their harmonization approach adapts key features of systematic review to identify and screen published LCAs followed by a meta-analytical procedure to adjust published estimates to ones based on a consistent set of methods and assumptions to allow interstudy comparisons and conclusions to be made. In a second study on methods, Zumsteg and colleagues (2012) propose a checklist for a standardized technique to assist in conducting and reporting systematic reviews of LCAs, including meta-analysis, that is based on a framework used in evidence-based medicine. Widespread use of such a checklist would facilitate planning successful reviews, improve the ability to identify systematic reviews in literature searches, ease the ability to update content in future reviews, and allow more transparency of methods to ease peer review and more appropriately generalize findings. Finally, Zamagni and colleagues (2012) propose an approach, inspired by a meta-analysis, for categorizing main methodological topics, reconciling diverging methodological developments, and identifying future research directions in LCA. Their procedure involves the carrying out of a literature review on articles selected according to predefined criteria.« less

Life cycle assessment was used to study the following six major stages of animal husbandry: feed grain planting, feed grain transportation and processing, livestock and poultry breeding, livestock and poultry gastrointestinal fermentation, manure management, and livestock and poultry product slaughter and processing. The greenhouse gas emissions from animal husbandry in Shandong Province were quantified for the entire 20-year period spanning from 2002 to 2021. This study also analyzed the emission patterns and characteristics associated with this life cycle assessment. The results show that over the past 20 years, the greenhouse gas emissions from animal husbandry in Shandong Province increased continuously, the greenhouse gas emission intensity decreased continuously, and both of these trends tended to be stable. From a life cycle standpoint, the primary sources of greenhouse gas emissions were gastrointestinal fermentation and the management of livestock and poultry manure. In terms of the structure of livestock and poultry breeding, poultry was the primary source of greenhouse gas emissions. The emission characteristics of the greenhouse gases produced by animal husbandry varied among different cities in Shandong Province. The main source of greenhouse gas discharged due to animal husbandry in Zibo and Binzhou was Ecattle; in Dongying, it was Esheep; and in the remaining cities, it was mainly Epoultry.

Addressing the social life cycle inventory analysis data gap: Insights from a case study of cobalt mining in the Democratic Republic of the Congo

Aluminum production is a major energy consumer and source of greenhouse gas (GHG) emissions. The regional transfer of the primary aluminum (PA) industry, which mainly consists of the processes of electrolysis and aluminum ingot casting, is currently an important international trend in aluminum industrial development. However, the changes in GHG emissions from aluminum production for such transfers are unclear. This study has established a life cycle assessment model of aluminum industry based on regional transfers in the context of China, determined the GHG emissions of PA and secondary aluminum (SA) production, examined the GHG emission changes of PA production based on regional industry transfer between the years 2007 and 2017, and explored seven driving factors that affect GHG emissions in the aluminum industry. GHG emissions per unit PA and SA production in China decreased by 18.6% and 6.3%, respectively, but the total GHG emissions from aluminum industry still increased by 2.2 times between the years 2007 and 2017. The driving factor analysis showed that the major positive effects of GHG emissions from China's aluminum industry from 2007 to 2017 included the production scale effect of SA and the energy structure effect. Existing regional transfers (between the years 2007 and 2017) did not deliver significant annual GHG emissions reductions. Currently, Xinjiang, Henan, Shandong, and Inner Mongolia are the main PA production provinces in China, although regional transfers have been implemented. This study provides a basis for the improvement and sustainable development of the aluminum industry, suggests policies for regional aluminum development, and proposes a beneficial layout of the aluminum industry.

Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices.

The carbon footprint of integrated milk production and renewable energy systems – A case study

A review of life cycle greenhouse gas (GHG) emissions of commonly used ex-situ soil treatment technologies

Background Family ranches are major sources of livestock-related greenhouse gas (GHG) emissions in global pastoral ecosystems. We conducted semi-structured interviews and collected data on livestock production and the livelihoods of 235 family ranches in a desert steppe of Inner Mongolia where intensive pastoral management is practiced. A cradle-to-farmgate life cycle assessment (LCA) was performed with functional units standardized as 1 kg live weight (LW) for beef cattle and meat sheep breeds. Structural equation modeling (SEM) was employed to elucidate the socioeconomic forcing mechanisms on GHG emissions. Results Live weight GHG emission varied substantially by livestock type, descending from cows (59.89 kg CO2e/kg) to yearlings (36.32 kg CO2e/kg), bulls (22.26 kg CO2e/kg), calves (20.92 kg CO2e/kg) and meat sheep breeds (19.66 kg CO2e/kg), and GHG emissions from livestock production accounted 77.95% of the total GHG emissions of the family ranches, more than three times those from household life consumption (22.05%). Enteric fermentation in livestock was the dominant GHG emission source (68.15%), followed by food consumption (8.58%) and coal combustion (8.13%). Among demographic characteristics, economic status appears the primary factor influencing the total GHG emission. Conclusions Our micro-scale analysis provides insight for addressing GHG mitigation in pastoral systems through coupling the socioeconomic forcing mechanisms on methane emissions. We advocate the use of methane-inhibiting feed additives and shifts toward heating systems that use renewable energy while sustaining pastoral life, offering actionable pathways for low-carbon transition in extensively grazed pastoral systems.

Municipal wastewater treatment plants (WWTPs) play an indispensable role in improving environmental water quality in urban areas. Existing WWTPs, however, are an important source of greenhouse gas (GHG) emissions and may not be able to treat increasingly complicated wastewater or meet stringent environmental standards. These WWTPs can be updated to address these challenges, and different technologies are available but with potentially different environmental implications. Life cycle assessment (LCA) is a widely used approach to identify alternatives with lower environmental footprint. In this study, LCA was applied to an actual urban WWTP, considering four scenarios involving upgrading and energy-resource recovery. The environmental performance with respect to life cycle GHG emissions and eutrophication impact was analyzed. The environmental benefits of reduced water pollution and energy and material displacement associated with energy-resource recovery process were also considered. The results showed tradeoffs among the four scenarios. Although upgrading the studied WWTP would meet discharge standard for total phosphorus and reduce total eutrophication impact by about 19%, it would increase GHG emissions by at least 16%. Besides, the energy-resource recovery mode for existing WWTP (S2) performs the best in terms of GHG emissions. For different biogas utilization methods, combined heat and power (CHP) system is superior to the existing method of delivering biogas to gas grid, in terms of energy recovery or reduction of GHG emissions and eutrophication impact. Our research results may provide a reference for plant managers to select the most environmentally friendly upgrade scheme and energy-resource recovery technique for future upgrade projects.

Life cycle assessment in support of sustainable transportation

دراینمقاله،میزانو ارزش انتشارگازهایگلخانه‌ای اکسید‌نیتروس(N2O) و دی‌اکسید‌کربن(CO2)حاصلازتولید حبوبات منتخب ایران (شامل نخود، لوبیا و عدس) با استفاده از مدل GHGE،برایسالزراعی91-90برآورد شده است.نتایج نشان‌داد که استان‌هایفارسوبوشهر، به‌ترتیبباتولیدسالانه271/79 و 004/0 تنN2O، بیشترینوکمترینمیزانتولیدگاز گلخانه‌ایN2Oرا دارامی‌باشند. همچنین استان‌هایلرستانوبوشهر نیز به‌ترتیب باتولیدسالانه83/10327 و33/1‌تنCO2،بیشترینوکمترینمیزانتولیدگاز گلخانه‌ایCO2را به‌خود اختصاص داده‌اند. مجموعهزینه‌هایزیست‌محیطی انتشار گازهای گلخانه‌ای N2O و CO2 کلکشورنیزحدود705/32‌میلیاردریالبرآوردگردید. باتوجهبه یافته‌ها، مدیریت کودهای نیتروژنه مصرفی در مزارعوتوسعهسیاست‌کاهشمیزانانتشاربه‌همراه مالیات زیست‌محیطی انتشار گازهای گلخانه‌ای بر سطوح مختلف تولید پیشنهاد شده ‌است. واژه‌های کلیدی: اکسید‌نیتروس، دی‌اکسید‌کربن، حبوبات، گازهای گلخانه‌ای

انتشار گازهای گلخانه‌ای و اثرات آن بر گرمایش جهانی یکی از چالش‌های جدی کشورهای توسعه‌یافته و درحال‌توسعه محسوب می‌شود. بر اساس پیمان کیوتو، کشورهای مختلف موظف به محاسبه و اعلام میزان انتشار گازهای گلخانه‌ای شدند. بررسی میزان انتشار گازهای گلخانه‌ای کشورهای مختلف این امکان را فراهم می‌آورد تا ضمن ارائه تصویری از سهم کشورها در تولید گازهای گلخانه‌ای، جایگاه ایران نیز در این مجموعه مشخص شود. این مقاله تلاش دارد تا میزان و ارزش انتشار گازهای گلخانه‌ای اکسید نیتروس (N2O) و دی‌اکسید کربن (CO2) حاصل از دانه های روغنی تولیدی منتخب در ایران (سویا، کلزا، ذرت دانه ای و سایر دانه های روغنی) را با استفاده از مدل GHGE، برای سال زراعی 91-90 برآورد نماید. نتایج نشان داد استان‌های خوزستان و زنجان به ترتیب، با تولید سالانه 49/341 و 004/0 تن، بیش ترین و کم ترین میزان تولید گاز گلخانه‌ای N2O را در سطح کشور دارا می‌باشند. همچنین استان‌های گلستان و هرمزگان نیز به ترتیب، با تولید سالانه 47/7841 و 24/0 تن دی‌اکسید کربن بیش ترین و کم ترین میزان تولید گاز گلخانه‌ای CO2 را به خود اختصاص داده‌اند. مجموع هزینه‌های انتشار گازهای گلخانه‌ای N2O و CO2 کل کشور نیز حدود 331/27 میلیارد ریال برآورد گردید. باتوجه به یافته ها، اصلاح و تغییر شیوه‌های مدیریتی کشاورزی نسبت به سطح زیرکشت محصولات زراعی، مدیریت و افزایش کارایی کودهای ازته مصرفی در مزارع و توسعه سیاست‌های کاهش میزان انتشار به‌همراه مالیات زیست-محیطی انتشار گازهای گلخانه ای به سیاست‌گذاران این عرصه پیشنهاد شد.

As global warming becomes increasingly severe, environmental consciousness has become critical in the design and operation of globally integrated supply chain networks. Product Carbon Footprint is defined as the life cycle Greenhouse Gas (GHG) emissions of goods and services and it can be considered as a simplified life cycle assessment restricted to a single impact category. In order for companies to better confront GHG emission issues, calculating product carbon footprint and analysing how various parameters affect the carbon footprint over the entire life cycle of a product is necessary. This paper studies the carbon footprint across supply chains and proposes a method of production carbon footprint analysis in a supply chain based on life cycle assessment, including the following: taking product life cycle as the span of carbon footprint analysis, with all kinds of complex information system as objects and then carrying out the carbon footprint knowledge extraction according to the concept model format in physical database; building a carbon footprint analysis ontology, which is related to product life cycle in supply chain environment; calculating the quantification of carbon footprint through GHG emissions over the entire life cycle, and designing a tool for product carbon footprint in supply chain environment.

Based on the localized data of environmental load, this study has establishedthe life cycle assessment (LCA) model of battery electric passenger vehicle(BEPV) that be produced and used in China, and has evaluated the energyconsumption and greenhouse gases (GHGs) emission during vehicle pro-duction and operation. The results show that the total energy consumptionand GHG emissions are 438GJ and 37,100kg (in terms of CO2 equivalent)respectively. The share of GHG emissions in total emissions at the productionstage is 24.6%, and 75.4% GHG emissions are contributed by the operationalstage. The main source of energy consumption and GHG emissions at vehicleproduction stage is the extraction and processing of raw materials. TheGHG emissions of raw materials production accounts for 75.0% in the GHGemissions of vehicle production and 18.0% in the GHG emissions of fulllife cycle. The scenario analysis shows that the application of recyclablematerials, power grid GHG emission rates and vehicle energy consumption rates have significant influence on the carbon emissions in the life cycle ofvehicle. Replacing primary metals with recycled metals can reduce GHGemissions of vehicle production by about 7.3%, and total GHG emissionscan be reduced by about 1.8%. For every 1% decrease in GHG emissionsper unit of electricity, the GHG emissions of operation stage will decrease byabout 0.9%; for every 1.0% decrease in vehicle energy consumption rate, thetotal GHG emissions decrease by about 0.8%. Therefore, developing cleanenergy, reducing the proportion of coal power, optimizing the productionof raw materials and increasing the application of recyclable materials areeffective ways to improve the environmental performance of BEPV.