Accounting for Embodied Carbon Emissions in Planning and Optimisation of Transport Activities During Construction

Using LCA to research carbon footprint for precast concrete piles during the building construction stage: A China study

Carbon emission scenarios of China's construction industry using a system dynamics methodology – Based on life cycle thinking

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

Carbon emission is further intensified as urbanization and industrialization continue to accelerate. China has maintained its rapid economic development and urbanization in the last 2 decades. The development of the construction industry has not only consumed a large number of energy sources but also resulted in significant carbon emissions, causing some environmental damage. Recognizing the major influencing factors of carbon emissions in the construction industry has become a research hotspot to alleviate environmental pollution caused by the construction industry and meet industrial demands for energy saving and emission reduction. In this study, the factors that influence annual carbon emissions of different building types in China from 2011 to 2018 were decomposed by Logarithmic Mean Divisia Index (LMDI) through a case study in Henan Province. The major influencing factors of carbon emissions have been identified. Results demonstrate that the per capita carbon emission in the construction industry in Henan Province remains high from 2011 to 2018, but it decreases year by year. Carbon emissions from the construction industry in Henan Province increase due to economic development and energy structure. Energy efficiency can inhibit carbon emissions from the construction industry in Henan Province. The obtained conclusions have a positive effect on analyzing annual variations in carbon emissions from the construction industry in a region, identifying influencing factors, and proposing specific countermeasures of energy saving and emission reduction.

Achieving low carbon emissions in buildings has a critical impact on controlling global greenhouse gas (GHG) emissions. With the boom in educational buildings, especially those with reinforced concrete structures, carbon emissions from such buildings are brought to the fore. Among building carbon emissions, embodied carbon emissions are closely related to building structure and materials. This paper aims to study the embodied carbon emissions of a Chinese educational building in the design stage with a quantitative method – process-based life cycle assessment, summarizing the carbon emission characteristics of construction materials and proposing corresponding optimization methods. The results indicate that local data of emission factors is preferred for calculating the embodied carbon emissions and the number of construction materials could be obtained through design estimates; that embodied carbon emissions from material manufacturing are much higher than those from material transportation; that steel and concrete are the two most carbon-emitting materials in the reinforced concrete frame structure educational building; and that using local and reused materials are the two main low-carbon optimization measures, with carbon emission reduction contribution rates of 19.7% and 80.3%, respectively, which reused and recycled construction materials should be considered a priority in reducing the embodied carbon emissions of buildings.

A scientific carbon accounting system can help enterprises reduce carbon emissions. This study took an enterprise in the Yangtze River basin as a case study. The accounting classification of carbon emissions in the life cycle of lime production was assessed, and the composition of the sources of carbon emission was analyzed, covering mining explosives, fuel (diesel, coal), electricity and high-temperature limestone decomposition. Using the IPCC emission factor method, a carbon life cycle emission accounting model for lime production was established. We determined that the carbon dioxide equivalent from producing one ton of quicklime ranged from 1096.68 kg CO2 equiv. to 1176.96 kg CO2 equiv. from 2019 to 2021 in the studied case. The decomposition of limestone at a high temperature was the largest carbon emission source, accounting for 64% of the total carbon emission. Coal combustion was the second major source of carbon emissions, accounting for 31% of total carbon emissions. Based upon the main sources of carbon emission for lime production, carbon emission reduction should focus on CO2 capture technology and fuel optimization. Based on the error transfer method, we calculated that the overall uncertainty of the life cycle carbon emissions of quicklime from 2019 to 2021 are 2.13%, 2.07% and 2.09%, respectively. Using our analysis of carbon emissions, the carbon emission factor of producing one unit of quicklime in the lime enterprise in the Yangtze River basin was determined. Furthermore, this research into carbon emission reduction for lime production can provide a point of reference for the promotion of carbon neutrality in the same industry.

During their life cycle, buildings not only consume a lot of resources and energy, but also produce a large amount of carbon emissions, which have a serious impact on the environment. In the context of global emissions reduction, the trend has been to low carbon buildings. As a major carbon emitting country, it is urgent to promote emission reduction in the construction industry and to establish a model for carbon emissions and calculation in buildings. To this end, this paper collates life cycle carbon emission calculation methods based on life cycle theory and establishes a mixed life cycle carbon emission calculation model for buildings to provide ideas for low carbon buildings in China. A case study of a hospital in Guangming City, Anhui Province is also conducted to verify the feasibility of the model. The results show that the total carbon emission of the hospital is 43283.66 tCO2eq, with the production phase, construction phase, use and maintenance phase and end-of-life phase accounting for 9.13%, 0.35%, 90.06% and 0.46% of the total carbon emission respectively. An analysis of the factors influencing carbon emissions at each stage is presented, and recommendations are given for corresponding emission reduction measures. The carbon emission calculation model based on the hybrid LCA proposed in this study enables a more comprehensive consideration of carbon emissions in the life cycle of a building, and has implications for the study of building carbon emission calculation.

The construction industry not only consumes a lot of energy but also emits large volumes of carbon dioxide. Most countries have established target reduction values of the carbon dioxide emissions to alleviate environmental burdens and promote sustainable development. The reduction in carbon dioxide emissions in the construction industry has been taking place in various ways as buildings produce large quantities of the carbon dioxide over their construction life cycle. The aim of this study is to assess and compare the carbon dioxide emissions of an ordinary reinforced concrete slab and the voided slab system applied to a case study involving a commercial-residential complex building in South Korea. Process-based life-cycle assessment (LCA) is adopted to compute the carbon dioxide emissions during the construction phase, which includes all processes from material production to the end of construction. The results indicate that the total CO2 emissions are 257,230 and 218,800 kg CO2 for the ordinary reinforced concrete slab and the voided slab system, respectively. The highest contributor to CO2 reduction is the embodied carbon dioxide emissions of the building materials, which accounts for 34,966 kg CO2. The second highest contributor is the transportation of the building materials, accounting for 3417 kg CO2.

Accurate and verifiable emission reductions are a function of the degree of transparency and stringency of the protocols employed in documenting project- or program-associated emissions reductions. The purpose of this guide is to provide a background for law and policy makers, urban planners, and project developers working with the many Greenhouse Gas (GHG) emission reduction programs throughout the world to quantify and/or evaluate the GHG impacts of Natural Gas Vehicle (NGVs). In order to evaluate the GHG benefits and/or penalties of NGV projects, it is necessary to first gain a fundamental understanding of the technology employed and the operating characteristics of these vehicles, especially with regard to the manner in which they compare to similar conventional gasoline or diesel vehicles. Therefore, the first two sections of this paper explain the basic technology and functionality of NGVs, but focus on evaluating the models that are currently on the market with their similar conventional counterparts, including characteristics such as cost, performance, efficiency, environmental attributes, and range. Since the increased use of NGVs, along with Alternative Fuel Vehicle (AFVs) in general, represents a public good with many social benefits at the local, national, and global levels, NGVs often receive significant attention in the form of legislative and programmatic support. Some states mandate the use of NGVs, while others provide financial incentives to promote their procurement and use. Furthermore, Federal legislation in the form of tax incentives or procurement requirements can have a significant impact on the NGV market. In order to implement effective legislation or programs, it is vital to have an understanding of the different programs and activities that already exist so that a new project focusing on GHG emission reduction can successfully interact with and build on the experience and lessons learned of those that preceded it. Finally, most programs that deal with passenger vehicles--and with transportation in general--do not address the climate change component explicitly, and thus there are few GHG reduction goals that are included in these programs. Furthermore, there are relatively few protocols that exist for accounting for the GHG emissions reductions that arise from transportation and, specifically, passenger vehicle projects and programs. These accounting procedures and principles gain increased importance when a project developer wishes to document in a credible manner, the GHG reductions that are achieved by a given project or program. Section four of this paper outlined the GHG emissions associated with NGVs, both upstream and downstream, and section five illustrated the methodology, via hypothetical case studies, for measuring these reductions using different types of baselines. Unlike stationary energy combustion, GHG emissions from transportation activities, including NGV projects, come from dispersed sources creating a need for different methodologies for assessing GHG impacts. This resource guide has outlined the necessary context and background for those parties wishing to evaluate projects and develop programs, policies, projects, and legislation aimed at the promotion of NGVs for GHG emission reduction.

This study was based on the global demand for low-carbon development. The multitrip vehicle mode is a promising approach to reduce carbon emissions in the vehicle routing problem (VRP). It was hypothesized that emission reductions might be achieved by replacing the single-trip vehicle mode with a multitrip mode. To evaluate the carbon emissions reduction potential of the multitrip mode accurately over the single-trip mode, the set-partitioning formulation was used to obtain the optimal single-trip solution VRP with the minimal carbon emissions and to construct a trip-chain-oriented set-partitioning formulation to obtain the optimal multitrip solution VRP with minimal carbon emissions. The two set-partitioning formulations could be exactly solved by CPLEX. Through a comparison of the single-trip and multitrip carbon emissions for picking up and delivering customers to an airport service, which was a special case of the VRP, it can be concluded that the multitrip mode could reduce carbon emissions by approximately 16%. To identify the situations under which carbon emissions could be efficiently reduced by replacing the single-trip mode with the multitrip mode, the influence factors were analyzed. On the basis of experimental results, a summary is provided of several managerial insights that can be used to reduce carbon emissions successfully by implementing the multitrip mode.

低碳导向下土地覆被演变模拟——以深圳市为例

Rice-crayfish farming represents a typical green and low-carbon alternative to rice monoculture. It is important to investigate the carbon sequestration and emission reduction effect of rice-crayfish farming to improve paddy soil quality, ensure food security, and address climate change challenges. In this study, we systematically evaluated the carbon sequestration and emission reduction effects of rice-crayfish farming through field experiment, carbon footprint assessment, and the DeNitrification-DeComposition (DNDC) model. Compared with rice monoculture, rice-crayfish farming increased the soil organic carbon (SOC) storage, and reduced the annual CH4 emissions, annual N2O emissions, and global warming potential (GWP) by 6.4, 2.4 and 6.2%, respectively. Field engineering, nutrient management and regional variations contributed to differences in carbon emissions and carbon footprints associated with rice-crayfish farming. Moreover, reduction of CH4 emissions was pivotal for decreasing carbon footprint in rice-crayfish farming. DNDC model simulation revealed that the carbon sequestration potential of the rice-crayfish system is influenced by agronomic practices (planting pattern, area proportion of culture ditch, proportion of straw returning, nitrogen fertilizer application, tillage depth, and irrigation regime) and regional climate, landform, and soil. Optimized rice-crayfish farming exhibited varying carbon sequestration effects across different regions. Conversion from rice monoculture to optimized rice-crayfish farming altered the regional carbon sequestration and source dynamics. This study provides a rationale for developing tailored strategies to maximize carbon sequestration and minimize carbon emissions at the regional or farm scales.

Life cycle assessment is an environmental method which estimates either a process or a building material within the cradle-to-grave cycle. Presently, it is one of a few tools that include all factors which may influence the environment. The authors used this tool to prove effects connected with potential efficient energy levels and a reduction in CO2 emissions within a building’s life cycle. For the purpose of our analyses, several types of single-family building were chosen and they were subjected to analysis in the fixed location of Warsaw. The research scope included a numerical analysis of the buildings concerning the level of embodied energies and the emission of greenhouse gases. The performed analysis proved that, within a 50-year cycle, the difference between the embodied energy from the best and worst building choices can amount to 14.87%, whereas a reduction in embodied carbon emissions can reach 20.65%. Each change in the building’s form and the type of building materials used, regardless of the usable area, influence the environmental impact. Therefore, this paper concludes that LCA, as a management tool, should be used cyclically as part of each phase of the design process. A multi-criteria method for selecting architectural solutions was proposed which considered minimum cumulative primary energy, minimum cumulative carbon emission and minimum cost of constructing a building.

The construction industry is actively working to improve its operations’ sustainability and reduce buildings’ ecological impact on climate change. One approach involves integrating Building Information Modeling (BIM) with Life Cycle Assessment (LCA) to streamline data input, calculate environmental impacts, and optimize output data. This case study focuses on using the One-Click LCA plugin to explore LCA-BIM integration for sustainable construction.The study examines the carbon emissions of steel and concrete frame public structures and assesses the role of surrounding trees in achieving carbon neutrality. Two innovative public buildings in China’s Zhejiang province serve as the case study’s subject. The One-Click LCA plugin in Revit is a quick and user-friendly tool, providing concrete and steel structure results and generating informative graphs for easy comparison.The findings reveal that the A1-A3 material stage during the design phase contributes the most to emissions and biogenic carbon storage. By demonstrating the practical implementation of LCA-BIM integration using the One-Click LCA plugin, this case study contributes to the knowledge base on sustainable construction practices. The results can guide decision-making for architects, engineers, and construction professionals, empowering them to make informed choices that minimize carbon emissions and promote environmentally-friendly design strategies.

BIM-based approach for the integrated assessment of life cycle carbon emission intensity and life cycle costs