A novel topology optimization method of welded box-beam structures motivated by low-carbon manufacturing concerns

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

Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total ...

Livestock production is under growing public and scientific scrutiny for its greenhouse gas (GHG) emissions. This article contains a preliminary assessment of the inclusion of upstream life-cycle GHG emissions in concentrated feeds design, using the most common nonlinear programming optimization algorithms to determine feed composition. First, GHG emissions are included as costs in a single criteria optimization problem. The unit price of GHG emissions was obtained using a genetic algorithm. Second, GHG emissions are included as a target function to minimize in a multi criteria optimization problem using goal attainment programming. Results obtained after both optimization methods were applied to two case studies, namely fattening pigs and rabbit feeds. Changing ingredients in concentrated feed blends has a marginal effect on GHG emissions due to mandatory nutritional constraints. If the optimization is unconstrained, the maximum possible decrease in GHG emissions is 27.5% for the pigs feed, accompanied by increasing costs and a decrease in feed nutritional quality. To maintain nutritional integrity, the maximum possible reduction in GHG emissions is 7.5%. Considering cost as an optimization variable in the problem, the maximum decreases are even lower. It is possible to decrease emissions by 71% for the rabbits feed, but the cost of the reduction is higher than the opportunity cost for farmers to reduce GHG emissions using other strategies. These results are qualitatively robust but critically depend on feed ingredients GHG emissions and cost data.

As addressed by many studies, greenhouse gas has a significant impact on the different aspects of life and more importantly on the whole environment. The excessive emission of green gas leads to climate change which is regarded as one of the most significant challenges of 21 century. Hence, in this regard, this paper has addressed the changing greenhouse gas (GHG) emissions in 18 countries of the MENA region. For this purpose, ten different scenarios of this disease's future status and its restrictions were considered in an input–output modelling framework. The empirical results indicated that the emission of greenhouse gas is reduced under all scenarios. However, some countries experience more reduction due to the restriction because of COVID-19 like Syria, Iran, Yemen and Lebenon. Based on the ninth scenario, Iran and Syria have the highest reduction in emission of greenhouse gas by 13.1 and 13.8 per cent, and based on the tenth scenario, Lebenan and Syria will experience the highest reduction in emission by about 13.1 and 17.9 per cent. The results show that according to scenario 10 (explosive intensification of the pandemic without the wave subsiding over a while) and scenario 9 (the pandemic worsens step by step without subsiding over a while), Syria and Iran have the highest reduction in greenhouse gas emissions, respectively. According to scenario 1 (rapid and complete control of disease), Bahrain, Qatar, and Kuwait have the lowest reduction in GHG emissions. Besides, the study draws several fruitful implications regarding environmental concerns as sectoral analysis such as Hotels and Restaurants, Retail Trade, Fishing, Wholesale Trade, and Transport sectors. Moreover, policymakers should be alert that notwithstanding all limitations, Private Households and Public Administration develop their emissions during the pandemic since quarantine intensifies the supply of these services. Surprisingly, none of the policy restrictions have a significant impact on GHG emissions from Education, Health, and Other Services, Petroleum,Chemical, and Non-Metallic Mineral Products, Textiles and Wearing Apparel, and Re-export & Re-import, demonstrating the robust and established nature of these sectors' activities. To control the emissions of the quarantine-neutral sectors, long- and mid-term structural and environmental policies should be considered. The researchers are guided by the novel implications in terms of how various industries might reduce emissions in different ways.Graphical abstractSupplementary InformationThe online version contains supplementary material available at 10.1007/s10668-021-02018-3.

Aktualnie ważnym wyzwaniem dla sektora rolniczego jest redukcja emisji gazów cieplarnianych (GHG) w celu złagodzenia skutków zmian klimatycznych. Istnieje potrzeba dokładnej identyfikacji źródeł emisji oraz upowszechnienia praktyk rolniczych, które przyczyniałyby się do zmniejszenia emisji we wszystkich ogniwach produkcji roślinnej. Do przeprowadzenia obiektywnych porównań i wyboru najlepszych rozwiązań technologicznych według kryterium emisyjności potrzebna jest szczegółowa ocena ilościowa emisji GHG. W opracowaniu przedstawiono ocenę emisji GHG w produkcji roślinnej za pomocą śladu węglowego (CF). Udział operacji technologicznych w powstawaniu CF scharakteryzowano na przykładzie rzepaku ozimego. Wyniki badań wskazują, że największe znaczenie w kształtowaniu CF ma proces nawożenia mineralnego. Wpływ pozostałych procesów na CF jest wielokrotnie mniejszy. Miejscem głównych emisji GHG w nawożeniu mineralnym rzepaku są emisje bezpośrednie i pośrednie GHG z pól. Po emisjach GHG z pól, produkcja nawozów stanowi drugie źródło emisji z nawożenia. Zmiany praktyk rolniczych polegających na zwiększeniu efektywności nawożenia azotowego oraz stosowaniu nawozów o niskich współczynnikach emisji stwarzają obecnie możliwość redukcji emisji GHG i przez to, tym samym mogą przyczynić się do zmniejszenia CF produktów roślinnych.

<p indent="0mm">Industrial civilization causes huge carbon emissions, accelerates climate change, and hinders the sustainable development of human society. The construction industry causes about 40% of annual global anthropogenic carbon emissions, within which the massive construction of concrete structures alone accounts for more than 10% of the global emissions. China’s national goals for carbon peaking, neutrality, and the low-carbon development consensus call for the low-carbon design theory of concrete structures in the construction industry. Starting from the scientific issues with the concrete structure-environment symbiotic system, this paper clarifies the indicators, design methods and tuning means of low-carbon structural design, aiming to lay a foundation and provide suggestions for the development of low-carbon design, and promote the sustainable development of concrete industry. By briefly reviewing the history of the concrete industry, we illustrate the trend of low-carbon transitions, for which it is urgently needed to shift the perspective of structural design from only centering on human needs to meeting the sustainable needs of the integrated system of concrete structures and environments. Based on the characteristics of carbon emissions and uptake of concrete structures, the significance of regulating concrete structures’ net embodied carbon emissions for climate change mitigation is clarified. Further, to cope with climate change, we put forward the scientific issues and design requirements for the concrete structure-environment symbiotic system. To facilitate the sustainable development of the concrete structure-environment symbiotic system, we focus the low-carbon design method on the quantitative characterization of structure-environment dynamic coupling. The structural sustainability indicator is established to simultaneously reflect the structural reliability and carbon emission level of concrete structures. Further, we sort out relevant evaluation and design methods into the evolution of low-carbon design from the structural reliability design considering sustainability to the sustainability design characterized by a bidirectional perspective, which means the design methodology has developed from the reliability guarantee of qualitative low-carbon strategies facing climate change to quantitative carbon emission target guarantee in the form of conditional probability control, which ensures both low-carbon emissions and reliable service performance during the life cycle of concrete structures under climate change. Further, in order to assist the low-carbon design regulation, we put forward the carbon emission-based 3R^+C principles, i.e., carbon reduction, carbon reuse, and carbon recycling, to construct a low-carbon design technology system with superimposable carbon emission reduction benefits among categories. Typical low-carbon technologies for concrete structures are classified following the three principles according to their main emission reduction advantages, i.e., embodied carbon reduction in material production, embodied carbon allocation by construction mode transition, and carbon uptake with a developed end-of-life management system, and their emission reduction potential and promotion prospects are explored. A lot of future work is needed for the innovative development and promotion of low-carbon design of concrete structures, which includes clarifying the carbon emission benchmarks and goals for the concrete industry, strengthening the identification and management of failure risks and possible failure consequences under climate change, enriching and improving available low-carbon design technologies, and developing codes and software for integrated low-carbon design.

To realize low-carbon design for tunnel construction, the authors explored the relationship between tunnel design and greenhouse gas (GHG) emissions. This study proposed typical design models of Chinese highway tunnels based on the lining design specifications and engineering design cases. The research modified the GHG emission calculation method based on the standard quota system. The marginal GHG emissions caused by a change of design parameters of tunnel lining were determined. The results show that the emissions from shotcrete, concrete arch wall, system bolts, and steel frames are sensitive to the change of design parameters, while steel mesh is not. As the design thickness increases, the emissions of the concrete arch wall, inverted arch, and shotcrete increase approximately linearly. The emission distributions of system bolts and steel frames under different spacing are given. Under the same longitudinal spacing condition, the emission ratio of I18 and I16 steel frames is 1.197, and that of I16 and I14 steel frames is 1.316. By defining the marginal emissions caused by the change of design parameters, this study carried out basic work for highway tunnel low-carbon designs. The research is of strategic significance for achieving energy conservation and emission reduction in the tunnel industry.

With their increasing shares of global emissions developing economies are increasingly being pressured to assume a greater role in global greenhouse gas (GHG) emission reduction. Developed countries have invested tremendously in and proclaimed renewable energy (RE) and associated smart power technologies as solutions to meet their energy demands and reduce their GHG emissions at the same time. However, in the developing economies, these technologies may not deliver the desired results because they have their unique characteristics and priorities, which are different from those of the developed world. Many GHG emission reduction technologies are still very expensive and not fully developed. For the developing economies, the adoption threshold may become very high. Therefore, the cost effectiveness and practicality of each technology in reducing GHG emission in the developing economies may be very different from that of the developed economies. In this paper, available RE and other GHG emission reduction technologies are individually considered in a case study on Sabah, one of the 13 states in Malaysia, in order to assess the effects of the individual technologies on GHG emission and electricity cost reductions.

BackgroundSocietal pressures exist to reduce greenhouse gas (GHG) emissions from farm animals, especially in beef cattle. Both total GHG and GHG emissions per unit of product decrease as productivity increases. Limitations of previous studies on GHG emissions are that they generally describe feed intake inadequately, assess the consequences of selection on particular traits only, or examine consequences for only part of the production chain. Here, we examine GHG emissions for the whole production chain, with the estimated cost of carbon included as an extra cost on traits in the breeding objective of the production system.MethodsWe examined an example beef production system where economic merit was measured from weaning to slaughter. The estimated cost of the carbon dioxide equivalent (CO2-e) associated with feed intake change is included in the economic values calculated for the breeding objective traits and comes in addition to the cost of the feed associated with trait change. GHG emission effects on the production system are accumulated over the breeding objective traits, and the reduction in GHG emissions is evaluated, for different carbon prices, both for the individual animal and the production system.ResultsMultiple-trait selection in beef cattle can reduce total GHG and GHG emissions per unit of product while increasing economic performance if the cost of feed in the breeding objective is high. When carbon price was $10, $20, $30 and $40/ton CO2-e, selection decreased total GHG emissions by 1.1, 1.6, 2.1 and 2.6% per generation, respectively. When the cost of feed for the breeding objective was low, selection reduced total GHG emissions only if carbon price was high (~ $80/ton CO2-e). Ignoring the costs of GHG emissions when feed cost was low substantially increased emissions (e.g. 4.4% per generation or ~ 8.8% in 10 years).ConclusionsThe ability to reduce GHG emissions in beef cattle depends on the cost of feed in the breeding objective of the production system. Multiple-trait selection will reduce emissions, while improving economic performance, if the cost of feed in the breeding objective is high. If it is low, greater growth will be favoured, leading to an increase in GHG emissions that may be undesirable.

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

At the UN climate change conference in Paris in November 2015, Norway committed itself to a 40% reduction in greenhouse gas (GHG) emissions by 2030 compared to 1990 levels. Agriculture accounts for 8% of Norway’s total GHG emissions. If GHGs from drained and cultivated wetland (categorized under land use, land use change and forestry) are included, the share is 13%; this for a sector that accounts for roughly 0.3% of GDP. As is the case in most countries, agriculture is currently exempt from emission reduction measures, including the European Union’s Emissions Trading System (ETS), in which Norway participates. But the country has recently signaled its intention to include agriculture in future emission reduction efforts. Consideration is being given to how best to achieve GHG reductions in the sector. A recent report by the Norwegian Green Tax Commission, established by the government to evaluate policy options for achieving emission reductions, (Government of Norway, 2015) emphasizes the importance of including agriculture. The Commission suggests that agricultural emissions should be taxed at the same rate as for other sectors. It also recommends that reductions in the production and consumption of red meat should be specifically targeted, through cuts in production grants to farmers and the imposition of consumption taxes. Unsurprisingly, this proposed policy shift is extremely controversial and faces resistance, particularly from the farmers’ unions. Farmers argue that the maintenance of domestic agricultural production is crucial for achieving national food security objectives, in addition to pursuing other aims such as the maintenance of economic activity in rural areas and landscape preservation. Food security, which has been a key policy objective since the end of the Second World War, has been interpreted in Norway as requiring high levels of selfsufficiency in basic agricultural commodities. To achieve this, substantial subsidies are provided to farmers and domestic prices of many commodities are kept at high levels by restricting imports. The Organization for Economic Cooperation and Development (OECD) estimates that the total financial support provided to Norwegian agriculture in 2015 was equivalent to 62% of the value of gross farm receipts, which made Norway (along with Switzerland) a leader in the amount of support provided to agriculture by the 50 OECD member and non-member countries monitored by the Organization (OECD, 2016). In this paper we analyze policy options for achieving a 40% reduction in agricultural GHG emissions, consistent with the economy-wide target, while imposing the restriction that national food production measured in calories should be maintained (the food security target). This is consistent with the way that the Norwegian government identifies the country’s food security objective. In section 2 we outline the current situation with respect to GHG emissions in Norwegian agriculture. In section 3 we illustrate the policy issues involved by considering two product aggregates that are intensive in the use of land for crop production (grainland) and grassland, respectively. The aggregates are based on data for the main commodities in Norwegian agriculture relating to GHG emissions, land use, caloric content, subsidies, and costs per unit of production. We show that even though the opportunity set (i.e., the production combinations that are possible within technical constraints) is narrow, a 40% cut in emissions is achievable by substituting from ruminant products that are intensive in the use of grassland to products based on grainland. We also show that the emissions reduction both reduces government budgetary costs and land use, i.e., ruminant products are characterized by relatively high subsidies and land use. Two-dimensional analysis ignores the fact that per unit emissions from dairy production are low compared to other ruminant products (i.e., beef and sheep production). Both in terms of production value and agricultural employment, dairy farming is the most important component of Norwegian agriculture. Consequently, milk production deserves to be separated from ruminant meat production. Finally in section 4, we present a detailed analysis 3 of policy options derived from a disaggregated model that includes all the major products in Norwegian agriculture. In the model-based analysis, we examine first the imposition of a carbon tax, while maintaining existing agricultural support policies and import protection, and achieving the food security (production of calories) target. Since the imposition of a carbon tax in agriculture presents both technical and political challenges, we then examine an alternative approach of changing the existing structure of agricultural support to approximate the same result. We show that it is possible to change current subsidy rates to mimic the carbon tax and calorie target solution. The explanation for this is that ruminant products not only generate high emissions per produced calorie, but they are also the most highly subsidized products. Meat from ruminants is relatively unimportant in achieving Norway’s food security objective of calorie availability.

The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA’s requirements for cellulosic biofuel if the leakage rate is higher than 9.7%. For the small biorefinery, there are no GHG emission benefits in the production of biomethane if the leakage rate is higher than 11.5%. Compared to system expansion, the use of energy and market value allocation methods generally results in higher estimates of GHG emissions for the primary biorefinery products (i.e., smaller reductions in emissions compared to reference systems).

Greenhouse gas (GHG) emissions reduction in the electricity sector: Implications of increasing renewable energy penetration in Ghana's electricity generation mix

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 themore » 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.« less

Indonesia has targeted 29 % Greenhouse gas (GHG) emissions reduction in 2030 and Industry is one of the big two contributors for GHG emissions. As an industry, mining is an energy-intensive industry, and reducing energy consumption is one of the strategies to improve mining environmental performance. The aim of this paper is to estimate the GHG emission reduction in a mining project through energy reduction initiatives. A copper mine in Indonesia with processing plant capacity of 120,000 t/d and operate 111 Caterpillar 793C Haul Truck was taken as a case study. This mine site has two sources of an electricity namely coal-fired power plant with 112 MW output and diesel power plant with 45 MW output. The analysis method for calculating CO2 emission is using IPCC method where fuel consumption and emission factor are two main variables for GHG emissions. Business as usual scenario (TIER 1) showed that the average of diesel fuel consumption for fleets operation generated 294,006 t CO2-eq/y. A coal-fired power plant with average coal consumption of 350 t/d/unit generated 1.15 Mt CO2-eq/y and diesel power plant consumed 4.35 ML/y produced 11,632 t CO2-eq/y. Two energy initiative programs were identified namely fuel conversion and used oil utilisation program. The initiative scenario focused on substituting, reducing and reusing of fossil fuels including coal, diesel fuel, and used oil. This scenario was estimated to contribute the carbon emission reduction (t CO2-eq) of 258,381 annually. The involvement of mining industry in carbon emission reduction is not only helping Indonesia in achieving its GHG emissions reduction target but also increases mine site environmental performance and company image.