Reduce GHG Emissions Research Articles

Assessing performance, economic costs and environmental benefits of high-performance ecological geopolymer concrete incorporating excavated rock and soil from tunnelling, fly ash and slag as reclaimed raw materials

Excavated rock and soil from tunnelling (ERST), fly ash (FA), and slag are one of the largest sources of solid waste and play an important role in reducing dependence on natural resources and solving the problem of solid waste accumulation. This study verifies the feasibility of high-performance ecological geopolymer concrete (HPEGC) incorporating ERST, FA and slag for engineering applications. The effects of different binding material to machine-made sand ratio (BMMSR) and SN/FS (the total mass of sodium silicate and NaOH solids to the total mass of the powdered raw material) on the slump, compressive strength, tensile strength, drying shrinkage, salt corrosion resistance of concrete and the microstructural deterioration process before and after salt corrosion were analysed by indoor tests and microscopic tests. The results showed that the hydration products generated at SN/FS of 10, 12, and 15 % could effectively fill the pores of HPEGC and improve the pore structure and interfacial properties of HPEGC by microminiaturisation of the pore size. HPEGC formed a dense three-dimensional reticulated polysilica-aluminate-like structure due to the coexistence of C-S-H gel, C-A-S-H gel, N-A-S-H amorphous gel, and Na2Al2Si3O10. HPEGC with SN/FS of 12 % and BMMSR of 0.36 showed 29.5 % and 18.9 % improvement in compressive and tensile strengths, better resistance to sulfate attack, and 4.5 % and 45 % reduction in economic cost and GHG emission, respectively, compared with ordinary Portland cement concrete (OPCC). The results of the study proved that the engineering application of HPEGC incorporating ERST, FA and slag as raw materials is promising, providing new solutions for global underground excavation materials and industrial solid waste, and effectively promoting the sustainable development of the construction industry.

A Review of Options and Costs for Mitigating GHG Emissions from the U.S. Dairy Sector

The U.S. dairy sector is a significant emitter of methane and nitrous oxide, with the US EPA estimating it produced around 90 Tg CO2 eq. in 2021. This paper reviews the literature on and evaluates various mitigation actions for reducing GHG emissions in the U.S. dairy sector, focusing on both direct and indirect emission sources. We conducted a narrative literature review based on the cradle to gate life-cycle assessment method, covering the entire dairy supply chain up until milk enters retail establishments, including dairy and feed producing farm practices, processing, transportation, and their associated emissions/costs. The papers included were selected over a three year process depending on discussions with experts and issues mentioned in the emerging literature. We review significant opportunities for the U.S. dairy sector to reduce emissions, particularly through improved enteric fermentation and manure management practices. Additionally, we cover the potential for mitigating indirect emissions from feed production, processing, and transportation, areas less frequently covered in existing studies. This review also covers a gap in the literature by integrating economic findings including cost analysis and incentives to mitigate based on the social value of emissions reductions.

Carbon emission reductions in the University of São Paulo’s transportation sector using hydrogen-powered vehicles

The transportation sector, especially diesel-powered buses in Brazil, faces a significant decarbonization challenge, contributing with 19.76 million tCO2-eq GHG emissions. Therefore, this study aims to calculate the achievable GHG emission reductions by implementing renewable hydrogen vehicles at the University of São Paulo. The methodological approach considers low-carbon hydrogen production using the ethanol steam reforming route, where energy and mass balances are performed throughout the hydrogen chain. Two models are developed to calculate CO2-eq emissions. Results show that replacing the current fleet of conventional internal combustion engine buses with hydrogen-based options leads to a significant annual reduction of 2658 tCO2-eq, approximately an 83% reduction as compared to the conventional one. Moreover, the total energy conversion efficiency, well-to-wheel, reaches 26.9% and 11.8% for hydrogen and conventional vehicles, respectively, without air-conditioning system, or 21.9% and 9.9% when air-conditioning is coupled, respectively. Notably, CO2-eq emissions increase by at least 38.3% and 15.5% due to the presence of that equipment, respectively. Finally, the results of total cost of ownership (TCO) showed that CAPEX represents only 7.14% of the TCO, being the fuel cost the major proportion for both technologies.

Factors Influencing Greenhouse Gas Reduction Measures in European Ports: Implications for Sustainable Investing

European Union cargo and container ports are under pressure to reduce GHG emissions and achieve carbon neutrality by 2050, as mandated by the European Commission. The pace of progress varies among ports. This study examined the characteristics influencing GHG reduction measures in European cargo and container ports and their implications for sustainable investing. The methods used in this study, such as linear regression models to analyze predictive variables, can be applied in sustainable investing to assess which factors most strongly predict a company’s environmental, social, and governance performance. Using linear regression models to analyze data from the 33 busiest European ports, we identified five predictive variables: port size, cargo mix, surrounding population density, access to the sea, and the economic wealth of the host country. Our findings revealed that the port size significantly correlates with the adoption of measures to reduce scope 1, 2, and 3 emissions. This study underscores the importance of contextual and operational factors in evaluating sustainability efforts across sectors. The results contribute to drawing parallels with the field of sustainable investing within finance. This offers valuable insights for sustainable investing, emphasizing the importance of considering various contextual and operational factors when evaluating the sustainability efforts of entities in different sectors.

Development of climate smart agriculture based on empowering farmers around forests through triple-helix collaboration

Background: The agricultural sector policy in Indonesia in facing climate change is to increase agricultural productivity and reduce GHG emissions through the development of Climate Smart Agriculture based on empowering farmers around forests. Methods: Qualitative methods produced descriptive data in the form of written or spoken words from people, and observable behaviour. Findings: Synergy and collaboration between the Government, Universities and the Community in the form of triple-helix collaboration through Climate Smart Agriculture activities, which are carried out through the following activity stages: 1) Technology Transfer Stage, including activities for making corn planting demonstration plots under coconut stands, making planting demonstration plots taro under cocoa stands, creation of Moringa plantation management demonstration plots on dry land; 2) Training Stage, activities are carried out to process agricultural products into secondary products, namely: Corn Flour, Corn Analog Rice, Taro Flour, Taro Analog Rice, Moringa Leaf Powder, and Moringa Leaf Tea; 3) Packaging and e-marketplace initiation stage, through packaging design, labeling, marketing via digital platforms and assistance; 4) Empowerment activities and strengthening the institutional capacity of agricultural extension workers and farmer groups are urgently needed to support the development of climate-smart agriculture. Conclusion: Innovations to support the development of Climate Smart Agriculture based on empowerment around forests through triple-helix collaboration will improve farming management through activities. Novelty/Originality of this Study: The research presents a novel triple-helix collaboration model for developing Climate Smart Agriculture, integrating government, university, and community efforts to enhance agricultural productivity while mitigating greenhouse gas emissions.

Environmental, economic and energy evaluation of alternative fuels for a steam power plant: Focus on biodiesel-nanoparticles utilization

Power plants are among the largest producers of GHGs. The fuel used in power plants is the main factor in the production of the emissions. Therefore, choosing a fuel that is environmentally optimal while being energy-efficient and economical is a key way to reduce GHG emissions. The addition of nanoparticles to biodiesel fuel not only improves the combustion efficiency of the fuel but also reduces the undesirable products. In this research, three supplementary fuels - fuel oil, diesel, and biodiesel-nanoparticles - are compared in terms of environmental, economic, and energy efficiency in a steam power plant. The changes in the power plant's self-consumption were measured by calculating the power consumption of the pump that delivers the fuel to the boiler. The results showed that diesel reduced the plant's efficiency by 0.00022 compared to using natural gas, which was the least of the other alternatives. The environmental analysis revealed that diesel produced the least amount of CO2 eq, but biodiesel-nanoparticle had a better CO2 footprint due to the higher absorption of CO2 in the cultivation phase of the raw material for biodiesel. The economic analysis for the fuels was carried out over ten years and based on the lifetime of the equipment purchased. Consequently, the total cost over the ten years for diesel was $967332.5161, which was $124475.8381 less than that for biodiesel-nanoparticle and $240935.3341 less than that for fuel oil. Finally, an overall comparison was made between the fuels using the AHP method. As the environmental criterion was the most important decision criterion, biodiesel-nanoparticle fuel was chosen with a marginal difference compared to diesel.

Modelling solar photovoltaic systems on dairy farms for cost savings and GHG emission reduction

Rising on-farm electricity demand, coupled with surges in electricity prices, has increased costs associated with milk production. Additionally, the use of grid electricity with a high carbon footprint depreciates the environmental performance of dairy farming. We assessed the potential of photovoltaic (PV) systems installed on dairy parlours under different policy incentives to reduce electricity costs and the carbon footprint of dairy farms in Ireland. The HOMER Pro software was employed to model electricity consumption, generation and economic performance of four 15-year PV project scenarios for 11 Irish farms. Scenarios considering the targeted agricultural modernisation scheme II (TAMS) and the microgeneration support scheme are assessed. The results show that PV systems are a feasible option to power dairy farms when current energy prices and inflation rates are applied. Small systems eligible for TAMS grants presented an average discounted payback period of 5 years, making them a better option for farmers than larger projects, which had an average payback period of 8.5 years. The deployment of PV systems reduced the GHG intensity of electricity consumed at the farms by up to 29 %.

Mapping the path to decarbonised agri‐food products: a hybrid geographic information system and life cycle inventory methodology for assessing sustainable agriculture

SummaryThe development of a decarbonised food industry will depend on a sustainable agricultural system where embodied food product greenhouse gas emissions (GHG) can be associated with agricultural production. The method presented demonstrates how mapping agri‐production can be used to calculate regional carbon footprints so GHG emission reduction is geographically strategic. Different agronomic and husbandry outcomes are mapped using Geographic Information Systems (GIS's) and carbon footprints are calculated using Life Cycle Inventory (LCI) libraries. The hybridised GIS‐LCI approach reports unique insights for decarbonisation, demonstrating how farming practices can be further integrated to best deliver food security. We use the GIS‐LCI method to show; (1), geography limits crop and livestock production types; (2), agri‐product density data can be used to calculate a food system carbon footprint; and (3), GIS's can be used to focus food policy for sustainability.

Accelerating decarbonization digitally: Status quo and potentials of greenhouse gas emission tracking and trading

To effectively mitigate climate change, policymakers worldwide established various GHG tracking and trading systems. In the light of ambitious climate goals, stricter regulations, and increasing demand for climate action, various groups such as researchers and governmental institutions suggested additional approaches. This paper addresses the complexity that arises from the breadth of suggested approaches and implemented systems for GHG tracking and trading. By doing so, it synthesizes relevant dimensions in a way that is understandable to enterprises and policymakers, enabling them to design meaningful systems incorporating the reduction of GHG emissions and advance cleaner production. Therefore, this paper presents a first-of-its-kind taxonomy of GHG tracking and trading approaches through a systematic literature review. It illustrates ten main design and implementation dimensions with 30 corresponding characteristics. To accelerate decarbonization, this paper sets impulses for future GHG tracking in the electricity sector based on semi-structured expert interviews. Consecutively, it provides policy directions for CO2-adaptive decision-making for enterprises, formulated as a Call for Action with seven prospective questions. These include, for example, questions concerning technical aspects like data management, legal issues like the sufficiency of existing data security and privacy regulations, as well as economic topics like the calculation of an appropriate local and temporal granularity.

Machine learning for gap‐filling in greenhouse gas emissions databases

AbstractGreenhouse gas (GHG) emissions datasets are often incomplete due to inconsistent reporting and poor transparency. Filling the gaps in these datasets allows for more accurate targeting of strategies aiming to accelerate the reduction of GHG emissions. This study evaluates the potential of machine learning methods to automate the completion of GHG datasets. We use three datasets of increasing complexity with 18 different gap‐filling methods and provide a guide to which methods are useful in which circumstances. If few dataset features are available, or the gap consists only of a missing time step in a record, then simple interpolation is often the most accurate method and complex models should be avoided. However, if more features are available and the gap involves non‐reporting emitters, then machine learning methods can be more accurate than simple extrapolation. Furthermore, the secondary output of feature importance from complex models allows for data collection prioritization to accelerate the improvement of datasets. Graph‐based methods are particularly scalable due to the ease of updating predictions given new data and incorporating multimodal data sources. This study can serve as a guide to the community upon which to base ever more integrated frameworks for automated detailed GHG emissions estimations, and implementation guidance is available at https://hackmd.io/@luke‐scot/ML‐for‐GHG‐database‐completion and https://doi.org/10.5281/zenodo.10463104. This article met the requirements for a gold‐gold JIE data openness badge described at http://jie.click/badges.

Advancements in Real-Time Monitoring of Enteric Methane Emissions from Ruminants

The agricultural sector is responsible for a significant proportion of global anthropogenic methane (CH4) emissions, with enteric CH4 produced from ruminant livestock representing approximately 28% of the total. The development of effective mitigation strategies necessitates the accurate and actionable monitoring of CH4 emissions. However, a considerable research gap remains concerning real-time monitoring techniques capable of supporting on-farm enteric CH4 mitigation strategies. To bridge this research gap, this study explores the current status of real-time enteric CH4 emission monitoring techniques and technologies for ruminants. The study achieves this by reviewing key biomarkers and proxies for ruminant emissions, examining established animal-based measurement techniques, exploring emerging technologies, and critically assessing technological limitations and opportunities. By shedding light on this research area, this study aims to assist stakeholders in developing a viable pathway for on-farm emission monitoring, with the hope of facilitating a meaningful reduction in GHG emissions from the livestock sector.

Distance to climate targets in agriculture in the EU

Abstract In the European Union (EU), national climate targets are formulated for aggregate sectors under the Effort-Sharing Regulation (ESR), incl. agriculture. We perform a cross-country analysis of current progress of the EU Member States (MSs) in reaching climate targets for 2030 in agriculture. Observing a remarkable heterogeneity within the EU, we allocated EU MSs into two homogeneous clusters: (1) EU MSs with relatively large distances to climate targets and/or poor progress over the years and (2) EU MSs with relatively small distances to climate targets and/or good progress. We discovered that the first cluster is characterised by more ambitious ESR targets, limited ability to reduce greenhouse gas emissions by increasing efficiency, and a higher share of mitigation measures that have not been implemented yet. These MSs furthermore pursue a wider range of goals, such as increasing biodiversity, ensuring sustainability, which is in line with the multifaceted role of the agricultural sector.

Fantastic wetlands and why to monitor them: Demonstrating the social and financial benefit potential of methane abatement through salt marsh restoration.

Salt marsh restoration has the potential to reduce greenhouse gas emissions thereby providing an opportunity for blue carbon crediting, but implementation has been limited to date because of insufficient data and validation. In this paper, we demonstrate the potential scale of methane emissions that could be avoided if salinity-reducing impairments are mitigated by applying findings from six salt marsh restoration sites in Massachusetts combined with a previously demonstrated application of the salt marsh salinity-methane relationship. We used calculations of these avoided emissions to estimate the social benefit of salt marsh restoration by calculating avoided costs. Of the six sites selected, restorations at two sites were successful in improving salinity which we used as a methane proxy. Our approach and findings demonstrate the potential benefits in developing consistent accounting methodologies to better track, prioritize, and implement wetlands restoration strategies to mitigate methane emissions and contribute toward state-level emissions reduction targets across some of the 475 Massachusetts salt marches with an existing tidal restriction. We found the potential for $12 -$26M in added social benefit from 176 tons of avoided methane across 932 hectares of degraded salt marsh in Massachusetts. A significant limitation in estimating benefits, however, is the lack of coordinated, widespread monitoring strategies to infer methane and other GhGs at scale. While not insurmountable, these challenges will need to be addressed for GhG emissions reduction and/or sequestration through salt marsh restoration to be accepted as an effective strategy. We conclude that while carbon crediting may offer benefits to marsh restoration and state greenhouse gas emissions reduction targets, there remain significant limitations because of a lack of project monitoring and data validation. In the worst case, this could result in the offsetting of actual greenhouse gas emissions with credits that are supported by indirect and less-than-rigorous monitoring data.

Pathways toward Climate-Neutral Red Meat Production

Ruminant livestock industries can support the climate stabilization ambitions of the Paris Agreement through interventions that reduce GHG emissions (predominantly biogenic methane) and sequester carbon in landscapes. This study explored pathways for the Australian red meat industry (grazing, feedlot finishing, and domestic processing) to become climate neutral, whereby the radiative forcing (RF) footprint is plateaued and there is no additional forcing contribution. Emissions timeseries (CO2, N2O, CH4) were compiled for 1990 to 2020 and projected to 2030 under a business-as-usual scenario (including an 18% increase in sheep and 13% increase in beef cattle) and with a range of production system and vegetation management interventions. The RF footprint peaked in 2018 at 7.13 mW/m2 and decreased to 7.07 mW/m2 in 2020. With the future expansion of the herd/flock and under business-as-usual conditions, the RF footprint is projected to increase by 2.8% by 2030. However, with a combination of interventions, production has the potential to increase with a decreasing RF footprint, a condition that can be described as climate neutral. The Australian red meat industry has made an historical contribution to global RF increase. However, with ongoing RF management, it is possible to increase food production within climate-neutral limits.

Tradable mobility credits for long-distance travel in Europe

There is an urgent need to devise policy instruments that will reduce GHG emissions to a sufficient extent in order to achieve the climate targets. Approximately 16% of all greenhouse gas emissions are generated by long-distance travel. Our objective is to estimate the impact of a Tradeable Mobility Credit (TMC) scheme − where the total emissions are fixed by design whereas the price is the outcome of travelers’ choices − will have on modal split and trip cancellation for long-distance leisure travel in Europe. To this end, we develop a market equilibrium model which accounts for travel and trading decisions. For our case study consisting of a travel demand of more than 300 million trips performed annually between 3,000 city-pair connections, the credit price that emerges in the market equilibrium state is 272€ per ton of CO2 under an emission reduction target of 30%. Due to the TMC, overall long-distance leisure travel demand is reduced by 20% and the share of air among the remaining trips decreases from 50 to 42% whereas the market share of rail increases from 23 to 26%. Modal shifts and trip cancellation rates vary greatly amongst OD-pair connections, depending on the local value-of-time and the extent of modal competition for the respective connection. Our findings contribute to the on-going debate surrounding instruments for stimulating sustainable (im)mobility, in particular in the context of the long-distance travel market.

Multi-scope decarbonization and environmental impacts evaluation for biomass fuels co-firing CHP units in China

Co-firing of waste biomass as low-carbon fuels in combined heat and power (CHP) units is an indispensable energy supply technology providing regional electricity and heat, especially in industrial parks, that can combat climate change and support the achievement of Sustainable Development Goals (SDGs) in China. In this study, we proposed a life cycle material-energy-carbon integrated GHG accounting framework for CHP units converting waste to energy with co-firing of sludge and biomass pellets, including supply and value chains. This framework enables the prediction of multi-scope GHG emissions and environmental impacts associated with co-firing based on the properties of biomass fuels. It facilitates the selection of suitable biomass fuels according to decarbonization or reduced environmental impact objectives. When considering CO2 emissions alone, co-firing with sludge appears to be a beneficial option due to the economic gains from waste disposal. However, this also leads to increased GHG emissions unless avoided emissions from original disposal are considered, thus highlighting the need to expand the regulatory framework pertaining to GHG emissions that recognizes non-CO2 GHG emissions. Additionally, the practice of co-firing biomass fuels presents a complex interplay between enhanced decarbonization effects but potentially more significant environmental impacts when the co-firing ratio increases, highlighting the trade-offs between enhanced decarbonization and environmental challenges. Leveraging this framework, our study evaluated the national decarbonization potential through the deployment of CHP units with sludge or biomass co-firing across various provinces, indicating that biomass pellets co-firing could lead to more substantial GHG emission reduction.

Sustainability Activities in a Hard-to-Abate Industry—A Real-Life Example

Marine sources of omega-3, proteins, and other nutrients are in increasing demand, while supply is struggling to meet this demand increase. A key focus for meeting the need for marine ingredients for human and animal nutrition is ensuring sustainable sourcing for both the oceans as well as other production types. Aker BioMarine is harvesting and producing marine ingredients from krill and this communication is intended to showcase how the harvesting and production of such ingredients are performed in a sustainable way. This communication is written to describe the krill fisheries’ management, to provide demonstration cases from CO2 hot spotting, and show how results from these are used to target GHG emission reduction. The initiatives that are taken to ensure sustainable fishing and production, as well as examples of short- and long-term actions to reduce and minimize the impact of all activities, are provided.

Regulatory compliance and operational efficiency in maritime transport: Strategies and insights

In recent years, with increasing maritime trade, the shipping industry has faced the challenge of mitigating escalating greenhouse gas emissions. This study investigates the cost mitigation strategies of shipping companies in response to three key regulations: the Carbon Intensity Indicator, the EU Emissions Trading System, and the FuelEU Maritime regulation. By proposing optimal speeds for container ships on the Asia–Europe route and examining the potential for carbon leakage, the study aims to predict strategies of shipping companies and derive insights for achieving sustainable regulatory compliance. The results provide a comprehensive analysis of the regulations' impact on operational costs and emissions, with the robustness of the findings confirmed through extensive sensitivity analyses. The discussion highlights the unintended consequences of current regulations that may deviate from the ultimate objectives of reducing GHG emissions and achieving sustainable maritime transport. Ultimately, the study seeks to support the development of effective maritime regulations that align with the operational strategies of shipping companies, emphasizing the need for a holistic approach to achieve the intended outcomes of environmental policies.

Integrating system dynamics and agent-based modeling: A data-driven framework for predicting electric vehicle market penetration and GHG emissions reduction under various incentives scenarios

As the growing deployment towards transportation electrification, a critical focus has emerged on quantifying the reduction contribution of greenhouse gas emissions from electric vehicles towards achieving carbon neutrality under diverse policy scenarios in the future. This necessitates a dynamic model that captures the evolving composition of the vehicle fleet and accurately forecasts the penetration and developmental trajectory of the electric vehicles in the car market. However, previous studies have largely overlooked the heterogeneity in user usage attributes, rendering them less effective in evaluating the impact of usage-based incentives on electric vehicle market penetration. To bridge this research gap, this study introduces an innovative, data-driven framework that integrates system dynamics and agent-based model. The proposed model can predict levels of electric vehicle penetration and corresponding greenhouse gas emission reductions within the private passenger vehicle sector, under a variety of policy scenarios. Our findings indicate that usage-based incentives, when implemented with optimal intensity, yield more significant emission reduction impacts and long-term economic benefits compared to conventional purchase-based subsidy. These insights not only furnish actionable policy suggestions to expedite the electric vehicle industry's growth in China but also offer valuable implications for other countries seeking to implement effective strategies for combating climate change and fostering sustainable transportation initiatives.

Hydrogen enriched LNG fuel for maritime applications – A life cycle study

This study evaluates the engine performance and life-cycle emissions of hydrogen enriched LNG as a pragmatic solution to more rapidly introducing hydrogen as marine fuel, while waiting for pure hydrogen fuel infrastructure to be built. Engine experiments in a 4-stroke marine diesel engine operating with a spark-ignited pre-chamber ignition system were conducted, and a wide range of engine exhaust emissions measurements including CH4, N2O, H2, and particulate matter (black carbon emission evaluation) were recorded at varying engine loads. The fuel compositions ranged from pure LNG operation to pure hydrogen operation and also included pure conventional diesel fuel oil for comparison. The research methodology integrates engine tests with a full well-to-wake life-cycle assessment (LCA). The impact of using 39.6% hydrogen by energy fraction in natural gas reduced GHG emission by 37.8% on a life-cycle basis at 50% engine load, which could mean a significant reduction of GHG emissions.