Greenhouse Gas Emission Reduction Potential Research Articles

Application of GIS in Introducing Community-Based Biogas Plants from Dairy Farm Waste: Potential of Renewable Energy for Rural Areas in Bangladesh

Dairy production is one of the most important economic sectors in Bangladesh. However, the traditional management of dairy cow manure and other wastes results in air pollution, eutrophication of surface water, and soil contamination, highlighting the urgent need for more sustainable waste management solutions. To address the environmental problems of dairy waste management, this research explored the potential of community-based biogas production from dairy cow manure in Bangladesh. This study proposed introducing community-based biogas plants using a geographic information system (GIS). The study first applied a restriction analysis to identify sensitive areas, followed by a suitability analysis to determine feasible locations for biogas plants, considering geographical, social, economic, and environmental factors. The final suitable areas were identified by combining the restriction and suitability maps. The spatial distribution of dairy farms was analyzed through a cluster analysis, identifying significant clusters for potential biogas production. A baseline and proposed scenario were designed for five clusters based on the input and output capacities of the biogas plants, estimating the location and capacity for each cluster. The study also calculated electricity generation from the proposed scenario and the net greenhouse gas (GHG) emissions reduction potential of the biogas plants. The findings provide a land-use framework for implementing biogas plants that considers environmental and socio-economic criteria. Five biogas plants were found to be technically and spatially feasible for electricity generation. These plants can collectively produce 31 million m3 of biogas annually, generating approximately 200.60 GWh of energy with a total electricity capacity of 9.8 MW/year in Bangladesh. Implementing these biogas plants is expected to increase renewable energy production by at least 1.25%. Furthermore, the total GHG emission reduction potential is estimated at 104.26 Gg/year CO2eq through the annual treatment of 61.38 thousand tons of dairy manure.

Anaerobic digestion of dairy cow and goat manure: Comparative assessment of biodegradability and greenhouse gas mitigation

This study evaluated the anaerobic digestion (AD) of dairy cow and goat manure from dairy farming operations. The physicochemical characteristics, biodegradability and greenhouse gas emissions (GHG) reduction potential were assessed. Dairy goat manure exhibited higher volatile solids (16 % vs. 10 %) and 34 % greater chemical oxygen demand content (COD) compared to cow manure, indicating better suitability for AD. However, biochemical methane potential tests revealed higher methane yields from cow manure (81 % biodegradability) compared to goat manure (26 % biodegradability), attributed to slower hydrolysis rates and recalcitrant composition of goat manure. Both manures displayed suboptimal carbon-to-nitrogen ratios (<20:1) and excessive levels of mineral nutrients such as calcium. The ammonia–nitrogen and volatile fatty acid levels remained below threshold limits throughout the anaerobic digestion process, indicating no significant accumulation or inhibition. Recovering biogas through AD showed potential GHG reductions of 64 % (2.21 t CO2-eq/cow·year) and 69 % (0.27 t CO2-eq/goat·year) compared to conventional manure management practices. While pretreatment and co-digestion could enhance biogas production, further research is needed to optimise these strategies for efficient resource recovery and environmental sustainability in dairy farming operations.Abbreviations: AD, anaerobic digestion; AWMS, animal waste management systems; BMP, biochemical methane potential; CHNS, carbon, hydrogen, nitrogen, and sulphur; C/N, carbon-to-nitrogen, COD, chemical oxygen demand; GC-FID, gas chromatography-flame ionisation detection; GHG, greenhouse gas; GWPM, global warming potential of methane; He, helium; ICP-MS, inductively coupled plasma mass spectrometry; I/S, inoculum-to-substrate ratio; IPCC, International Panel on Climate Change; NH3-N, ammonia–nitrogen; SD, standard deviation; TBMP, theoretical biochemical methane potential; TN, total nitrogen; TS, total solids; VFAs, volatile fatty acids; VS, volatile solids.

A GIS-based assessment of the carbon emission reduction potential of the solar-enhanced char-cycling biomass pyrolysis process in China

Bioenergy and solar energy are the two widely used renewable energies, which have great potential to satisfy the global energy demand. Solar enhanced char-cycling biomass pyrolysis (SCCP) was proposed to integrate bioenergy and solar energy, could be used to make bioenergy fully carbon-negative. A geographical information system (GIS) based method was used to assess the GHG reduction potential and biofuel production potential of SCCP in China. Existing datasets were used to obtain geographical potential and biomass resource amount. Process simulation was conducted to obtain the technical data. The geographical potential results showed that with a DNI (direct normal irradiance) threshold of 1400 kWh/m2, the national suitable area for SCCP plant construction was 3.25 % of the total national area, the total convertible biofuel potential ranges from 1.86E+06 to 1.94E+06 GWh with different concentrating solar technologies. When considering biochar sequestration, the GHG emission reduction potential increased further, the total GHG emission reduction potential increased from 13.97 Mt CO2 eq to 15.42 Mt CO2 eq. Notably, Yunnan has the highest GHG emission reduction potential per unit of energy when running the pyrolysis process with solar energy, which was −8.58 g CO2 eq/kWh. The results revealed that the SCCP process could further decarbonize biofuel production in China.

Optimizing dietary habits for climate benefits in China: Greenhouse gas emissions and sustainable substitution strategies

The transition in dietary patterns will impact future food consumption and greenhouse gas emissions (GHGs). In this study, we employed the Intergovernmental Panel on Climate Change (IPCC) coefficient method to evaluate the GHGs associated with dietary consumption across 31 provinces in China from 1978 to 2022. Additionally, we simulated the greenhouse gas emission reduction potential and the spatio-temporal changes under five food substitution scenarios for the period 2022–2050. The results indicated that GHGs from animal-based foods increased the most, rising from 1673.1 Mt. CO2eq in 1978 to 6660.3 Mt. CO2eq in 2022, with pork being the largest source of emissions, accounting for approximately 44 %. The grain-based food substitution scenario resulted in the lowest GHG emissions, about 533.88 Mt. CO2eq. Conversely, the plant-based food substitution scenario had the highest emissions, reaching 635.49 Mt. CO2eq. This study provides a benchmark for improving regional dietary structures and formulating policies aimed at reducing GHGs through dietary consumption.

Greenhouse gas emission reduction potential in road tunnels – Can we reach the European Union goals with existing materials and technologies?

To achieve the European Uniońs climate goals, the Norwegian transport sector has committed to decrease the Greenhouse gas (GHG) emissions by 2030. For infrastructure projects, the GHG emissions from construction must be reduced by 40 %, while the emissions from maintenance must be cut by 50%. This paper investigates how realistic the GHG emission reduction goals are, if available low carbon materials and technologies are fully adopted. To examine this, we have chosen a typical Norwegian road tunnel from which two carbon emission scenarios are presented. While tunnels represent a specific subset of road infrastructure, this study showcases that implementing sustainable practices in drill and blast tunnel construction can align with the European Union’s ambitious 2030 targets. Besides this, the findings can assist stakeholders to get advice on the environmental impacts of tunnel designs.

Pyrite and Sulfur Autotrophic Denitrification for Simultaneous Nitrogen and Phosphorus Removal and Greenhouse Gas Emission Reduction Potential

Pyrite and Sulfur Autotrophic Denitrification for Simultaneous Nitrogen and Phosphorus Removal and Greenhouse Gas Emission Reduction Potential

National Greenhouse Gas Emission Reduction Potential from Adopting Anaerobic Digestion on Large-Scale Dairy Farms in the United States.

Waste-to-energy systems can provide a functional demonstration of the economic and environmental benefits of circularity, innovation, and reimagining existing systems. This study offers a robust quantification of the greenhouse gas (GHG) emission reduction potential of the adoption of anaerobic digestion (AD) technology on applicable large-scale dairy farms in the contiguous United States. GHG reduction estimates were developed through a robust life cycle modeling framework paired with sensitivity and uncertainty analyses. Twenty dairy configurations were modeled to capture important differences in housing and manure management practices, applicable AD technologies, regional climates, storage cleanout schedules, and methods of land application. Monte Carlo results for the 90% confidence interval illustrate the potential for AD adoption to reduce GHG emissions from the large-scale dairy industry by 2.45-3.52 MMT of CO2-eq per year considering biogas use only in renewable natural gas programs and as much as 4.53-6.46 MMT of CO2-eq per year with combined heat and power as an additional biogas use case. At the farm level, AD technology may reduce GHG emissions from manure management systems by 58.1-79.8% depending on the region. Discussion focuses on regional differences in GHG emissions from manure management strategies and the challenges and opportunities surrounding AD adoption.

Energy efficiency and greenhouse gas emission reduction potential of solar PV and biomass-based systems for a food processing plant

The industrial sector is one of the most energy-intensive sectors, with a share of nearly 38 % (156 EJ) of all energy used globally in 2020. Historical energy demand and consumption data from a poultry processing plant have been analyzed to lower greenhouse gas emissions (GHG) and reliance on traditional energy sources. The study includes energy, economic, and emissions analyses for (a) solar photovoltaic (PV) systems, (b) biomass fuels, and (c) coal-fired with wood. Fixed, single, and two-axis tracking solar PV systems that are company-owned and funded by banks are considered. The historical energy consumption data of the plant shows that 52.36 % of energy demand is met by electrical energy and 47.63 % by thermal energy. The yearly electricity demand is 9,938 MWh, costs $1,192,560, and emits 5117.6 tCO2. Thermal energy demand is based on an annual use of 898 tonnes of coal and 71.6 tonnes of liquefied petroleum gas (LPG), which costs $ 143,681 and emits 2977.7 tonnes of carbon dioxide (tCO2). Feasibility of 1.3 MW, fixed axis company-owned, solar PV plant shows an annual electricity production of 1876 MWh, GHG emission reduction of 965.9 tCO2 with a payback period of 3.4 years. Biomass system delivers yearly fuel cost savings of $25,724, reducing 2784 tCO2 with a 1.9-year payback period. Co-firing biomass offers a 3.58 % fuel cost saving and 557 tCO2 with a 0.93-year payback period. It concluded that the wood fuel feedstock biomass option is most suitable renewable energy resource for such large-scale poultry facilities.

Integrated Optimization Study of Electric Bus Fleet Transformation

With the increasing social demand for sustainable and environmentally friendly transportation, the transformation of public transportation systems has become an important issue. In this paper, three mathematical models are developed to synthesize the ecological consequences, financial models and transition scenarios in the transition from diesel to electric bus fleet. In Problem 1, this paper adopts the Life Cycle Assessment (LCA) method to examine the full life cycle energy consumption of the product. The model comprehensively considers the main raw material production stage, vehicle assembly and distribution stage, vehicle driving stage and vehicle scrapping and dismantling stage, as well as the production stage of all types of energy added to the vehicle driving stage, i.e., the production stage of fuels and electricity, and finally applies Gabi, the life cycle evaluation software developed by PE Germany, to carry out the evaluation of the life cycle energy consumption and greenhouse gas emissions. Finally, the energy-saving potential of pure electric buses reaches 12.69%, and the GHG emission reduction potential reaches 6.05%. The results are applied to the bus fleet in Beijing, and it is calculated that the replacement of the bus fleet with pure electric buses can save 21.87% of energy and bring about a total GHG emission reduction of 60,700 tons. In Problem 2, this paper adopts the research method of life cycle cost (LCC). The model quantifies all the technical, material, human and organizational measures involved in the whole bus system process into cost indicators, and then builds a financial model for the transition of the fleet to a pure electric bus fleet based on the model, which provides a reliable basis for the bus company's decision-making. From a long-term perspective, the public transport company to choose a pure electric bus fleet will be more economically efficient, but need to bear the costly transition to the acquisition of costs. Overall, this paper comprehensively explores the smart bus fleet transformation problem through three complementary models. It provides strong support for decision makers from the perspectives of life cycle cost, financial planning and environmental friendliness. The combined use of these models makes the article more comprehensive and provides useful lessons for future bus fleet transformation.

Effect of Input Subsidy Reduction on Greenhouse Emission Reduction Potential in Paddy Production Systems in Karnataka State of India

Increasing concerns and call for reduction in Greenhouse gas (GHG) emission have necessitated the search for broader and all-inclusive policy initiatives, extending into agricultural production, where high carbon energy inputs are used. One classical policy strategy for GHG emission reduction, has been taxation. However, given the critical role of agriculture, especially in developing economies, policies that directly or indirectly increase agricultural inputs costs and reduce their demand require stronger theoretical, conceptual and empirical support to ensure that while agri-environmental quality is promoted, welfare of farming households, food security and overall economic growth are not compromised. Using paddy production in Karnataka state in India, the study assessed effects of agricultural input taxation (reduction in rice input subsidy) on future demand for such inputs and their effect on GHG emission reduction, vis-a-viz production and welfare losses. In microeconomic modelling framework, we applied quadratic almost ideal demand system and stochastic efficiency functions in the analysis of the data. Data for the study, a micro-level farm data, was obtained from Cost of Cultivation Scheme (CSS) for irrigated and non-irrigated production systems, covering the period 2009 -2018 production seasons. Specifically, the study used three future tax regime scenarios- 10%, 20% and 30% input subsidy reduction rates, to model an optimum greenhouse emission reduction potential. The results revealed that inputs evaluated were normal with inelastic demand functions; many input coefficients implied significant complementary relationships; irrigated paddy production system had higher estimates of GHG emissions. Input taxation (reduction in subsidy) under all the three scenarios effectively, resulted in declined inputs consumption patterns, and subsequently led to significant decrease in greenhouse emissions. The highest GHG emission reduction potential was observed in irrigated farming system. Greenhouse emission reduction potential was optimal at moderate subsidy reduction policy rate of 10%. It is recommended that, given the inelastic estimates derived, moderate tax (reduction in subsidy) policy option on inputs would yield effective greenhouse mitigation with appropriate compensation through effective integrative schemes.

Environmental and economic analysis of the transformation of paper mill sludge treatment technologies in China.

Paper mill sludge (PMS) is featured with a high content of cellulose and hemicellulose, and using its characteristics to make paperboard can achieve a high-value utilization of PMS, which has attracted growing interest. In this study, currently prevalent landfill, incineration technologies (generating heat and electricity by incineration), and three paperboard technologies (medium density fiberboard, pulp board, and corrugated paper) were evaluated and compared via life cycle assessment (LCA) and life cycle costing (LCC) methods. LCA results show that the PMS-to-pulp board outperforms others with an energy conservation and emission reduction (ECER) value of - 2.86 × 10-8, while the landfill exhibits the highest overall environmental impact with an ECER value of 4.80 × 10-9. LCC results reveal that the PMS-to-pulp board delivers the highest economic profit with $257.357, while the landfill is the lowest with $ - 35.63. The PMS paperboard technologies are more economically friendly than the incineration technologies due to additional electricity/steam consumption during the PMS pre-drying process in incineration. In addition, different scenarios were set up to explore national GHG emission reduction potential by increasing paperboard technologies application rate and reducing the proportion of landfill and incineration. The scenario analysis suggests that replacing 90% of landfill and incineration ratio with PMS paperboard technologies could tremendously improve the overall emission reduction performance with - 9.08 × 1010 kg CO2 eq. This result indicates that the PMS treatment technology transformation has a significant favorable impact on the achievement of the "carbon neutrality" target.

Analysis on Driving Factors, Reduction Potential, and Environmental Effect of Inorganic Fertilizer Input in Chongqing

In this study, we sought to quantify the effect of planting structure change on fertilizer input and environmental cost in Chongqing and develop scientific and rational strategies for chemical fertilizer reduction. Based on the crop fertilizer quota standard and large sample farmer survey data under the medium productivity level in Chongqing, we evaluated and analyzed the application reduction potential and environmental benefits of fertilizer with the difference method and life cycle assessment. The results showed that:① since Chongqing became a municipality directly under the central government (1997), Chongqing crop planting structure had greatly changed, and the proportion of food crop (rice, corn, wheat, bean, and potato) decreased by 21%. The area of fruits and vegetables increased from 3.36×105 hm2 to 1.05×106 hm2, and their proportion increased by 20%. ② Nearly 55% of fertilizers had been consumed by vegetable (37%) and citrus production systems, and 11%, 12%, and 12% of fertilizers were consumed by rice, corn, and potato, respectively. ③ The total fertilizer reduction of the Chongqing planting industry could reach up to 1.69×105 tons during the period of "the 14th Five-Year Plan," with a fertilizer reduction potential of 18.6%. The fertilizer reduction potential (reduction amount) of rice, corn, citrus, and vegetables would reach 0.3% (2.9×102 tons), 12% (1.45×104 tons), 21% (3.65×104 tons), and 30% (1.18×105 tons), respectively. On the other hand, the rape system was insufficient in phosphorus potassium fertilizers, and the corn tended to be insufficient in potash fertilizer. ④ The current production level was low, and the nitrogen loss, greenhouse gas emissions, and eutrophication potential in the planting industry of Chongqing reached 1.81×105 tons (N), 1.43×107 tons (CO2-eq), and 1.74×105 tons (PO4-eq). With the increase in the realization degree of the crop quota standard (60%-100%), the reactive nitrogen loss, greenhouse gas emissions, and eutrophication potential decreased by 14.9%-24.9%, 10.1%-16.7%, and 13.8%-23%, respectively. The structure of the planting industry in Chongqing significantly changed, the total fertilizer consumption in Chongqing tended to decline gradually, and the fertilization intensity of commercial crops stayed at a high level. The agricultural fertilizer reduction potential and the reactive nitrogen and greenhouse gas emission reduction potential were large, especially for citrus and vegetable production systems. However, it is also necessary to pay attention to insufficient corn potash fertilizer and rape phosphorus potassium fertilizer investment and carry out collaborative promotion of fertilizer reduction.

Policies and measures for energy efficiency improvement at households: A bibliometric analysis

Recently, governmental subsidies have led to increased renewable energy adoption and household CO2 emissions reduction. However, energy efficiency improvement and greenhouse gas emission reduction potential in households’ sector are not yet fully realized. Decision-making by individuals is also a crucial factor in adopting energy-efficient and renewable energy technologies, which is why this study analyses some important behavioral change-linked issues. This study also focuses on various policies and measures to achieve energy efficiency improvements in households, such as use of renewable energy sources, renovation of residential buildings, use of energy efficient appliances etc. The methodology of the study contains a bibliometric analysis in the field of energy efficiency at households, covering the years of publication 2010-2023 and organizing all documents into 9 classifications. Among them 6 classifications have been further considered: Citation analysis; Authors’ networks; High impact journals of publishing; Knowledge mapping of co-authorship collaboration among institutions; Co-authorship among countries; Keywords concurrence analysis. Following a systematic literature review the bibliometric findings reveal the steady increase of literature production in the field of energy efficiency at households, showing also the pivotal role of institutions among developed and industrialized economies. Moreover, there is a densely and steadily growing network of keywords reported, implying the thematic expansion of this topic from the modelling-pilot scales towards the real world and in field applications. Finally, identified research constraints of energy efficiency improvement are that of: high costs, lack of information and knowledge, low priority to environmental and climate change mitigation concerns, and resistance to behavioral change.

Global Warming Potential and Life Cycle Cost of Conventional and Potentially Low-Carbon Philippine Swine Production Systems

This study identified and evaluated conventional and low-carbon swine production systems through a review of literature and visits to commercial farrow-to-finish swine farms in the Philippines, aiming to recommend a swine production system that cost-effectively reduces GHG emissions. Parameters assessed were greenhouse gas (GHG) emission, carbon and payback period, and return on investment through conduct of life cycle assessment. The identified conventional technologies are open-sided housing system, slatted flooring, modified manual feeding system, nipple drinker, and scrapper and power sprayer as cleaning systems. The identified low carbon technologies are low protein swine feed formulation supplemented with amino acids and partial substitution of soybean meal with Protein-Enriched Copra Meal (PECM), open-sided housing with cemented flooring, manual feeding system, bite ball valve, scrapper combined with power sprayer as cleaning system, and biogas digester as manure management system. These entailed a GHG emission reduction potential of 31.93% in reference to the conventional system. The low carbon production system accounted for higher return on investment of 36.75% and shorter payback period at 2.72 years, compared to the conventional system that yielded 19.96% and 5.01 years, respectively. The identified low carbon swine farm production system can be a cost-effective alternative to the conventional production system.

Greenhouse gas contribution and emission reduction potential prediction of China's aluminum industry

The aluminum industry, with its traditionally high energy consumption, high emissions and high pollution, is facing increasing pressure to reduce greenhouse gas (GHG) emissions in China. This study analyzes the trajectory and characteristics of GHG emissions during the lifecycle of China's aluminum industry (CAI) from 2011 to 2020, and identifies key driving factors affecting the changes in GHG emissions from CAI. The results indicate that the GHG emissions of CAI mainly come from indirect emissions generated by electricity production (over 69 %). Electrolytic aluminum is the largest sub process of GHG emissions in CAI. In addition, the total energy consumption effect is the main driving factor for the increase in GHG emissions from CAI. On this basis, emission reduction measures are proposed, the economic benefits and applicability of various emission reduction measures are analyzed, and the grey prediction model GM (1,1) is used to predict the GHG emission reduction potential of CAI in 2030. According to analysis, the GHG emission reduction efficiency of CAI is expected to reach 86 % by 2030, and can produce an annual economic benefit of 2.93 × 109RMB. This study will provide a theoretical basis for GHG emission reduction in CAI and even the global aluminum industry (GAI).

Research Progress on Iron- and Steelmaking Iste Slag-Based Glass-Ceramics: Preparation and GHG Emission Reduction Potentials

Promoted by carbon neutrality and solid iste policies, iron- and steelmaking iste slag (ISWS)-based glass-ceramics have drawn attention because of their contribution to achieving the net-zero carbon emissions goal for the iron- and steelmaking industry. However, a holistic estimation of the preparation, property and GHG (greenhouse gas) emission abatement of ISWS-based glass-ceramics is still under exploration. In this paper, research progress on preparing glass-ceramics from ISWS discharged from the traditional iron- and steelmaking industry is reviewed. Then, the influence of ISWS’s chemical characteristics on the preparation of glass-ceramics and the products’ performance are discussed. In addition, the potential of GHG emission reduction related to the promotion of ISWS-based glass-ceramics is measured. It is found that ISWS-based glass-ceramics can avoid 0.87–0.91 tons of CO2 emissions compared to primary resource routes. A scenario simulation is also conducted. If the technology could be fully applied in the ironmaking and steelmaking industries, the results suggest that 2.07 and 0.67 tons of indirect CO2 reductions can be achieved for each ton of crude steel production from blast furnace–basic oxygen furnace (BF-BOF) and electric arc furnace (EAF) routes, respectively. Finally, a “dual promotion” economic mode based on national policy orientation and the high demands on metallurgical iste slag (MWS)-based glass-ceramics is proposed, and the application prospects of MWS-based glass-ceramics are examined. These application prospects will deepen the fundamental understanding of glass-ceramic properties and enable them to be compounded with other functional materials in various new technologies.

Sustainability of large-scale commercial biogas plants in Nepal

Interest in large-scale compressed biogas (CBG) and biogas for electricity generation is increasing due to these technologies’ potential for addressing dual energy and waste management challenges. However, sustainable operation of large-scale commercial biogas plants requires attention to numerous factors, including technical aspects (feedstock types, plant size, operational parameters, and biogas and fertilizer utilization strategies), costs (capital investment and operational), and affordability, as affected also by subsidies. This study conducts a case study of the sustainability of an existing operational large-scale biogas plant in Nepal, considering its operational condition, financial status, and environmental benefits under designed capacity and actual operating conditions. Design parameters related to biogas and digestate production, financial viability, and greenhouse gas (GHG) emission reduction potential were compared with the realized outcomes of the plant. Operational and financial data for the plant were obtained through visits to the plant supplemented by interviews of the plant manager. The analysis reveals that both the feedstock and digester efficiencies are much lower than the design expectations, by 55% and 62%, respectively. This has led to reductions in the production of biogas and biofertilizers by 72% and 90%, respectively. Moreover, while the internal rate of return (IRR) of the plant at design capacity was 23%, it is indeterminate for the actual operating condition, as the net present value is negative for all discount rates. The biogas plant does generate environmental benefits; the GHG emissions avoided are estimated to be around 274 tons of CO2 equivalent per year under the actual operating conditions. Given these results, it is clear that improving the operational performance of large-scale biogas plants in contexts such as this one should be a priority. Moreover, the findings can help policymakers, investors, and other stakeholders make better plans for future development of biogas facilities, insisting on more realistic and careful assessments of technical and financial viability.

Digging deeper: Assessing the predictive power of common greenhouse gas accounting tools for soil carbon sequestration under organic amendment

Effective project implementation and quantification of emissions reduction in climate-smart agriculture initiatives face challenges in measurement, monitoring, and verification. To address these challenges, predictive models are regularly used to estimate the emissions reduction potential of land management changes and to prioritize funding for projects. Despite their growing utility, few studies have evaluated the performance of publicly available model tools using site specific data. This study evaluated the performance and utility of four common model tools that represent the three Intergovernmental Panel on Climate Change model tiers to predict soil organic carbon storage and estimate greenhouse gas emissions on working lands under organic matter amendment. Field data from two long-term, compost application experiments in Washington State formed the basis for model simulations using DayCent, COMET-Farm, Cool Farm, and the Washington State Climate Smart Estimator (WaCSE). Soil carbon sequestration and emissions estimates varied among the evaluated models, which was expected given their differential data requirements and input capabilities. COMET-Farm, although easier to use, exhibited a higher level of bias compared to DayCent, which was expected as a mixed tier model. The DayCent model, the model engine for the COMET-Farm tool, demonstrated the ability to explain ∼50% more of the variation in the observed values compared to COMET-Farm when initiated using the same parameters. Cool Farm was unsuitable for estimating SOC sequestration benefits from compost application primarily because it did not add carbon to the soil pool following amendment. The differences in emissions estimates derived from WaCSE compared with other tools could be attributed solely to its highly constrained input parameters and basis in tier 1 emissions factors. We conclude that online tools can provide rapid estimates of greenhouse gas emissions reduction potential over larger areas or groups of farms but should be used with caution for site-specific estimates. Hence, it is crucial to clarify the intended purpose of an assessment and the designed function of model tools when evaluating their suitability for prioritizing funding for climate-smart agriculture initiatives at the individual farm level.

Earthworms increase soil greenhouse gas emissions reduction potential in a long-term no-till Mollisol

Earthworm activity and plant residues in the soil can strongly influence soil organic carbon (SOC) dynamics. However, studies on how earthworms, especially epigeic and endogeic species alone or together, affect the main soil greenhouse gas (GHG) emissions (CO2 and N2O) and SOC under the long-term no-till (NT) and conventional tillage (CT) in Mollisols in Northeast China are unclear. The effects of two different species of earthworms (epigeic, Eisenia nordenskioldi; endogeic, Metaphire tschiliensis) on the soil GHG emissions and the SOC content were studied in NT and CT soils in a 337-day mesocosm experiment. The presence of earthworms enhanced the soil cumulative CO2 and N2O emissions in both NT and CT soils, and the soil GHG emissions (expressed in terms of the global warming potential, GWP) were increased by 20.43 %–42.99 % in NT soil and by 0–55.62 % in CT soil, respectively. Compared to E. nordenskioldi, the presence of M. tschiliensis (endogeic species) significantly increased soil GHG emissions. Earthworms in NT soil induced less soil GHG emissions than those in CT soil. The presence of earthworms did not increase the SOC content in CT soil but significantly increased the SOC content in NT soil. Our study suggests that earthworms in the long-term no-till soil can contribute to the reduction of soil GHG emissions. This research helps to understand the effects of different ecological categories of earthworms on soil GHG emissions and SOC dynamics under different tillage systems and to mitigate soil GHG emissions.

Willingness to pay for climate change mitigation measures in households: Bundling up renewable energy, energy efficiency, and renovation

AbstractThrough their consumption behavior, households are responsible for more than 70% of total global greenhouse gas emissions. Therefore, the GHG emission reduction potential due to the household behavior is very high. Energy consumption is the main source of the GHG emission in households. There are two main ways to reduce GHG emissions in households: use of renewable energy, energy efficiency improvement, and energy conservation due to changes in the energy use patterns. The highest energy saving potential in households is linked with building renovation, followed by the use of energy efficient appliances (including lighting). Renewable energy microgeneration technologies in households also provide opportunities for GHG emission reduction. Although there have been many policies developed to reduce GHG emissions from energy consumption in households, they still need to be more effective. This paper aims to assess willingness of Lithuanian households to reduce GHG emissions from energy consumption in households by embarking on energy renovation of buildings, use of energy efficient appliances and use of renewable energy technologies. The willingness to pay for these GHG emission reduction measures allows to compare household preferences with respect to available support measures and assess the adequacy of such measures. The paper also discusses household attitudes toward the main policies and measures for GHG emission reduction. The results show the highest willingness to pay for energy efficient appliances, followed by renewable energy technologies. The willingness to pay for energy renovation is the lowest one and such s measure requires significant state support.