Greenhouse Gas Mitigation Options Research Articles

The greenhouse gas benefits of corn ethanol – assessing recent evidence

In 2010, the U.S. Environmental Protection Agency (EPA) released a life-cycle analysis of the greenhouse gas (GHG) emissions associated with the production and combustion of corn ethanol. EPA projected that by 2022, the emissions profile of corn ethanol from a new refinery would be 21% lower than that of an energy equivalent quantity of gasoline. Since 2010, the 21% value has dominated policy discussions and federal regulations related to corn ethanol as a renewable fuel and a GHG mitigation option. It is now 2018 and new data, scientific studies, technical reports, and other information allow us to examine the emissions pathway corn-ethanol has actually followed since 2010. Using this information, we assess corn ethanol's current GHG profile at 39–43% lower than gasoline. We also develop two projected emissions scenarios for corn ethanol in 2022. These scenarios highlight opportunities to produce ethanol with emissions that are 47.0–70.0% lower than gasoline. Many countries are now developing or revising renewable energy policies. Typically, biofuel substitutes for gasoline are required to reduce GHG emissions by more than 21%. Our results could help position U.S. corn ethanol to compete in these new and growing markets.

Increases in soil sequestered carbon under conservation agriculture cropping decrease the estimated greenhouse gas emissions of wetland rice using life cycle assessment

Wetland rainfed rice (Oryza sativa L.), which covers 60 million hectares in South Asia, contributes significantly to agricultural greenhouse gas (GHG) emissions. Mitigation strategies for GHG emissions by wetland rice production are of considerable importance. Life cycle assessment of GHG emissions can be used to assess the mitigation potential of new rice production practices such as seedling establishment on non-puddled soil. The aim of the study was firstly to determine the GHG mitigation potential of rain-fed rice production by changing to non-puddled transplanting and increased crop residue retention and secondly to determine the addition contribution of soil carbon sequestration to net GHG emissions with the altered crop establishment approach. A cradle to farm-gate Life Cycle Analysis was used to calculate GHG emissions associated with monsoon rice production in rice-based intensive cropping systems of Northwest Bangladesh. The non-puddled transplanting and low residue retention decreased the net life cycle assessment GHG emissions (CO2eq) by 31% in comparison with the current puddled transplanting and increased crop residue retention. By contrast, non-puddling with increased residue retention reduced emission of the net GHG by 16% in comparison with current puddling and low residue retention. Regardless of rice establishment practices, CH4 was the most prevalent GHG emission comprising 63–67% of the total GHGs, followed by 17–20% from CO2 emissions from the field. The GHG emissions tonne−1 rice after accounting for soil carbon storage ranged from 1.04 to 1.18 tonne CO2eq for non-puddling with low and increased crop residue retention, respectively. The inclusion of soil carbon in the footprint equation represents a 26% reduction of estimated GHG emissions under non-puddled soil with increased residue retention. Overall, non-puddled transplanting with increased crop residue retention was an effective GHG mitigation option in wetland monsoon rice production because the increased yield and extra soil organic carbon storage more than offset its higher CH4 emissions than with low residue retention.

Decreasing the carbon footprint of an intensive rice-based cropping system using conservation agriculture on the Eastern Gangetic Plains

Emerging conservation agriculture (CA) technologies are being applied in rice-upland cropping systems and their potential to mitigate greenhouse gas emissions of the whole rice-based cropping systems could be significant in South Asia especially if they increase soil organic carbon (SOC) stocks. A streamlined life cycle assessment was conducted in the Eastern Gangetic Plains (Bangladesh) to determine greenhouse gas emissions from successive crops of monsoon rice (Oryza sativa), mustard (Brassica juncea) and irrigated rice under CA practices in contrast with the conventional crop establishment practice while accounting for changes in SOC. The life cycle greenhouse gas tonne−1 rice equivalent yield was assessed for four cropping practices: a) traditional crop establishment practices with farmers’ practice of minimal residue return, or b) CT with return of increased residues; c) strip planting (for mustard)/transplanting on non-puddled soils (for rice) with farmers’ practice of minimal residue return or; d) strip planting/non-puddled transplanting with increased residue return. The global warming potential values for the 100-year timescale were used to calculate CO2eq emissions within the system boundary. The net life cycle greenhouse gas emissions after allowing for changes in SOC sequestration varied from 0.73 to 1.12 tonne CO2eq tonne−1 rice equivalent yield. In the annual cropping system, methane (CH4) released from on-farm stage of the life cycle assessment, particularly from the rice crops, represented the dominant contributor to life cycle greenhouse gas emissions. The greenhouse gas emitted by machinery usage during the on-farm stage (irrigated rice), CO2 emission from soil respiration (monsoon rice), and greenhouse gas related to manufacture of inputs (mustard) were secondary sources of emission, in that order of priority. The non-puddlled transplanting of soil with low and increased residue retention were the most effective greenhouse gas mitigation options when sequestered SOC was taken into account (they avoided 35% of the net life cycle footprints compared with current farmers’ practice) in footprints of component crops of the rice-upland cropping system. The CA approaches being developed for the Eastern Gangetic Plains involving strip planting or non-puddled transplanting of rice have potential to mitigate global warming potential of intensive rice-based triple cropping systems but the life cycle assessment approach needs to be applied to a more diverse range of rice-based cropping systems.

Environmental and Economic Evaluation for Biogas Generation in Jordan as a Greenhouse Gas Mitigation Option

Reduction of Landfill Gases (LFG) positively affects the environment because they contain greenhouse gas emissions like CO2, CH4 and other trace gases. Therefore, one of the solutions to mitigate the climate change impacts is using landfill recovery system. Al Ghabawi Landfill was chosen as a case study and the model used to predict the amount of landfill gases generated from the landfill is based on the IPCC (Intergovernmental Panel on Climate Change) default method. The estimation was based on quantification of waste quantities and components. Preliminary economic study was made to evaluate the feasibility of constructing power generation plants over the lifetime of the proposed project by assuming a case of using landfill gas recovery and a case without integrating any landfill gas. This study found that the Landfill gases utilization in landfills is considered satisfactorily enough both in electric energy production and in mitigating greenhouse gases.

Greenhouse gas emissions and mitigation options for German wine production

In the light of a dire need to reduce greenhouse gas emissions (GHG) from food value chains, this paper analyses GHG emissions from wine production based on primary data from 5 wineries, one wine cellar and 9 grape producers in Germany and explores main emission sources based on their contributions to variance. Considering system boundaries from cradle to gate we found a 90% confidence interval for results between 0.753 and 1.069 kg CO2e per bottle of wine. Main contributors to variance were bottle weight (31%), electricity usage (18%), heat (11%), yield (−9%), and diesel use in vineyards (9%). Looking at production process phases, 19% of emissions resulted from the production of wine grapes, while 81% were attributable to the winery phase, mainly to the packaging materials (57%). Exploring the mitigation potential of a reduction in bottle weight, reuse of glass bottles, increase in packaging volume and renewable energies, we found that the reuse of glass bottles deserves close attention from wine producers, consumers, and policy makers who strive for an effective decarbonization of the wine value chain. The mitigation potential of the reuse of an average bottle exceeds the mitigation potential from a reduction in bottle weight by more than threefold. A combination of the replacement of grid electricity by renewable energies, bottle weight reduction and reuse can curb GHG emissions per bottle of wine by 47%.

Opportunities to mitigate greenhouse gas emission from paddy rice fields in Indonesia

Human activities including modern agriculture have increased the concentration of atmospheric greenhouse gas (GHG) since the industrial age. The agricultural sector is a source for three primary GHG emissions: methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). Numerous management practices can potentially mitigate GHG emissions from rice fields. Before implementing the practices, it is critical to evaluate its impact on GHG emissions and rice production. The aim of this study is to explore the management practices from paddy fields in Indonesia as mitigation of GHG emission without any yield loss. There were some trade-offs between CH4 and N2O emissions. Continuous flooding triggered largely CH4 emissions and reduced N2O emissions. Organic fertilizer tended to decrease N2O emissions. Nevertheless, inorganic fertilizer e.g. urea application led to an increase of N2O emissions. Promising mitigation options of GHG emission from rice cultivation are the application of water management, a nitrification inhibitor, iron supplement, rice cultivars selection, nutrient (organic-inorganic) management, cultivation method. The effectiveness of the GHG mitigation options varied while acceptability of mitigation options will depend on the extent to which sustainable production will be achieved or maintained.

Co-design and assessment of mitigation practices in rice production systems: A case study in northern Vietnam

Rice production systems are an important source of agricultural greenhouse gas (GHG) emissions. Mitigation techniques, such as alternate wetting and drying, have been developed but have often not taken into consideration the constraints imposed by the practices and preferences of farmers. Since GHG mitigation benefits are not obvious at smallholder farm level, it is essential to design site-specific mitigation technologies with the participation of local stakeholders. The purpose of the present study was to adapt a participatory approach to designing and assessing mitigation practices for the dissemination of climate-friendly rice production systems. To improve the hybridization of scientific and local knowledge, a participatory five-step approach to prototyping was applied: (i) diagnosis based on a literature review and survey of stakeholders, (ii) design of mitigation practices based on laboratory trial and local knowledge (that of farmers, agricultural advisors and regional stakeholders), (iii) testing in growth chambers, (iv) testing in farmers' fields and (v) dissemination and assessment. The study was conducted in An Luong village, Red River Delta, northern Vietnam. In the study area, rice residue burning is restricted and farmers have to incorporate residue into the soil. Current water management practices, i.e. conventional continuous flooding and adopted midseason drainage, are not enough to reduce GHG emissions from added residues. Two new water management practices (pre-planting plus midseason drainage and early plus midseason drainage) were designed in participation with local stakeholders, and subsequently tested in the laboratory and in the field with the participation of local farmers. Future mitigation practices were assessed based on the yield, GHG emissions reduction and feedbacks of local stakeholders. Early plus midseason drainage proved to be an effective and feasible mitigation option for rice production in the area. Here we show that participation of local stakeholders in co-designing process help to identify the feasible GHG mitigation options, further it facilitates smallholder rice farmers to implement mitigation practices in their fields.

Independent data for transparent monitoring of greenhouse gas emissions from the land use sector – What do stakeholders think and need?

The agriculture, forestry and other land use (AFOLU) sectors contribute substantially to the net global anthropogenic greenhouse gas (GHG) emissions. To reduce these emissions under the Paris Agreement, effective mitigation actions are needed that require engagement of multiple stakeholders. Emission reduction also requires that accurate, consistent and comparable datasets are available for transparent reference and progress monitoring. Availability of free and open datasets and portals (referred to as independent data) increases, offering opportunities for improving and reconciling estimates of GHG emissions and mitigation options. Through an online survey, we investigated stakeholders’ data needs for estimating forest area and change, forest biomass and emission factors, and AFOLU GHG emissions. The survey was completed by 359 respondents from governmental, intergovernmental and non-governmental organizations, research institutes and universities, and public and private companies. These can be grouped into data users and data providers. Our results show that current open and freely available datasets and portals are only able to fulfil stakeholder needs to a certain degree. Users require a) detailed documentation regarding the scope and usability of the data, b) comparability between alternative data sources, c) uncertainty estimates for evaluating mitigation options, d) more region-specific and detailed data with higher accuracy for sub-national application, e) regular updates and continuity for establishing consistent time series. These requirements are found to be key elements for increasing overall transparency of data sources, definitions, methodologies and assumptions, which is required under the Paris Agreement. Raising awareness and improving data availability through centralized platforms are important for increasing engagement of data users. In countries with low capacities, independent data can support countries’ mitigation planning and implementation, and related GHG reporting. However, there is a strong need for further guidance and capacity development (i.e. ‘readiness support’) on how to make proper use of independent datasets. Continued investments will be needed to sustain programmes and keep improving datasets to serve the objectives of the many stakeholders involved in climate change mitigation and should focus on increased accessibility and transparency of data to encourage stakeholder involvement.

Marginal abatement cost curves for agricultural climate policy: State-of-the art, lessons learnt and future potential

Abstract Combatting climate change has risen to the top of the international policy discourse. Effective governance necessitates the generation of concise information on the costs-effectiveness of policy instruments aimed at reducing atmospheric greenhouse gas (GHG) emissions. The marginal abatement cost curve (MACC) approach is a framework commonly used to summarise information of potential mitigation effort, and can help in identifying the most cost-effective managerial and technological GHG mitigation options. Agriculture offers key opportunities to mitigate GHG emissions and utilise carbon (C) sink potentials. Therefore, a number of countries have developed national agricultural MACCs in the last decade. Whilst these MACCs have undoubtedly been catalysers for the information exchange between science and policy, they have also accentuated a range of constraints and limitations. In response, each of the scientific teams developed solutions in an attempt to address one or more of these limitations. These solutions represent ‘lessons learned’ which are invaluable for the development of future MACCs. To consolidate and harness this knowledge that has heretofore been dispersed across countries, this paper reviews the engineering agricultural MACCs developed in European countries. We collate the state-of-the-art, review the lessons learnt, and provide a more coherent framework for countries or research groups embarking on a trajectory to develop an agricultural MACC that assesses mitigations both within the farm gate and to the wider bioeconomy. We highlight the contemporary methodological developments, specifically on 1) the emergence of stratified MACCs; 2) accounting for soil carbon sequestration 3) accounting for upstream and downstream emissions; 4) the development of comprehensive cost-calculations; 5) accounting for environmental co-effects and 6) uncertainty analyses. We subsequently discuss how the mitigation potential summarised by MACCs can be incentivised in practice and how this mitigation can be captured in national inventories. We conclude that the main purpose of engineering MACCs is not necessarily the accurate prediction of the total abatement potential and associated costs, but rather the provision of a coherent forum for the complex discussions surrounding agricultural GHG mitigation, and to visualise opportunities and low-hanging fruit in a single graphic and manuscript.

Development of a Framework for the Assessment of Energy Demand-Based Greenhouse Gas Mitigation Options for the Agriculture Sector

Abstract. This study assesses greenhouse gas (GHG) mitigation options for the agriculture sector. The Long-range Energy Alternatives Planning (LEAP) model was used to develop a framework to assess future trends in energy demand and associated GHG emissions for the agriculture sector and to assess various GHG mitigation options associated with energy consumption. A business-as-usual (reference) scenario and 32 GHG mitigation scenarios were developed for the years 2009-2050 using the LEAP model. A case study for Alberta, Canada, was conducted. In the model, GHG mitigation scenarios were developed for the energy demand side (e.g., farm machines, farm transportation, lighting, and ventilation) based on efficiency improvements and the use of renewable energy. The mitigation scenarios were divided into two planning horizons based on technology penetration: slow penetration (2009-2050) and fast penetration (2009-2030). For each planning horizon, 16 scenarios were assessed. Of all farm machines, efficient diesel tractors have the highest GHG mitigation potential: 12.35 MT of CO2 equivalent by 2050 and 4.7 MT of CO2 equivalent by 2030. In addition, GHG abatement cost curves show that biodiesel tractors and efficient diesel tractors have the highest GHG mitigation potential, with attractive abatement costs of -$62 and -$11 tonne-1 of CO2 mitigated by 2050, respectively. Keywords: Abatement cost, Agriculture sector, Energy efficiency, GHG mitigation, LEAP model.

Greenhouse gas and ammonia emissions and mitigation options from livestock production in peri-urban agriculture: Beijing – A case study

Abstract Livestock production in peri-urban areas constitutes an important sub-sector of the agricultural production system in China, and contributes to environmental degradation and local air borne pollution contributing to smog. As a result, local policies are being implemented to safeguard the environment. However, there has been little attempt to quantify the impact of environmental policies on livestock production structure, spatial distribution and their related greenhouse gases (GHGs) and ammonia (NH3) emissions. Here, we calculated the inventories of GHGs and NH3 emissions for 2010 and 2014 for peri-urban livestock production in Beijing, using reliable spatially explicit data, which was collected from 1748 industrial farms in 2010 and 2351 industrial farms in 2014, including pig, dairy, beef cattle, poultry and sheep farms. Our estimates indicated that total industrial livestock production increased by 17% between 2010 and 2014, even under the more strict environmental protection polices, with farm size decreasing by between 7% and 47%. Up to 50% of the industrial livestock farms have remained in operation, with the rest closing down or being moved to other regions. Following this trend, total GHGs emission decreased from 5.0 to 4.5 Tg CO2-eq between 2010 and 2014. Most of the GHGs emission reduction was due to the lowering of energy related carbon dioxide (CO2) emission in 2014. Total NH3 emission decreased from 102 to 96 Gg between 2010 and 2014, mainly due to more stringent environmental regulations for new and extended farms (increased in farm size), e.g. Discharge standard for pollutants for livestock and poultry breeding. Our study identified that GHGs and NH3 emission hotspots were concentrated in suburban areas (around the city centre and with less agricultural resource and population density) in 2010. However, between 2010 and 2014 these hotspots moved to the exurban plain and mountain area following the closure or sub-division of intensive farms in suburban regions and construction of new and small farms in exurban areas (around the suburban and with more agricultural resource and lower population density). Scenario analysis suggests that total GHGs emission can be reduced by up to 1.0 Tg CO2-eq (23% of total livestock sector emissions) in Beijing, using a combination of modifications of farm type, livestock diet and manure management. The integrated scenario can reduce CH4, N2O and NH3 emissions by 27%, 9% and 35%, compared to the reference scenario. Within this short period of time (5 years), policies have had direct impacts on peri-urban livestock production in Beijing, resulting in marked changes in the structure of different livestock sectors, as well as the GHGs and NH3 emission inventories and their spatial distribution. Our analysis clearly shows that the success of these (and future) polices relies on optimizing spatial management of new livestock production systems. Policy and farmer guidance should focus on optimizing livestock diet and on-farm manure management, industrial production systems and the pig and poultry sectors in peri-urban regions.

Site-specific feasibility of alternate wetting and drying as a greenhouse gas mitigation option in irrigated rice fields in Southeast Asia: a synthesis

ABSTRACTThis study comprises a comprehensive assessment, integration, and synthesis of data gathered from a 3-year field experiment conducted at four sites in Southeast Asia, namely Hue, Vietnam; Jakenan, Indonesia; Prachin Buri, Thailand; and Muñoz, Philippines, to assess the site-specific feasibility of alternate wetting and drying (AWD) as a greenhouse gas (GHG) mitigation option in irrigated rice fields. AWD effectively reduced water use compared to continuous flooding (CF) but did not significantly reduce rice grain yield and soil carbon content in all sites. Methane (CH4) emissions varied significantly among sites and seasons as affected by soil properties and water management. AWD reduced CH4 emissions relative to CF by 151 (25%), 166 (37%), 9 (31%), and 22 (32%) kg CH4 ha−1 season−1 in Hue, Jakenan, Prachin Buri, and Muñoz, respectively. In Prachin Buri and Muñoz, AWD reduced CH4 emissions only during the dry season. Site-specific CH4 emission factors (EFs) ranged 0.13–4.50 and 0.08–4.88 kg CH4 ha−1 d−1 under CF and AWD, respectively. The mean AWD scaling factors (SFs) was 0.69 (95% confidence interval: 0.61–0.77), which is slightly higher than the Intergovernmental Panel on Climate Change (IPCC)’ SF for multiple aeration of 0.52 (error range: 0.41–0.66). Significant reductions in the global warming potential (GWP) of CH4+nitrous oxide (N2O) by AWD were observed in Hue and Jakenan (27.8 and 36.1%, respectively), where the contributions of N2O to the total GWP were only 0.8 and 3.5%, respectively. In Muñoz, however, CH4 emission reduction through AWD was offset by the increase in N2O emissions. The results indicate that the IPCC’s SF for multiple aeration may only be applied to irrigated rice fields where surface water level is controllable for a substantial period. This study underscores the importance of practical feasibility and appropriate timing of water management in successful GHG reductions by AWD.

Towards a low-carbon electric power system in Mexico

The energy sector is one of the largest sources of Greenhouse Gas (GHG) emissions in Mexico and the World due to the intensive use of fossil fuels. This article is developed on and examines from an environmental and economical approach an alternative scenario towards a Mexican Low Carbon Electric Power System, by analyzing 36 GHG mitigation options on the electric demand side, namely −23 for an energy-efficient use and 4 for distributed generation, across the residential, commercial, public, industrial and energy sectors and, 9 options of electric power generation with Renewable Energy Sources (RES) on the electric power supply side. Our results reveal that, regarding the GHG baseline, towards 2020, this alternative scenario minimizes 33% of the GHG emissions, and towards 2035 these emissions are dramatically minimized at 79%. Furthermore, results also show that there is a possibility to reach a GHG peak in the electric power industry in very few years with this alternative scenario. Moreover, it is found that this alternative scenario will entail no cost in the analyzed period; on the contrary, it creates a global economic benefit of over 8000 MUSD, where 74% is related to the application of the mitigation options in the electric demand sectors and the remaining 26% comes from RES technologies in the electric power supply. Results show that the implementation of this alternative scenario requires an incremental investment of almost than 2 Billion USD/year within the analysis period. Lastly, it is shown that national goals for the electric power sector that have been recently established in the General Climate Change Law, the Energy Transition Law as well as the proposed Intended Nationally Determined Contribution in the Paris COP21 Agreements are feasible for achievement in this alternative scenario.

Water level, vegetation composition, and plant productivity explain greenhouse gas fluxes in temperate cutover fens after inundation

Abstract. Peat extraction leaves a land surface with a strong relief of deep cutover areas and higher ridges. Rewetting inundates the deep parts, while less deeply extracted zones remain at or above the water level. In temperate fens the flooded areas are colonized by helophytes such as Eriophorum angustifolium, Carex spp., Typha latifolia or Phragmites australis dependent on water depth. Reeds of Typha and Phragmites are reported as large sources of methane, but data on net CO2 uptake are contradictory for Typha and rare for Phragmites. Here, we analyze the effect of vegetation, water level and nutrient conditions on greenhouse gas (GHG) emissions for representative vegetation types along water level gradients at two rewetted cutover fens (mesotrophic and eutrophic) in Belarus. Greenhouse gas emissions were measured campaign-wise with manual chambers every 2 to 4 weeks for 2 years and interpolated by modelling. All sites had negligible nitrous oxide exchange rates. Most sites were carbon sinks and small GHG sources. Methane emissions generally increased with net ecosystem CO2 uptake. Mesotrophic small sedge reeds with water table around the land surface were small GHG sources in the range of 2.3 to 4.2 t CO2 eq. ha−1 yr−1. Eutrophic tall sedge – Typha latifolia reeds on newly formed floating mats were substantial net GHG emitters in the range of 25.1 to 39.1 t CO2 eq. ha−1 yr. They represent transient vegetation stages. Phragmites reeds ranged between −1.7 to 4.2 t CO2 eq. ha−1 yr−1 with an overall mean GHG emission of 1.3 t CO2 eq. ha−1 yr−1. The annual CO2 balance was best explained by vegetation biomass, which includes the role of vegetation composition and species. Methane emissions were obviously driven by biological activity of vegetation and soil organisms. Shallow flooding of cutover temperate fens is a suitable measure to arrive at low GHG emissions. Phragmites australis establishment should be promoted in deeper flooded areas and will lead to moderate, but variable GHG emissions or even occasional sinks. The risk of large GHG emissions is higher for eutrophic than mesotrophic peatlands. Nevertheless, flooding of eutrophic temperate fens still represents a safe GHG mitigation option because even the hotspot of our study, the floating tall sedge – Typha latifolia reeds, did not exceed the typical range of GHG emissions from drained fen grasslands and the spatially dominant Phragmites australis reed emitted by far less GHG than drained fens.

CO2 mitigation in Thailand’s low-carbon society: The potential of renewable energy

ABSTRACTThis study aims at the development of Thailand’s low-carbon society in 2030 by using the Asia-Pacific Integrated Model/Extended Snap Shot model for analysis of greenhouse gas (GHG) mitigation through renewable energy (RE) utilization. This article presents the potentials of RE in power generation, industrial, and transport sectors in Thailand for GHG mitigation in 2030. The deployment of the RE sources is used in the analyses with potentials of mini-hydro of 390 MW, wind power of 960 MW, solar power of 600 MW, biomass energy of 4,400 MW, biogas power of 144 MW, waste to power of 192 MW, bioenergy of 4,634 ktoe, and RE for thermal of 8,088 ktoe in 2030. According to the proposed development, the amount of GHG emissions is estimated based on business-as-usual (BAU) without mitigation measures and countermeasures with GHG mitigation options of adopted RE technologies available during 2005–2030. Results show that annual GHG emissions in the base year of 2005 are 185,983 kt-CO2. In 2030 the GHG emissions in the BAU scenario will increase to 563,730 kt-CO2 or 3.03 times higher than the base year 2005. The GHG emissions in the 2030 can be decreased dramatically to 443,043 kt-CO2, and accounted for 21.4% of GHG reduction by deployment of RE technologies.

Estimated Greenhouse Gases Emissions from Mobile and Stationary Sources in the Limestone and Basalt Rock Mining in Thailand

Mineral processing can become more environmentally sustainable by integrating practices that reduce all environmental impact of mining operations. Along with pollution problems, global climate change is presently one of the most important environment concerns. This research aimed to identify all potential sources and also compare the net emissions of greenhouse gases (GHGs) from the limestone and basalt rock mining operations in Thailand. Limestone (Plant I) and basalt (Plant II) rock mining located in the central and the northeast of Thailand were selected as research case studies. The results indicated that the total amount of GHGs emitted from limestone mining operation were approximately 1,457.61 and 1,753.73 tCO2-eq in 2014 and 2015, respectively. Estimated GHGs intensity ranged between 18.83 to 22.36 kgCO2-eq/tonne of rock product. Similarly, over 2014 to 2015, the range of total GHGs emissions from basalt rock mining was about 1,467.27 to 1,670.18 tCO2-eq. Interestingly, estimated GHGs intensity of basalt mining was roughly two times greater than limestone rock mining (31.85 to 35.72 kgCO2-eq/tonne of product). By scope, direct emission from transport-related activities in both limestone and basalt rock mining was by far the largest source of emissions (45-62%) compared to indirect emission from purchased grid-electricity (34-40%). Some GHGs mitigation options and also challenges ahead for archiving environmental sustainability in the mining industry in Thailand were further raised.

Estimating agro-ecosystem carbon balance of northern Japan, and comparing the change in carbon stock by soil inventory and net biome productivity

Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for agriculture. We have used crop-level yields, modeled heterotrophic respiration (Rh) and land use data to estimate spatio-temporal changes in regional scale net primary productivity (NPP), plant C inputs, and net biome productivity (NBP) in northern Japan's arable croplands and grasslands for the period of 1959–2011. We compared the changes in C stocks derived from estimated NBP and using repeated inventory datasets for each individual land use type from 2005 to 2011. For the entire study region of 2193ha, overall annual plant C inputs to the soil constituted 37% of total region NPP. Plant C inputs in upland areas (excluding bush/fallow) could be predicted by climate variables. Overall NBP for all land use types increased from −1.26MgCha−1yr−1 in 1959–0.26MgCha−1yr−1 in 2011. However, upland and paddy fields showed a decreased in NBP over the period of 1959–2011, under the current C input scenario. From 1988, an increase in agricultural abandonment (bush/fallow) and grassland cover caused a slow increase in the regional C pools. The comparison of carbon budgets using the NBP estimation method and the soil inventory method indicated no significant difference between the two methods. Our results showed C loss in upland crops, paddy fields and sites that underwent land use change from paddy field to upland sites. We also show C gain in grassland from 2005 to 2011. An underestimation of NBP or an overestimation of repeated C inventories cannot be excluded, but either method may be suitable for tracking absolute changes in soil C, considering the uncertainty associated with these methods.

Reduced-order modelling of flexible CCS and assessment using short-term resource scheduling approach

CCS (Carbon Capture and Storage) can allow conventional fuels for electricity generation to be used while achieving deep reductions in GHG (Greenhouse Gas) emissions at the cost, though, of reduced efficiency and capacity relative to an electricity system without CCS. It has been proposed that the deployment of generating units with CCS that are flexible—in particular, that can moderate their CO2 recovery in response to market conditions—would mitigate some of the disbenefit associated with the technology. This paper uses the short-term resource scheduling approach to assess the value of flexible generating units with CCS (Carbon Capture and Storage); generating unit part-load performance, variability of CO2 recovery, and detailed operation of an electricity system including transmission and reliability constraints are considered simultaneously. A parametric study of the performance of a coal-fired generating unit with CCS is undertaken using an Aspen Plus® steady-state model and a reduced-order model representing the Pareto optimal frontier of the unit is developed using regression analysis. The base economic dispatch underlying the electricity system simulator is extended to accommodate flexible generating units with CCS. The flexible generating unit with CCS is added to the IEEE RTS’96 (Institute of Electrical and Electronics Engineers One-Area Reliability Test System—1996) and the operation of the modified IEEE RTS’96 is simulated for one week. The results are contrasted with results taken from Alie et al. (2015) for the base IEEE RTS’96 and an IEEE RTS’96 with “fixed” CCS. “Flexible” CCS is effective at reducing GHG emissions, though to a slightly lesser extent than was observed via “fixed” CCS. However, with GHG regulation in place, flexibility markedly increases the net energy benefit of the generating unit with CCS and this was achieved not through adjustment of CO2 recovery in order to moderate output but, rather, by increasing the generating unit's ability to successfully compete to provide reserve power. Performance metrics that do not consider the impact of GHG mitigation options on energy benefit may not correctly rank GHG mitigation options.

Foreword to ‘National Agricultural Manure Management Program – Greenhouse Gas Mitigation Options For Intensive Livestock Industries’

Foreword to ‘National Agricultural Manure Management Program – Greenhouse Gas Mitigation Options For Intensive Livestock Industries’

Greenhouse gas implications of novel and conventional rice production technologies in the Eastern-Gangetic plains

Wetland rice (Oryza sativa L.) production contributes 55% of agricultural greenhouse gas (GHG) emissions in the world. Hence any new technology with the potential to reduce the GHG emissions of wetland rice could make a significant contribution to total global warming mitigation by agriculture. We applied a streamlined life cycle assessment to the effect of a novel unpuddled transplanting of rice and of increased crop residue retention on GHG emissions from rice fields in the Eastern Gangetic Plains. We compared them with the conventional puddling of soils and current residue retention for transplanting. The GHG emissions from one tonne of rice production for the following four cropping practices were studied: a) conventional puddled transplanting with low residue retention (CTLR); b) conventional puddled transplanting with high residue retention (CTHR); c) unpuddled transplanting following strip tillage with low residue retention (UTLR) and; d) unpuddled transplanting with high residue retention (UTHR). The emissions recorded on-farm and emissions related to pre-farm activities were converted to CO2-eq using Global Warming Potential (GWP) values of GHGs for 20-, 100- and 500-year time horizons. The GHG emissions of 1 tonne of rice varied from 1.11 to 1.57 tonne CO2-eq in the 100-year horizon. For all four treatments, soil methane (CH4) was the predominant GHG emitted (comprising 60–67% of the total) followed by emission from on-farm machinery use. The UTLR was the most effective GHG mitigation option (it avoided 29%, 16% and 6% of the total GHG emissions in comparison with CTHR, CTLR and UTHR, respectively) in wetland rice production. The novel minimum tillage establishment approach for rice involving strip tillage followed by UT has potential to increase global warming mitigation of wetland rice in the Eastern Gangetic Plains, but further research is needed to assess the role of increased residue retention.