Estimate Greenhouse Gas Emissions Research Articles

Estimated Greenhouse Gas Emissions from PFAS Treatment of Maine Drinking Water

State law requires the adoption of a maximum contaminant level (MCL) for PFAS contamination in drinking water by June 1, 2024. While discussion of mitigation options has included the degree of risk reduction and the cost of treatment, indirect environmental effects are missing from the conversation. Until other technologies are developed, water treatment in Maine will likely rely on the established, energy-intensive method of PFAS adsorption (binding) to granular activated carbon. We conducted an inventory of greenhouse gas emissions associated with water treatment using this treatment media to fill gaps in the discussion. We found that greenhouse gas emissions for water treatment to bring PFAS down to the current interim standard are substantial, raising the footprint of an average user by 6.7–18 percent. We use this information to discuss implications for policymaking.

Integrated approach for the estimation of regional low carbon potential: Application for Ho Chi Minh City, Viet Nam

Currently, multidisciplinary integrated and quantitative methodologies are necessary for policymakers in deciding a reasonable and acceptable target of greenhouse gas (GHG) reduction as well as realization of mitigation actions. Therefore, this study aims to develop an integrated methodology to harmonize the top-down and bottom-up approaches to support the development of low carbon actions at the regional or city level based on their energy-saving programs and technology status. This integrated approach is necessary to bridge the theoretical and empirical frontiers of modeling in quantifying and analyzing the feasibility of the local police framework and international cooperation in terms of climate mitigation projects. The top-down approach uses the Extended Snapshot (ExSS) tool to estimate GHG emissions and reduction potential based on macro socioeconomic information. Meanwhile, the technology-based bottom-up approach is a method to estimate the reduction potential of GHG emissions by accumulating specific energy-saving projects. Parameters related to energy service demand, energy efficiency, energy share, and dispersed power generation are harmonized in the integration process via a set of equations. Under the assumption of socioeconomic growth of Ho Chi Minh City (HCMC), which is a 1.37 times increase for population and a 4.41 times increase for GDP growth in 2030 compared to 2013, the total energy consumption will increase 3.73 times compared to 2013, which is nearly 26 million toe (Mtoe) in 2030. The total GHG emissions will also increase 4.02 times, reaching nearly 117.2 MtCO2eq if HCMC does not consider any climate change mitigation actions. However, if HCMC successfully implements the mitigation projects discussed and quantified in this study, the total GHG emissions might be lower, approximately 85.6 MtCO2eq. Analysis of the results from the two scenarios (BaU and CCAP) shows that the energy saving potential is approximately 15.0% and that the total GHG emissions reduction potential of HCMC (excluding the potential from grid power, which is outside the effort of HCMC) is 20.7% of BaU’s emissions, which is between the 8-25% reduction target of Vietnam intended nationally determined contribution. By looking at the disaggregation of reduction potential by each sector and project, policymakers can prioritize mitigation measures to meet the GHG emissions reduction target or to maximize GHG emissions reduction potential. The integrated approach requires the consistency between classifications in top-down (driving force based) and bottom-up (technology based) approaches as well as the modification and bridging of the top-down sectors and the bottom-up categories with detailed data. This method is very applicable for cities or regions that are developing climate change action plans with precise technological information.

Development of Dndc-Bc Model to Estimate Greenhouse Gas Emissions from Rice Paddy Fields Under Combination of Biochar and Controlled Irrigation Management

Development of Dndc-Bc Model to Estimate Greenhouse Gas Emissions from Rice Paddy Fields Under Combination of Biochar and Controlled Irrigation Management

Agri-pellets as alternative fuels for coal-fired power plants in Canada

PurposeLignite coal-fired power plants are the main electricity generators in the province of Saskatchewan, Canada. Although burning lignite coal to generate power is economical, it produces significant greenhouse gases making it a big challenge to Canada’s international commitment on emission reduction. However, abundant agricultural crops and sawdust produced in Saskatchewan put the province in a good position to produce and use agri-pellets as an alternative fuel to generate electricity. This study aims to conduct an economic and environmental analysis of the replacement of lignite coal by agri-pellets as the fuel for Saskatchewan’s coal-fired power plants.Design/methodology/approachThe study estimates the economic and environmental costs and benefits of two alternative fuels for power plants. The economic analysis is based on the pellet production and transportation costs from farms to production sites and from the production sites to power plants. In the production process, biomass precursors are densified with and without additives to produce fuel agri-pellets with appropriate mechanical durability and high heating value per volume unit. The environmental analysis involves estimation of greenhouse gas emissions and their social costs for lignite coal and different types of agri-pellets under different scenarios for pellet production and transportation.FindingsThe results show that although the total cost of electricity is lower for coal than agri-pellets, the gap shrinks when social costs and specifically a carbon price of $50/tonne are included in the model. The cost of electricity in lignite coal-fired power plants would also be on par with agri-pellets-fired power plants if the carbon price is between U$68 and $78 per tonne depending on the power plant locations. Therefore, a transition from coal to agri-pellet fuels is feasible if a high-enough price is assigned to carbon. The method and the results can be generalized to other places with similar conditions.Research limitations/implicationsThere are a few caveats in this study as follows. First, the fixed costs associated with the transformation of the existing coal-fired power plants to pellet-fired plants are not considered. Second, the technological progress in the transportation sector, which would favor the net benefits of using pellets versus coal, is not included in the analysis. Finally, the study does not address the possible political challenges facing the transition in the context of the Canadian federal system.Practical implicationsThe study results indicate that the current carbon price of $50 per tonne is not sufficient to make the agri-pellets a feasible source of alternative energy in Saskatchewan. However, if carbon pricing continues to rise by $15 annually starting in 2022, as announced, a transition from coal to agri-pellets will be economically feasible.Social implicationsCanada is committed to reduce its emission according to the Paris agreement, and therefore, needs to have a concrete policy to find alternative energy sources for its coal-fired power plants. This study examines the challenges and benefits of such transition using the existing agri-pellet resources in Saskatchewan, a province with abundant agricultural residues and coal-fired power plants. The findings indicate that a significant emission reduction can be achieved by using agri-pellets instead of coal to produce electricity. The study also implies that the transition to renewable energy is economical when social costs of carbon (carbon tax) is included in the analysis.Originality/valueAs far as the authors know, this is the first study providing a socio-economic analysis for a possible transition from the coal-fired power plants to a more clean and sustainable renewable energy source in one of the highest carbon dioxide (CO2) producer provinces in Canada: Saskatchewan. The study builds upon the technical production of three agri-pellets (oat hull, canola hull and sawdust) and estimates the economic and environmental costs of alternative fuels under different scenarios.

Nitrogen Intake and Its Partition on Urine, Dung and Products of Dairy and Beef Cattle in Chile

Nitrogen that is excreted through the urine and dung of cattle is an important source of nitrous oxide and ammonia emissions. In Chile, several studies have evaluated nitrogen (N) intake and its partitioning into urine and dung from beef and dairy cattle, however, there are no studies collating all data into one central database, which would allow an estimation of N excretion and its key variables to be developed. The aim of this study was to determine the N partition (milk or meat, urine and dung) and variables influencing the nitrogen use efficiency (NUE) and urinary N excretion of cattle based on a database generated from Chilean studies. The search of studies was carried out using a keyword list in different web-based platforms. Nitrogen excretion into urine and dung was calculated using equations reported in the literature for beef and dairy cattle. Mixed models were used to identify variables influencing the N partitioning. Nitrogen intake and its partitioning into the animal product, urine and dung were higher for dairy compared to beef cattle. For dairy cattle, NUE was influenced by milk yield, the non-fibrous carbohydrates (NFC)/crude protein ratio, acid detergent fiber intake and milk urea N (MUN), while urinary N excretion was influenced by milk yield, MUN and NFC intake. For beef cattle, N intake and its excretion were greater for grazing compared to the confined system, while NUE was greater for confined animals. This database supplies new information on N intake and its partitioning (milk, meat, urine and dung) for dairy and beef cattle, which can be used for the estimation of greenhouse gas emissions from pasture-based livestock in Chile. Additionally, our study supplies new information on nutritional variables determining NUE and urinary N excretion for dairy cattle, which can be used by farmers to reduce N excretion into the environment.

Прогнозна оцінка викидів парникових газів від використання природного газу в економіці України

The article presents a retrospective review of natural gas consumption and greenhouse gas emissions from its consumption. It is determined that greenhouse gas emissions in the country as a whole decreased from 1990 to 2019 by 62.4%, emissions from natural gas consumption – by 71.7%. The potential for energy saving from structural changes in the economy is determined at the level of 5.2 billion m3 and the technological potential for energy saving from the introduction of energy saving measures and replacement of natural gas with other fuels in heat generating plants, including measures implemented in household sector, at the level of 7.5 billion m3 in 2040. Using the method of forecasting long-term demand for energy resources developed at the Institute of General Energy, the forecast of natural gas demand in Ukraine until 2040 is developed for the conservative scenario of economic development taking into account structural changes and technological energy saving in the country and enlarged sections of the economy. Slight growth in natural gas demand is projected to reach 32.9 billion m3 in 2040. The forecast of greenhouse gas emissions only from the use of natural gas by consumer groups and by the country as a whole is calculated. According to the assumption of moderate economic growth and the implementation of energy-saving measures, it is expected to reduce greenhouse gas emissions from natural gas use in 2030 (compared to 2017) and gradually increase after 2030. Therefore, to reduce greenhouse gas emissions after 2030, it is necessary to implement measures and technologies for the decarbonization of the country's economy. To assess the capability of meeting the target already set in Ukraine's 2nd National Contribution to the Paris Agreement, it is necessary to determine projected emissions not only from the use of natural gas but also from the use of coal and petroleum products, and to estimate emissions from other sources, including leakages. Determining the estimation of greenhouse gas emissions from leakages is a separate task. The obtained results allow to determine the largest sources of greenhouse gas emissions from natural gas consumption in the country's economy and to focus further research on identifying ways to reduce emissions. Keywords: forecast, demand, natural gas, greenhouse gas emissions, energy saving potential, populatio

A new framework for assessing the environmental impacts of circular economy friendly soil waste-based geopolymer cements

Portland cement is one of the principal constituents used as a building material and is responsible for high energy consumption and greenhouse gas (GHG) emissions. Any attempt to reduce cement usage would make savings in energy usage and GHG emissions. A case study of Portland cement (CEM-I) replacement using alkali activated soil filter cake as a geopolymer mortar is presented to demonstrate application of a three-stage GHG emission estimation and comparison methodology using a process-based life cycle assessment (LCA) study, with a focus on benchmarking environmental sustainability. Results indicate that the alkali activated soil filter cake reduced total GHG emissions by 31% compared with CEM-I, which equates to 110 kgCO2-eq/m3. Transportation by rail was found to be more sustainable compared with by road, with an overall higher GHG emission reduction of between 5 and 10%. For road transport, heavy goods vehicles (HGV) of between 3.5t and 5.7t recorded the highest GHG emissions whilst articulated lorries recorded the lowest GHG emissions. Furthermore, the results also demonstrated that a bulk carrier is the most environmentally sustainable option for overseas raw material transportation. Monte-Carlo simulations signified the likelihood of achieving lowered GHG emissions when considering commercial production and inventory changes across different countries varies from 18% to 71%. These results highlight the importance of critical analysis of several factors which contribute towards overall environmental sustainability, prior to decision making on sustainable materials. Further research is encouraged on developing processes and methodologies to prioritize selection of sustainable materials to optimize sustainable benefits.

The impact of migration background, ethnicity and social network dispersion on air and car travel in the UK

While there is a saturation of car mileage per head in developed countries, international air travel has grown rapidly until 2020, making it crucial to better understand its drivers. An often-overlooked factor here is migration. Previous research suggests that individuals with migration background and/or from ethnic minorities tend to have more environmentally sustainable everyday travel patterns, due to lower car use. Yet there is evidence suggesting that their air travel-related emissions are higher than average, possibly due to visits to the home country and the trips required to maintain spatially distant social ties. However, migration background and social network attributes are typically not included in quantitative studies of air travel. In this paper, we analyse data from the 2011–2013 UKHLS survey, which provides information on annual car mileage and frequency of air travel for private purposes, allowing us to derive rough estimates of greenhouse gas emissions. We estimate regression models for these outcomes, including migration background, ethnicity, and social network predictors. We find that: i) first-generation migration background is associated with lower car mileage, but higher levels of air travel; ii) this effect is less pronounced or absent for less recently-arrived migrants and second- and third-generation migrants; iii) spatially dispersed social networks are positively associated with both air and car travel; iv) the association between migration background and air travel is partly accounted for by social network dispersion. We conclude by discussing implications for future research and air travel demand management policies.

Advancing greenhouse gas emission factors for municipal wastewater treatment plants in China

Estimations of greenhouse gas (GHG) emissions from municipal wastewater treatment plants (MWTPs) remain significant uncertainties in China owing to a lack of reliable emission factors (EFs). This study developed a framework to obtain multi-level (technology, province, and nation) GHG EFs of MWTPs using a database containing 3107 MWTPs in China and published site-specific monitoring data. Results show that GHG EFs of different technologies range widely from 180.0 to 615.7 g CO2-eq/t wastewater, and significant differences are also observed among different provinces in China (190.5–600.3 g CO2-eq/t wastewater), which are generally lower than the previous estimates. It confirms the importance of more detailed technology classification and considering the technological disparity of different provinces in refining GHG estimations of MWTPs. To test the feasibility of the developed EFs, we compared GHG emissions from MWTPs based on multi-level EFs at different spatial and temporal scales. Similar estimation results imply that selecting corresponding EF depending on the availability of activity data would simplify GHG estimations of MWTPs without sacrificing much accuracy. This study contributes a set of well-developed EFs to improve the estimates of GHG emissions from MWTPs, and also offers a method to develop GHG EFs for other sectors.

Dichotomous analysis of gaseous emissions as influenced by the impacts of COVID-19 in Brazil: São Paulo and Legal Amazon.

Atmospheric contaminants severely impact air quality in large global urban centers. The emergence of COVID-19 in China in December 2019 and its expansion around the world reduced human activities on account of the implementation of a social isolation policy. In Brazil, COVID-19 arrived in February 2020, and a policy of social isolation was adopted in March by state governments; this work aimed to evaluate pollutant gas emissions in Brazil in the face of the pandemic. In the city of São Paulo, the concentrations of nitrogen dioxide (NO2) and carbon monoxide (CO) were analyzed at three automatic monitoring stations of the Environmental Company of the State of São Paulo (CETESB). In this way, reductions in concentrations of these gases were observed after the decree of social isolation on March 24, due to a noticeable drop in vehicle traffic in the city. A reduction in concentrations of NO2, between 53.6 and 73%, and a decrease in concentrations of CO, from 50 to 66.7%, were obtained at the monitoring stations. Another impact caused by COVID-19 was the increase in deforestation and fires was identified in the Brazilian Legal Amazon after social isolation, due to the decrease in the inspection of environmental agencies. The fires produce thermal degradation of the biomass, generating polluting gases and material particulate. These atmospheric contaminants are extremely harmful to the health of Amazonian populations. Summed to the expansion of COVID-19 in this region, all these factors combined cause the public health system to collapse. CO2eq emissions increase estimates, according to the Greenhouse Gas Emissions Estimation System technical report, ranged from 10 to 20% in 2020, compared to those from 2018. If Brazil maintains deforestation at this pace, it will be difficult to meet the emission reduction targets agreed at COP21.

Addressing Peatland Rewetting in Russian Federation Climate Reporting

Rewetting is the most effective way to reduce greenhouse gas (GHG) emissions from drained peatlands and must significantly contribute to the implementation of the Paris Agreement on Climate within the land sector. In 2010–2013, more than 73 thousand hectares of fire-prone peatlands were rewetted in the Moscow Region (the hitherto largest rewetting program in the Northern Hemisphere). As the Russian Federation has no national accounting of rewetted areas yet, this paper presents an approach to detect them based on multispectral satellite data verified by ground truthing. We propose that effectively rewetted areas should minimally include areas with wet grasslands and those covered with water (cf. the IPCC categories “rewetted organic soils” and “flooded lands”). In 2020, these lands amounted in Moscow Region to more than 5.3 and 3.6 thousand hectares, respectively. Assuming that most rewetted areas were former peat extraction sites and using IPCC default GHG emission factors, an overall GHG emission reduction of over 36,000 tCO2-eq year−1 was calculated. We furthermore considered the uncertainty of calculations. With the example of a 1535 ha large rewetted peatland, we illustrate the estimation of GHG emission reductions for the period up to 2050. The approach presented can be used to estimate GHG emission reductions by peatland rewetting on the national, regional, and object level.

Estimation of greenhouse gas emission from household activities during the COVID-19 pandemic in Binjai City, North Sumatera

Household activities have the potential to produce greenhouse gas emissions. The government’s policy to work and study from home during the COVID-19 pandemic affects greenhouse gas emissions produced by household activities, starting from energy and waste and liquid waste produced, so it is necessary to carry out an emission inventory. The purpose of this study is to calculate greenhouse gas emissions (CO2 and CH4) from household activities in Binjai City during the COVID-19 pandemic and determine emission reduction scenarios that can be carried out in Binjai City. The calculation method used is based on the 2006 IPCC (Intergovernmental Panel in Climate Change) guidelines. CO2 emissions resulting from the use of LPG are 2025.80 tons CO2e/month, the use of fuel for daily transportation activities is 3484.84 tons CO2e/month, and electricity usage is 14956.66 Ton CO2e/month. CH4 emissions produced from domestic liquid waste are 417.14 tons CO2e/month, and household waste is 27.54 tons CO2e/month. The COVID-19 pandemic increases GHG emissions from household electricity consumption in Binjai City by ± 7% and reduces GHG emissions from fuel consumption by 3.5%.

Estimation of Nocturnal Greenhouse Gas Emissions in Yekaterinburg in 2018–2019

Estimation of Nocturnal Greenhouse Gas Emissions in Yekaterinburg in 2018–2019

The effects of progress in genetics and management on intensities of greenhouse gas emissions from Norwegian pork production

The environmental sustainability of food production systems, including net greenhouse gas (GHG) emissions, is of increasing importance. In Norwegian pork production, animal performance is high in terms of reproduction, growth, and health. The development and use of an IPCC methodology-based model for estimating GHG emissions from pork production could be helpful in identifying the effects of progress in genetics and management. The objective was to investigate whether an IPCC methodology-based model was able to reflect the effects of the progress in genetics and management in pork production on the GHG emissions per kg carcass weight (CW). It is hypothesized that this progress has led to low GHG emissions intensities in Norwegian pork compared to global levels and that expected improvements will give a lasting reduction in GHG emissions intensities. A model ‘HolosNorPork’ for estimating net farm gate GHG emissions intensities was developed, including allocation procedures, at the pig production unit level. The model was run with pig production data from in average 632 farms from 2014 to 2019. The estimates include emissions of enteric and manure storage methane, manure storage nitrous oxide emissions, as well as GHG emissions from production and transportation of purchased feeds, and direct and indirect GHG emissions caused by energy use in pig-barns. The model was able to estimate the effects on net GHG emissions intensities from pork production on the basis of production characteristics. The estimated net GHG emissions intensity was found to have decreased from on average 2.49 to 2.34 kg CO2 eq. kg−1 CW over the investigated period. For 2019 the net GHG emission for the one-third lower performing farms was estimated to 2.56 kg CO2 eq. kg−1 CW, whereas for the one-third medium and one-third best performing farms the estimates were 2.36 and 2.16 kg CO2 eq. kg−1 CW, respectively. The net GHG emissions intensity for pork carcasses from boars was estimated to be 2.07 kg CO2 eq. kg−1 CW. For the health regimes investigated, Conventional and Specific-Pathogen Free (SPF), the estimated GHG emissions intensities for 2019 were 2.37 and 2.24 kg CO2 eq. kg−1 CW, respectively. The effects on net GHG emissions intensities of breeding and management measures were estimated to be profound, and this progress in pig production systems contributes to an on-going strengthening of pork as a sustainable source for human food supply.

Emissions of CH4 and CO2 from Wastewater of Palm Oil Mills: A Real Contribution to Increase the Greenhouse Gas and Its Potential as Renewable Energy Sources

Palm oil mill effluent (POME) treatment in Indonesia is still predominant using an open pond system. This system has the weakness of the unknown and uncontrollable value of greenhouse gas (GHG) emissions into the atmosphere. This study estimated GHG emissions (CH4 and CO2) from anaerobic ponds and their potential as a renewable energy source and obtain GHG emission conversion coefficients for each kg of COD POME and ton of crude palm oil (CPO). Gas samples were collected using a closed static chamber. GHG sample concentration testing was done using Gas Chromatography with a flame ionization detector (FID) and thermal conductivity detector (TCD). The results showed that the emission rate of CH4 and CO2 in the anaerobic pond POME treatment was relatively high, 261.93 and 595.99 g/m2/day, respectively, equivalent to 48.572 t CO2-eq/day or 14,571.5 t CO2-eq/year. CO2 emissions were greater than two times CH4 emissions, both spatially and temporally. There was a process of facultative biodegradation, aerobic and or anaerobic process according to the biotic-abiotic environment and the levels of organic components in the substrate. In anaerobic ponds, the optimal requirements for the biodegradation process tended to be unfulfilled, so the emission rate of CH4 was less than CO2. The GHG conversion coefficient was obtained, namely each kg of COD from POME emitted 6.266 kg CO2-eq of GHG; for each m3 of POME emitted by 0.163 t CO2-eq of GHG; and 0.556 t CO2-eq/t CPO. The maximum potential for POME to energy conversion was 1.045 MWe with a power capacity of 8,603 MWh/year.

The global and regional costs of healthy and sustainable dietary patterns: a modelling study

SummaryBackgroundAdoption of healthy and sustainable diets could be essential for safe-guarding the Earth's natural resources and reducing diet-related mortality, but their adoption could be hampered if such diets proved to be more expensive and unaffordable for some populations. Therefore, we aimed to estimate the costs of healthy and sustainable diets around the world.MethodsIn this modelling study, we used regionally comparable food prices from the International Comparison Program for 150 countries. We paired those prices with estimates of food demand for different dietary patterns that, in modelling studies, have been associated with reductions in premature mortality and environmental resource demand, including nutritionally balanced flexitarian, pescatarian, vegetarian, and vegan diets. We used estimates of food waste and projections of food demand and prices to specify food system and socioeconomic change scenarios up to 2050. In the full cost accounting, we estimated diet-related health-care costs by pairing a comparative risk assessment of dietary risks with cost-of-illness estimates, and we estimated climate change costs by pairing the diet scenarios with greenhouse gas emission footprints and estimates of the social cost of carbon.FindingsCompared with the cost of current diets, the healthy and sustainable dietary patterns were, depending on the pattern, up to 22–34% lower in cost in upper-middle-income to high-income countries on average (when considering statistical means), but at least 18–29% more expensive in lower-middle-income to low-income countries. Reductions in food waste, a favourable socioeconomic development scenario, and a fuller cost accounting that included the diet-related costs of climate change and health care in the cost of diets increased the affordability of the dietary patterns in our future projections. When these measures were combined, the healthy and sustainable dietary patterns were up to 25–29% lower in cost in low-income to lower-middle-income countries, and up to 37% lower in cost on average, for the year 2050. Variants of vegetarian and vegan dietary patterns were generally most affordable, and pescatarian diets were least affordable.InterpretationIn high-income and upper-middle-income countries, dietary change interventions that incentivise adoption of healthy and sustainable diets can help consumers in those countries reduce costs while, at the same time, contribute to fulfilling national climate change commitments and reduce public health spending. In low-income and lower-middle-income countries, healthy and sustainable diets are substantially less costly than western diets and can also be cost-competitive in the medium-to-long term, subject to beneficial socioeconomic development and reductions in food waste. A fuller accounting of the costs of diets would make healthy and sustainable diets the least costly option in most countries in the future.FundingGlobal Panel on Agriculture and Food Systems for Nutrition and Wellcome Trust.

Non-Sewered Sanitation Systems’ Global Greenhouse Gas Emissions: Balancing Sustainable Development Goal Tradeoffs to End Open Defecation

Discharge of excreta into the environment and the use of decentralized sanitation technologies, such as septic tanks, pit latrines and ecological sanitation variants (i.e., container-based sanitation), contribute to greenhouse gas (GHG) emissions but have remained poorly quantified. The purpose of this analysis was to investigate the impacts that meeting Sustainable Development Goal (SDG) 6.2 (i.e., ending open defecation by 2030) would have on SDG 13 (i.e., combatting climate impacts). The current Intergovernmental Panel on Climate Change GHG estimation methodology was used as the basis for calculations in this analysis, augmented with improved emission factors from collected data sets for all types of on-site sanitation infrastructure. Specifically, this assessment focused on the three different service levels of sanitation (i.e., improved, unimproved and no service) as defined by UNICEF and WHO as they pertain to three Shared Socioeconomic Pathways. This analysis considered the 100-year global warming potential values in carbon dioxide equivalents of methane and nitrous oxide that can be emitted for each scenario and decentralized sanitation technology. Ultimately, six scenarios were developed for various combinations of pathways and sanitation technologies. There was significant variability between the scenarios, with results ranging from 68 Tg CO2eq/year to 7 TgCO2eq/year. The main contributors of GHG emissions in each scenario were demonstrated to be septic tank systems and pit latrines, although in scenarios that utilized improved emission factors (EFs) these emissions were significantly reduced compared with those using only standard IPCC EFs. This analysis demonstrated that using improved EFs reduced estimated GHG emissions within each SSP scenario by 53% on average. The results indicate that achieving SDG sanitation targets will ultimately increase GHG emissions from the current state but with a relatively small impact on total anthropogenic emissions. There is a need for the continued improvement and collection of field-based emission estimations to refine coarse scale emissions models as well as a better characterization of relevant biodegradation mechanisms in popular forms of on-site sanitation systems. An increase in the understanding of sanitation and climate change linkages among stakeholders will ultimately lead to a better inclusion of sanitation, and other basic human rights, in climate action goals.

Greenhouse Gas Emissions Analysis Working toward Zero-Waste and Its Indication to Low Carbon City Development

Low carbon city development and greenhouse gas (GHG) emission mitigation in urban communities are urgent. There is great potential to improve the GHG inventory at the community level. Meanwhile, building zero-waste cities and improving waste treatment efficiency have been significant environmental issues due to the rapid increase of waste generation. This research aims to develop a community-scale GHG emission inventory of the waste sector and improve its accuracy and consistency through applying the bottom-up approach. This study covers both direct and indirect emissions categories of the waste sector with the goal of building a zero-waste community. Honjo Waseda community, located in Japan, was used as a case study community. Energy consumption waste treatment sectors were evaluated and calculated through first-hand field data. GHG emission estimation of the waste sector included waste incineration, residential wastewater, and waste transport. The highest emissions originated from Beisiagate supermarket due to the large waste amount produced, and the CO2-biomass carbon emissions reached approximately 50% of the total emissions. Furthermore, a quantitative analysis of the implementation of new technologies was also conducted. This study created proposals for GHG emission reduction toward a zero-waste community through the comparison of three cases. Case 1 was business as usual; Case 2 proposed a combination of incineration bio-gasification (MBT); Case 3 introduced a combination of solid recovered fuel (SRF) and a bio-gasification system. SRF contributed the most to emission reduction, and Case 3 exhibited the highest energy recovery. Furthermore, comparing the GHG emissions produced by the use of SRF for power generation and heat supply revealed that using SRF as a heat supply reduced more GHG emissions than using SRF for power generation.

Criteria for Estimating Greenhouse Gas Emissions from Transport

At the present stage, economic research on climate change and its main problem requires in-depth scientific study and analysis of various factors. An important source of air pollution is the energy sector, especially solid and liquid fuels used for technological purposes in thermal power plants. In Georgia, 1/5 of the total electricity generated is produced in thermal power plants. The article analyses Greenhouse gas emissions in Georgia by sectors and sub-sectors as well the criteria for estimating fuel combustion, such as net calorific value of fuel and carbon content standard indicators. The formula for calculation of CO2, CH4 and N2O emissions from the transport vehicles is developed in this work.

Food Loss-Reducing Intervention Strategies for Potato Smallholders in Kenya—A Positive Business Case with Reduced Greenhouse Gas Emissions

This paper is focused on intervention scenarios for smallholder potato value chains in Kenya that improve yields, reduce losses, minimize greenhouse gas (GHG) emissions and increase economic performance and food security. For that, business models and GHG emission estimates are developed, based on the existing data, combined with relevancy and time-to-impact analysis using practical real-life information from stakeholders in the potato sector, which is the second largest agricultural crop in Kenya after maize. The results show that profitability, environmental improvement and food security can go hand in hand with realistic short-term interventions for potato production at smallholder farms.