Indirect Greenhouse Gas Emissions Research Articles

The carbon footprint of cataract surgery in Spain

Background and purposeClimate change is one of the most important threats to human health nowadays. The healthcare industry produces a significant part of greenhouse gases (GHG) emissions. The aim of this study is to assess direct and indirect GHG emissions due to cataract surgery in Spain to identify opportunities for improving. MethodsThis observational case series study estimates and analyses the carbon footprint of a single cataract surgery using phacoemulsification in Ávila Hospital. ISO standard 14064 was applied. ResultsThe carbon footprint of a single cataract surgery in Ávila Hospital was 86.62kg CO2eq. Medical and pharmaceutical equipment were responsible for 85% of GHG emissions. ConclusionsCollaboration between pharmaceuticals and ophthalmologists is important to improve the environmental impact of cataract surgery. Future research is needed to introduce changes that do not compromise patient and surgeon safety. Green surgery models could play an encouraging role in the new global health scene.

The assessment of energy-related greenhouse gas emissions in China's chemical industry

The chemical industry has a large production scale, many products, and very complex processes, so estimating the greenhouse gas (GHG) it produces is not easy. Few comprehensive assessment models at the national level are studied. Emission sources of most models are not complete, and data are outdated. The paper conducts a comprehensive assessment of GHG emissions in China's chemical industry. The emission sources cover direct and indirect emissions. The chemical industry is divided into three main sub sectors to explore GHG flows. GHG flows are examined through chemical production and consumption, and then the emission reduction potential is predicted based on technological developments. The assessment results show that crude oil and coal are the main sources of direct GHG emissions. The indirect GHG emissions are mainly from North China and Northwest China. GHG emissions in the power grid regions are directly related to the distribution of the chemical industry in China. Coal chemical industry has the most GHG emissions. The analysis of driving factors shows that the output effect is the main factor of GHG emissions. Scenario analysis shows that the baseline scenario will reach 6195.95 Mt in 2030. Under the technological improvement scenarios, 589.01 Mt emission reduction can be achieved by 2030 compared with the baseline scenario. Based on the results of the study, this paper provides some policy recommendations.

At the intersection of life cycle assessment and indirect greenhouse gas emissions accounting

At the intersection of life cycle assessment and indirect greenhouse gas emissions accounting

Experimental evaluation for potential drop in refrigerants under high-ambient conditions

Compliance with the Kyoto Protocol and United Nations Sustainable Development Goals requires nations to lower greenhouse gas emissions. Air conditioners, as contributors to direct and indirect emissions of greenhouse gases, can play a major role in limiting global warming to 1.5 °C above pre-industrial levels. Nations classified as Article Five parties, including 147 nations, are required to completely phase out Hydrochlorofluorocarbons including R-22 in 2040. Some of these nations reside in extremely hot climates, and new refrigerants perform poorly under hot weather conditions. While the time is ticking to the phaseout, transitional solutions can be used to move away from R-22 to facilitate the phase-down, especially for units that are still in service.In this paper, a comparative experimental assessment of R453A and R458A as drop-in replacements for R22 is presented. This study aims to evaluate the performance of the two refrigerants to assess their suitability for countries residing in hot climates during the transitional phase-out and phase-down of refrigerants. R22 is used as the baseline refrigerant because it is widely used in developing nations and performs well under high ambient temperatures, reaching as high as 50 °C. Six ambient temperatures (35 °C, 40 °C, 46 °C, 48 °C, 50 °C, and 52 °C) were tested to evaluate the performance of a concealed ducted split air-conditioning unit. The unit rated cooling capacity is 10.39 kW at 48 °C. The measured cooling capacity in comparison to that of R22 was between 87 % and 96 % and 88 % to 96 % for R453A and R458A, respectively, over the tested range of temperatures. The coefficient of performance compared to the baseline showed degradation of 6 %–17 % and 3–10 % for R435A and R458A, respectively. The compression ratio increased by 9 % to 15 % on average for both tested alternative refrigerants over the tested temperature range. It is concluded that R458A performs well as a drop-in alternative refrigerant to R22 and surpasses that of R453A, as it showed slightly less deviation in coefficient of performance.

Water-Energy-Carbon Nexus: Greenhouse Gas Emissions from Integrated Urban Drainage Systems in China.

Greenhouse gas (GHG) emissions from integrated urban drainage systems (IUDSs), including sewer, wastewater treatment plants (WWTPs), and receiving water systems, have not yet been integrated due to the lack of modeling tools. Here, we updated the computable general equilibrium-based System Dynamics and Water Environmental Model (CGE-SyDWEM), a recently developed model simulating the water-energy-carbon nexus at the watershed level, to calculate the direct and indirect (electricity use and external) GHG emissions from IUDSs considering carbon mitigation strategies and water engineering practices. The updated CGE-SyDWEM was applied to an estuary watershed in Shenzhen, the fourth largest city in China. With increasing socio-economic development and water infrastructure systems upgrading, GHG emissions are projected to increase from 129.2 (95% CI: 95.9-162.5) kt in 2007 to 190.7 (144.8-236.6) kt in 2025, with 89% from WWTPs (direct: 17%; electricity use: 65%; and external: 7%), 10% from the sewer (direct: 1% and electricity use: 9%) and 1% from receiving waters (direct). Carbon mitigation can reduce GHG emissions by 7% and emission intensity by 6% by 2025, with 63% contributed by external emission reduction from chemical uses. The integrated model can aid water, energy, and carbon decision-makers in finding cost-effective solutions for water and energy security in the future.

BIM can help decarbonize the construction sector: Primary life cycle evidence from pavement management systems

Transforming the construction sector is key to reaching net-zero, and many stakeholders expect its decarbonization through digitalization, but no quantified evidence has been brought to date. This article proposes the first environmental quantification of the impact of Building Information Modeling (BIM) in the construction sector. Specifically, the direct and indirect greenhouse gas (GHG) emissions generated by a monofunctional BIM to plan road maintenance – a Pavement Management System (PMS) - are evaluated using field data from France. The related carbon footprints are calculated following a life cycle approach, using different sources of data – including ecoinvent v3.6 – and the IPCC 2013 GWP 100a characterization factors. Three design-build-maintain pavement alternatives are compared: scenario 1 relates to a massive design and surface maintenance, scenario 2 to a progressive design and pre-planned structural maintenance, and scenario 3 to a progressive design and tailored structural maintenance supported by the PMS. First, results show the negligible direct emissions due to the PMS existence – 0.02% of the life cycle emissions of scenario 3's pavement, e.g. 0.52 t CO2eq for 10 km and 30 years. Second, the base case and two complementary sensitivity analyses show that the use of a PMS is climate-positive over the life cycle when pavement subgrade bearing capacity improves over time, neutral for the climate otherwise. The GHG emissions savings using BIM can reach up to 14 and 30% of the life cycle emissions respectively compared to scenario 2 and 1, and resp. 47 and 65% when restraining the scope to maintenance and rehabilitation and excluding original pavement construction. Third, the neutral effect of BIM in case of a deterioration of the bearing capacity of the subgrade may be explained by design practices and safety margins, that could in fact be enhanced using BIM. Fourth, the decarbonization potential of a multifunctional BIM is discussed, and research perspectives are presented.

Towards Mandatory SPP for Buildings/Works

The European Green Deal and the Circular Economy Action Plan are bringing about a tectonic shift in public procurement from the traditional market opening approach focused on ‘how to buy’ towards a framework for ‘what’ is bought. Buildings account for 40% of the EU’s energy consumption and 36% of energy-related direct and indirect greenhouse gas emissions. In the EU, heating, cooling and domestic hot water account for 80% of households’ energy. Logically, buildings are at the core of EU policy and legislation proposals aiming at fighting climate change. This article focuses on the role SPP is to play with reference to buildings and more generally to works procurements and this specifically in the light of the reform proposals following from the European Green Deal and the Circular Economy Action Plan. It highlights both the progress proposed and the limitations that may yet be corrected during the legislative process.

Towards Mandatory SPP for Buildings/Works

The European Green Deal and the Circular Economy Action Plan are bringing about a tectonic shift in public procurement from the traditional market opening approach focused on ‘how to buy’ towards a framework for ‘what’ is bought. Buildings account for 40% of the EU’s energy consumption and 36% of energy-related direct and indirect greenhouse gas emissions. In the EU, heating, cooling and domestic hot water account for 80% of households’ energy. Logically, buildings are at the core of EU policy and legislation proposals aiming at fighting climate change. This article focuses on the role SPP is to play with reference to buildings and more generally to works procurements and this specifically in the light of the reform proposals following from the European Green Deal and the Circular Economy Action Plan. It highlights both the progress proposed and the limitations that may yet be corrected during the legislative process.

Comparative study of Decrease in Direct (CO2) and Indirect Green House Gases (CO, NOx, SO2) Emissions from the Coal fired Thermal power Plants Using Energy from Municipal Solid Waste

Comparative study of Decrease in Direct (CO2) and Indirect Green House Gases (CO, NOx, SO2) Emissions from the Coal fired Thermal power Plants Using Energy from Municipal Solid Waste

Greenhouse gas emission inventory of Can Tho City using Bilan Carbone method

Greenhouse gas (GHG) emission inventory has always been considered a crucial first step towards any development of climate change mitigation plans and measures. In this paper, the Bilan Carbone (Carbon Balance) version 6, an easy-to-use Excel-based GHG inventory tool developed by the French Environment and Energy Management Agency, is used to make an inventory of GHG emissions generated within Can Tho City’s territory. The data used for the direct and indirect GHG emissions were collected from Can Tho City’s 2020 Statistical Yearbook, relevant businesses, and administrative units. Ten sectors, namely Energy Industry, Industrial Processes, Tertiary Sector, Residential Sector, Agriculture and Fishing, Transporting Goods, Travel by People, Construction and Highways, End-of-life Waste, and Food, were taken into account for the related analysis. Considering all GHGs cited in the Kyoto Protocol coupled with emission factors updated for Vietnam and the magnitude of emission sources, we found out that the total GHG emission of Can Tho City in 2020 is 4,311,952 tons of CO2 equivalent (CO2e) with an average of approximately 3.5 tons of CO2e per capita. Residential Sector, Industrial Processes, and Travel by People contribute the most to the total GHG footprint of the city, in which Residential Sector accounts for the largest share (743,346 tons of CO2e, making up 17.2% of the total GHG emission). Industrial Processes ranks second with 727,504 tons of CO2e (representing 16.9%), and Travel by People is third with 619,823 tons of CO2e, accounting for 14.4%. Some scientific and realistic interpretations of such sectorial findings are also provided to facilitate the next step of initiating and carrying out associated GHG mitigation measures for the city.

Identifying an over tenfold variation in carbon intensities of coal mines in China by multi-scale multi-benchmark accounting

Complete and accurate accounting of greenhouse gas (GHG) emissions from coal mines in China is a critical basis for identifying mitigation potential and making reduction strategies. Previous studies based on the emission factor method and life cycle assessment are limited in accounting scope completeness, data reliability, or result applicability at multiple scales and benchmarks. The objective of this study was to carry out a multi-scale multi-benchmark GHG accounting of Chinese coal mines to build a shared understanding and facilitate discussion on this topic. We established a complete accounting model to cover upstream indirect, direct, and downstream indirect GHG emissions related to coal mining. A total of 1151 operating coal mines were investigated to model site-level carbon emissions based on mass and energy benchmarks and then aggregated to 99 cities, 19 provinces, and the country for accounting. The results showed an over 14-fold variation in mass-based site-level accounting, with the highest uncertainty of less than 15%. This variability performed almost the same at city-level aggregating, whereas narrowed to over twofold at the provincial level. Energy-based accounting presented an over 17-fold variation at the site-level with a similar uncertainty to mass-based accounting. Such variability was narrowed to over sevenfold and approximately threefold in the city- and province-level aggregations, respectively. The national average mass- and energy-based carbon footprint of coal mining were 0.39 kg CO2-eq/kg and 0.0185 kg CO2-eq/MJ, respectively, in which approximately 36% of the total GHG emissions were omitted if mining methane escape was reported only. These results suggest improving the methane utilization rate and optimizing coal production and consumption patterns, which implicates cleaner production and sustainable development strategies for the coal industry in China. The conclusions are helpful to identify individual carbon emission gaps, clarify regional emission responsibilities, coordinate the national carbon neutrality process, and promote a low-carbon coal supply system.

The impact of solids retention time on Greenhouse Gases Emissions from biological wastewater treatment processes

Biological wastewater treatment is linked to direct and indirect greenhouse gases (GHGs) emissions, thus new approaches on design and operation of wastewater treatment plants (WWTPs) must be adopted aiming towards GHGs emissions’ mitigation. This study evaluates the impact of solids retention time (SRT) on GHGs (CO2 and N2O) emissions of activated sludge (AS) wastewater treatment processes with nutrients removal operating at 10, 30 and 180 days SRT. The 180 days SRT represents the complete solids retention AS process (CRAS), which introduces a novel WWTP design and operation approach for excess sludge reduction. The evaluation of GHGs emissions and process performance via ASDM model and Bridle methodology showed that the total N2O emissions increased together with increasing dissolved oxygen and SRT. CRAS process achieved 97,4% and 96,2% excess sludge reduction compared to AS process with SRT of 10 d and 30 d respectively, with total direct emissions in CRAS process being respectively higher by 20,0% and 12,2%. The lower total indirect emissions in CRAS process compensate for the higher direct emissions. At high influent loads, the balance in GHGs emissions tilts in favour of CRAS process due to management of increased excess sludge quantities, rendering CRAS process a more sustainable choice.

Carbon Footprint Differentiation in the Japanese Residential Sector Due To Income‐Driven Divergences in Consumption and Time Allocation

AbstractHouseholds are responsible for a large fraction of the direct and indirect emissions of greenhouse gases (GHG) at the national level. However, emission patterns are not homogeneous within the residential sector, with several factors affecting them. This study explores how income‐related divergences in consumption and time allocation affect the carbon footprint of the Japanese residential sector. To achieve this, we combine data on emission intensities from national input‐output tables with household‐level consumption and time allocation data from two large‐scale nationally representative surveys. Overall, we find that indirect emissions account for approximately 78% of the overall carbon footprint of the residential sector across the studied income groups. The overall carbon footprint and the emissions of several individual consumption categories follow an N‐shaped curve, with some of the lower‐income groups having disproportionately higher emissions compared to middle‐ and higher‐income groups. Conversely, emissions for other individual consumption categories increase almost linearly with income. This points to the fact that different factors can affect emissions across income groups. Specifically, the N‐shaped curves are driven by the propensity of lower‐income households to spend more time at home and rely on inefficient technologies, while the linear trend is driven by the propensity of higher‐income households to consume more. A detailed understanding of how these factors affect emissions patterns can provide useful insights for designing and implementing effective policies to achieve decarbonization the residential sector.

Analyzing greenhouse gas emissions from municipal wastewater treatment plants using pollutants parameter normalizing method：a case study of Beijing

Wastewater treatment plants (WWTPs) contribute increasing amounts of greenhouse gases (GHGs), due to rapid development and increasingly stringent wastewater discharge limits in China. In this study, GHG emissions from 38 WWTPs in Beijing were estimated using the pollutants parameter normalizing method (PPNM) and the effects of various factors were analyzed. The result showed that, the total GHG emissions of Beijing WWTPs in 2017 were 1 045 661.5 t CO2-eq (tons of CO2-equivalent), the direct and indirect emissions were 186 366.0 and 859 295.5 t CO2-eq, respectively. The average emission intensity was 0.603 kg CO2-eq/m3. Direct and indirect GHG emissions were influenced by various factors, such as treatment process, influent parameters and treatment scale. The anaerobic-anoxic-oxic (AAO) process demonstrated low emission intensities (0.092 kg CO2/m3), while biofilm processes (MBBR) obtained relatively high emission intensities (0.277 kg CO2/m3). Direct GHG emission has a positive correlation with the amount of pollutant removed and low influent pollutant concentrations (chemical oxygen demand [COD]<300 mg/L and total nitrogen [TN] <20 mg/L) can lead to high indirect GHG emission intensities. The low power utilization efficiency of small-scale WWTPs (<1 × 107 t/a; 6.60 kWh/kg COD; 30.54 kWh/kg TN) contributed to additional GHG emissions. Compared with the GHG emissions in Shanghai in 2016, higher influent pollutant concentrations and stricter discharge limits contributed to higher GHG emission intensity in Beijing for both direct (0.108 kg CO2/m3) and indirect (0.496 kg CO2/m3) emissions. The comparison results between cities indicated that the PPNM method achieved a more accurate account of GHG emissions, and the analysis results provided support for carbon emission reduction.

Direct and indirect greenhouse gas emissions under conventional, organic, and conservation agriculture

Farm activities contribute to approximately one-third of Greenhouse Gas (GHG) emissions. Most of the GHG in the atmosphere comes from carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The main objective of this research is to investigate direct and indirect GHG emission in five different agroecosystems, contrasted by tillage agricultural, farm practices (oat and maize-fava and vetch).CO2, N2O y CH4 concentrations were measured using two closed static chambers. Total biomass and production costs were determined. Indirect emissions were calculated from fuel used in producing and packing of synthetic fertilizers and herbicide, and sheep manure mineralization. The results showed that CO2 was the gas that most contributes to GHG emissions followed by the CH4 and NO2. The agrosystem with reduce tillage and synthetic inputs had the highest emissions (979 CO2 eq kg ha−1). Agrosystems using synthetic inputs (conventional and reduce tillage) showed higher indirect emissions (958 and 856 CO2 eq kg ha−1 respectively). Maize in monoculture produced more than the systems with rotation or intercropping. Reduced tillage with intercropping and organic inputs was the most expensive to produce but had the least gas emission per dollar invested and per kilogram of biomass produced while conventional tillage agrosystems with organic or synthetic inputs stored little carbon in the soil, produced less biomass per unit area and presented higher CO2 eq emissions per unit of biomass.

Novel climate tort? The New Zealand Court of Appeal decision in Smith v Fonterra Co-operative Group Limited and others

In Smith v Fonterra the New Zealand High Court and Court of Appeal struck out all causes of action in proceedings seeking orders that seven New Zealand companies cease direct and indirect greenhouse gas emissions by 2030 grounded in the three distinct claims of negligence, public nuisance and a proposed novel tort referred to as “breach of duty”. The Court of Appeal's judgment is under appeal before the New Zealand Supreme Court. This commentary seeks to open up discussion around the reasons given for the various aspects of the judgment. In particular the commentary puts the view that there is scope for the creation of a novel common law climate tort. This tort must be forward-looking and preventive in orientation and may differ fundamentally from existing torts.

Challenges in carbon footprint evaluations of state-of-the-art municipal wastewater resource recovery facilities

Wastewater treatment is an important source of direct and indirect greenhouse gas (GHG) emissions, which some wastewater operators report and account for CO2-eq impacts through carbon footprint evaluations. We investigated the challenges with GHG emissions’ accounting of three state-of-the-art energy-efficient wastewater resource recovery facilities (WRRFs) and reviewed their CO2 accounting reports. Our study aimed to highlight the major contributors and factors to estimate emissions, including direct N2O and CH4 emissions and propose recommendations for public reporting of CO2 accounting of WRRFs. We categorised emissions as direct (scope 1), background (scope 2), downstream and avoided emissions (scope 3A and 3B) and evaluated how a change in emission factor may affect how close the WRRFs are to reaching CO2 neutrality. The results show that electricity consumption and direct emissions constitute between 20 and 70% of actual CO2-eq emissions and therefore need careful consideration.All three plants have increasingly offset scope 2 emissions over 2014–2019, resulting in a total reduction of approximately 3211 tons CO2-eq, corresponding to 72% of their needed cuts by 2030 set by the Danish government.No standard factors are used across the plants to estimate emissions. We propose some general recommendations that wastewater operators can apply to correctly report and account for CO2-eq emissions. We also recommend that operators move their long-term focus from CO2 neutrality to CO2-eq reduction and make an effort to measure and quantify scope 1 direct emissions properly. A tax on N2O emissions should be introduced in future policies.

Quantifying the land-based opportunity carbon costs of onshore wind farms

The development of onshore wind energy impacts the land where it is constructed, together with competition for natural resources between the energy and land sector. The loss of terrestrial carbon stocks and ecosystem services from land use change to wind farms can be interpreted as the opportunity cost that landowners give up by choosing to construct wind farms on their land. Here, we spatially quantify the impact onshore wind farms have on land when we factor in the opportunity carbon (C) costs. We found that, the construction of 3848 wind turbines in Scotland generated 4.9 million tonnes of carbon dioxide (CO 2 ) emissions from land use change. On average the emission intensity of land use change in peatland is 560 g CO 2 kWh −1 , in forestry is 88 g CO 2 kWh −1 , in cropland is 45 g CO 2 kWh −1 , and in pastureland is 30 g CO 2 kWh −1 . In the worst land use change scenario, the displacement of Dystrophic basin peat habitats generated 1760 g CO 2 kWh −1 , which is comparable to the life cycle emissions of fossil-fuel technologies such as coal and gas-fired electricity generation. In arable land, the loss of harvestable crop to wind power was forfeited for a gain in opportunity costs up to £15.4 million over a 25 year operating life. Considering the short-term value of CO 2 in the trading market, the opportunity carbon costs of onshore wind farms can range from £0.3 to £65.0 per MWh of electricity generated per year. These findings highlight that the preservation of terrestrial carbon stocks and crop production in the land sector require the development of new payment schemes that can compete economically against the monetary benefits that landowners can access from lease agreements agreed with energy companies. This ensures also that wind turbines are geographically placed to protect ecosystem C stocks, and to minimize the carbon intensity of the electricity generated. • The displacement of terrestrial carbon stocks is crucial to quantifying the environmental impact of onshore wind energy. • Direct and indirect greenhouse gas emissions are quantified spatially based on land cover types and wind farm characteristics. • Emissions of land use change from the construction of 3848 wind turbines across Scotland vary from 16 g CO 2 kWh −1 in shrubland to 1760 g CO 2 kWh −1 in peatland. • Opportunity costs of onshore wind farms range from £0.30 to £65.0 per MWh of electricity generated per year.

Net-Zero Action Recommendations for Scope 3 Emission Mitigation Using Life Cycle Assessment

Greenhouse gas emissions anywhere across the value chain cause the global temperature to rise. A responsible net-zero strategy is reducing and removing direct and indirect greenhouse gas emissions. The current net-zero actions aim to offset rather than reduce or remove life cycle greenhouse gas emissions (GHG). Unless the demands/consumptions are reduced, net-zero actions will merely be a burden-shifting practice. Scope 3 emissions are considered in the life cycle assessment (LCA) of goods and services and account for direct and indirect emissions with imported goods and services. Scope 3 emission tariff seems an effective way to shift consumption patterns to carbon-neutral options. This article explores tools and systems for ‘just transition’ using three buckets of scientific questions: (1) Technical: which GHG to remove, when, where, and by what mechanism; (2) Social-Policy: how to share GHG obligations between stakeholders to deliver the UN SDGs; (3) Data: how to create robust, trusted, and transparent data for reporting, accounting, and actions. Building on the analyses, this study recommends thirteen scientific evidence-based net-zero actions.

The climate cost of saving water by different plastic mulching patterns

Global water shortage and climate change are two of the most significant challenges for our planet, and how to coordinate their relationship is a problem unsolved. In this study, we proposed the synchronization index of water-saving and CO2 mitigation to evaluate the climate cost of saving water by different plastic mulching patterns and explore way to improve the synchronization. The water-saving performance, carbon footprint, and the synchronization index were analyzed for three typical plastic mulching patterns, namely conventional partial plastic mulching, full plastic mulching, and “one film for two years” mulching. The results indicated that all three types of plastic mulching systems were effective in reducing the water footprint of crop production, with full plastic mulching showing the best performance in terms of improving crop yields and water savings. The application of plastic mulching mainly influences the carbon footprint through increasing indirect greenhouse gas emission, accelerating soil organic carbon decline and increasing N2O emission. Area-scale carbon footprint showed a significant positive relationship with the input amounts of plastic film, and the sort order of yield-scale carbon footprint was partial plastic mulching > full plastic mulching > “one film for two years” mulching. Calculated synchronization index was -0.35 kg CO2-eq m−3, -0.10 kg CO2-eq m−3, and 0.50 kg CO2-eq m−3 for partial plastic mulching, full plastic mulching, and “one film for two years” mulching, respectively. Full plastic mulching and partial plastic mulching resulted in an additional 0.35 and 0.10 kg of CO2-eq for saving one cubic meter of water, and only “one film for two years” mulching resulted in simultaneous water savings and greenhouse gas mitigation. This study suggests that water savings achieved using conventional partial plastic mulching have costs in terms of climate change. Faced with the dual pressure of global water shortages and climate change, controlling input amounts of plastic film and prolonging the lifetime of the film are simple and effective way to coordinate water savings and greenhouse gas mitigation. Moreover, the results of this study suggested that water savings and GHG emission mitigation cannot necessarily be achieved simultaneously and that searching for both water-saving performance and its synchronization with GHG mitigation should become a new paradigm for the development of water-saving technologies in the future.