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Methane, both enteric and from manure management, is the most important greenhouse gas from ruminant livestock, and its mitigation can deliver substantial decreases in the carbon footprint of animal products and potentially contribute to climate change mitigation. Although choices may be limited, certain feeding-related practices can substantially decrease livestock enteric CH 4 emission. These practices can be generally classified into 2 categories: diet manipulation and feed additives. Within the first category, selection of forages and increasing forage digestibility are likely to decrease enteric CH 4 emission, but the size of the effect, relative to current forage practices in the United States dairy industry, is likely to be minimal to moderate. An opportunity also exists to decrease enteric CH 4 emissions by increasing dietary starch concentration, but interventions have to be weighed against potential decreases in milk fat yield and farm profitability. A similar conclusion can be made about dietary lipids and oilseeds, which are proven to decrease CH 4 emission but can also have a negative effect on rumen fermentation, feed intake, and milk production and composition. Sufficient and robust scientific evidence indicates that some feed additives, specifically the CH 4 inhibitor 3-nitrooxypropanol, can substantially reduce CH 4 emissions from dairy and beef cattle. However, the long-term effects and external factors affecting the efficacy of the inhibitor need to be further studied. The practicality of mass-application of other mitigation practices with proven short-term efficacy (i.e., macroalgae) is currently unknown. One area that needs more research is how nutritional mitigation practices (both diet manipulation and feed additives) interact with each other and whether there is synergism among feed additives with different mode of action. Further, effects of diet on manure composition and greenhouse gas emissions during storage (e.g., emission trade-offs) have not been adequately studied. Overall, if currently available mitigation practices prove to deliver consistent results and novel, potent, and safe strategies are discovered and are practical, nutrition alone can deliver up to 60% reduction in enteric CH 4 emissions from dairy farms in the United States. [ABSTRACT FROM AUTHOR]

• Accounting methods of agricultural methane are summarized. • Influencing factors of emission sources from agricultural sources were analyzed. • Mitigation strategies based on accounting and actual situation are proposed. Methane is one of the major greenhouse gases (GHGs) and agriculture is recognized as its primary emitter. Methane accounting is a prerequisite for developing effective agriculture mitigation strategies. In this review, methane accounting methods and research status for various agricultural emission source including rice fields, animal enteric fermentation and livestock and poultry manure management were overview, and the influencing factors of each emission source were analyzed and discussed. At the same time, it analyzes the different research efforts involving agricultural methane accounting and makes recommendations based on the actual situation. Finally, mitigation strategies based on accounting results and actual situation are proposed. This review aims to provide basic data and reference for agriculture-oriented countries and regions to actively participate in climate action and carry out effective methane emission mitigation. [Display omitted] [ABSTRACT FROM AUTHOR]

The pressure on reducing greenhouse gas emissions has increased since the focus on climate change mitigation has grown. As the human development index is directly related to per capita energy consumption, sustainable energy production with reduced carbon footprint is the essential pathway for cleaner environment. Over numerous existing biological processes, hydrogen production via photo fermentation and photolysis of water is considered a more sustainable and economical method of hydrogen production. While both biological modes suffer from certain limitations, such as low yields and low production rates, practical implementation is still a long way off due to these limitations. The unique properties of nanomaterials (NMs) can help increase the efficiency of the biomass to biohydrogen process in significant ways. Applications of organic and inorganic nanoparticles in photocatalytic and photo fermentative hydrogen production is discussed in this paper. This review reports a wide range of applications of nanomaterials including the details of photo fermentative microorganisms and their mechanism of action. The maximum photo fermentative bio-H 2 production was reported in the presence of SiC–Fe 3 O 4 (3.02 mol H 2 /mol acetate), Ni (41 mol H 2 /mol sugar), graphite-C 3 N 4 (64.2 mol H 2 /mol sugar) whereas photocatalytic bio-H 2 yield was highest when Pd–Ni/CdS (54 mmol/g.h), Ni-MO/g-C 3 N 4 (1785 mmol/g.h) and CuO/TiO 2 (20.3 mmol/g.h) nanoparticles were employed. To design photocatalytic systems for practical and scalable use, the future research should be focused on deeper theoretical knowledge of mechanisms of light harvesting, ± charge separation and transport, surface biochemical reactions, semiconductor–liquid interactions, and reactor dynamics. [Display omitted] • Recent developments for improving water photolysis and photo-fermentation are reviewed. • Applications of organic and inorganic nanoparticles in hydrogen production are discussed. • The working principle and mechanism of hydrogen production are discussed. • The influence of key operating factors are presented. • Scope for future research was presented. [ABSTRACT FROM AUTHOR]

• Whole site methane emissions from composting plants were measured using tracer gas. • Methane emission rates from composting facilities were within 8.0–42.5 kg CH 4 h−1. • Emission factors ranged between 1.56 and 5.21 kg CH 4 Mg−1 wet feedstock. • Emissions were higher during working hours than after the plant closed for the day. • Emissions were ∼ 50% higher in spring and summer in comparison to autumn and winter. Methane is a potent greenhouse gas contributing to climate change. Reliable data for methane emissions from the waste management sector are paramount in terms of providing national methane budgets and developing climate mitigation efforts. This study quantified total methane emissions and characterised temporal as well as operational emission patterns at five commercial composting plants in Denmark. Methane emissions were measured over a one-year period, using the tracer gas dispersion method. The results show that methane emission rates ranged from 8.0 ± 0.1 to 42.5 ± 1.5 kg CH 4 h−1 and were significantly affected by factors including the type of feedstock and composting technology, treated feedstock mass, operational patterns and season. The results indicate that the highest methane emission factors were obtained at the combined anaerobic digestion and open windrow composting plant (4.51–5.21 kg CH 4 Mg−1 wet garden/park waste (GPW) and food waste), followed by open windrow plants co-composting GPW, sewage sludge and straw (3.49–3.76 kg CH 4 Mg−1 wet feedstock). The lowest methane emission factors were found at open windrow composting plants treating GPW (1.56–3.24 kg CH 4 Mg−1 wet feedstock). Emissions tended to be higher when measurements were performed during working hours, in comparison to when they were measured after the plant closed for the day. At one plant, emissions were measured monthly over one year, and emissions were about 50% higher in spring and summer in comparison to autumn and winter. [ABSTRACT FROM AUTHOR]

• The choice of post-use wood treatment significantly affects emissions and radiative forcing. • Post-use wood treatment may lead to adverse outcomes in low carbon systems. • Recycling and reusing stand out as crucial features for low carbon and future contexts. This study investigates the climate change effects in terms of greenhouse gas emissions and radiative forcing resulting from different pathways of processing wood materials when they reach the end-of-life stage. The shares of combustion, landfill, recycling, and reuse, which vary with the pathways of post-use wood, influence the material and energy production systems. The dynamics of CO 2 and CH 4 emissions, together with the cumulative radiative forcing of each pathway, are evaluated from various regional system perspectives. The results show that the choice of a treatment pathway for post-use wood could strongly influence the profile of greenhouse gas emissions and, consequently, the global warming potential. Taking into account the situation of the reference material and energy production systems, the post-use wood can have unfavorable consequences for the climate, as in the case when the material and energy production systems are based on the low-carbon energy of natural gas. However, from the perspective where the treatment of post-use wood influences the quantity of forest biomass on the forest floor, the increased share of reuse and recycling contributes positively to the climate change mitigation, but only during the early stage. Under such a context, options relying on carbon capture and storage to handle biogenic CO 2 emissions at energy conversion facilities could cause a cooling effect on the Earth's atmosphere. [ABSTRACT FROM AUTHOR]

Climate change is real and so are its unequal impacts on different geographies and societies. Food systems are estimated to produce a third of global greenhouse gas emissions, of which meat is a major contributor. An emerging challenge is feeding a growing population and fulfilling its protein needs, while limiting the climate footprint. Though more environment friendly alternative sources of proteins are becoming available, their acceptance will depend upon attitudes, beliefs, and behavioural choices. For Muslims, who comprise about a quarter of the world's population, religious guidance plays an important role in consumption patterns and food choices. This review looks at consumption practices among Muslims in the context of food system impacts on greenhouse gas emissions, and the need for optimal sources of protein for nutrition and achieving food security. It discusses what is permissible (halāl) or prohibited (harām) for Muslims and how that is determined based on two primary sources – the Qur'an and the Hadith – and other secondary sources relied upon by Muslim legists. It then reviews what is known about three alternative protein sources – plant-based diets, insects and cultured meat, and the Islamic ethical and legal position related to these foods. The findings show conflicting scholarly opinions and a limited understanding of Muslim attitudes to alternative protein sources. Better understanding will be required for enhancing food security, while limiting food related greenhouse gas emissions. • Greenhouse gas emissions from anthropogenic activities are drivers of climate change, with a third coming from food systems. • Balancing nutrition with the environmental costs of traditional protein sources is an emerging challenge. • Alternative proteins, which are eco-friendlier compared to meat, are becoming available and affordable. • Muslims make up a quarter of the world's population and rely on Islamic guidance for food consumption. • The attitudes of geographically diverse Muslim societies towards alternative proteins remains largely unexplored. [ABSTRACT FROM AUTHOR]

Agriculture contributes to global climate change by producing 20–25% of greenhouse gases (GHGs). CO 2 is released from deforestation and land conversion, methane from rice paddy fields, and nitrous oxides from overfertilization. An increasing world population requires a change in the agro food systems, including a reduction in chemical fertilizers and pesticides as well as the production and access to food. Greenhouse gas (GHG) emissions have created a global climate crisis which requires immediate interventions to mitigate the negative effects on all aspects of life on this planet. As current agriculture and land use contributes up to 25% of total GHG emissions, plant scientists take center stage in finding possible solutions for a transition to sustainable agriculture and land use. In this article, the PlantACT! (Plants for climate ACTion!) initiative of plant scientists lays out a road map of how and in which areas plant scientists can contribute to finding immediate, mid-term, and long-term solutions, and what changes are necessary to implement these solutions at the personal, institutional, and funding levels. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emission mitigation and climate change adaptation in urban communities are urgent. There is enormous potential to improve the GHG inventory at the community level. This research aims to develop a community-scale GHG emission inventory and improve its accuracy and consistency through a bottom-up approach. This study covers direct and indirect emissions categorized into three scopes and selects the Honjo Waseda community in Japan as a case study community. Energy consumption from different sectors (the residential and commercial, transport, and waste management sectors) is evaluated and calculated through Residential Energy Estimation based on the Daily Activities (REEDA) database, National Census, and first-hand field data. The outcome revealed that the residential and commercial sector emissions rank highest in the total GHG emissions of the community, with a value of 39 %. Translated into the scope concept, the emissions under scopes 2 and 3 account for 39 % and 61 %, respectively. Furthermore, a sensitivity analysis of the implementation of green technologies to reduce GHG emissions is also conducted. Mechanical biological treatment (MBT) implementation could yield the largest emission reduction (18 %–22 %), followed by implementing electric vehicles, ultralightweight vehicles, photovoltaic systems, and ground heat utilization. [Display omitted] • GHG emission mitigation and climate change adaptation of urban communities are urgent. • Evaluate GHG emission at community level from scope 1–3 through a bottom-up approach. • Develop models for evaluating emissions from residential and commercial transport, and waste management sectors. • Propose scenarios and evaluate sensitivity analysis on green technologies implementation. [ABSTRACT FROM AUTHOR]

Agricultural production and climate change strongly influence each other and there are significant efforts to minimize negative impacts in both directions. In particular, breeding progress has succeeded in reducing the carbon footprint (CFP) of cereals over time. However, there is widespread certainty that climate change-related weather extremes have led to stagnation of cereal yields in many global production regions. We assume that climate change-related yield stagnation is also evident in variety trials in Germany, which has to date only been shown for on-farm yields. Furthermore, we expect that the stagnation in yields also leads to a stagnation in the downward trend of CFP, and that heat and drought stress in particular increase the CFP of cereals. In addition, we hypothesize that the site-specific soil quality largely determines stress induced increases in CFP. We conduct a partial life cycle assessment (LCA) with German variety trial data from 1993 to 2021 and determine the greenhouse gas emissions per unit of land (GHGL), as well as the CFP of winter wheat, winter rye, and winter barley. Further, we evaluate the time trends of yield, GHGL, and CFP using linear and quadratic plateau models. In addition, we calculate spatio-dynamic weather indices (WIs) for moderate, severe and extreme heat and drought stress. Using mixed models, we estimate the explanatory power and effect size of heat and drought WIs on the CFP. Finally, we present the spatial differences of heat and drought on the CFP at different soil qualities. We show yield plateaus in all crops and stagnating GHGL trends, resulting in a stagnation of the downward trend of CFP, especially for rye and barley. We highlight that heat and drought increase the CFP of all crops. However, the impact of heat and drought on the CFP varies greatly with soil quality across all crops. We conclude that climate change-induced weather extremes are major challenges not only for cereal production and food security but also for climate change mitigation in the agricultural sector, highlighting the importance of high-yield locations, alongside variety selection and resource-efficient management, for climate change mitigation. This study is the first that proves significant yield stagnation in German variety trials. Moreover, this study is the first to analyze the impact of heat and drought stress on cereal CFP, with novel results that proof that climate adaptation will become a crucial aspect of climate change mitigation in field crops. • First study that finds a yield plateau in wheat, rye, and barley variety trial data. • Heat and drought stress increases the Carbon Footprint (CFP) of cereals. • Larger variation in CFP between sites than between years in all crops. • Plateau interrupts downward trend of CFP due to negative E development. • Climate change induced abiotic stress hampers efforts in climate change mitigation. [ABSTRACT FROM AUTHOR]

Straw application is an effective and common measure to improve soil quality but generally increases greenhouse gas (GHG) emissions. The combined application of biochar and straw has been proposed to mitigate these emissions. However, the effects of the combined application of biochar and maize straw, particularly at different proportions, on GHG emissions remain inadequately understood. In this study, an incubation experiment was conducted with five treatments: soil only (CK), 1 % maize straw application (TS), 0.7 % maize straw +0.3 % biochar application (S7B3), 0.5 % maize straw +0.5 % biochar application (S5B5) and 0.3 % maize straw +0.7 % biochar application (S3B7). The study also considered the effect of 1 % biochar application (TB) from our previous study with the same soil type and incubation condition. Carbon isotope technology was utilized to trace CO 2 sources and assess the priming effects on soil organic carbon (SOC) mineralization. The results showed that TB reduced CO 2 emission, while TS increased CO 2 emission due to maize straw decomposition and its positive priming effect on native SOC mineralization. S7B3, S5B5 and S3B7 also increased CO 2 emissions, but with significantly lower emissions than TS, in the order of TS > S7B3 > S5B5 ≥ S3B7. The positive priming effects of S7B3, S5B5 and S3B7 on native SOC mineralization weakened over time and eventually turned negative. TB, TS and combined applications reduced N 2 O emission due to decreased substrates (NH 4 + and NO 3 −) for nitrification and denitrification, induced by promoting microbial fixation of inorganic nitrogen. The reduction effects on N 2 O emission of combined applications were superior to those of TS and TB, with S5B5 demonstrating the best efficacy. TS increased CH 4 emission, while S7B3, S5B5 and S3B7 reduced CH 4 emission. The reduction effects of CH 4 emission with combined applications were superior to that of TB, and S5B5 exhibited the lowest CH 4 emission. Unlike soils with higher nitrogen content, where N 2 O emission dominated the global warming potential (GWP), CO 2 emission dominated the GWP in this study, resulting in increased GWP in TS, S7B3, S5B5 and S3B7, but with significantly lower values for S7B3, S5B5 and S3B7 compared to TS. In conclusion, our study suggests that the combined application of biochar and maize straw, especially S5B5, could effectively mitigate GHG emissions promoted by maize straw application, especially in soils with higher nitrogen content. [Display omitted] • Biochar and maize straw co-application reduced CO 2 emission promoted by maize straw application. • The priming effect of co-application on SOC shifted from positive to negative over time. • Co-application reduced stimulation of CH 4 emission caused by maize straw application. • Co-application exhibited superior efficacy in reducing N 2 O emissions. • The optimal co-application ratio for mitigating greenhouse gas emissions was 1:1. [ABSTRACT FROM AUTHOR]

Livestock are an important component of livelihoods in smallholder dairy systems in Africa, but are characterized by low animal productivity and large environmental impacts per unit of animal product (e.g. greenhouse gas emissions (GHG) intensities). Governments in African countries have set ambitious targets for dairy systems, but development of climate-smart strategies has been hindered by a scarcity of baseline data and local intervention trials. We use a rich dataset from smallholder mixed dairy systems in Kenya to determine whether national climate and development goals for 2030 can be met using locally appropriate interventions. Interventions considered included improved herd management and feed interventions. We conducted a yield gap analysis to determine the scope of the existing milk yield gaps, then evaluated the extent to which yield gaps could be closed using interventions in a second step. We outscaled our results to the national level to determine the potential impact of adopting our interventions on national dairy production and GHG emission goals using the FAO Global Livestock Environmental Assessment Model – interactive (GLEAM-i) tool. Our analysis showed that substantial yield gaps exist in Kenyan dairy systems (39 to 49% of attainable yields). These gaps could be closed by intervention packages but not by individual interventions alone. Our outscaled scenarios showed interventions can reduce milk GHG emission intensities (−6.5 to −27.4%), while absolute emissions would increase in most scenarios (−3.9 to +25.9%). To meet national milk production goals, we estimated that a large increase in animal numbers is needed by 2030 compared to 2010 (from ∼2.7 M to 4.5–7.1 M heads of cattle). However, most scenarios fell short of the emissions target (−4% to +48%) by 2030. It may be possible to narrowly meet Kenyan national milk production and GHG emission goals by 2030. National goals for milk production and reducing GHG emissions were only marginally compatible in Kenya. Other sectors of the economy will need to reduce emissions to ensure that food and nutrition security objectives are not jeopardized. In order to achieve national milk goals, there will be need to be a consummate increase in animal numbers even with the adoption of multiple interventions. To meet Kenya's national emissions goals, widespread adoption of several locally appropriate interventions will be required. International support will be needed to meet Kenya's conditional Nationally Determined Contributions under the 2015 Paris Agreement, as well as food and nutrition security goals. [Display omitted] • Livestock are a primary source of GHG emissions in African countries, but demand for animal products is increasing. • Assessed milk yield gaps for dairy systems in Kenya and outscaled results to national level to determine milk and climate goals can be reached by 2030 using interventions. • Large milk yield gaps exist in Kenya, but gaps can be at least partially closed using locally appropriate interventions. • At the national scale, locally appropriate interventions reduced GHG emission intensities but increased absolute emissions. • All except one scenario fell short of Kenya's national emissions target by 2030, even with adoption of interventions. [ABSTRACT FROM AUTHOR]

To effectively mitigate climate change, policymakers worldwide established various GHG tracking and trading systems. In the light of ambitious climate goals, stricter regulations, and increasing demand for climate action, various groups such as researchers and governmental institutions suggested additional approaches. This paper addresses the complexity that arises from the breadth of suggested approaches and implemented systems for GHG tracking and trading. By doing so, it synthesizes relevant dimensions in a way that is understandable to enterprises and policymakers, enabling them to design meaningful systems incorporating the reduction of GHG emissions and advance cleaner production. Therefore, this paper presents a first-of-its-kind taxonomy of GHG tracking and trading approaches through a systematic literature review. It illustrates ten main design and implementation dimensions with 30 corresponding characteristics. To accelerate decarbonization, this paper sets impulses for future GHG tracking in the electricity sector based on semi-structured expert interviews. Consecutively, it provides policy directions for CO 2 -adaptive decision-making for enterprises, formulated as a Call for Action with seven prospective questions. These include, for example, questions concerning technical aspects like data management, legal issues like the sufficiency of existing data security and privacy regulations, as well as economic topics like the calculation of an appropriate local and temporal granularity. • Presenting a first-of-its-kind taxonomy of GHG tracking and trading approaches through a systematic literature review. • Creating targeted knowledge for enterprises and policymakers for designing meaningful systems to reduce GHG emissions. • Setting impulses for future GHG tracking in the electricity sector based on semi-structured expert interviews. • Providing policy directions for CO 2 -adaptive decision-making for enterprises, formulated as a Call for Action. [ABSTRACT FROM AUTHOR]

• Climate policy should be diversified to meet the needs of all countries. • The ability of renewable energy to solve the emissions problem is questioned. • The energy efficiency has no statistically significant changes in 2010–2020. • There is a contradiction between Sustainable Development Goals 7 and 13. Improving energy efficiency is considered to be important and cost-effective strategies to reduce greenhouse gas emissions, which is crucial in the face of global climate change. This study hypothesizes that there are significant differences in the impact of energy efficiency on economic and energy systems. Using quantile regression method, the impact of economic and energy characteristics on energy-related greenhouse gas emissions in 120 countries over the period 2010–2020 is investigated. Detailed analyses are conducted by dividing the countries into 12 groups based on gross national income per capita (Atlas method) and the share of resource rents in gross domestic product. A macro-level system of indicators for assessing energy efficiency is proposed, which can be linked to the economic and energy characteristics of the systems: National Energy Efficiency, Energy Intensity Ratio, Primary Energy Production Efficiency, Industrial Sector Energy Efficiency, Share of Low Carbon Energy, Population Energy Efficiency. The findings show that (1) global energy efficiency has remained largely unchanged over the decade; (2) there are differences in energy efficiency between fossil fuel producing and non-fossil fuel producing countries; (3) the factors that have an inverse effect on emissions in fossil fuels dependent countries include industrial energy efficiency and population energy efficiency, which are far from exhausting their potential; (4) despite the recognized importance of energy efficiency, its impact on reducing greenhouse gas emissions globally has been unnoticeable. The study highlights that Sustainable Development Goals 7 and 13 on energy affordability and emission reductions are conflicting and require harmonization of mechanisms to achieve them, such as balancing climate change mitigation investments, identifying the potential for energy efficiency improvements across economy or improving energy saving practices. The overall conclusion suggests that there is an urgent need to review current decarbonization and energy efficiency initiatives, given the lack of significant global progress in reducing greenhouse gas emissions or improving energy efficiency between 2010 and 2020. [ABSTRACT FROM AUTHOR]

Carbon tax is a policy instrument that facilitate the phase-out of coal as a chemical feedstock and help China achieve an early carbon peak. However, the policy design is challenged by the complex dynamics of global warming potentials (GWP) from upstream methane emissions, which have a short atmospheric lifetime but a high climate impact. In this study, we compared the life-cycle GWP of two propylene production routes in China: Coal-to-Olefin (CTO) and Propane Dehydrogenation (PDH). We also conducted a cost-profit analysis that incorporates the carbon tax, considering uncertainties in the dynamic radiative forcing of methane. We derived a range of optimal carbon tax rates that can enhance the economic competitiveness of low-carbon propylene routes PDH and discourage the expansion of coal-fed CTO propylene routes. Results show that, for the propylene sector in China, the carbon tax rate should be between 86 and 600 Chinese Yuan (CNY) or 12–84 US dollars (USD) per ton of carbon dioxide equivalent (CO2e), which corresponds to 1–10% of the typical propylene price in the Chinese market. Our study provides spatiotemporal insights into the carbon tax for China's propylene sector to decarbonize and control upstream methane emissions. Since propylene is one of the key raw materials for chemical (e.g., plastic) productions, our analysis contributes to the climate benefits of global chemical trade. • Carbon tax contributes to controlling upstream methane emissions from coal-based chemical production. • Time-horizon is crucial for taxing carbon, especially as short-lived greenhouse gas emissions affect propylene producers' profits. • Carbon tax is necessary at provincial scale since the intensity of methane emissions from coal and propane feedstock supply chains vary regionally. [ABSTRACT FROM AUTHOR]

We perform an ex-ante life cycle assessment, integrating cradle-to-gate greenhouse gas emissions into an off-grid energy system model. By applying a multi-objective optimization, minimizing both costs and carbon dioxide equivalent (CO 2 e) emissions, we find the Pareto boundary between these two goals. As a case study, we chose the power supply to an astronomical observatory in Chile, using mostly solar power and energy storage in batteries and hydrogen. We compare the ex-ante study to a prior ex-post life cycle assessment, and furthermore dive into sensitivities of our model regarding component lifetimes and costs. We find (i) low-hanging fruit in lowering emissions with small cost increases, (ii) ex-ante life cycle assessments' possibility to find less CO 2 e intensive power systems compared to ex-post conducted studies, (iii) a pronounced sensitivity of the optimization model on assumed lifetimes of energy storage components. This study shows the importance of including life cycle CO 2 e emissions into the optimization objective of energy system models. This method uncovers the environmental and economic trade-offs associated with high shares of renewable energies in off-grid energy systems. • We integrate life cycle assessment (LCA) into an off-grid energy system optimization. • The applied case study powers a remote astronomical telescope in Chile. • A multi-objective optimization finds Pareto curves at varying costs and lifetimes. • Low-hanging fruit shows low additional system costs to reduce CO 2 e impacts. • In contrast, a separate LCA did not find such trade-offs in costs and CO 2 e emissions. [ABSTRACT FROM AUTHOR]

Climate protection goals and the transformation of the mobility sector are pushing the shipping industry to develop new propulsion systems emitting fewer or no greenhouse gases. One promising approach to eliminate greenhouse gas emissions from ships is a hybrid propulsion system powered by fuel cells and batteries. A high-temperature solid oxide fuel cell (SOFC) can supply heat and the electrical power demand in combination with a battery. Due to the low dynamic performance of the SOFC when faced with sudden load changes, a battery is responsible for providing the power for the dynamic load components. To ensure the resource-efficient operation of the propulsion components, intelligent energy management methods are required for power distribution control. Implementing a machine-learning-based energy management method based on twin-delayed deep deterministic policy gradient (TD3) improves the overall system efficiency, lifetime, and fuel economy compared to conventional energy management methods. To verify the technical feasibility of the propulsion system including its controls, the system is tested in a hardware-in-the-loop (HIL) environment. By implementing the TD3-based algorithm within the energy management used on the test bench, hydrogen consumption was reduced by approximately 10% and the remaining battery capacity after five years was 6% higher in comparison to conventional energy management methods. [Display omitted] • Hybrid electric propulsion system for a marine application. • Development of machine-learning-based energy management algorithms. • Validation measurements with propulsion components. • Assessment of the economic performance for a large cruise ship application. [ABSTRACT FROM AUTHOR]

Excessive application of synthetic fertilizer has resulted in serious soil degradation and significant greenhouse gases (GHGs) fluxes in farmlands. Partial organic substitution for synthetic fertilizer was considered as a possible strategy for sustainable agricultural development, but its potential effects on soil quality, GHGs emissions, and crop productivity remain unclear. A field experiment across 3-year was conducted to evaluate the responses of soil quality, nitrous oxide (N 2 O), carbon dioxide (CO 2), and methane (CH 4) emissions, and crop yields to different ratios of organic fertilizer (OF) to synthetic fertilizer (SF). Six treatments were included: non-fertilization (CK); total SF; total OF; 15 %, 30 %, and 45 % organic substitution (LO, MO, and HO). Soil cumulative N 2 O emission was decreased with increasing organic substitution ratios, mainly attributing to the reducing soil NH 4 + content. However, organic substitution increased soil CO 2 and CH 4 emissions due to the high manure-driven C input, consequently promoting global warming potential (GWP). Meanwhile, soil organic C, total N, P, available P, K, and C-acquisition enzyme activities were increased with organic substitution, resulting the higher soil quality index (SQI) under HO and OF. HO enhanced the annual yield of wheat and maize by 7.2 % and 13.0 % compared with SF and OF, respectively. The positive relationship between crop yield and SQI indicated that the yield-enhancing effect with partial organic substitution was mainly attributed to the improved synchronization in nutrient supply and soil fertility. Overall, partial organic substitution, especially 45 % organic substitution represents a viable strategy to improve soil quality and crop productivity while mitigating N 2 O emission in wheat-maize rotation systems. However, organic substitution promoted the GWP through stimulating soil CO 2 and CH 4 emissions. Further investigations of optimize fertilization managements are still needed to reduce manure-induced CO 2 and CH 4 emissions to achieve higher climate change mitigation. [Display omitted] • Organic substitution increased soil CO 2 and CH 4 emissions while reducing N 2 O emission. • HO and OF improved the SQI through increasing soil biochemical properties. • HO increased annual yield of wheat and maize compared with SF and OF. • Crop yield was positively related to the SQI. [ABSTRACT FROM AUTHOR]

Scientists have reached a consensus that limiting global warming to 1.5 °C necessitates achieving net-zero greenhouse gas emissions across all economic sectors. Numerous research institutes have prepared decarbonization strategies for the global and regional chemical industries, utilizing modeling and systems analysis to identify decarbonization pathways with different combinations of low-carbon technologies. However, technology choices and scenario designs vary widely across studies, which precludes generalizability and complicates the use of data and results by the broader decarbonization scenario modeling community. Given the varied scopes and objectives inherent in different system models, there is no standardized set of technology data for use in decarbonization pathways analysis. A systematic literature review of 27 relevant studies was performed, which found opportunities for improving technology representation, technology readiness, scenario consistency, demand factors, and policy interventions, among other quantitative elements. Only 7 out of 27 reviewed studies investigated all types of mitigation technologies, and only 3 studies included all data elements aligning with the proposed rubric in this paper. Considering these opportunities, this review proposes a comprehensive dataset structure and consistent scenario definitions that can enable more comprehensive, comparable, robust, and replicable net-zero decarbonization scenarios by modelers of the chemicals industry moving forward. [Display omitted] • Gaps in included technologies, data, and scenario elements in net-zero pathway modeling of the chemical sector are identified. • 80 % of the reviewed studies lack consideration of demand changes and policy implementations in their scenarios • 67 % of the reviewed studies overlooked technology readiness levels in deployment assumptions • Best-practice dataset structures are proposed to improve future modeling studies • Best-practice elements for more robust designs of decarbonization scenarios are proposed [ABSTRACT FROM AUTHOR]

• Intercropping with reduced N input increases deep C storage while reducing GHG emissions. • Double-legume rotation increases C content in management-sensitive SOC pools. • Alley cropping in Mediterranean regions achieved the goals of 4 ‰ initiative. • Deep burial of straw sequestered SOC primarily by increasing POC and MAOC. • No-till maintains soil quality more than it mitigates climate change. [ABSTRACT FROM AUTHOR]

Cocoa production is a leading driver of deforestation in the humid-tropics of West Africa. Reconciling climate change mitigation with livelihoods of farmers requires identification of production strategies to concurrently improve yield and profit while curtailing emissions of greenhouse gases (GHG). Using a 2021 plot-survey conducted in Ghana's Eastern region, we evaluated yields, GHG emissions, and value of production (VOP) (a profit indicator) across a typology representing the diversity of systems at plot-level. The typology was constructed by first stratifying plots according to shade levels and variety (hybrid vs. Amazonia) which resulted in three systems: Hybrid sun , hybrid variety under full-sun (little to no shade); Hybrid shade , hybrid and moderate shade (13–25 shade trees ha−1); and Amazonia, Amazonia under predominantly moderate shade. Next, factor analysis and clustering were used to group plots within each system according to cocoa yield, vegetation, management, and (local) climate conditions. Cluster analysis showed that fertiliser, weeding, pruning, hand pollination, cocoa tree density, and shade tree densities of differing heights were most influential for determination across systems. Hybrid shade had the highest net GHG removal rate at −6.8 ± 1.7 (± 95% CI) Mg CO 2 eq ha−1 yr−1: 48% and 127% higher (emissions more negative) respectively over Amazonia and Hybrid sun. Hybrid shade additionally had the highest average and least variable VOP among production systems at 669 ± 564 USD ha−1 yr−1, compared to Hybrid sun and Amazonia at 404 ± 442 and 213 ± 280 USD ha−1 yr−1 respectively. These results point to hybrid cocoa grown under moderate shade of 13–25 shade trees ha−1 as optimal for reconciling climate change mitigation with development in West African cocoa. • Study concurrently evaluates financial profits and GHG balances (N 2 O & CH 4 emissions, CO 2 removals) in West African cocoa. • Plot-level indicators are evaluated across a typology obtained from sample-stratification and clustering. • Hybrid cocoa under moderate shade (13-25 shade trees ha-1) had GHG removal increment of 127% over same variety without shade. • This system too had higher mean profits, thus best reconciling GHG mitigation and economic development for the region. [ABSTRACT FROM AUTHOR]

Efforts to enhance greenhouse gas (GHG) emission reduction in East Asia play a pivotal role on both global and regional scales in advancing climate mitigation strategies. This study aimed to better constrain anthropogenic CO 2 emission estimates by expanding the network of near-surface in-situ stations for CO 2 observations across South Korea. To achieve an optimal CO 2 network design, we conducted an Observing System Simulation Experiment (OSSE) coupled with the Stochastic Lagrangian Transport model (STILT), utilizing meteorological data from the Korean Integrated Model (KIM). Our inversion setup incorporated two CO 2 emission datasets with a 0.1o resolution: EDGAR v6 for prior emissions and GRACED for truth emissions. A uniform model-mismatch error of 3 ppm was introduced across sites. The effectiveness of the existing five in-situ stations, termed the base network, in South Korea was evaluated to gauge their ability to constrain CO 2 surface flux estimates. However, the findings revealed a reduction in flux uncertainty of only 29.2%, which fell short of the desired uncertainty reduction goal. In this base network, the Lotte World Tower (LWT: 37.5126°E, 127.1025°E) in Seoul and the Anmyeondo (AMY: 36.538576° N, 126.330071° E) site in Taean county stood as major contributors, with estimated reductions of 17.48% and 6.35%, respectively. Consequently, we proposed and developed an extended network, identifying seven candidate sites based on consideration of logistical factors, existing infrastructures, and proximity to the emission source regions. An incremental optimization scheme ranked their contributions, resulting in an additional 25% reduction, bringing the total to 54.13%. However, it is noteworthy that diminishing returns (ranging from 13% to less than 0.1%) were observed with an increase in station count mainly due to the possibility that adding a station earlier in the sequence might render subsequent stations redundant. Despite this, the proposed CO 2 network successfully reduced uncertainty in emissions, narrowing the gap with the objectives of the Global Greenhouse Gas Watch (G3W). • Designing CO 2 near-surface observation network over South Korea. • New stations selected considering logistic factors, existing infrastructures, and proximity to emission sources. • The base network was able to reduce 29.18% of the uncertainty in CO 2 emissions. • Extending network, by adding new seven candidate sites, led to a total uncertainty reduction of 54.13%. [ABSTRACT FROM AUTHOR]

Natural climate solutions (NCS) offer immediate and cost-effective ways to tackle the climate crisis by transforming atmospheric carbon to soil carbon or avoiding greenhouse gas emissions. However, the climate mitigation potential and economic costs of NCS for cropping systems in China remain inconclusive. The major objectives of this study are (i) to estimate the NGHG reduction potential across Chinese main cropping systems caused by NCS, (ii) to quantify the economic costs of adopting optimal management with different abatement potentials. The Denitrification-Decomposition (DNDC) model was used to estimate the NGHG, including SOC sequestration, N 2 O emissions, and CH 4 emissions. After calibration, we ran the DNDC model with derived data at municipality-level. We estimated the NGHG under current management, adopting optimal management individually, and integrated optimal management to project the maximum NGHG reduction potential caused by NCS. We used the marginal abatement cost method to estimate the economic cost. The four natural climate solutions, N fertilization management (NFM), straw returning management (SRM), tillage management (TM), and rice irrigation management (RIM) can reduce national NGHG in main cropping systems by approximately 118.8 Tg CO 2 -eq, 116.3 Tg CO 2 -eq, 35.2 Tg CO 2 -eq, and 74.4 Tg CO 2 -eq, respectively. The integrated optimal management may potentially reduce NGHG by 256.9 Tg CO 2 -eq, equivalent to 90.2% of current NGHG, and 80% of which can be realized at the price of CN¥ 285 (Mg CO 2 -eq)−1. We further identify the priority NCS for different crops and regions and conclude that nitrogen fertilization management should be the priority NCS at the national level. Our findings highlight the great potential of NGHG reduction by adopting NCS precisely and the importance of optimizing agricultural management as a whole, and they will help policy makers to develop smart-agriculture in China. [Display omitted] • Estimating net greenhouse gas emissions (NGHG) reduction potentials of agriculture. • IPCC recommended tier 3 method was applied for seven cropping systems in China. • The integrated optimal management may potentially reduce NGHG by 256.9 Tg CO 2 -eq. • 80% of NGHG mitigation can be realized at the price of CN¥ 285 (Mg CO 2 -eq)−1. • The priority NCS was identified for different crops and regions. [ABSTRACT FROM AUTHOR]

Drained peatland currently contributes 7.5% of Germany's total national greenhouse gas emissions. The National Peatland Protection Strategy adopted by the German government in 2022 recognizes that these emissions need to be reduced significantly to meet the country's climate change mitigation commitments. The present study employs a global dynamic computable general equilibrium model to assess the economic and greenhouse gas emission impacts of alternative agriculture-focused peatland rewetting scenarios for Germany up to 2030. In contrast to partial-analytic approaches, the global general equilibrium approach allows to take consistent account of economic ripple-on effects and carbon leakage effects triggered by peatland rewetting. The results suggest that in the medium term towards 2030 a reduction in annual emissions from agricultural peatland use by up to 45% are attainable at marginal private abatement costs between 27 and 61 Euro/tCO 2 e. Carbon leakage effects due to induced indirect land use change in Germany and the rest of the European Union reduce the global net emission reduction impact by 0.7 to 1.0% of the direct emission reduction. The effects on food prices remain small in all scenarios. In conclusion, a sizable reduction of Germany's land-use-related emissions is achievable at a low macroeconomic cost by moving beyond the moderate ambitions of the National Peatland Restoration Strategy. [ABSTRACT FROM AUTHOR]

As a response to the increasing threat to sport events from climate change and expectations around climate change mitigation, sport event managers increasingly engage in environmentally-related initiatives that aim to reduce GHG emissions. One of the major contributors to GHG emissions at large sport events is spectators' travel and, thus, their associated modal choices. Building on the Sport Logistics Framework (SLF) and using the case study of Rapid Vienna, the largest football club in Austria, this study investigates spectators' modal choice to systematically assess the total GHGs emitted by spectators at a professional football home game. Data was obtained from two sources: a) an extensive data set collected on Rapid Vienna season ticket holders, and b) three surveys at home games which, together, constituted 3317 valid responses. The calculation of the GHG emissions resulted in 99,548 kg GHG emissions per home game or 6.0 kg GHG emissions per spectator. It was also found that 42.4 per cent spectators arriving by car emit 71.6 per cent of GHG emissions, while in contrast, 52.8 per cent of spectators using public transport emit 27.1 per cent of GHG emissions. The results also indicate that the possession of an annual public transport ticket seems to determine travel behavior, i.e. the majority of spectators with an annual ticket are using it, while spectators without a ticket are using a car. As such, this paper not only provides an opportunity for academics and managers to benchmark the data in order to identify initiatives to reduce the impact of GHG emissions, but also allows for the systematic measuring of the environmental impact of fan and spectator travel. • Fan travel to professional football games is a major contributor to GHG emissions. • We assess fans' modal choices and their carbon footprint at a football home game. • The home game emits a total 99,548 kg GHG emissions or 6.0 kg GHG emissions per fan. • We found that 42.4% fans arriving by car emit 71.6% of GHG emissions. • The study allows for benchmarking and systematic measuring of fan travel behavior. [ABSTRACT FROM AUTHOR]

Cities represent unique spaces for climate mitigation where wide-ranging action to reduce emissions meets ambition and collaboration. This research work distils climate neutrality narratives for 362 cities that expressed interest in the European Mission on 100 Climate-Neutral and Smart Cities and focuses on the 112 cities selected to spearhead the process of reaching climate neutrality by 2030 (representing a mitigation potential of 318.3 megatonnes of carbon dioxide equivalent emissions). The method involves steps that profile the characteristics of these cities, enunciate cross-cutting patterns in cities' visions by thematic groupings, and compare 14 contextual factors with 77 possible main barriers. There are both similarities and differences among the results as a basis for learning together and certain barriers can be relatively more dominant in some thematic groupings, such as fragmentation of responsibilities. As a synthesis of the main findings, the original analyses are used to derive and prioritise nine high-level recommendations based on the cities' visions, contextual factors, and expected main barriers. Opportunities for mobilising transformative change relate to transforming siloed into integrated approaches, inclusive climate governance and collaborations, innovative financing, welfare and just transition as well as planning, implementation, and policy coherence. The advances provide pioneering steps for stimulating co-learning processes among Mission Cities and beyond to support the transition to climate neutrality and open up opportunities to progress together in climate action while producing impact with global reach. [Display omitted] • Visions and narratives for achieving climate neutrality by 2030 are enunciated across cities. • The 112 Mission Cities represent an emissions reduction potential of 318.3 MtCO 2 eq. • Thematic groupings are formed by cross-comparing degree of ambition and collaboration. • Recommendations are prioritised based on enablers and barriers in the thematic groupings. • Cross-cutting patterns in cities' visions provide opportunities to stimulate co-learning. [ABSTRACT FROM AUTHOR]

Sub-Saharan Africa is a region with a large population living without electricity. This study investigates the grid balancing role of bioenergy in a sub-Saharan Africa's fully renewable power sector to address the energy poverty challenge in the region, using Ghana as a case country. Two methods are employed: the bioenergy estimation method, for deriving Ghana's technical bioenergy potential, and the LUT model, for the power sector transition modelling. The Ghanaian bioenergy potential of 48.3 TWh is applied on the power sector using the LUT model to develop six alternative scenarios, emphasising on the role of bioenergy, greenhouse gas emissions costs, and climate change mitigation policies. The results of the Best Policy Scenario reveal that with an electrical efficiency of 37.2%, 18 TWh of electricity, which is 16.9% of Ghana's electricity demand by 2050, could be produced from bioenergy for grid balancing. Also, the levelised cost of electricity declines from 48.7 €/MW in 2015 to 36.9–46.6 €/MWh in 2050. Whereas the cost of electricity increases to 76.4 €/MWh in the Current Policy Scenario without greenhouse gas emissions costs. The results show the viability of a relatively cheap and bioenergy balanced sustainable renewable power system for the sub-Saharan African region. • The role of modern bioenergy is examined in renewable energy (RE) dominated power systems. • A comprehensive bioenergy potential assessment for the case of Ghana is presented. • Bioenergy provides flexibility in hybrid solar PV-battery dominated power systems. • Levelised cost of electricity for 100% RE ranges from 37 - 46.6 €/MWh in 2050. • Sustainable modern bioenergy contribution in power systems substantially reduces system costs. [ABSTRACT FROM AUTHOR]

The environmental impact of battery electric vehicles (BEVs), which are an integral part of climate change mitigation measures, depends on charging strategies, such as uncontrolled charging, controlled charging (V1G), and discharging (V2G). However, the impact is unclear because power system operation involves the cost of carbon dioxide (CO 2) emissions and flexibility requirements for imbalances caused by renewable energies. To clarify the robustness of the environmental impact of BEVs, we assessed the interactions between CO 2 prices and flexibility requirements in Japan in 2030 using a production cost model. The results showed that uncontrolled charging increases CO 2 emissions, whereas V1G or V2G reduces them. Further, the impact of BEVs was non-monotonic with respect to CO 2 prices, implying that policymakers should carefully evaluate CO 2 prices to achieve decarbonization as BEVs do not always reduce CO 2 emissions. This study provides useful insights for policymakers in countries with low-cost, inflexible, and high-emission power plants. [ABSTRACT FROM AUTHOR]

Rice, as a main crop, contributes to food security in Asia. However, its by-product, rice straw, poses challenges as it is often disposed of unsustainably. This research investigates the environmental performance of a 1000 m3 rice straw biogas pilot plant in Laguna, Philippines. A lifecycle assessment identified the climate change impact of the biogas system, straw burning and soil incorporation. In addition to GWP100, the global temperature potential's dynamic climate effects were assessed, including integrated radiative forcing and instantaneous temperature effects. The timeframe of the biogenic emission fluxes of rice production is particularly relevant as the sequestered CO 2 during plant growth is partly released as methane and CO 2 , depending on the straw management practices. Straw burning had the highest net emission impact. However, straw incorporation has the highest short-term radiative forcing and temperature increase. The biogas system provided significant short- and long-term GHG emission reduction of up to 68 % when biogas replaced burning or soil incorporation and the use of fossil fuels. Still, considerable uncertainties remain about fugitive methane emissions, handling and post-processing of the digestate. While single GHG emission figures on a GWP100 basis are useful for informing decision-making, this single-metric approach limits understanding of rice production's short- and long-term impacts. Additionally, our assessment emphasises the necessity for governance frameworks that promote sustainable practices in rice farming, as banning rice straw burning may result in less favourable outcomes from soil incorporation, whereas integrating biogas offers a solution benefiting rice-growing communities and global sustainability efforts. • Biogas from rice straw reduces emissions by up to 69 %. • Soil incorporation of straw has highest short-term (20 years) temperature increase. • Assessing more than one metric and timeframe supports more informed decision-making. • Governance frameworks enabling bioenergy integration support SDG 3, 7 and 13. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different INM treatments affected soil N and C fractions; • INM produced one emission peak for CO 2 and CH 4 , whereas two for N 2 O from rice agroecosystem; • Significant positive correlation of dehydrogenase (DH) enzyme with CO 2 and N 2 O emissions; • GHG intensity index and yield of rice increased in the order rice stubble > FYM > Azolla ; • CH 4 emission is the dominant contributor to GHG intensity from the rice agroecosystem. The Intergovernmental Panel on Climate Change recognize to agriculture the responsibility for about 15 % of global anthropogenic greenhouse gas (GHG) emissions, contributing to global warming. The increasing nutrient inputs in industrial agriculture affect the GHG concentration in the atmosphere and varies substantially due to rate and type of fertilizers applied to the crops, making the management more or less sustainable. In this perspective, this study has investigated at small scale the effect of different adjusted agricultural management practices, based on different nutrient dosage, to optimize the effect of rice cropping systems on carbon dioxide (CO 2), methane (CH 4) and nitrous oxide (N 2 O) emissions. Farmyard manure (FYM), rice stubbles and Azolla integrated with chemical fertilizers have been correlated with microbial and enzymatic activities, and with different carbon and nitrogen fractions in acid Inceptisol. Results have revealed that the integrated nutrient management used in rice-rice agroecosystem yielded a peak for CO 2 and CH 4 emissions, whereas two peaks for N 2 O emission. This study has shown an increase in greenhouse gas emission intensity (GHGI) and grain yield of rice in the following order: rice stubbles > FYM > Azolla and it has confirmed CH 4 emission as the dominant contributor to GHGI from the rice-rice agroecosystem. When analyzed together GHGs emission and soil properties, a positive correlation was found with biological properties as well as with the different carbon and nitrogen fractions in soil. The highest GHGI has been highlighted in the treatment where recommended dose of chemical fertilizers has been combined with rice stubbles, primarily due to the increase in CH 4 emissions. In contrast, the lowest GHGI has been exhibited in Azolla treated plot, probably due to the cumulative effects of the photosynthetic rate of Azolla , the release of oxygen from the Azolla roots, and the physical protection capacity of the Azolla cover, which partially avoid the CH 4 diffusion from the standing water. The seasonality did not affect the estimated rates of GHGI that have been lower both in case of winter and autumn rice compared to previous studies, probably for dissimilarities in management practices. Further research is required in other cropping sequences for addressing the ecological contribution of smallholder agriculture to help reducing GHG emissions, thus, mitigating global warming with actions at local scale. [ABSTRACT FROM AUTHOR]

This study investigates the impact of alternative fertilization practices on the yield-scaled global warming potential (YS-GWP) in almond orchards. Almond production is a contributor to greenhouse gas emissions, primarily due to nitrogen-based mineral fertilizers. This research aims to identify strategies that reduce the environmental footprint of almond cultivation while maintaining yield. Field experiments were conducted in an almond orchard using three alternative fertigation practices: Advance Grower Practice (AGP), Pump and Fertilize (P&F), and High Frequency Low Concentration (HFLC). AGP is the current practice used by producers to meet annual N demand for almond tree growth; P&F is a reduction in applied N rate in response to measured N concentrations in the groundwater so that the added N and groundwater N reach the same total N applied; HFLC is a practice of applying smaller N rates per individual event. HFLC uses a greater number of fertigation events to reach similar total annual N load as other treatments. Cumulative N 2 O and CH 4 emissions were used to determine GWP by converting the emissions to carbon dioxide equivalents (CO 2 eq) within a 100-year horizon. Nitrous oxide emissions were multiplied by a radiative forcing potential CO 2 eq of 298 and CH 4 by 25 (UNFCCC, 2007). The results revealed that both P&F and HFLC reduced the YS-GWP compared to AGP. HFLC demonstrated 52–78% decrease in GWP per unit of almond yield compared to AGP, while P&F showed 48–58% decrease over AGP. These reductions were attributed to the reduced nitrous oxide emissions associated with P&F and HFLC. Further, P&F and HFLC tended to have higher N use efficiency than AGP. We demonstrate that adopting alternative fertilization practices can effectively mitigate the environmental footprint of almond orchards while maintaining crop yields. These practices offer viable options for almond growers to reduce greenhouse gas emissions, enhance sustainability, and contribute to climate change mitigation. • Applying nitrogen fertilizer at a lower amount and higher frequency reduces nitrous oxide emissions. • This practice tends to have higher nitrogen use efficiency than standard practice. • It maintains commercial yields at the same level as the standard practice. • It lowers Yield Scaled Global Warming Potential more than the standard practice. [ABSTRACT FROM AUTHOR]

Southeast Asia (SEA) is a key producer and exporter of rice, accounting for around 28% of rice produced globally. To effectively mitigate greenhouse gas (GHG) emissions in SEA rice systems, field methane (CH 4) and nitrous oxide (N 2 O) emissions have been intensively studied. However, an integrated assessment of system-level GHG emissions which includes other carbon (C) balance components, such as soil organic carbon (SOC) or energy use, that can positively or negatively influence the net capacity for climate change mitigation is lacking. We conducted a systematic review of published research in SEA rice systems to synthesize findings across four main components of net system emissions: (1) field GHG emissions, (2) energy inputs, (3) residue utilization beyond the field, and (4) SOC change. The objectives were to highlight effective mitigation opportunities and explore cross-component effects to identify tradeoffs and key knowledge gaps. Field GHG emissions were the largest contributor to net system emissions in agreement with existing scientific consensus, with results showing that practices such as floodwater drainage and residue removal are sound options for CH 4 mitigation. On the other hand, increasing SOC potentially provides a large GHG mitigation opportunity, with long-term continuous rice cropping and practices such as residue incorporation and biochar application promoting SOC increase. A reduction in energy inputs was mainly achieved by optimizing agrochemical use, especially N fertilizers. For residue utilization beyond the field, GHG emission mitigation mainly came from preventing open field burning through residue removal. Removed residue can subsequently be used for producing energy that offsets GHG emissions associated with conventional fuel sources (e.g. fossil fuel-based electricity generation) or substituting material used in other production systems. Integrating all four components of net system emissions into one analysis underscores the following two main takeaways. First, the components of field GHG emissions and SOC change are the biggest opportunities for reducing net system emissions and need to be considered for effective climate change mitigation. Second, the reduction of C inputs through residue removal and increased soil aeration through multiple drainage will lower CH 4 emissions but may also potentially decrease SOC stocks over time. Hence, we argue that future research needs to consider cross-component effects to optimize net system emissions, specifically the "stacking" of best management practices for mitigation related to field GHG emissions or SOC change in long-term experiments. • Net system emissions include field CH 4 /N 2 O emissions, energy inputs, residue utilization, and SOC change. • Integrated review highlights cross-component effects of management including tradeoffs. • Field GHG emissions and SOC change are the largest opportunities for mitigation. • Reduced C inputs and drainage decrease CH 4 emissions, but may negatively affect SOC. • "Stacking" of best management practices is a key knowledge gap that warrants research. [ABSTRACT FROM AUTHOR]

To foster the energy transition towards a low carbon economy, countries must set and report climate policy instruments. Since the Paris Agreement, nations have been strongly encouraged to increase ambitions and reduce carbon emissions in the coming decades. However, a wave of emerging parties has gained momentum around the world, advocating a hostile stance on climate change mitigation policies. Brazil, one of the traditional leaders of the climate agenda, has experienced an uptake in its greenhouse gas emissions, with no expectation of reversing this trend. The government has signaled that only economically attractive mitigation options will be considered. For this reason, it is crucial to develop scenarios that consider this upward trend. The model estimates carbon emissions at the highest level of detail available, providing abatement cost over time. The results indicate that Brazil has potential to meet its transport related NDC commitments, with 13% cuts by 2030 (26MtCO 2 e) achieved with an intensive use of biofuels. However, the cost-benefit of this strategy would not correspond to the mitigation potential, with financial losses above 1US$/tCO 2 e. The most suitable alternatives would be investments in electromobility and infrastructure, with gains exceeding 200US$/tCO 2 e. These outcomes may aware decision-makers about the cost-effectiveness of certain policies. • We conduct an in-depth assessment of transport-related energy transition paths for 2030. • Three scenarios were developed based on different political commitment. • Brazil has potential to meet its transport related NDC commitments. • The most suitable alternatives would be investments in electromobility and infrastructure. • The outcomes may aware decision-makers about the cost-effectiveness of certain policies. [ABSTRACT FROM AUTHOR]

Crop residue burning is a common practice in many parts of the world that causes air pollution and greenhouse gas (GHG) emissions. Regenerative practices that return residues to the soil offer a 'no burn' pathway for addressing air pollution while building soil organic carbon (SOC). Nevertheless, GHG emissions in rice-based agricultural systems are complex and difficult to anticipate, particularly in production contexts with highly variable hydrologic conditions. Here we predict long-term net GHG fluxes for four rice residue management strategies in the context of rice-wheat cropping systems in Eastern India: burning, soil incorporation, livestock fodder, and biochar. Estimations were based on a combination of Tier 1, 2, and 3 modelling approaches, including 100-year DNDC simulations across three representative soil hydrologic categories (i.e., dry, median, and wet). Overall, residue burning resulted in total direct GHG fluxes of 2.5, 6.1, and 8.7 Mg CO 2 -e in the dry, median, and wet hydrologic categories, respectively. Relative to emissions from burning (positive values indicate an increase) for the same dry to wet hydrologic categories, soil incorporation resulted in a −0.2, 1.8, or 3.1 Mg CO 2 -e change in emissions whereas use of residues for livestock fodder increased emissions by 2.0, 2.1, or 2.3 Mg CO 2 -e. Biochar reduced emissions relative to burning by 2.9 Mg CO 2 -e in all hydrologic categories. This study showed that the production environment has a controlling effect on methane and, therefore, net GHG balance. For example, wetter sites had 2.8–4.0 times greater CH 4 emissions, on average, than dry sites when rice residues were returned to the soil. To effectively mitigate burning without undermining climate change mitigation goals, our results suggest that geographically-target approaches should be used in the rice-based systems of Eastern India to incentivize the adoption of regenerative 'no burn' residue management practices. • Efforts to build SOC for climate change mitigation, while simultaneously avoiding burning, may have unintended consequences. • Tier 1, 2, and 3 modelling approaches were used to compare no-burn rice residue pathways. • Field hydrology had a dominant effect on methane emissions. • Soil incorporation of residues increased emissions relative to open burning, except in comparatively dry fields. • Biochar is estimated to have the lowest GHG emissions of the evaluated 'no burn' alternatives. [ABSTRACT FROM AUTHOR]

Animal production faces challenges related to thermal comfort, air quality, and carbon dioxide (CO 2) emissions, thereby the need for more efficient and sustainable systems due to climate change. This study examines green roofs and their potential to absorb atmospheric CO 2 and reduce heat load through photosynthesis and evapotranspiration, resulting in decreased energy consumption and increased CO 2 emissions. The maximum CO 2 concentration limit in animal production facilities is 3000 ppm. Depending on the ventilation system used in broiler production facilities, the CO 2 concentration can exceed 2000 ppm. Dark House poultry facilities tend to have higher concentrations reaching up to 777 ppm. In pig farming, the nursery sector has higher concentrations of CO 2 , exceeding 1200 ppm. In dairy farming, the number of milkings, the type of ventilation system and local climatic conditions can affect the CO 2 concentration, reaching values of up to 1401 ppm. C3 plants have a CO 2 saturation point at 800 ppm and C4 plants at 200 ppm. The CO 2 balance in animal production facilities that use a green roof can be done considering the CO 2 produced and the CO 2 absorbed. Green roofs are therefore considered a sustainable solution for animal production. Its implementation enhances air quality in the facilities, supporting the reduction of environmental impacts and mitigation of climate change effects caused by the agroindustry. This investigation underscores the significance of green roofs, emphasizing their environmental, social, and economic benefits, as well as their applicability in animal production. • It is possible to estimate the CO 2 balance in animal production facilities with a green roof. • Green roof can improve air quality in animal production. • Green roof can reduce the thermal stress of the animals in the premises. • Green roof can contribute to the sustainability of animal production. [ABSTRACT FROM AUTHOR]

Tillage practices have major impacts on soil properties, grain yield, soil carbon sequestration, and greenhouse gas emissions. Conservation tillage is an agriculture practice aiming to minimize soil disturbance and protect soil structure. It is reported that more and more croplands are being converted from conventional tillage to conservation tillage in China. However, the information is lacking as to where and when conservation tillage practice is implemented at a regional and national scale. The objectives of this study are 1) to develop a new framework for classifying tillage practices with a random forest model and Google Earth Engine platform to overcome the limitations in mapping tillage practices across China; and 2) to map the spatiotemporal patterns of tillage practices across Chinese croplands from 2016 to 2020. We generated a 1 km grid dataset for tillage practices across Chinese croplands during 2016–2020 based on Sentinel-2 imagery. First, we generated two ground reference sample pools about tillage practices based on literature review and high-resolution maps. Then, we produced Sentinel-2 features during the tillage period by composting 18 bands related to the ratios of returned crop residues. Next, we trained an optimal random forest (RF) classifier by conducting a cross-validation. Finally, we applied the optimal RF classifier to composited features to produce tillage maps from 2016 to 2020. The validation with ground reference samples shows that the classification results have an overall accuracy of 0.80. Comparisons at a provincial scale show the estimated proportion of conservation tillage is significantly correlated with statistic data with R2 being 0.88. Results show that conservation tillage practice is adopted in about 36% of Chinese croplands, mainly distributed in northeast China, northwest China, and the North China Plain. The proportion of conservation tillage ranged from 29% to 40% during 2016–2020 although with a large spatial heterogeneity. This study develops a sound framework to map tillage practices and provides more details about the spatiotemporal patterns of tillage practices, supporting regional planning of agricultural management and climate change mitigation. [ABSTRACT FROM AUTHOR]

The food we eat plays a large role in greenhouse gas emissions. Climate labeling is one way to increase sustainable food consumption by making consumers mindful of their consumption choices. Many initiatives communicate food's climate impact; however, it is unclear whether these labels are effective in changing food consumption behavior. Based on a review of climate label research and existing labels, three label designs were created and tested in an experimental online survey with a convenience sample of 249 Austrian residents (63.9% female; 54.2% aged 18–29 years) to determine whether the visual communication of a food product's climate footprint influences food choices. Compared to no climate impact labels, communicating the climate footprint nudged participants towards climate friendlier food choices in half of the product choice sets (meat, grains, broccoli, and tomatoes). Label designs B and C consistently led to more sustainable choices. Not all labels were equally effective, suggesting that label design is key in stimulating climate-friendlier choices. The design features used to convey climate impact can better help consumers understand the impact of food and make more informed decisions when food shopping, however we find that how these features come together in a label design also play a role. Producers looking to convey their products' impact are advised to not only consider what information they put on their packaging (i.e., climate footprint) but also how this information is presented (i.e., holistic design of climate labels). • Climate labels can stimulate sustainable food choices. • Certain design features are more effective in nudging sustainable food consumption. • Not all climate labels are equally effective in nudging sustainable food choices. • Three label variations based on traffic-light categorical bar scales were designed. [ABSTRACT FROM AUTHOR]

The depth and breadth of the climate crisis is well known, all sectors, industry, government and the individual have the potential to reduce emissions to slow or stop catastrophic climate change. To determine and evaluate the (revealed) preferences of the public in reducing their personal carbon emissions, a conjoint analysis survey, using the PAPRIKA (Potentially All Pairwise RanKings of all possible Alternatives) method, was distributed to the public in a city in the south of England (Southampton). Knowledge of the deep-seated preferences of the public makes a fundamental contribution to future climate actions because it enables publicly acceptable system change to be developed. Results showed the public were unwilling to make large-scale lifestyle changes, even if they would cause large emission reductions. There was a clear preference for making relatively easy, convenient changes to behaviour rather than making more difficult personal lifestyle changes involving diet and transportation. A significant value-action gap is evident, with the public showing high awareness of the seriousness of climate change but showing an unwillingness to make deep cuts to their personal emissions. Demography and personal factors had a relatively low influence over preferences with trends generally staying the same across demographic groups, aside from income brackets. Participants believed that reductions in emissions should come from a 'group effort' from all levels of government, business, environmental groups and individuals. Few participants placed themselves as individual drivers of carbon emission reduction. In order to reduce emissions some form of intervention needs to be made, as the public are not personally willing to make large-scale reductions in carbon emissions, regardless of their environmental awareness or demography. • Public's views on approaches to carbon reduction investigated via conjoint analysis. • Preference for low intensity, 'easy' behaviours not challenging lifestyle changes. • Demographic & personal factors have low influence on carbon reduction preferences. • High awareness of severity of climate change, impacts/priority; also high anxiety. • Desire to consume & "carry on as normal" outweighs self-reported concerns/attitudes. [ABSTRACT FROM AUTHOR]

Plastics account for 4.5% of global greenhouse gas (GHG) emissions, which are hard-to-abate due to the use of fossil fuels as feedstock. Our study develops a cradle-to-gate life cycle assessment of bioethylene production, exploring 33 pathways across Brazil, the EU, and the US. It aims to understand whether substituting fossil-based ethylene with bioethylene contributes to lowering carbon emissions, and in which of the relevant bioenergy-producing regions/countries the valorisation of biofuels as feedstocks would provide a less carbon-intensive bioethylene production. Results indicate that bioethylene production through catalytic dehydration of sugarcane bioethanol in Brazil presents lowest GHG emission. This pathway could deliver up to −2.1 kg CO 2 e/kg ethylene when accounting for biogenic carbon storage in long-lived applications such as infrastructure. In contrast, beef tallow performs the poorest as a raw material, regardless of whether land-use change (LUC) emissions are considered. When biogenic carbon storage is factored out, none of the pathways outperforms conventional fossil-based steam cracking; however, some are within the fossil-based range indicating potential indirect benefits through reduced refinery utilisation. Our study underscores that biomaterials production as a climate mitigation strategy must be on par with circular economy measures and the conservation of native forestry ecosystems. These results are particularly relevant to policymakers and industries seeking to align polymer manufacturing with sustainability objectives. • Bio-ethylene cradle-to-gate GHG emissions were assessed for 33 pathways. • Sugary, starch, lignocellulosic and oily crops are raw materials for bio-ethylene. • Local specificities such as biogenic carbon storage and land-use are critical to LCA GHG emissions. • Sugarcane bioethanol dehydration route yielded 2.1 kgCO 2 e captured per of kg ethylene. • Climate mitigation and circular economy policies must be designed coherently. [ABSTRACT FROM AUTHOR]

Mitigating greenhouse gas emissions is an essential element of climate change policies. This paper explores Dutch dairy farmers' adoption behaviour of climate change mitigation measures using a Self-regulated Stage model of Behavioural Change. It tests the statistical relationship of stage-specific socio-psychological factors with individual farmer's intentions of planning or adopting on-farm climate mitigation measures. In addition, it tests the statistical relationship of intentions on four stages (pre-decisional, pre-actional, actional, post-actional). The empirical application focuses on data from specialised Dutch dairy farmers registered with the Farm Accountancy Data Network. Our findings suggest that negative emotion, personal norm, perceived goal feasibility, action planning, and coping planning vary significantly by stage. Furthermore, personal norm, attitude, goal intention, behavioural intention, and implementation intention are found to be statistically significant and positive influencing factors on adopting climate mitigation measures. Lastly, farmers younger than 45 years old with full agricultural education and farms with high livestock density are more likely to have taken steps in adopting mitigation measures. [ABSTRACT FROM AUTHOR]

Anthropogenic greenhouse gas emissions (GHGE) are behind climate change. In Chile, food system is the second source of GHGE. Changing Chileans dietary patterns is key to reducing such emissions. There is geographic variability in terms of dietary patterns within the country. Here we investigated the dietary GHGE in five different geographical zones, along with the main contributing food groups and socio-demographic variables. Data for 4676 individuals were obtained from the 2010–2011 National Survey of Food Consumption. The carbon footprint value of each food was obtained from studies using life cycle assessment methodology. Median and percentiles of dietary GHGE were calculated, expressed in kilograms of carbon dioxide equivalent per person per day (kgCO 2 eq/person/d) and compared among zones by Kruskal-Wallis and Dunn's tests. Logistic regression models were fitted to analyzed associations among the variables of interest and quartiles of GHGE. Diet-related GHGE ranged from 3.50 (2.34–5.12) in the North-Central Zone to 4.66 (2.89–6.69) kgCO 2 eq/person/d in the South zone. Meat accounted for 53–58% of the GHGE in all the zones, followed by dairy products with 12–13%. Higher GHGE were significantly associated with energy intake (kcal/d) in all of the zones, with high socioeconomic level in the North-Central, South and Metropolitan zones, and with urban residence in the South-Central zone. Tailored policies considering geographic variability are warranted to promote healthy and sustainable diets among the Chilean population. • Differences in dietary greenhouse gas emissions were determined among five Chilean geographical zones. • South and Metropolitan region showed the highest GHGE while North showed the lowest. • Meat and dairy were the most contributing foods in all zones. • GHGE were positively associated with energy intake in all zones & with high socioeconomic level in three zones. • The promotion of sustainable diets in Chile must consider the geographical specificities. [ABSTRACT FROM AUTHOR]

Micro-level concerns about climate change can not only affect individual low-carbon behaviors but also exert intense pressure on carbon emission reduction strategies and policy design. However, whether public concern about climate change can affect per capita carbon emission is still unclear. Based on panel data from 30 provinces in China and 188,943 climate change-related blogs from 2012 to 2019, this research investigates the impact of public concern on per capita carbon emissions. Results show that, in general, public concern about climate change has a significant negative impact on per capita carbon emissions in China, indicating that climate crisis awareness has a supervisory effect on greenhouse gas emissions. Nevertheless, the effects of different public concerns on per capita carbon emissions are different, with the topics of "low-carbon appeal" and "concern for future" have significant positive impacts on per capita carbon emissions, while the topics of "carbon governance performance" and "climate change mitigation strategies" have significant negative impacts on per capita carbon emissions. The findings yield new opportunities to delve into the relationship between the externality of people's will and governmental behaviors and provide in-depth insights for decision-makers to develop tailor-made solutions towards carbon reduction and sustainable development. [Display omitted] [ABSTRACT FROM AUTHOR]

Air pollution and climate change are currently common global concern issues. Understanding the main pollution sources of fine particulate matter (PM 2.5) and carbon dioxide (CO 2), and the drivers that accelerate their concentrations can provide novel insights into the co-benefits of air-quality improvement and climate change mitigation. Hence, in this study, we conducted source apportionment of PM 2.5 and CO 2 , and obtained impacts of common sources on PM 2.5 -CO 2 using an ensemble source apportionment method. Then, machine learning (ML) methods were utilized to study the effects of different drivers (including main pollution sources and meteorological factors) on PM 2.5 and CO 2. The results demonstrate that coal combustion (40%), vehicle exhaust (37%), and industrial emissions (23%) were the main common sources of PM 2.5 and CO 2. Controlling the combustion of fossil fuels and long-term vehicle electrification still hold significant importance for reducing pollutions and carbon emissions. The results of data-driven ML models show that temperature had the highest effect among meteorological factors, reflecting the seasonal changes of CO 2 and PM 2.5. The study provides a feasible framework for exploring co-benefits of clean air policies on greenhouse gas emissions based on online observation dataset. [Display omitted] • Variation characteristics and sources of PM 2.5 , and CO 2 were analyzed. • Machine learning methods reveal the impact of drivers on PM 2.5 and CO 2. • Secondary sources are still the focus of particle pollution prevention and control. • Controlling the combustion of fossil fuels benefits mitigation of PM 2.5 and CO 2. [ABSTRACT FROM AUTHOR]

The main objective of this study is to analyze and compare greenhouse gas emission profiles, dynamics thereof, and the climate change mitigation efforts of the major players in the global climate change arena, namely the G7 and BRICS countries that are accounting for more than 60% of the world greenhouse gas emissions as in 2017. Given that the energy sector is the major source of the greenhouse emissions in these countries, the framework of sustainable energy development indicators was applied to the comparative analysis. The analysis revealed the differences among the groups of countries in terms of greenhouse gas emission profiles and development trends of these profiles. The convergence of greenhouse gas emission profiles can be noticed between G7 and BRICS countries during 1990–2017 period. Greenhouse gas emissions per capita has decreased in G7 countries and increased in BRICS countries. Energy intensity, economic growth and carbon factor are the main drivers of greenhouse gas emissions per capita growth in both groups of countries. Carbon factor represents carbon intensity of a country's energy sector and is measured by greenhouse gas emissions per unit of total primary energy supply. The impact of carbon factor was least significant among the main drivers in both groups. Energy intensity was the major driver of decrease in greenhouse gas emissions per capita for both groups, however, the economic growth exceeded the contribution of energy intensity in BRICS countries and greenhouse gas emissions have increased in this group during investigated period. The comparative analysis of greenhouse gas emission profiles development trends and the main drivers of these trends in both groups of countries provides important insights in shaping future climate change mitigation policies and developing greenhouse gas emission reduction targets. Due to the high greenhouse gas profiles, low GHG reduction commitments and insufficient climate change mitigation the Perform, Achieve and Trade (PAT) scheme in India efforts in both groups there is danger of postponing implementation of Paris commitments and achieving the 1.5° target. The policies implemented in high ranked countries, like or Integrated Resources Planning in South Africa or measures under Energy efficiency directive in EU can be applied in low ranked countries by providing the substantial contribution to the country's climate targets. Image 1 • The GHG profiles of G7 and BRICS were converging during 1990–2017. • GHG/capita has decreased in G7 countries and increased in BRICS countries. • Energy intensity, economic growth and carbon factor - the main drivers of GHG/capita. • Energy intensity - the major driver of decrease in GHG/capita for both groups. • However, the economic growth exceeded the contribution of energy intensity in BRICS. [ABSTRACT FROM AUTHOR]

• This paper tests the relationship between multimodality and CO 2 emissions. • Multimodal trips are less polluting than unimodal trips, if controlled for distance. • More-multimodal persons have lower emissions, notably if controlled for distance. • Multimodality is only weakly associated with CO 2 emissions. • Trip distance contributes more to CO 2 emissions than the level of multimodality. Encouraging multimodality as a tool to reduce exclusive car use is seen as a key ingredient of transport policies aimed at reducing greenhouse gases emissions, such as CO 2. These policies are based on the assumption that increasing multimodality will contribute to a reduction in emissions. Yet, hardly any scientific attention has been paid to the empirical relationship between multimodality and CO 2 emissions. This article addresses this unexplored question at both the individual and trip level using the English National Travel Survey. We find that the level of multimodality is only weakly associated with CO 2 emissions. It is only when controlling for levels of travel activity (trip frequency, total distance travelled) that a moderate association in the expected direction is observed (i.e. that higher levels of multimodality correspond with lower CO 2 emissions). This suggests that greater levels of travel activity among multimodals tend to offset the benefits derived from their more diverse modal choices. Similar patterns emerge from the trip-level analyses: higher emissions are found for (the typically longer) multimodal trips compared to unimodal trips, even when the only mode used is the car. However, for trips over similar distances, multimodal trips do have lower emissions. While there is merit in encouraging greater multimodality, this can hardly be the only or primary goal of climate mitigation policies in the transport sector. More attention needs to be paid to the key role of high levels of travel activity, and how these could be reduced. [ABSTRACT FROM AUTHOR]

With the growing need for residential buildings as a result of population growth, the building sector is a high-priority area in climate change due to its large share of CO 2 emissions, the significant energy saving opportunities it represents, and the increasing expectations for occupant comfort. This paper presents the results of climate change impact assessment on a typical mid-rise residential building in four representative cities with different climatic characteristics in Turkey. Three different scenarios that characterize different solutions towards space cooling are developed, from naturally ventilated to fully air-conditioned. The energy requirements and corresponding CO 2 emissions due to space conditioning as well as occupant thermal comfort are the investigated building performance metrics. The preliminary results based on energy simulations indicate that pronounced overheating will be experienced in the future, which will have a strong effect on cooling energy use and/or occupant comfort. The projected energy demand also points to the future need to explore measures for climate change adaptation of buildings and the importance of the decarbonization of the electricity industry for climate change mitigation. The analysis results presented in this paper provide a basis for future studies on building retrofit for climate change. • Evaluation of climate change impact on a typical residential building in Turkey. • Cooling is to dominate thermal loads due to increased temperatures. • Warmer climates to be influenced most by negative effects. • Severe overheating for poorly ventilated, highly insulated buildings. • Adaptation measures needed for climate-proofing existing buildings. [ABSTRACT FROM AUTHOR]

Freshwater bodies are found as significant sources of greenhouse gas to the atmosphere, but their quantitative significance is not yet clear. The rapid increase in hydropower dams and associated emissions has received much attention from hydropower industries, environmentalists, and policymakers from across the globe. The tropical/subtropical eco-regions are, particularly, considered as hotspots from greenhouse gas production point of view as the emitted gases are playing a critical role in climate change. The present paper reviews the uncertainty and limitations of greenhouse gas measurement from Chinese freshwater bodies based on available data. Literature reported that carbon dioxide emission from Chinese lakes falls in the range of 0.01–2.16 μmol m−2s−1 except for Poyang Lake. The CO 2 emission from Chinese hydropower reservoirs is estimated as 0.15–1.11, while for rivers, it is 0.44–4.12 μmol m−2s−1. The methane and nitrous oxide emissions are, however, found less than carbon dioxide emission. The CO 2 emission falls in the range of −0.17–0.54 and 1.08–1.70, respectively higher than global lakes and rivers, while the global reservoirs have emission in the range of −0.17–2.98 μmol m−2s−1. The paper also reports the challenges in the estimation and prediction of greenhouse gas emissions from hydropower reservoirs along with suggested mitigation measures. Image 10945 • GHG emissions have been limited by data availability and inconsistencies in methodological approach. • Investigate uncertainty and limitation of GHG measurement. • Literature reveals CO 2 emission from Chinese rivers is twice than lakes and four times than hydropower reservoirs. • CH 4 and N 2 O emissions are however found less than CO 2 emission. • Suggested mitigation measures to minimize the impact of GHG on climate change. [ABSTRACT FROM AUTHOR]

The lack of safely managed sanitation services is a major global public health and ecological sustainability challenge. Ecological sanitation (EcoSan) technologies designed to close the "poop loop" through the capture, treatment, and beneficial reuse of human feces can meet this interconnected challenge. EcoSan has the potential to mitigate climate change through the reduction of greenhouse gas (GHG) emissions, yet the climate impacts of EcoSan are poorly understood. We measured GHG emissions (carbon dioxide, CO 2; methane, CH 4 ; and nitrous oxide, N 2 O) from two EcoSan operations in Haiti, as well as two anaerobic waste stabilization ponds and a grass field where sewage is known to be illegally deposited. Carbon dioxide was the major constituent of total GHG emissions from both EcoSan systems. Nitrous oxide emissions were similar across both EcoSan systems, however CH 4 emissions were significantly higher in the system with moister pile conditions. Highest CH 4 fluxes were observed during the first two months of composting in both EcoSan systems. In a paired-comparison, we found that piles with a soil lining had four-fold lower CH 4 emissions and three-fold lower N 2 O emissions compared to piles with a cement lining. Overall climate-forcing effects of emissions from EcoSan were favorable relative to waste stabilization ponds and unmanaged disposal on grass fields. In contrast to EcoSan, CH 4 emissions dominated net emissions from waste stabilization ponds, accounting for 94% of net emissions, and N 2 O emissions were negligible. Methane emissions from waste stabilization ponds were up to 250 times higher than those from EcoSan compost piles. The grass field had a significantly higher CH 4 flux than EcoSan, and the highest N 2 O flux rate observed. Our data suggest that EcoSan systems can contribute to climate change mitigation by reducing GHG emissions relative to alternative sanitation pathways, and EcoSan management conditions can be optimized to minimize emissions. • Greenhouse gas emissions from ecological-based sanitation (EcoSan) systems are poorly quantified. • Composting human waste reduced methane emissions compared to stabilization ponds. • Climate-forcing effects of EcoSan emissions were less than alternative pathways. • Management of compost piles that reduces moisture minimizes methane emissions. [ABSTRACT FROM AUTHOR]

Sustainable agricultural and food processing practices are often proposed as attractive strategies enabling food systems to respond to the challenges posed by climate change in terms of adaptation and mitigation. However, information on the actual contribution to climate change provided by sustainable food production systems is lacking in literature. With the intention to contribute to a more informed debate, this study aims at quantify the actual impact on climate of sustainable practices applied to a grape-to-wine system in Italy. The overall budget of greenhouse gas (GHG) fluxes is assessed at wine farm level, from the vineyard to the final bottle of wine, through an integration of methods, including the eddy covariance technique, the life cycle assessment (LCA) and the IPCC guidelines. All the components of the GHG budget have been considered: the (a) biogenic GHG fluxes and the (b) anthropogenic GHG emissions generated for the grape production as well as the (c) carbon stock change due to the vineyard management and the (d) anthropogenic GHG emissions generated by the transformation of grape into wine. At the vineyard level, the overall GHG budget resulted to be close to zero, showing a potential carbon neutrality of sustainable viticulture: the sum of biogenic GHG fluxes (a) and the carbon stock change (c) resulted in a net carbon sink with a potential contribution to climate change mitigation of −0,27 ± 1,11 Mg CO 2 eq year−1 per hectare; while the anthropogenic GHG emissions (b) for the sustainable vineyard management accounted for 0,24 ± 0,05 Mg CO 2 eq ha−1 year−1. The total carbon footprint (b + d) of sustainable wine is 0,79 ± 0,14 kg CO 2 eq per bottle, with 15% attributable to the agricultural phase and 85% to the transformation of grape into wine. These findings indicate that sustainable wine production has in general a lower contribution to climate change. In particular, sustainable practices applied to viticulture can turn the system into a net carbon sink able to totally compensate the anthropogenic emissions for the vineyard management. Therefore, sustainable viticulture allows food production with a potential carbon neutrality without exacerbating climate change. • Sustainable viticulture allows food production with a potential carbon neutrality without exacerbating climate change. • Sustainable viticulture generates biogenic GHG fluxes that turn the agrosystem into a net carbon sink. • Anthropogenic GHG emissions in sustainable vineyard are low and can be totally compensate by the net carbon sink. • The carbon footprint (CF) of sustainable wine is 0,79 ± 0,14 kg CO 2 eq per bottle. • Sustainable wine production has in general a lower contribution to climate change. [ABSTRACT FROM AUTHOR]

Highlights • LAC GHG efficiency in agricultural sector using within and across country metrics. • 5 Countries offset agriculture emissions with land-use-related carbon sequestration. • Small Caribbean island-states report the worst-case decoupling elasticity scenario. • Top decoupling countries are not equivalent to high factor productivity countries. Abstract The paper explores the relationship between production and greenhouse gas (GHG) emissions in the agricultural sector of Latin America and the Caribbean (LAC) between 1990 and 2015. By appraising how GHG emissions have changed with respect to agricultural production (elasticity), we are able to classify countries into six decoupling states. While the decoupling elasticity provides information for assessing the evolution within countries, we introduce a performance ratio for country comparison by calculating GHG emissions over agricultural production for 2015 and using the global distribution as benchmark. The information from both measurements serves to identify various country and sub regional situations. The findings illustrate that countries with performance ratios in the top 25% and under the best-case elasticity scenario (of strong decoupling) are not necessarily the same as the ones usually identified under factor productivity analyses, suggesting that environment-specific policy incentives and tools play a key role in enhancing sustainable agricultural production. Another major finding is that very few countries in the region (and worldwide) are able to offset agriculture emissions with land use-related carbon sequestration practices. Lastly, the evidence on small Caribbean island-states reporting the worst-case elasticity scenario (of strong negative decoupling) and performance ratios close to the world median, further supports the need for development plans related to climate change mitigation and adaptation in this sub region. [ABSTRACT FROM AUTHOR]

Abstract The use of residual biomass for the production of bioenergy and biomaterials is often suggested as a strategy to avoid negative effects associated with dedicated biomass production. One potential source is biomass from landscape management. The goal of this study was to find the lowest net greenhouse gas (GHG) emissions of various applications of residual biomass from landscape management. GHG balances of thirteen residual biomass applications were calculated and compared to their respective conventional counterfactuals. As a case study, the potential contribution to climate change mitigation through the use of residual biomass available from vegetation management in floodplains of the Dutch Rhine delta were quantified. The greatest GHG benefits are achieved when using woody biomass to produce heat (−132 kg CO 2 -eq./tonne wet biomass) and grassy biomass to produce growth media (−229 kg CO 2 -eq./tonne wet biomass). In contrast, composting grassy biomass for fertiliser replacement on agricultural fields results in the largest GHG burdens of 62 kg CO 2 -eq./tonne wet biomass. The findings imply that residual biomass from landscape management can contribute to both GHG benefits and burdens, depending on the application. Higher benefits were found for bioenergy than for biomaterial applications. Biomass applications should be chosen with care and consideration of their counterfactuals. Highlights • A life cycle GHG analysis of residual biomass applications was performed. • Counterfactuals were defined to evaluate various application options. • Generally higher benefits were found for bioenergy than for biomaterial applications. • Composting grassy biomass for growth media achieves the highest GHG benefits. • Using woody biomass for the production of heat also provides net GHG benefits. [ABSTRACT FROM AUTHOR]