Greenhouse Gas Emission Intensity Research Articles

The Impact of RED III Directive on the Use of Renewable Fuels in Transport on the Example of Estonia

Over the past two decades, there has been an increasing use of biofuels worldwide, especially in Europe. The main objective is to reduce greenhouse gas emissions, particularly carbon dioxide (CO2), from transportation. The regulation of fuels produced from biomass and other renewable sources at the EU level is primarily governed by the Renewable Energy Directive (RED). As of today, RED III directive has come into effect, significantly altering the EU fuel market by 2030. The main change involves an increase in the share of renewable fuels in transport and the non-use of first-generation fuels. Since all EU member states are obliged to comply with the RED III directive, it is essential to assess the current status of each member state in meeting the requirements for transport fuels. Therefore, the aim of this article is to analyze the impact of the RED III directive on the use of renewable fuels in the transport sector. Specifically, it provides an overview of various RED directives' requirements, analyzes the shares of renewable fuels in fossil diesel in Estonia under different RED III compliance scenarios, and presents an overview of the situation regarding the use of renewable fuels in Estonia. The article is based on a literature review, and fuel share calculations are based on RED III directive calculation methodologies. The results of the study indicate that if the requirement for the share of renewable energy used in transport is 29%, using only HVO (Hydrotreated Vegetable Oil) to achieve this goal would require replacing 30.3% of diesel with HVO. In cases where there is a requirement to reduce the greenhouse gas emission intensity of fuels in the transport sector by at least 14.5% by 2030, the volumetric share of HVO fuel must meet certain criteria based on the raw material. For example, fuel produced from residues must contain a minimal amount of biocomponents. In this context, biologically derived oil is initially used, such as in food preparation. Subsequently, after its use in food preparation, it is processed into fuel. The article also addresses cases where biogas is introduced as a renewable component in replacing diesel.

The greenhouse gas reduction effect of critical peak pricing for industrial electricity: Evidence from 285 Chinese cities, 2003–2019

This paper assesses the impact of the Pilot of Critical Peak Pricing for Industrial Electricity (PCPPIE) on industrial Greenhouse Gas (GHG) emissions by employing the Difference-in-Differences (DID) methodology. It is found that the cities participating in PCPPIE underwent a significant 11.3% reduction in the GHGs emitted per industrial enterprise. These findings remain robust across various methodologies, including staggered DID estimators, propensity score matching, instrumental variable methods, and spatial econometric regression. The generalized DID analysis shows that a higher critical peak price corresponds to a more substantial decrease in GHG emissions. PCPPIE achieves weaker GHG reduction in higher-administrative level cities but stronger in those with higher industrial share, and the effectiveness of PCPPIE is compromised by cross-regional electricity imports. PCPPIE reduces GHG emission intensity of the power industry and contributes to additional reductions in GHG emissions from other sources by fostering green technological innovation and facilitating energy substitution. The practical significance of this paper is to reveal a richer dynamic mechanism for China's green and sustainable development, indicating that critical peak pricing is a power pricing strategy worthy of strengthening and optimization in the process of China's carbon peak and carbon neutrality.

Life Cycle Greenhouse Gas Emissions in Maize No-Till Agroecosystems in Southern Brazil Based on a Long-Term Experiment

Life Cycle Greenhouse Gas Emissions in Maize No-Till Agroecosystems in Southern Brazil Based on a Long-Term Experiment

Effects of Controlled-release Blended Fertilizer on Crop Yield and Greenhouse Gas Emissions in Wheat-maize Rotation System

The increasing use of nitrogen fertilizers exerts extreme pressure on the environment (e.g., greenhouse gas emissions, GHGs) for winter wheat-summer maize rotation systems in the North China Plain. The application of controlled-release fertilizers is considered as an effective measure to improve crop yield and nitrogen fertilizer utilization efficiency. To explore the impact of one-time fertilization of controlled-release blended fertilizer on crop yield and GHGs of a wheat-maize rotation system, field experiments were carried out in Dezhou Modern Agricultural Science and Technology Park from 2020 to 2022. Five treatments were established for both winter wheat and summer maize, including no nitrogen control (CK), farmers' conventional nitrogen application (FFP), optimized nitrogen application (OPT), CRU1 (the blending ratio of coated urea and traditional urea on winter wheat and summer maize was 5:5 and 3:7, respectively), and CRU2 (the blending ratio of coated urea and traditional urea on winter wheat and summer maize was 7:3 and 5:5, respectively). The differences in yield, nitrogen fertilizer utilization efficiency, fertilization economic benefits, and GHGs among different treatments were compared and analyzed. The results showed that nitrogen application significantly increased the single season and annual crop yields of the wheat-maize rotation system (P < 0.05). Compared with those of FFP, the CRU1 and CRU2 treatments increased the yields of summer maize by 0.4% to 5.6%, winter wheat by -5.4% to 4.1%, and annual yields by -1.1% to 3.9% (P > 0.05). N recovery efficiency (NRE), N agronomic efficiency (NAE), and N partial factor productivity (NPFP) were increased by -8.6%-43.4%, 2.05-6.24 kg·kg-1, and 4.24-10.13 kg·kg-1, respectively. Annual net income increased by 0.2% to 6.3%. Nitrogen application significantly increased the annual emissions of soil N2O and CO2 in the rotation system (P < 0.05) but had no effect on the annual emissions of CH4 (except for in the FFP treatment in the first year). The annual total N2O emissions under the CRU1 and CRU2 treatments were significantly reduced by 23.4% to 30.2% compared to those under the FFP treatment (P < 0.05). Additionally, nitrogen application significantly increased the annual global warming potential (GWP) of the rotation system (P < 0.05), but the intensity of greenhouse gas emissions was reduced due to the increase in crop yields. Compared with that under FFP, the annual GWP under the CRU1 and CRU2 treatments decreased by 9.6% to 11.5% (P < 0.05), and the annual GHGs decreased by 11.2% to 13.8% (P > 0.05). In summary, the one-time application of controlled-release blended fertilizer had a positive role in improving crop yield and economic benefits, reducing nitrogen fertilizer input and labor costs, and GHGs, which is an effective nitrogen fertilizer management measure to promote cleaner production of food crops in the North China Plain.

Optimization of nutrient management improves productivity, quality and sustainability of albino tea cultivar Baiye-1.

Proper nutrient management is crucially important to the sustainable development of tea production. Compared to normal green-leaf cultivars, albino tea cultivars produce green tea of superior quality characterized by high contents of amino acids as a result of the hydrolysis of chloroplast proteins at albinism. However, the advantage of albino tea cultivars was offset by inferior growth and yield performance because of low contents of chlorophylls and limited photosynthesis capacity. Our understanding about the nutrition characteristics of albino tea cultivars was very limited. A four-year field experiment was conducted to develop proper nutrient management for Baiye-1 to overcome its weakness of low productivity without a tradeoff in tea quality and environmental risks. The nutrient management schemes were formulated by optimizing the rate and ratio of nitrogen (N), phosphorus, potassium and magnesium together with substitution of chemical fertilizers with organic manures. The total amounts of nutrients in the optimized schemes were reduced by 25% compared to the local farmers' practice (FP). Results showed that optimized rates and ratio of nutrients together with partial substitution of chemical fertilizers with rapeseed cake manure more considerably improved albino tea yield, the contents of free amino acids, total polyphenol and catechins relative to FP. Partial substitution of chemical fertilizers with commercial livestock manure decreased tea quality, which was likely caused by a dilution effect of increasing tea yield and decreasing N status of tea plants. Full organic substitution of chemical fertilizers by rapeseed cake manure improved tea yield and quality but had relatively low agronomic efficiency and profit. The effect of optimized nutrient management schemes was associated with the improvement of nutritional status in tea plants. The present work demonstrated that the optimization of nutrient management considerably improved albino tea yield, quality and profit while decreased the application rate of fertilizers and the intensity of greenhouse gas emissions.

Can converting raw straw into biochar incorporation achieve both higher maize yield and lower greenhouse gas emissions intensity in drought-prone environment?

Converting raw straw into biochar is considered an effective strategy for soil carbon sequestration. However, it remains uncertain whether biochar is more environmentally friendly for achieving higher crop yield in comparison to raw straw in drought-prone regions. Here, a 5-year experiment with three treatments (no incorporation(CK), raw straw incorporation(SI) and straw-derived biochar incorporation(BI)) was conducted to examine the effects of SI and BI on soil physicochemical properties, grain yield (GY), and greenhouse gas (GHG) emissions. Results indicated both SI and BI increased soil water content (SWC), soil temperature (ST), soil porosity, field capacity, pH, total nitrogen and soil organic carbon (SOC) compared with CK. On average, seasonal soil CO2 emission increased significantly by 42.3% in SI and 16.8% in BI, respectively; seasonal N2O emission increased by 26.9% in SI, while decreased by 17.5% in BI. Particularly, the 5-year average GY was as high as 9.4 t ha-1 in BI, significantly higher than that of SI and CK. The 5-year average global warming potential (GWP) increased by 57.9% and 24.6% under SI and BI, respectively, compared with CK. As a result, the average GHG emission intensity (GHGI) increased by 32.0% in SI, whereas it declined by 8.9% in BI. Attribution analysis showed that the CO2 emission primary driven GHGI change under SI, contributing up to 76.4% to GHGI increase. Conversely, the GY increase primary driven GHGI change under BI, contributing to 55.0% GHGI decrease. Therefore, converting raw straw into biochar incorporation acts as an environment-friendly strategy for higher yield harvest.

Assessing agricultural greenhouse gas emission mitigation by scaling up farm size: An empirical analysis based on rural household survey data

Agriculture is a major contributor to greenhouse gas (GHG) emissions. Farm size affects agricultural production inputs and thus has impacts on agricultural GHG emissions. However, the effects and mechanisms behind this are still unclear. In this paper, we identified the effects and mechanisms of farm size on agricultural GHG emissions, based on survey data about over 20,000 rural households in China from 2009 to 2016. Firstly, we calculated the agricultural CO2, CH4, and N2O emissions using the life-cycle analysis (LCA). Secondly, the impacts of farm size on GHG emissions intensity were explored with a fixed effect model, based on the long-term rural household survey data. Finally, the mechanisms were tested by the mediation effect model. The results showed that a 1 % increase in farm size, on average, could reduce the GHG emissions intensity of rural households by 0.245 % from 2009 to 2016. The mechanism analysis showed that the larger farm size reduced GHG emissions intensity mainly by reducing the non-fixed input intensity and raising fixed input investment. By identifying the impacts and mechanisms of farm size on agricultural GHG emissions, this paper aims to provide insights for policymakers to achieve China's goal of reaching carbon neutrality by 2060.

Assessing the impact of environmental performance on corporate financial performance: A firm-level study of GHG emissions in Africa

Utilizing comprehensive firm-level data from 2005 to 2021 across various African nations, our study investigates the effect of a firm's greenhouse gas (GHG) emissions on its corporate financial performance (CFP). The research yields the following findings. First, we find that GHG emission intensity exerts a significantly negative impact on CFP measured by return on assets (ROA) and return on equity (ROE). This effect is consistently substantiated across different measurements of GHG emission intensity and CFP. Second, our analysis includes a series of stringent robustness assessments, all of which affirm the stability and resilience of our primary findings. Third, following the Paris Agreement, a decrease in GHG emission intensity correlates with a further rise in ROA and ROE. Additionally, we emphasize the pivotal role of industry-specific characteristics and regional variables in shaping the connection between GHG emission intensity and CFP. Our findings underscore that the influence of GHG intensity on a firm's financial performance is particularly pronounced within high-emission sectors in contrast to their low-emission counterparts. Furthermore, we show that the impacts of GHG emission intensity on CFP are primarily driven by firms operating in Southern Africa. Fourth, to recognize potential endogeneity concerns within the GHG emission-CFP relationship, we employ a two-stage least-squares regression (2SLS) approach. This method utilizes industry-level GHG emission intensity as the principal instrumental variable (IV), and in order to further mitigate endogeneity issues, we incorporate both lagged GHG intensity and the instrument proposed by Lewbel (2012) based on heteroskedasticity as additional IVs alongside the kinky least squares method by Kiviet (2020). The results derived from our 2SLS estimates consistently corroborate the negative effect of GHG emission intensity on CFP. Finally, our empirical findings carry significant implications for both corporations and policymakers.

Evaluation of Increasing Dietary Concentrations of a Multi-Enzyme Complex in Feedlot Lambs' Rations.

The objective of this study was to evaluate the effects of increasing levels of the M-E complex (xylanase, glucanase, cellulase, and invertase) Optimax E® on the performance of growing lambs, their digestibility, and their rumen microbiota, and to estimate NEm, NEg, and ruminal methane levels. Forty lambs (Katahdin x Dorset; 22.91 ± 4.16 kg) were randomly assigned to dietary concentrations of ME (0, 0.2, 0.4, and 0.8% DM) and fed individually for 77 days. Increasing M-E improved feed conversion (p < 0.05) as well as NEm and NEg (p < 0.05), which were associated with increased in vivo DM and NDF digestion (linear and quadratic p < 0.01). Few microbial families showed abundancy changes (Erysipelotrichaceae, Christensenellaceae, Lentisphaerae, and Clostridial Family XIII); however, the dominant phylum Bacteroidetes was linearly reduced, while Firmicutes increased (p < 0.01), resulting in a greater Firmicutes-to-Bacteroidetes ratio. Total Entodinium showed a quadratic response (p < 0.10), increasing its abundancy as the enzyme dose was augmented. The daily emission intensity of methane (per kg of DMI or AGD) was reduced linearly (p < 0.01). In conclusion, adding the M-E complex Optimax E® to growing lambs' diets improves their productive performance by acting synergistically with the rumen microbiota, modifying the Firmicutes-to-Bacteroidetes ratio toward more efficient fermentation, and shows the potential to reduce the intensity of greenhouse gas emissions from lambs.

Mitigating methane emissions and global warming potential while increasing rice yield using biochar derived from leftover rice straw in a tropical paddy soil

The sustainable management of leftover rice straw through biochar production to mitigate CH4 emissions and enhance rice yield remains uncertain and undefined. Therefore, we evaluated the effects of using biochar derived from rice straw left on fields after harvest on greenhouse gas emissions, global warming potential (GWP), and rice yield in the paddy field. The experiment included three treatments: chemical fertilizer (CF), rice straw (RS, 10 t ha−1) + CF, and rice straw-derived biochar (BC, 3 t ha−1 based on the amount of product remaining after pyrolysis) + CF. Compared with CF, BC + CF significantly reduced cumulative CH4 and CO2 emissions, net GWP, and greenhouse gas emission intensity by 42.9%, 37.4%, 39.5%, and 67.8%, respectively. In contrast, RS + CF significantly increased cumulative CH4 emissions and net GWP by 119.3% and 13.8%, respectively. The reduced CH4 emissions were mainly caused by the addition of BC + CF, which did not increase the levels of dissolved organic carbon and microbial biomass carbon, consequently resulting in reduced archaeal abundance, unlike those observed in RS + CF. The BC + CF also enhanced soil total organic carbon content and rice grain yield. This study indicated that using biochar derived from leftover rice straw mitigates greenhouse gas emissions and improves rice productivity in tropical paddy soil.

The emission intensity of the freshwater aquaculture production value chain in Georgia

This contribution assesses the greenhouse gas (GHG) emission intensity among two freshwater aquaculture sub-chains: both the carp and catfish and the trout and sturgeon sub-chains in Georgia. The data were derived from 155 semi-structured interviews conducted in Georgia in 2021. The GHG per kilogram of production and per Georgian Lari (GEL) of value added of specific farm types were calculated. Emission intensity per kg of production is similar for both sub-chains, while value-added differs more significantly. Our results show the existence of economies of scale in trout production due to the ability of larger farms to use less feed per kilogram of fish. From this perspective, increasing the production scale can lead to lower emission intensity and improved economic performance. In the case of the carp sub-chain, economies of scale are not present. Therefore, we recommend conducting research on increasing the scale of production through the use of larger ponds. This solution brings obvious economic benefits, but from an environmental point of view, it may pose certain threats. Moreover, the countereffects of scaling production, such as wild fish depletion, water pollution, and the spreading of fish diseases and the farmed fish escaping, must also be adequately addressed.

A three-year record of CO2, CH4 and N2O emissions in maize fields influenced by mulching methods on the Loess Plateau, China

Exploring optimal mulching methods for maize production is critical to achieving a balance between maximizing yield and reducing negative environmental impacts in dryland agriculture. Therefore, a 3-yr field experiment was conducted to investigate the effects of three mulching methods—biodegradable plastic film mulching (BM), maize straw mulching (SM), and no mulching (NM)—on spring maize yield, greenhouse gas (GHGs) emissions (CO2, CH4, and N2O), soil factors, the net ecosystem GHG balance and greenhouse gas emission intensity (GHGI) on the Loess Plateau of China. The result showed indicated that CO2 and N2O are the primary sources of GHGs in dryland maize production. The yield of BM significantly increased 1.43–1.99 t ha−1 compared to NM, CO2 emissions (on average 32.83%) compared to the NM. And BM showed suitability for N2O emissions (3.7–11.2%). SM increased CO2 and N2O emissions (by 9.43–13.17% and 24.96–33.64%, respectively) compared to the NM. Structural equation model analysis showed that soil temperature was the most direct factor to affect GHGs. SM was the sink of net ecosystem GHGs, BM and NM were the source of net ecosystem GHGs. These results indicated that mulching emerges as a promising strategy for dryland agriculture. BM method can be used when the primary goal was to improve yield, while SM method is a better choice when the primary goal was to improve soil organic carbon sequestration and reduce net GHGs emissions. This study clarified the impacts of mulching methods on three GHGs emissions to provide information support for sustainable agriculture on the Loess Plateau.

Substituting Partial Chemical Fertilizers with Bio-Organic Fertilizers to Reduce Greenhouse Gas Emissions in Water-Saving Irrigated Rice Fields

Conventional water and fertilizer management practices have led to elevated greenhouse gas emissions from rice fields and decreased the efficiency of water and fertilizer utilization in agricultural land. The implementation of water-saving irrigation and the substitution of chemical fertilizers with organic alternatives can influence CH4 and N2O emissions in rice fields. However, it remains unclear how the simultaneous application of both methods will affect the CH4 and N2O emissions in rice fields. Therefore, two irrigation methods (F: flooded irrigation; C: controlled irrigation) and three fertilization modes (A: full chemical fertilizer; B: bio-organic fertilizer replacing 15% chemical nitrogen fertilizer; C: bio-organic fertilizer replacing 30% chemical nitrogen fertilizer) were set up through field experiments to explore the effect of greenhouse gas emission reduction in rice fields by combining controlled irrigation and bio-organic fertilizers. Substituting some chemical fertilizers with bio-organic fertilizers can lower the peak CH4 and N2O fluxes in rice fields, leading to a decrease in the cumulative CH4 and N2O emissions by 11.9~29.7% and 10.8~57.3%, respectively. The reductions led to a considerable decrease in the global warming potential (GWP) and the greenhouse gas emission intensity (GHGI) by 16.1~48.1% and 16.3~48.1%, respectively. Controlled irrigation significantly reduced CH4 emissions by 55.2~69.4% compared with flooded irrigation in rice fields. However, it also increased N2O emissions by 47.5~207.9%, considerably reducing their GWPs by 11.8~45.5%. Neither bio-organic fertilizer substitution nor controlled irrigation significantly affected rice yield. Replacing 15% of chemical nitrogen fertilizers with bio-organic fertilizers in controlled irrigation rice fields can minimize rice GWP and GHGI. The study’s results are of significant importance for enhancing the regulation of greenhouse gases in farmland and achieving sustainable agriculture through cleaner production.

Relationship between Dairy Cow Health and Intensity of Greenhouse Gas Emissions.

The dairy industry is facing criticism for its role in exacerbating global GHG emissions, as climate change becomes an increasingly pressing issue. These emissions mostly originate from methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). An optimal strategy involves the creation of an economical monitoring device to evaluate methane emissions from dairy animals. Livestock production systems encounter difficulties because of escalating food demand and environmental concerns. Enhancing animal productivity via nutrition, feeding management, reproduction, or genetics can result in a decrease in CH4 emissions per unit of meat or milk. This CH4 unit approach allows for a more accurate comparison of emissions across different animal production systems, considering variations in productivity. Expressing methane emissions per unit allows for easier comparison between different sources of emissions. Expressing emissions per unit (e.g., per cow) highlights the relative impact of these sources on the environment. By quantifying emissions on a per unit basis, it becomes easier to identify high-emission sources and target mitigation efforts accordingly. Many environmental policies and regulations focus on reducing emissions per unit of activity or output. By focusing on emissions per unit, policymakers and producers can work together to implement practices that lower emissions without sacrificing productivity. Expressing methane emissions in this way aligns with policy goals aimed at curbing overall greenhouse gas emissions. While it is true that total emissions affect the atmosphere globally, breaking down emissions per unit helps to understand the specific contributions of different activities and sectors to overall greenhouse gas emissions. Tackling cattle health issues can increase productivity, reduce GHG emissions, and improve animal welfare. Addressing livestock health issues can also provide favourable impacts on human health by reducing the prevalence of infectious illnesses in livestock, thereby mitigating the likelihood of zoonotic infections transmitting to humans. The progress in animal health offers the potential for a future in which the likelihood of animal diseases is reduced because of improved immunity, more effective preventative techniques, earlier identification, and innovative treatments. The primary objective of veterinary medicine is to eradicate clinical infectious diseases in small groups of animals. However, as the animal population grows, the emphasis shifts towards proactive treatment to tackle subclinical diseases and enhance production. Proactive treatment encompasses the consistent monitoring and implementation of preventive measures, such as vaccination and adherence to appropriate nutrition. Through the implementation of these measures, the livestock industry may enhance both animal well-being and mitigate the release of methane and nitrous oxide, thereby fostering environmental sustainability. In addition, advocating for sustainable farming methods and providing farmers with education on the significance of mitigating GHG emissions can bolster the industry's endeavours to tackle climate change and infectious illnesses. This will result in a more robust and environmentally sustainable agriculture industry. This review seeks to conduct a thorough examination of the correlation between the health condition of cattle, the composition of milk produced, and the emissions of methane gas. It aims to identify areas where research is lacking and to provide guidance for future scientific investigations, policy making, and industry practices. The goal is to address the difficulties associated with methane emissions in the cattle industry. The primary global health challenge is to identify the causative relationship between climate change and infectious illnesses. Reducing CH4 and N2O emissions from digestive fermentation and animal manure can be achieved by improving animal well-being and limiting disease and mortality.

Importance of reducing GHG emissions in power transmission and distribution systems

Reducing greenhouse gas (GHG) emissions in the power transmission and distribution (T&D) network is crucial for achieving carbon peaking and carbon neutrality. However, there has been a lack of focus on this topic, despite the dramatic replacement of traditional high-emission power generation systems with clean and renewable energy sources. This study aims at investigating the GHG emissions in the T&D network based on life cycle assessment (LCA). A life cycle carbon assessment (LCCA) model of the T&D network is established, and the GHG emission intensity of China's T&D system is predicted. It is found that the GHG emission intensity of T&D in China was approximately 66 gCO2eq/kWh in 2012 and decreased to around 32 gCO2eq/kWh in 2022, of which GHG emissions of the T&D network were mostly caused by electricity loss. The contributions of infrastructure GHG emissions are analyzed, and alternative scenarios are conducted to explore the driving factors of the GHG emissions of T&D infrastructure. A prediction towards year 2060 regarding carbon neutrality indicates that the GHG emissions of T&D will account for at least 16% of total GHG emissions from China's power grid system by 2060. This implies that reducing GHG emissions in T&D should be one of the primary tasks, especially when the clean energy dominates in the electricity mix.

Quantifying greenhouse gas emissions mitigation potential in China's agricultural plastic greenhouses

To promote sustainable intensification and provide guidance for decisionmakers, we must understand the potential for mitigating greenhouse gas emissions in greenhouse cultivation. Therefore, this study aimed to evaluate the greenhouse gas emission mitigation potential of agricultural plastic greenhouses in China using a combination of life cycle assessment, data envelopment analysis, and scenario analysis. We found that: (1) In China, the mean mitigation potential for greenhouse gas emission intensity related to the crop production inputs of agricultural plastic greenhouses is 1.67 kt CO2-eq/km2, demonstrating a remarkable mitigation rate of 47 %. This mitigation potential, driven mostly by fertilizer use, exhibited a spatial pattern characterized by high mitigation rates in the southern regions compared to those in the northern regions; (2) in scenarios S1 and S2, the greenhouse gas emission intensity mitigation potential of greenhouse construction materials was 0.645 kt CO2-eq/km2 and 0.968 kt CO2-eq/km2, respectively, with steel being the primary contributor to mitigation; (3) under scenarios S1 and S2, the greenhouse gas emission mitigation rates for China's agricultural plastic greenhouses were 42 % and 48 %, respectively. This study highlights the greenhouse gas emission mitigation potential of China's agricultural plastic greenhouses. To ensure sustainability in plastic greenhouses, emphasis should be placed on optimizing fertilizers and extending the lifespan of construction materials.

Long-term management of rice agroecosystem towards climate change mitigation

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 (CO2), methane (CH4) and nitrous oxide (N2O) 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 CO2 and CH4 emissions, whereas two peaks for N2O 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 CH4 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 CH4 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 CH4 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.

Dietary Concentrate Supplementation Increases Milk Production and Reduces Predicted Greenhouse Gas Emissions Intensity in Pasture-based Commercial Dairy Farms

Controlled studies have extensively documented that concentrate supplements typically increase enteric methane (CH4) emissions and milk yield and reduce emissions per unit of milk produced and dry matter intake. However, there have been no studies conducted to determine the effect of concentrate on predicted greenhouse gas emissions from dairy farms representing the Australian pasture-based farming system. Thus, this study sought to determine how dietary concentrate supplementation affects enteric and manure CH4, and N2O of Australian pasture-based dairy farms. The Australian Dairy Carbon Calculator was used, which incorporates emission factors and methodologies used in the National Greenhouse Gas Inventory as reported to the International Panel on Climate Change. Primary data were collected and analyzed from 120 commercial farms in Australia's major dairy regions. Then the farms were divided into 4 groups based on their dietary concentrate supplementation: ≤ 1 (low; 15 farms), 1-2 (moderate;35 farms), 2-3 (high; 35 farms), and ≥ 3 (very high; 35 farms) ton (t) of concentrate dry matter per cow per year. Sources of greenhouse gas emissions were CO2 from concentrate production, enteric CH4, and manure CH4 and N2O. Total dry matter intake, milk yield, and daily enteric CH4 production (g/day) quadratically increased with concentrate level, whereas greenhouse gas emission intensity of milk production (kg CO2eq/kg fat and protein corrected milk) decreased by 14% for farms supplementing with ≥ 3 tDM/cow per year compared with those supplementing with ≤ 1 tDM/cow per year of dietary concentrate. The emissions of N2O and CH4 from manure increased quadratically and linearly, respectively, with the increasing supplementation of concentrate. Farms supplementing 2-3 tDM/cow per year showed substantial increases in gross income, gross margin, earnings before interest and tax, and net income ($/cow/year) compared with those supplementing of ≤ 1, 1-2, and ≥ 3 tDM/cow per year. In conclusion, increasing dietary concentrate supplementation for dairy cows resulted in increased milk production per cow, reduced greenhouse gas emissions per unit of milk produced, and increased income and profit. However, a comprehensive life cycle assessment study is needed to account for carbon sequestration by other farm components such as pastures and trees, which were not considered in the present study. In addition, the present study was based on modeling and did not gather ground truth information for DMI, digestibility, crude protein, and urinary and fecal N excretion. Therefore, data should be interpreted with caution, and studies gathering such information are encouraged.

Structural decomposition analysis of agricultural Non-CO2 greenhouse gas emission intensity in China

Agriculture is China's primary emitter of non-CO2 greenhouse gas (GHGs) emissions, and it is crucial to understand the drivers and contributions of agricultural non-CO2 GHGs emission intensity (ANCGI) for formulating effective emission reduction policies. Based on a decomposition analysis approach, this study explains the factors that driving the change of ANCGI from the perspectives of environment, economy, and scale. And by calculating the contribution of these three factors in 31 Chinese provinces between 2000 and 2019 using the Logarithmic Mean Divisia Index (LMDI) technology. The findings show that the ANCGI in China has declined by about 3.6% per year on average over the past 20 years, and the main factor affecting its decline is the economic level, contributing more than one third. The ANCGI is negatively impacted by the environment, with a contribution value of −1.60%; and the scale effect contributes 1.21% to the decrease in the ANCGI. Therefore, improving the level of agriculture environment in each province and transitioning to a high-quality development model are important ways to reduce the ANCGI in China.

THE PERFORMANCE OF KUALA LUMPUR’S CARBON EMISSIONS IN THE CONTEXT OF URBAN PLANNING

Cities are responsible for 70% of greenhouse gas (GHG) emissions on a global scale, and cities play an important role in reducing GHG emissions. It is essential for Kuala Lumpur to consider reducing the city's GHG emissions. The city's GHG emission inventory can track and monitor the effectiveness of the climate action plans that has been implemented. The aim of this study is to identify the performance level of GHG emissions in Kuala Lumpur between 2010 and 2019. It is also to identify the performance of Kuala Lumpur's GHG emissions in 2019 in comparison to the global and Malaysian level. Data is calculated using the Global Protocol for Community-Scale Greenhouse Gas Emissions Inventory (GPC), which is recognised and utilised globally. Secondary data for the years 2010 and 2019 was analysed as well as the performance of the Kuala Lumpur GHG emission profile in 2019. With three (3) identified sources of emissions, Kuala Lumpur managed to reduce its GHG emission intensity from 2010 by 74.07% in 2019. The city's GHG emission was recorded at 15,675 ktCO2eq in 2019. The stationary energy sector contributes higher GHG emission than other sector, with 12,043 ktCO2eq (76.83%), followed by the transportation sector with 3,180 ktCO2eq (20.29%) and the waste sector with 452 ktCO2eq (2.88%). As of 2019, Kuala Lumpur's absolute carbon contribution to the global average is 0.03%, whereas Malaysia's absolute carbon contribution is 4.74%. Additionally, the city contributes just 0.07 kgCO2eq/RM (30.17%) to Malaysia's total GHG emission intensity.