Greenhouse Gas Emission Intensity Research Articles

42 Environmental Impacts of Improving Forage Use Efficiency in Beef Cattle

Abstract As population grows, so does the demand for high quality protein, and beef ranks among the greatest in terms of nutrient density per caloric intake. Maintaining the sustainability of beef cattle production systems has been one of the main priorities of researchers worldwide. Because the global demand for beef production is projected to increase, the contribution of beef production to greenhouse gas emissions will increase. One of the most useful tools available to researchers to reduce the carbon footprint of beef production is the selection for more feed efficient cattle. The use of residual feed intake as a criterion for selection has been demonstrated to have potential impact on the carbon footprint of beef systems, by reducing emissions intensity. Greenhouse gas emissions intensity involves the carbon footprint per unit of product (e.g., beef or milk produced) and it is the main metric to be considered when assessing the environmental impact of production systems. Great advances have been made in terms of improving the digestibility of forage resources. However, because of the impact that fiber digestion has on enteric methane production, these improvements in forage digestibility need to be considered in the context of emissions intensity. Advances in forage breeding such as the incorporation of brown mid-rib traits, have undoubtedly led to improvements in fiber digestion and animal productivity. Fewer studies have examined the impact of this technology on greenhouse gas emissions. A great opportunity exists to begin assessing the impact of new technologies such as the use or fibrolytic enzymes and prebiotics, with the potential of enhancing fiber digestibility. Global beef production will continue to rely heavily on high-forage diets for at least some segments of the production system. Assessing the impact of new technologies to enhance fiber digestion in the context of greenhouse gas emissions per unit of product will be essential to maintain the sustainability of beef production systems.

Livestock greenhouse gas emission and mitigation potential in China

Livestock is an important source of greenhouse gas emissions (GHGE) in China. Understanding the greenhouse gas (GHG) emission trends and reduction strategies in livestock is crucial for promoting low-carbon transformation of the livestock sector (LS) and achieving the goal of “carbon peak and carbon neutralization”. First, based on the life cycle assessment and IPCC coefficient methods, we calculated the GHGE of the LS in 31 provinces of China from 2000 to 2020 and identified the temporal and spatial evolution of GHG emission intensity. The LMDI method was then used to analyze the influence of efficiency, structure, economy, and population size on GHGE. Finally, the STIRPAT model was used to simulate the future evolution trend of the LS emissions under the SSPs scenario. The results revealed that the GHGE in the life cycle of livestock production decreased from 535.47 Mt carbon dioxide equivalent (CO2e) in 2000 to 532.18 Mt CO2e in 2020, and the main source was CH4 emissions from enteric fermentation of livestock. Economic and efficiency factors markedly influenced the changes in GHGE from the LS in China. Further, economic factors contributed >40% to the increase in GHGE in most provinces. Under the SSP1, SSP2, and SSP4 scenarios, livestock production can achieve the carbon peak target in 2030. Under the baseline scenario (SSP2), the GHGE of China's LS in 2030 and 2060 are expected to be 491.48 Mt CO2e and 352.11 Mt CO2e, respectively. The focus of mitigation measures for livestock production in the future is to optimize the production structure of the LS, promote the low-carbon transformation of the energy structure of livestock feeding, and establish an efficient and intensive management model. In addition, we focus on emission reduction in key areas, such as Northeast and Northwest China, while optimizing diet and reducing food waste from the consumer side.

Carbon pricing and firms’ GHG emissions: Firm-level empirical evidence from East Asia

This study investigates the impacts of carbon pricing policies on firms' greenhouse gas (GHG) emissions. We include two carbon pricing policies: carbon tax and emission trading scheme (ETS) at national and sub-national (province) levels, measured as policy existence (binary variable) and carbon price (continuous variable). Firms' GHG emissions are measured as total emissions and emission intensity. Using unique recent firm-level data from 2010 to 2021 from three East Asia countries (Japan, the Republic of Korea (ROK), and the People's Republic of China (PRC)), we obtain the following key findings. First, the national carbon pricing policy significantly reduced firms' GHG emissions and GHG emission intensity in Japan and the ROK. The greater the carbon price, the greater the impact. Second, the subnational carbon pricing policies implemented in two provinces of Japan (Saitama and Tokyo) decreased firms' GHG emissions. Third, heavy industry sectors such as energy, utilities, and industrials experienced a substantial decrease in GHG emission intensity due to the carbon pricing policy. Finally, our main results are robust to different model specifications and various measures of firms' GHG emissions. Although literature studying the ex-post impact of carbon pricing on emissions at country and sector-level is abundant, this paper contributes to the existing literature providing empirical evidence of the impact of carbon pricing policies on firms' emissions using firm-level data, which is highly limited especially in Asia.

Sustainable maize intensification through site-specific nutrient management advice: Experimental evidence from Nigeria

There is growing evidence on the impacts of site-specific nutrient management (SSNM) from Asia. The evidence for Sub-Saharan Africa (SSA), where SSNM developments are more recent and where conditions concerning soil fertility and fertilizer use differ importantly from those in Asia, is extremely scarce. We evaluate a SSNM advisory tool that allows extension agents to generate fertilizer recommendations tailored to the specific situation of an individual farmer’s field, using a three-year randomized controlled trial with 792 smallholder farmers in the maize belt of northern Nigeria. Two treatment arms were implemented: T1 and T2 both provide SSNM information on nutrient use and management, but T2 provides additional information on maize price distributions and the associated variability of expected returns to fertilizer use. We estimate average and heterogenous intent-to-treat effects on agronomic, economic and environmental plot-level outcomes. We find that T1 and T2 lead to substantial increases (up to 116%) in the adoption of good fertilizer management practices and T2 leads to incremental increases (up to 18%) in nutrient application rates, yields and revenues. Both treatments improve low levels of nutrient use efficiency and reduce high levels of greenhouse gas emission intensity, after two years of treatment. Our findings underscore the possibility of a more gradual and sustainable intensification of smallholder agriculture in SSA, as compared with the Asian Green Revolution, through increased fertilizer use accompanied by improved fertilizer management.

The potential for mitigating greenhouse gas emissions and minimizing yield losses using the negative pressure irrigation system

Efficient strategies for reducing agricultural greenhouse gas (GHG) emissions without yield penalties are crucial for sustainable agricultural development in the context of population increases and global warming. This study investigates the efficacy of negative pressure irrigation (NPI) in mitigating GHG emissions, as well as its impact on crop yield, global warming potential (GWP), and GHG emission intensity (GHGI), using surface irrigation (CK) as the control. The NPI system operated at three water pressure levels: NPI1 (-2 kPa), NPI2 (-4 kPa), and NPI3 (-6 kPa). The results revealed a notable pattern under NPI: a single peak in GHG emissions that remained consistently, and much lower than CK for the majority of the vegetable season, directly results in the lower cumulative GHG emissions and GWP from NPI than those from CK. Notably, the central region, located near the emitter, exhibited significantly lower GWP compared to the edge region, accompanied by higher yields, leading to a lower GHGI. Based on the findings, the -2 kPa water pressure level demonstrated the optimal performance in sustaining crop yields for Chinese chives while effectively reducing GWP and GHGI. Additionally, regions situated 20 cm on both sides of the emitter under -2 kPa NPI were identified as suitable areas for crop cultivation, offering higher yields and lower GWP and GHGI compared to CK. These results emphasize the win-win situation by balancing vegetable yield while reduced GHG emissions.

Manure substitution with appropriate N rate enhanced the soil quality, crop productivity and net ecosystem economic benefit: A sustainable rainfed wheat practice

Partial substitution of organic fertilizer is adopted to increase production and alleviate farmland greenhouse gas (GHG) emissions. However, there is a lack of integrated assessment of soil quality, crop productivity, and environmental benefits through organic fertilizer substitution. Therefore, an in-situ experiment was conducted with the single nitrogen (N) treatments (120, 180, 240 kg N ha−1, expressed with N120, N180, N240, respectively) and partial substitution with manure fertilizer (each N treatment decreased by 30 kg N ha−1 and plus 2 t ha−1 pig manure, expressed with NM120, NM180, NM240, respectively) for rainfed wheat production on the Loess Plateau. A comparison between N and NM treatments showed that manure substitution treatments: 1) increased soil quality index by 50.9 − 57.4%, grain yield by 9.0 − 42.9%, total N accumulation by 8.6 − 31.1% and nitrogen recovery efficiency by 10.7 − 76.9%; 2) decreased N2O emission by 10.6 − 15.3% and CH4 uptake by 2.9 − 3.6%, whereas increased CO2 emission by 5.1 − 6.7%; 3) reduced the carbon footprint by 1.7 − 2.3 time mainly by the soil organic carbon sequestration. The global warming potential (GWP), Greenhouse gas emission intensity (GHGI), grain yield and net ecosystem economic benefit (NEEB) increased as the fertilizer rates increasing. NM180 had higher yield (average 6022 kg ha−1) and lower GWP (16489 kg CO2-eq ha−1) than N180, which obtained the smaller GHGI (2.67 kg CO2-eq kg−1) and maximum NEEB (4150 RMB ha−1). Overall, manure partial substitution with appropriate N rate enhances soil quality, crop productivity and environment benefit, which is a sustainable rainfed wheat practice.

Identifying methods to reduce emission intensity of centralised Photovoltaic deployment for net zero by 2050: Life cycle assessment case study of a 30 MW PV plant

AbstractPhotovoltaics (PV) is one of the most effective and necessary energy sources to mitigate climate change. The broad electrification scenario projects the PV market to grow from 1 TW in 2022 to over 63 TW in 2050. While increasing PV production will significantly reduce the emission intensity of electricity generation, it is still important to minimise the overall environmental impact of such a large industry. In this study, we investigated the intensity of greenhouse gas (GHG) emissions of a 30 MW PV plant using a life cycle assessment (LCA). Based on the LCA, we propose a roadmap to reduce emissions from PV manufacturing and deployment. Decarbonising significant factors like aluminium and concrete production or the electricity demand to produce PV modules can greatly reduce the carbon budget related to PV production. Our study shows that the global warming potential (GWP) per kWh can be reduced from 11.2 to 1.7 g CO2‐eq/kWh over the lifetime of the PV system (85% reduction). Using the aspects to decarbonise PV production, the roadmap is demonstrated. The cumulative GWP to reach 63 TW is initially estimated to be 44 Gt CO2‐eq. Our decarbonising roadmap demonstrated that such significance can be reduced by over 37 Gt CO2‐eq, equivalent to a whole year emission in year 2022.

Calculation of greenhouse gas emissions of urban rail transit systems in China

In China, the total energy consumption and greenhouse gas (GHG) emissions will reach considerable levels based on the current speed of urban rail transit system development. Based on the life-cycle assessment theory, this research constructs an urban rail transit system GHG emission assessment method, calculates emission outputs based on resource inputs from actual investigated data and makes a quantitative analysis of GHG emissions. The results show that in recent years, the GHG emission of urban rail transit construction and operation in China is between 2000 × 104 and 4200 × 104 tonnes of carbon dioxide equivalent (tCO2e) per year. The proportions of the construction and operational phases in this emission are 57 and 43%, respectively. In the construction phase, the GHG emission intensity per unit mileage of shield tunnels and per unit area of stations is about 1.3 × 104 tCO2e/km and 3.71 × 104 tCO2e/ha, respectively. In the operational phase, the GHG emission intensity per unit trip is 0.084 kg carbon dioxide equivalent/passenger-km. The entire life-cycle GHG emission per kilometre of urban rail transit systems is 11.69 × 104 tCO2e (with a service life of 50 years) in China. The construction phase and operation phase generated about 18.73 and 81.27% of this emission, respectively. The preliminary conclusions of this study may help shed light on the emission reduction potential of urban rail transit systems and the emission reduction targets in China.

Spatial heterogeneity of factors affecting GHG emission intensity in urban water supply and wastewater treatment systems in China

The water supply and treatment in urban water systems (UWS) consume massive energy, quantitative estimate of the intensity of their accompanying GHG (Greenhouse Gas) emissions is important to clarify the major source of the GHG for UWS. Herein, on the city scale, the intensity of energy consumption and GHG emissions of the water supply and wastewater treatment systems were calculated, based on the operating data of 5972 water or wastewater treatment plants in China. Results showed that the water supply system consumed 38.6 billion kWh of electrical energy and accounted for 26.8 Mt CO2-eq GHG emissions, accordingly of 14.4 billion kWh and 21.9 Mt CO2-eq for the wastewater treatment system. For wastewater treatment, significant spatial autocorrelation was observed for the intensities of energy consumption and GHG emission, and the clustering areas highly matched with the topography, especially the N2O and CH4 emissions high-high clustering in the Loess Plateau and Inner Mongolia Plateau. Screened by multi-scale geographically weighted regression, the annual precipitation was found to be the main factor influencing the intensities, with a higher regression coefficient than social factors (e.g., GDP and population density). And a clear spatial heterogeneity was observed with the regression coefficient distributed higher in the northwest than in the southeast, with a gap of 2.3–7.5 times. This study provides systematic estimation results of energy consumption and GHG emissions intensity in urban water supply and wastewater treatment systems on the city scale in China, quantifies regional differences in energy consumption and GHG emission intensity of UWS, and revealed the inequality of UWS in regions with different basic conditions while facing low-carbon transformation. Our findings provide a reference for the formulation of regionally targeted UWS low-carbon transition policies.

GHG emissions reduction patterns from waste sectors after forced source separation

Waste management is the bridge to balance resource conservation and climate change protection, and source separation is the pre-requirement to improve the recycling rate and normal human behavior. In this work, greenhouse gas (GHG) emission patterns were investigated from waste sectors from 2016 to 2021 in Shanghai, where force MSW source separation was first implemented in China since 2019. The GHG emission in the waste sector increased from 3.06 (2016) to 9.28 (2021) Mt CO2-eq due to the increase of waste disposal amounts from 7.35 (2016) to 11.83 Mt (2021). With the implementation of forced source separation in Shanghai on July 1st, 2019, the proportion of kitchen waste and water content decreased by 37.31% and 20.74% in dry waste, resulting in the increase of low heating value (LHV) by 99.39% (13,160 kJ/kg). The waste disposal system was optimized by employing resource recycling and anaerobic digestion of wet waste, and the corresponding GHG emission intensity decreased from 0.29 to 0.24 t CO2-eq per ton MSW. Three scenario analyses, including the Business-As-Usual (BAU) scenario, New Policy (NP) scenario, and Low-carbon (LC) scenario, were conducted to study the influence of the grid emission factor, wet waste disposal capacity, incineration power generation efficiency, and lower waste plastic proportion on the GHG emissions. The results showed that the GHG emission intensity would reach 0.28, 0.21, and 0.12 t CO2-eq per ton MSW in the BAU, NP, and LC scenarios. Optimizing waste disposal mode and reducing waste plastic from sourced separation was critical to reduce GHG emissions more effectively from the waste sector.

Emission intensities in EU countriesʼ food production systems and their market resilience during the 2020 global economic turmoil

One effect of the 2020 global pandemic was market turmoil over the food production system. Such strong market shocks can also affect the environment, for example, through changes in the greenhouse gas (GHG) emission intensity of production. The purpose of this study was to calculate and evaluate comparable GHG emission intensity indicators for food production systems and their production stages in European Union (EU) countries. An index decomposition analysis of the obtained indicators was conducted to determine the structural and intensity effects. The three original contributions of this analysis were index decomposition of emission intensity, consideration of more GHGs, and expansion of the study period to include 2018–2020. The results from the majority of countries confirm the research hypothesis that the emission intensity at the agricultural (on-farm) production stage in EU countries in 2020 increased in relation to the emission intensity of the remaining stages of the food production system. The overall emission intensity of food production systems increased from 0.83 CO2-eq per 1 GDP in PPP in 2019 to 0.86 in 2020. However, this was caused solely by the increase in emission intensity at the agricultural production stage, from 2.40 CO2-eq per 1 GDP in PPP to 2.65 in 2020. On average, emission intensity did not increase at other stages of the food production systems in EU countries. Our findings indicate the low market resilience of agriculture to the 2020 economic turmoil, causing the low market power of agricultural producers in relation to the remaining stages of the food production value chain. These results were confirmed by the higher intensity index and lower structural index between 2019 and 2020 in the majority of the analyzed countries, caused by the decline in the share of agriculture in the GDP structure of food production, with a simultaneous increase in its intensity over time.

The impact of corporate environmental management practices on environmental performance

AbstractThis study draws on neo‐institutional theory to examine how and why corporate environmental management practices might affect environmental performance. It contributes to the literature by using a large, global data set to investigate the impact of 10 corporate environmental management practices on greenhouse gas emissions or emissions intensity. It focuses on greenhouse gas emissions which pose an existential threat to the people and planet, and the environmental management practices of corporations whose effectiveness has provoked cynicism and claims of “greenwash”. Our results are based on a dynamic, robust and large‐scale econometric analysis, which includes tests of association and Granger causation in comparison with earlier research. A key finding, which is of interest not only to the academic literature but also to policymakers and managers, is that environmental performance impacts environmental management practices but not vice versa, supporting the hypothesis that corporations adopt these practices as a symbolic legitimizing device rather than a genuine attempt derived from moral obligation to reduce their greenhouse gases or carbon intensity.

Study of the impact of industrial restructuring on the intensity of greenhouse gas emissions: empirical data from China

Study of the impact of industrial restructuring on the intensity of greenhouse gas emissions: empirical data from China

Low-carbon effects of constructing a prefabricated subway station with temporary internal supports: An innovative case of Shenzhen, China

The traditional cast-in-site (CIS) construction method for subway stations has presented significant challenges to the construction industry in light of the growing labor shortage, prefabricated technology represents a promising alternative. This study introduces a novel prefabricated subway station structure, characterized by the innovative features of "Internal support + Large components + Full assembly." Additionally, the technical processes of the newly designed temporary internal support system for the case station are presented in detail. A greenhouse gas (GHG) emissions quantification model based on construction decomposition is established using the life cycle assessment (LCA) method to assess the low-carbon effect of constructing prefabricated subway stations. Moreover, an integrated project quota GHG emissions inventory is created. The findings demonstrate that the GHG emissions of the full-assembled structure, per unit area, are 6.55% lower than those of the CIS structure, resulting in an emission reduction benefit of 11.21 t CO2e. Notably, structural optimization and reduced material loss rates contribute to an 8.47% decrease in embodied emissions of materials. On average, the GHG emission intensity of the full-assembled station structure during transportation and on-site assembly is higher than that of the CIS structure, amounting to 4.48 t CO2e for a single ring-structure. Regarding GHG emissions during construction, the main structure and the exterior-protected structure of the case station account for 53.62% and 39.24% of the total emissions, respectively. Compared to prefabricated subway station using the temporary anchor cable supporting structure, the temporary internal support system could avoid unnecessary occupation of underground space, which is vital for the sustainable development of underground space in big cities.

Greenhouse gas emissions embodied in the U.S. solar photovoltaic supply chain

Solar photovoltaic (PV) electricity is considered to be an important source of electricity generation in the quest for net-zero carbon emissions. However, the growth of solar electricity is creating both increased material demands and increased greenhouse gas (GHG) emissions from silicon and PV manufacturing (also referred to as embodied GHG emissions of solar electricity). Here we analyze the silicon and solar PV supply chain for the United States (U.S.) market and find that the embodied GHG emissions of solar PV panel materials (such as silicon), manufacture, logistics, and installation in the U.S. given the current supply chain are 36 g CO2e kWh−1 of solar electricity generated. Eighty-five percent of the embodied GHG emissions are from PV panel production processes in China and other Asia–Pacific countries. Moving the silicon and PV manufacturing to the U.S. would reduce the embodied GHG emissions of solar electricity by 16% from its current level, primarily because of the lower GHG emission intensity of the U.S. electrical grid and the lower GHG emissions for aluminum electrolysis in North America. Future scenario analysis shows that by 2030, with the U.S. PV domestic supply chain and its decarbonized grid electricity and aluminum production, as well as improving PV conversion efficiency, the embodied GHG emissions of solar electricity in the U.S. will be reduced to 21 g CO2e kWh−1.

Assessment of the straw and biochar application on greenhouse gas emissions and yield in paddy fields under intermittent and controlled irrigation patterns

Water-saving irrigation and straw and biochar application are common agronomic practices in rice production, and their profound impact on greenhouse gas (GHG) emissions from paddy soils cannot be ignored. A three-year field experiment was conducted in typical paddy fields in the subtropical region of eastern China. The methane (CH4) and nitrous oxide (N2O) emissions with straw or biochar application under intermittent irrigation (II) and controlled irrigation (CI) patterns were systematically assessed, and relevant soil physicochemical properties were measured to clarify the internal linking mechanisms. Five treatments were established: conventional flooding as the control group (CG), intermittent irrigation + straw (II + S), intermittent irrigation + biochar (II + B), controlled irrigation + straw (CI + S), and controlled irrigation + biochar (CI + B). The cumulative CH4 emissions with II + S, II + B, CI + S, and CI + B were reduced by 11.2%, 33.2%, 14.1%, and 40.3%, respectively； while the cumulative N2O emissions increased by 20.2%, 5.8%, 13.6%, and 1.2%, respectively (three-year average). Each treatment significantly reduced the global warming potential (GWP) by 10.1–44.8%, and increased rice grain yield by 7.9–13.3%, significantly reducing the greenhouse gas emission intensity (GHGI) by 16.7–46.7%. With II and CI, straw or biochar application increased the soil pH, ground temperature at 5 cm depth, and soil nitrogen levels and regulated the SOM and DOC contents, which may be closely related to greenhouse gas emission regulation and improvements to soil fertility. Notably, the decrease in the soil mcrA/pmoA gene abundance ratio was a dominant factor in CH4 reduction. Overall, each treatment has the potential to reduce GHG emissions and increase crop productivity in paddy fields, and CI + B achieved the best results. These practices facilitate the development of optimal management strategies for rice cultivation.

Effects of Typical Cropping Patterns of Paddy-Upland Multiple Cropping Rotation on Rice Yield and Greenhouse Gas Emissions

In response to the limitations of traditional double rice cropping models, this study constructed five typical rice planting models in the middle reaches of the Yangtze River, namely “Chinese milk vetch-early rice-late rice (CK/CRR), Chinese milk vetch—early rice—sweet potato || late soybean (CRI), rapeseed—early rice—late rice (RRR), rapeseed—early rice—sweet potato || late soybean (RRI) and potato—early rice—late rice (PRR)” to study the annual emission characteristics of greenhouse gases under different planting models. The results showed the following: (1) From the perspective of total yield in two years, the CRI treatment reached its maximum, which was significantly higher than that of other treatments by 9.30~20.29% in 2019 (p < 0.05); in 2020, except for the treatment of RRI, it was significantly higher than other treatments by 20.46~30.23% (p < 0.05). (2) The cumulative emission of CH4 in the double rice treatment is generally higher than that in paddy-upland rotation treatment, while the cumulative emission of N2O in the paddy-upland rotation treatment is higher than that in the double rice treatment, but the total amount is much lower than the cumulative emission of CH4. Therefore, CH4 emissions from rice fields still occupy most of the GHGs. (3) The global warming potential (GWP) and greenhouse gas emission intensity (GHGI) of different planting patterns in rice fields in 2020 were higher than those in 2019, and the GWP and GHGI of double rice cropping treatment is higher than that of paddy-upland rotation treatments. During the two years, the GWP of CRR treatment reached its maximum and was significantly higher than that of other treatments by 48.28~448.90% and 34.43~278.33% (p < 0.05). The GHGI of CRR was significantly higher than that of CRI and RRI by 3.57~5.4 and 1.4~3.5 times (p < 0.05). Based on the comprehensive performance of greenhouse gas emissions over the two experimental years, RRI and CRI have shown good emission reduction effects, which can significantly reduce greenhouse gas emissions from paddy fields, are conducive to reducing global warming potential and greenhouse gas emission intensity and conform to the development trend of “carbon neutrality”. Therefore, considering high-yield, low-temperature chamber gas emissions, the Chinese milk vetch—early rice—sweet potato || late soybean model performs well and has the best comprehensive benefits. It is of great significance for optimizing the rice field planting mode in the middle reaches of the Yangtze River.

Accounting for and Comparison of Greenhouse Gas (GHG) Emissions between Crop and Livestock Sectors in China

The synergistic greenhouse gas (GHG) emission reduction of the crop production (CP) and livestock farming (LF) sectors is of great significance for food security and low-carbon development, especially for China, the world leader in agricultural production. In this paper, the GHG emissions from the CP and LF sectors are accounted for and compared, and the spatial econometric model is adopted for comparative study based on the panel data from 1997 to 2021. The results show that: (1) The total amount and intensity of GHG emissions from both sectors showed obvious spatial heterogeneity and spatial dependence, and the spatial distribution pattern was relatively stable. (2) The influence of each factor on the GHG intensity and spatial characteristics of CP and LF varies widely. For the CP sector, economic development (local effect −0.29, adjacent effect +1.13), increased urbanization rate (−0.24, +0.16), agricultural structure (−0.29, +0.05), and urban-rural disparity (−0.03, +0.17) all reduce the GHG intensity of local region, while increasing the GHG intensity of its adjacent areas, signifying leakage. The economic structure (+0.06, +0.16), agricultural finance support (+0.02, +0.26), mechanization level (+0.05, +0.03), and land occupancy rate (+0.54, +0.44) all play a role in increasing the GHG intensity of CP in the local region and its adjacent areas. The disaster degree (−0.03, −0.03) also reduced the GHG intensity of CP. For the LF sector, economic structure (+0.08, +0.11), urban-rural disparity (+0.11, +0.21), agricultural development level (+0.03, +0.50), and increased land occupancy rate (+0.05, +0.01) can improve the GHG intensity of the one region and adjacent areas. Economic development (+0.03, −0.15), urbanization rate (+0.04, −0.30), agricultural structure (+0.09, −0.03), and disaster degree (+0.02, −0.06) can increase the GHG intensity of the local region while reducing the GHG intensity of adjacent areas. Based on the results, under the background of carbon peaking and carbon neutralization(dual-carbon) goals, this study first puts forward collaborative emission reduction measures for CP and LF, respectively, then further rises to sector synergy and regional synergy, and constructs the countermeasure system framework of collaborative emission reduction from three levels, to provide guidance and reference for the realization of dual goals of agricultural GHG reduction and food security.

Influence of 36 years of integrated nutrient management on soil carbon sequestration, environmental footprint and agronomic productivity of wheat under rice-wheat cropping system

A long-term field experiment was conducted to study the effects of different combinations of integrated nutrient management (INM) on carbon sequestration and wheat yield in a rice-wheat cropping system. The experiment consisted of 11 treatments that were replicated three times. The organic manures used in the study included farmyard manure (FYM), wheat straw (WS), and green manure (GM) with Sesbania aculeata. The results of the experiment revealed that the application of 50% of the recommended dose of fertilizers (RDF) along with 50% nitrogen (N) through FYM during rice cultivation, and RDF during wheat cultivation, led to a significant increase in soil organic carbon (SOC). Specifically, the SOC content was enhanced by 46.4% (18.29 Mg ha-1) compared to RDF in rice and wheat, resulting in a C sequestration rate of 0.22 Mg ha-1 year-1. These increases were higher in treatments that combined organic and inorganic inputs. Additionally, the application of 50% RDF and substituting 50% of the nitrogen with FYM during wheat cultivation resulted in a 24.7% increase in grain yield compared to RDF in rice and wheat. The INM treatments, showed significantly (p ≤ 0.05) higher agronomic efficiency (AE) of nitrogen (N), phosphorus (P) and potassium (K), partial factor productivity (PFP) of N, P and K, and carbon pool index (CPI) compared to the application of inorganic fertilizers at the recommended dose. Moreover, the INM treatments also exhibited lower greenhouse gas (GHG) emission intensity. Application of neither chemical fertilizers nor organic manure (T1) resulted in maximum GHG emission intensity (328.1 kg CO2 eq Mg−1 yield). Based on these findings, it can be concluded that the combined use of inorganic fertilizers and organic manures significantly increased crop yield and soil organic carbon sequestration while reducing GHG emissions in a rice-wheat cropping system in the eastern Indo-Gangetic Plains (EIGP) of India.

Data-driven analysis of using flow control devices and extended reach wells on SAGD well performance

The industry's current trend to reduce Capital Expenditures (CapEx) and to minimize the environmental impacts has led to drilling long lateral wells and developing key innovative tools like Flow Control Devices (FCDs). This study analyzed the relative performance of various FCD deployments using data from major Steam-Assisted Gravity Drainage (SAGD) projects in Western Canada, spanning from 1997 to mid-2022. The goal is to investigate the impact of FCD deployment and increasing the lateral length on SAGD well performance in terms of boosting oil produciton and lowering cumulative Steam Oil Ratio (cSOR).This paper utilizes a normalization technique to evaluate the production history of wells, considering geological and operational parameters. Following our confidential conversations with experts in the industry, wells exceeding 850 m in lateral lengths are labeled as “long”, while those below 850 m are labeled as “short”. Eventually, normalized oil production and cSOR for all wells are analyzed. A comparison is made between short and long wells that are completed or retrofitted with FCDs, giving an insight into the role of completion design on the relative performance of SAGD wells.Reservoir thickness and reservoir quality are assessed for each well using contour maps and Gamma Ray (GR) log images. These images are digitized using image processing codes developed in our study. On average, across all projects, wells equipped with FCDs produced up to 52% more normalized oil than those without FCDs, and cSOR decreased to 18%. Long wells, on average, had lateral lengths 38% greater than short wells and produced 18% more normalized oil than all short wells. When comparing long wells with and without FCDs, the normalized oil production is improved by up to 36%, and cSOR is lowered by up to 17%. Furthermore, comparing long wells with FCDs to short wells without FCDs reveals that the normalized oil production is improved by up to 96%, and cSOR is lowered by up to 26%. The results highlight the synergistic benefits of combining longer wells with FCDs to improve normalized oil production and cSOR. The historical production analysis show that installing FCDs is the key enabler and an innovative strategy to increase productivity, reduce cSOR, and make longer wells more productive.The findings indicate that FCDs might increase oil production and decrease cSOR for SAGD well-pad developments, allowing operators to reduce Greenhouse Gas (GHG) emissions intensity. The findings may be used to examine paradigm shifts in the development of heavy oil deposits as technology advances while keeping the project economics into account.