Total CO2 Research Articles

ОЦІНКА ЕКОЛОГІЧНИХ ЗБИТКІВ ВІД ВИКИДІВ ТРАНСПОРТНО-ЛОГІСТИЧНИХ ЗАСОБІВ В КОНТЕКСТІ СТАЛОГО РОЗВИТКУ

This article thoroughly examines the environmental damage caused by emis-sions from transportation and logistics vehicles in Odesa, within the framework of sustai-nable development objectives. It presents a detailed analysis of the main pollutants emitted by vehicles using gasoline, diesel, and liquefied petroleum gas, underscoring the significant contribution these emissions make to both local and global environmental issues. The study highlights the substantial volumes of greenhouse gases produced and the current lack of economic regulatory mechanisms to manage them effectively. Comparative analysis of global environmental tax rates on CO2 demonstrates Ukraine's position as having the lowest rate, suggesting inadequate regulatory measures. Through methodical calculations, it was deter-mined that Odesa's total CO2 emissions for the year 2022 amounted to 1,089,421.9 tons. This resulted in an estimated environmental damage cost of $893,326 USD, which remains uncompensated due to regulatory shortcomings.The findings emphasize the necessity of integrating such emission data into environ-mental damage assessments and implementing robust economic instruments to regulate emissions. Additionally, the paper explores strategic approaches to enhance emission regu-lations, including the potential introduction of more stringent environmental taxes or cap-and-trade systems, and suggests ways to align these with international environmental stan-dards. The broader implications of such regulatory adjustments are discussed, particularly their role in facilitating sustainable urban development. This comprehensive analysis aims to provide policymakers and urban planners with an understanding of the environmental stakes involved and practical steps towards achieving sustainability in urban transportation systems. By comparing Ukraine’s policies to international standards, the research offers valuable insights into potential reforms that can drive the sustainable future for Ukraine. Keywords: transportation and logistics vehicles, environmental damage, sustainable development, greenhouse gases, emission regulation, environmental tax.

Optimizing Perishable and Non-Perishable Product Assignment to Packaging Lines in a Sustainable Manufacturing System: An AUGMECON2VIKOR Algorithm

Identifying appropriate manufacturing systems for products can be considered a pivotal manufacturing task contributing to the optimization of operational and planning activities. It has gained importance in the food industry due to the distinct constraints and considerations posed by perishable and non-perishable items in this problem. Hence, this study proposes a new mathematical model - according to knowledge discovery as well as an assignment model to optimize manufacturing systems for perishable, non-perishable, and hybrid products tailored to meet their unique characteristics. In the presented model, three objective functions are taken into account: (1) minimizing production costs by assigning the products to the right set of manufacturing systems, (2) maximizing the product quality by assigning the products to the systems, and (3) minimizing total CO2 emissions of the machines. A numerical example is utilized to evaluate the performance of AUGMECON2VIKOR compared to AUGMECON2. The results show that AUGMECON2VIKOR obtains superior Pareto solutions across all objective functions. Furthermore, the sensitivity analysis explores the positive green impacts, influencing both cost and quality.

The Optimisation of Storage Conditions for Pomegranate Juice during Its Maritime Transport

It is estimated that the transport of plant-based food may be responsible for 50% of total CO2 emissions. The situation becomes highly unfavourable when the transported cargo deteriorates. Therefore, the optimisation of storage conditions during transport is a part of the concept of reducing food loss and waste. Moreover, it is an essential element of sustainable development. This study aimed to compare the stability of selected quality parameters of pomegranate juice under simulated conditions imitating maritime transport. The content of polyphenols and the ability to reduce free radicals were considered the critical quality parameters of this juice. The Folin–Ciocalteu method (polyphenols content) and the Brand-Williams method (ability to reduce free radicals) were used during the study. The simulation of maritime transport conditions consisted of different juice storage conditions. The differentiation was conducted regarding temperature, type of gas that filled the packaging, and mixing related to the ship’s motions during transport. The highest quality of pomegranate juice was ensured by modifying the atmosphere with nitrogen and lowering the temperature. It is also important that mixing the juice does not reduce its quality but stabilises it.

An integrated assessment of the financial and environmental impacts of exterior building insulation application

In the literature, optimum thermal insulation thickness on building's exterior was examined by many researchers. Optimum insulation thickness was generally studied with the aim of minimizing the total cost, and suitable values were determined within this scope. In this study, it has also considered the amount of CO2 released into the atmosphere due to the fuels used in building heating and cooling processes, as well as insulation materials, in addition to the total cost. This study has been focused on optimization of the determination of the ideal insulation thickness of buildings by simultaneously minimizing the total cost and CO2 emission, using the knee point approach. In this context, a multi-objective optimization study has been conducted for thermal insulation applied to buildings located in different climatic zones considering the solar radiation. A comprehensive analysis has been carried out to determine the impact of the heating source type (natural gas, electricity, fuel oil), insulation material (expanded polystyrene, extruded polystyrene, mineral wool, polyurethane foam), climatic zone (I, II, III, IV) and the purpose of the building's use (summer house, winter house or all-season house) on the optimum insulation thickness. The degree-day approach has been used to calculate annual energy consumption, and accordingly the life-cycle cost (LCC) method has been used in economic analysis. The optimum insulation thicknesses have been calculated with two separate objectives: one to minimize only the total cost and the other to minimize only the CO2 emissions. It has been found that when the primary goal of insulation application is to minimize CO2 emissions, the calculated optimum insulation thicknesses are consistently higher compared to situations where the main goal is minimizing total cost. Furthermore, for various climatic zones and different purpose of the building's use, an ideal insulation thicknesses that simultaneously minimizes both the cost and CO2 emissions have been identified. In this research, the equations providing environmentally optimum insulation thicknesses to minimize CO2 emissions have been derived and presented to researchers. Finally, the conclusion is drawn that the knee point approach can be applied in insulation scenarios where two objective functions need simultaneous optimization.

Performance assessment of LC3 concrete structures considering life-cycle cost and environmental impacts

Developing green materials for infrastructure construction is of vital importance for sustainable development. Limestone calcined clay cement (LC3) is an appropriate alternative for the reduction of CO2 emissions and resource consumption in the cement industry. Recycled concrete aggregate (RCA), seawater and sea sand are potentially advantageous from a sustainability perspective, especially in coastal regions. Fiber-reinforced polymer (FRP) bars with excellent corrosion resistance are ideal alternative materials for steel bars in a corrosive environment. In this paper, a new type of green concrete structure incorporating LC3, seawater, sea sand, RCA, and FRP bars was investigated, and the performance was assessed to verify the considerable sustainable advantages while considering life cycle cost and environmental impacts. The results showed that the proposed LC3 concrete exhibited lower environmental impacts: compared with traditional concrete, and the CO2 and energy consumption of LC3 concrete were reduced by 32%–41.7% and 23.3%–28%, respectively. Although the initial cost was higher for LC3 and CFRP bars, this disadvantage could be offset by their longer service life and lower maintenance costs during their life cycle. Compared with traditional RC structures, the total cost, CO2 and energy consumption in the life cycle were reduced by 39%, 30.5%–65.4%, and 18.5%–58.9% for the LC3 concrete structure, respectively. In contrast to the life cycle cost, the LC3 replacement ratio had a negative effect on the environmental indices for the LC3 concrete and structure. Considering the promising advantages in economy and environmental impact, the proposed LC3 concrete and structure provides an effective approach for the sustainable development of the construction industry.

Multi-objective optimisation model of a low-cost path to peaking carbon dioxide emissions and carbon neutrality in China

A low-cost path system for achieving carbon neutrality in China was modelled using multi-objective programming by integrating industrial production, electric power, heating, transportation, and forest carbon sequestration. We aimed to minimise the total system cost, CO2 emissions, and air pollutants. The constraints included China's targets of peaking CO2 emissions before 2030; achieving carbon neutrality before 2060; ensuring industry, power, heating, and transportation supplies; promoting green energy; and implementing emission control. The model accounted for industries with high coal consumption, such as steel and chemical industries. Various power sources were considered, including coal-fired, nuclear, wind, and solar energy. Forest carbon sink and carbon capture and storage technologies were employed to achieve the emission reduction goals. The model, which was validated using available research data, offered cost-effective path schemes and exhibited high validity. Our findings emphasise the importance of structural adjustments and emission control, with electric power, heating, and transportation sectors showing higher feasibility and providing greater contributions to achieving carbon neutrality than other industries. Conversely, industrial transformation in sectors such as iron and steel, chemical, and construction materials had low feasibility and limited contribution. The modelling outcomes provide valuable insights for developing low-cost, carbon emission-targeted transportation structures in China's complex system. The results presented here demonstrate the global applicability of this method in contributing to plans aimed at meeting key carbon reduction targets.

Impact of lockdown policies on urban traffic conditions and carbon dioxide emissions based on an emission model on the link level in hour granularity

This study presents an emission model at the link level, with hourly granularity, incorporating traffic conditions and driving characteristics to analyze the impact of lockdown measures on carbon dioxide (CO2) emissions within an urban road network. A case study in Beijing, China, utilizing comprehensive datasets, was conducted. More than 25 million data points from floating cars and 13 million activity data records from light-duty vehicles were collected and employed in this study. The results reveal significant changes in traffic conditions during lockdown compared to the post-lockdown period. However, driving characteristics remained consistent between the two periods. The temporal and spatial aspects of CO2 emissions are examined in detail. Furthermore, we quantified the emissions reduction resulting from "working from home," which accounted for 9.1% of the total daily CO2 emissions from light-duty vehicles post-lockdown. The model developed in this study is transferable, providing a valuable tool for researchers to analyze the spatial and temporal characteristics of urban road traffic and emissions at high resolution. These findings have practical implications for the implementation of urban carbon-reduction policies, such as working from home.

Examining the consumption of oil on total factor productivity and CO2 emissions: an analysis of highly oil-consuming countries

PurposeThis study aims to examine the impact of oil consumption on carbon dioxide (CO2) emissions and total factor productivity (TFP) in highly oil-consuming countries of the world from 1995 to 2019.Design/methodology/approachFor this purpose, fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) are applied.FindingsFMOLS and DOLS models reveal that oil consumption, human capital, population, trade openness and nonrenewable energy have a significant positive effect on CO2 emissions. While information and communication technology (ICT), as proxied by mobile and natural resources, has a significant negative effect on CO2 emissions. In the case of TFP, oil consumption, ICT and natural resources have a significant positive effect on the TFP. On the other hand, trade openness, population, human capital and nonrenewable energy have a significant negative effect on TFP. The results of this study can help to provide policy recommendations to reduce CO2 emissions in studied highly oil-consuming countries of the world.Originality/valueDue to the threat to sustainable development, climate change has become a major topic for debate around the world. The influence of oil consumption on CO2 emission and TFP is less known in the available literature. Another significance of this study is that many researchers considered aggregate energy consumption to study this relationship, but the authors have studied the effect of energy consumption, particularly from oil in the top oil-consuming countries, which is a significant shortcoming of the present research.

Estimation of greenhouse gas emissions using linear and logarithmic models: A scenario-based approach for Turkiye's 2030 vision

Turkiye pledged to considerably reduce its greenhouse gas (GHG) emissions by the year 2030 as a part of its commitment under the Paris Agreement. The problem with analyzing mitigation of greenhouse gas emissions requires generation of accurate, reliable and consistent emission forecasts. This study aimed to accurately forecast Turkiye's total CO2 emissions per capita and per capita CO2 emissions from energy industries, industrial processes and agricultural sectors till 2030 using linear and logarithmic models based on increasing and decreasing scenarios. Turkiye's total CO2 emissions per capita in 2030 could reach to 7.6 and 7.7 tons of CO2, with total emissions of about 635 and 643 million tons (Mt) based on linear and logarithmic models, respectively. Linear modeling results showed that per capita CO2 emissions from Turkiye's energy industries, industrial processes and agricultural sectors could reach to 5.3, 0.9 and 0.9 tons in 2030, respectively, while logarithmic modeling results yielded that per capita CO2 emissions from Turkiye's energy industries, industrial processes and agricultural sectors could be 5.5, 1.1 and 0.9 tons in 2030, respectively. The accuracy of fit for linear and logarithmic models was assessed by calculating root mean square error (RMSE < 0.2036) and mean absolute percentage error (MAPE < 12.3347) values which showed that the models fitted well with the timeline data. In conclusion, Turkiye's greenhouse gas emissions can be reduced if utilization of renewable energy sources in the country's energy portfolio is increased, and the shares of energy intensive processes in the industrial and agricultural sectors are reduced.

(Poster Award Winner 1) Investigating the Impact of Ethylene Carbonate Reaction Pathways on the Solid Electrolyte Interphase in Li-Ion Batteries

A high-performing Li-ion battery relies heavily on the solid electrolyte interphase (SEI), which is composed of various decomposition products, primarily from reduced additives or electrolyte species such as ethylene carbonate (EC). The composition of the SEI evolves and continues to form during the operation of a Li-ion battery, making it challenging to fully understand through post-mortem analysis alone. To gain a complete understanding of the EC reaction pathways and their respective contributions to the SEI, it is necessary to employ analytical techniques that monitor the battery during operation. Online Electrochemical Mass Spectrometry (OEMS) is one such technique that can sample the gas composition of a battery, providing an overview of voltage-dependent gas evolution processes.1 This presentation focuses on two EC reaction pathways that occur on a model carbon electrode.2 The first pathway, the "EC ring-opening" reaction pathway, is initiated by hydroxides/alkoxides at potentials above 1.5 V vs. Li+/Li and is associated with CO2 evolution.3 , 4 The second pathway, the "EC reduction" pathway, occurs at potentials below 0.9 V vs. Li+/Li and is identified by C2H4 evolution.5 Both reaction pathways contribute to the formation of the SEI, and they compete with each other. If EC ring-opening is favoured, it can suppress EC reduction. Figure 1 illustrates the competing relationship between the two different EC reaction pathways, where the addition of EC ring-opening initiators (H2O) increases CO2 and reduces C2H4. It is essential to consider all possible EC reaction pathways, not just the desired one, when forming the SEI. The presentation concludes with a discussion of the potential implications that EC ring-opening may have on a Li-ion cell. Figure 1 . Comparison between the total CO2 and C2H4 evolution during the initial cyclic voltammetry cathodic sweep in a Glassy carbon | 1 M LiPF6 EC:DEC | LiFePO4 cell. References R. Lundström and E. J. Berg, J. Power Sources, 485, 229347 (2021).R. Lundström, N. Gogoi, X. Hou, and Berg Erik J., Submitted (2023).M. Metzger, B. Strehle, S. Solchenbach, and H. A. Gasteiger, J. Electrochem. Soc., 163, 1219–1225 (2016).L. Gireaud, S. Grugeon, S. Laruelle, S. Pilard, and J.-M. Tarascon, J. Electrochem. Soc., 152, A850 (2005).R. Imhof and P. Novák, J. Electrochem. Soc., 145, 1081–1087 (1998). Figure 1

Comparing Commercially Available Gas Diffusion Layers in the Electrochemical CO2 Reduction Reaction

One of the most urgent challenges of our society is the continuously rising level of CO2 in the atmosphere, caused by anthropogenic emission, including different point sources (e.g., cement factories, automobiles, airplanes). The electrochemical CO2 reduction reaction (CO2RR) can be an alternative route for the chemical- and energy industries to convert CO2 into useful products (e.g., carbon monoxide, methane, ethylene), hence providing a value-added approach for CO2 neutralization1.In our work we employed a zero gap electrolyzer cell (active area = 8 cm2), where the catalyst coated electrodes are separated by only a Grade-T Sustainion® X37-50 anion exchange membrane (AEM). As the cathode we used Ag nanoparticle coated gas diffusion layers and as the anode we used Iridium Black coated Ti frit. During the experiments, an anolyte was recirculated continuously through the anode side and humidified CO2 was fed to the cathode side. Beyond the cell structure and membrane, the applied catalyst coated gas diffusion layer (GDL) is one of the most critical elements, determining the efficiency of CO2RR. In this work we compared commercially available GDLs in the CO2RR. All GDLs are used in identical electrochemical cells, under the same experimental conditions2.Our goal was to provide a comprehensive conclusion of the most frequently used commercially available GDLs in CO2RR. We studied the effect of the microporous layer (MPL), the PTFE content, the thickness, and the structure of the selected GDLs. One-hour long chronoamperometric measurement revealed some trends and important differences - in case of five of the tested GDLs (Sigracet 28BC, Sigracet 39BB, Freudenberg H23C6, Toray H60 MPL and Elat LT 1400W), the CO partial current density exceeded 500 mA cm−2 already at 3.0 V cell voltage. To unravel which structural parameters affect the electrolyzer performance the most, the results were compared along a few selected properties (Figure 1.): (A) whether they contained MPL or not, (B) the PTFE content, (C) the overall thickness, and (D) the structure of the GDL.<Figure 1.> Figure 1. Comparing commercially available gas diffusion layers in the CO2RR. Partial current densities for CO and H2 production during one-hour long chronoamperometric CO2RR measurements at ΔU = 3.0 V, applying different GDL based cathode GDEs with Ag catalyst. The electrolyte solution was 0.1 M CsOH, humidified CO2 was fed to the cathode at a flow rate of 12.5 cm3 cm−2 min−1 and the temperature of the electrolyzer cell was 60 °C. The error bars represent the deviations of two consecutive analyses during the same measurements.Long-term electrolysis experiments (100 hours) were performed with two GDLs, the Sigracet 39BB and the Toray H60 MPL. Throughout the long-term electrolysis, a stable total current density and CO formation selectivity was measured in both cases. Throughout our study, to understand the differences among their electrochemical behavior, of the various GDLs, we characterized their wetting properties and microstructure before the electrochemical measurements. The structure and morphology of the GDLs were characterized with SEM, micro-CT and contact angle measurements. References (1) Samu, A. A.; Kormányos, A.; Kecsenovity, E.; Szilágyi, N.; Endrödi, B.; Janáky, C. Intermittent Operation of CO2 Electrolyzers at Industrially Relevant Current Densities. ACS Energy Lett. 2022, 1859–1861(2) Samu, A. A.; Szenti, I.; Kukovecz, Á.; Endrődi, B.; Janáky, C. Systematic Screening of Gas Diffusion Layers for High Performance CO2 Electrolysis. Commun. Chem. 2023, 6 (1), 1–9 Supported by the KDP-2021 program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation fund. Figure 1

Energy, exergy, environmental, and economic (4E’s) analysis of a solar driven humidification-dehumidification desalination system: An experimental investigation

A solar-driven humidification-dehumidification (SDH-DH) desalination system has shown to be a highly efficient and viable solution to meet the freshwater needs of a community. However, the solar air heater based on flat plate collector, imposes constraints on their efficiency. The current work focuses on the development of an SDH-DH desalination system. This system is comprised of a solar air heater that utilizes a double-ends open evacuated tube collector, a humidifier equipped with cellulose pad packing material, and a dehumidifier based on a direct evaporative cooler. The current SDH-DH desalination system is operated in two modes, namely open loop and closed loop, at four distinct process air flow rates. The system's performance indices are evaluated based on energy, exergy, environmental and economic analysis. The solar air heater is capable of generating hot air at an approximate average temperature of 100 °C, while maintaining an airflow rate of 150 kg/h. This enhances the efficiency of the humidifier, resulting in a freshwater production rate of about 2.43 L/m2/day at a cost of 0.027 $/L. Moreover, the use of an evaporative cooler-based dehumidifier effectively mitigates the issue of fouling that arises during the condensation process. The system achieved the maximum mean energy efficiency of 25.39 % and exergy efficiency of 4.59 % in a closed loop configuration, with an air flow rate of 150 kg/h. The total CO2 reduction amounts to 119.08 tons during the designated duration.

Techno-economic assessment of a novel integrated multigeneration system to synthesize e-methanol and green hydrogen in a carbon-neutral context

A novel and efficient multigeneration system aiming to achieve near-zero CO2 emissions is proposed. The system employs a methanol production process utilizing captured CO2 from the flue gas of a biomass-gasification plant. The proposed system successfully generates green H2 through water electrolysis, supported by thermal power, with a portion of the hydrogen reacting with CO2 to produce e-methanol. Additionally, the system produces other valuable products, including power, cooling, O2, and CO2, in a coherent manner, benefiting from a low-emission framework and exhibiting high thermodynamic performance. The proposed multigeneration system consists of a biomass-gasification-based power plant, a water electrolyzer, a methanol generation unit, a carbon capture unit, and a steam jet ejector-based refrigeration cycle. The integrated multigeneration system is analyzed from the energy, exergy, and economic aspects. The results demonstrate the system's ability to achieve production rates of 430.25 kg/h of e-methanol and 190 kg/h of green H2. Furthermore, the energy and exergy efficiencies of the system are found to be 78.13% and 71.63%, respectively. The CO2 emissions analysis reveals that the proposed system significantly reduced total CO2 emission to 78.5% (0.61 kgCO2/kg). The total cost of production is estimated to be 0.087 $/kg.

Carbon and Energy Efficient Ethanol Electrosynthesis By Acidic CO2 Reduction

The electrochemical CO2 reduction reaction (CO2RR) is one way of mitigating the rising levels of anthropogenic CO2 emissions. Most of the advancements in the CO2RR field have been implemented in basic or neutral electrolytes where a major fraction of the input CO2 converts to carbonate ions through reaction with OH– (Science 360, 783-787 (2018); Nat. Catal. 5, 564-570 (2022)). These approaches result in low carbon efficiency (the percentage of CO2 converted per total CO2 input), typically below 20% toward multicarbon products, resulting in severe energy and cost penalty (Nat. Sustain. 5, 563-573 (2022)).Performing CO2RR in acidic conditions reduces reactant loss to carbonates. In this condition, the (bi)carbonate ion crossover/formation is countered by the high proton concentration in the electrolyte. However, the unshielded cathode surface favors the hydrogen evolution reaction (HER) over CO2RR due to the high availability of protons and the fast kinetics of the HER (Science 372, 1074-1078, (2021); Nat. Catal. 4, 654-662 (2021)).Here, we have developed an interfacial cation matrix (ICM) to modulate the local microenvironment on the cathode surface. The ICM increases the local pH and electric field, promoting multicarbon production. Additionally, we have designed a Copper-Silver catalyst to tune the selectivity towards alcohol production. We improved the ethanol FE to 45% at 200 mA/cm2, which, to our knowledge, represents the highestethanol FE in membrane electrode assembly literature. The system maintains a high carbon efficiency (60%) resulting in a total energy cost of 263 GJ/tonne ethanol, which is the lowest value among current ethanol-producing CO2 electrolysers.

Process optimization, energy consumption analysis, and environmental assessment of total CO2 capture from syngas based on [NEMH][Ac] protic ionic liquid

Process optimization, energy consumption analysis, and environmental assessment of total CO2 capture from syngas based on [NEMH][Ac] protic ionic liquid

COMPARATIVE ANALYSIS BETWEEN AHP MOORA AND AHP-ELECTRE METHOD FOR OPTIMAL ELECTRIC AND SOLAR-POWERED SHIPYARD SITE SELECTION

Transportation is the second largest emitter of CO2 in the world, accounting for 25% of total CO2 emissions. To achieve a zero-carbon shipping industry, Indonesia can use its high sun exposure to generate electrical energy by using solar cell technology, which converts solar energy into electrical power. To answer the challenge, this research will start with the site selection of electric and solar-powered shipyards. This research tries to solve the problem of selecting the best location for electric and solar-powered shipyards by using the Multi-Criteria Decision Making (MCDM) method. The purpose of this research is to get the optimal location of electric and solar shipyards using AHP-MOORA and AHP-ELECTRE methods. There are three alternative locations in the location selection. Alternatives 1 and 3 are in Paciran District, Lamongan Regency, East Java Province, and alternative 2 is in Serang Regency, Banten Province. Alternative site 1 has an area of 38 ha and is located in Sidokelar Village, Paciran Sub-district. Decision-makers determine the parameters that will be evaluated from each alternative location, such as slope, soil type, rainfall, and 18 other criteria. In determining the weighting of parameters, a method that has a consistency test is needed so that the weight results obtained are consistent and objective. The study result shows that alternative location 1 is the best location for the electric and solar-powered shipbuilding industry, the same conclusion using the AHP-MOORA Integration approach and the AHP weighting ELECTRE Integration approach.

Toward a low carbon path: Do E-commerce reduce CO2 emissions? Evidence from China

To address global climate change, achieving carbon peak and carbon neutrality has become a global consensus. However, the means to simultaneously achieve carbon reduction and promote green economic development, particularly in developing countries, require further investigation. This study evaluates the impact of e-commerce on CO2 emissions. Through an examination of the effects of the National E-Commerce Demonstration City (NEDC) policy from 2006 to 2017, this paper reveals that e-commerce growth facilitated by the NEDC policy resulted in a 7.89% reduction in total CO2 emissions and a per capita reduction of 1.1146 tons in the pilot cities. Mechanism analysis demonstrates that the upgrading of industrial structure, development of digital finance, and the growth of innovation and entrepreneurship serve as primary pathways for this impact. The robustness of the findings is supported by parallel trend tests, placebo tests, and additional sensitivity analyses. Furthermore, the research reveals that the NEDC policy exhibits a more significant reduction in CO2 emissions in cities with higher levels of economic development and non-resource-based cities. Welfare analyses show that the NEDC policy has significant socio-economic effects. These findings provide new evidence on the environmental effects of the digital economy and offer insights into achieving carbon neutrality.

BRICS and the climate challenge: navigating the role of factor productivity and institutional quality in CO2 emissions.

The BRICS countries are important contributors to global efforts aimed at preventing a climate catastrophe. These countries account for half of the total emissions generated by the G20 nations. In this context, this paper examines the relationship between total factor productivity (TFP) and CO2 emissions (CE) in BRICS countries from 1996 to 2022, with institutional quality serving as a moderating factor. Moreover, a diverse range of methodologies was employed to address the problem of cross-sectional dependence; i.e., the CS-ARDL technique is used to analyze the relationship between variables in both the long and short-run. The AMG and CCEMG methods are employed for robustness analysis, while the Dumitrescu-Hurlin causality test is used to assess causality. Our empirical analysis demonstrates that TFP is positively associated with CE. Conversely, we find that institutional quality has a negative impact on CE. Furthermore, the study confirms that the interaction between TFP and institutional quality has a negative effect on CE. This implies that an improvement in institutional quality leads to a decrease in CE, as it strengthens the regulatory system governing CE and reduces pollution. Environmental policy must include economic flexibility and policy unpredictability in order to meet CO2 reduction targets. In addition, the study has identified bidirectional causal links between CE and variables such as TFP, institutional quality, and other control variables. According to our study, the BRICS countries should encourage digitalization and renewable energy production while preserving a reasonable standard of institutional quality since they have significant resource advantages in the renewable energy sector.

Deep-sourced CO2 emissions from the Eastern Himalaya Syntaxis and the Tengchong Volcanic Field, southeast Tibet

The India-Asia collision zone is believed to play a central role in Earth's geological carbon budget. The processes controlling soil CO2 flux and mechanism at this continental subduction zone margin remain however poorly constrained. Here, we focus on hydrothermal CO2 emissions from southeast Tibet, specifically from the Eastern Himalaya Syntaxis (EHS) and the Tengchong Volcanic Field (TVF), with the twin goals of informing models of carbon cycling and ascertaining the source of hydrothermal degassing systems. In-situ measurements of soil CO2 flux from the Aqiong, Caquka, Nongchaka, Rongduo, and Woka hydrothermal fields of the EHS yield average soil CO2 fluxes of 72, 5, 13, 66, and 10 g m−2 day−1, respectively. Regional heat flow, tectonic regimes, and CO2 content in the spring gas are plausible controlling factors for soil CO2 flux, which is crucial to quantifying total CO2 output in continental collision zones. The compositions and He-C-N isotopes of hydrothermal volatiles from two study regions are reported here as well. Analysis of the He-C-N isotopes in terms of distances to the Jiali fault and the nearest Holocene volcano confirms that the Jiali fault and Holocene volcanoes have a significant impact on discharging deep-sourced CO2 from the EHS and TVF hydrothermal systems to the surface. The 3He/4He values of EHS hydrothermal volatiles (92 to 98°E), combined with previous data (82 to 92°E), show a clear increasing trend from south to north. Thus, we propose an updated model of enriched mantle wedge source for the EHS hydrothermal volatiles, based on multi-component mixing calculations of the He-CO2 systematics. The EHS hydrothermal volatiles exhibit systematics spatial variations from the core location to the bilateral segments, suggesting the highest 3He/4He ratio and carbonate-rich characteristics at the core location possibly controlled by the asthenosphere upwelling caused by the deep fragmentation structure.

Quantifying China's iron and steel industry's CO2 emissions and environmental health burdens: A pathway to sustainable transformation

Assessing the iron and steel industry's (ISI) impact on climate change and environmental health is vital, particularly in China, where this sector significantly influences air quality and CO2 emissions. There is a lack of comprehensive analyses that consider the environmental and health burdens of manufacturing processes for ISI enterprises. Here, we present an integrated emission inventory that encompasses air pollutants and CO2 emissions from 811 ISI enterprises and five key manufacturing processes in 2020. Our analysis shows that sintering is the primary source of air pollution in the ISI. It contributes 71% of SO2, 73% of NOx, and 54% of PM2.5 emissions. On the other hand, 81% of total CO2 emissions come from blast furnaces. Significantly, the contributions of ISI have resulted in an increase of 3.6 μg m−3 in national population-weighted PM2.5 concentration, causing approximately 59,035 premature deaths in 2020. Emissions from Hebei, Jiangsu, Shandong, Shanxi, and Inner Mongolia provinces contributed to 48% of PM2.5-related deaths in China. Moreover, the transportation of air pollutants across provincial borders highlights a concerning trend of environmental health inequality. Based on the research findings, it is crucial for ISI manufacturers to prioritize the removal of outdated production capacities and adopt energy-efficient and advanced techniques, along with ultra-low emission technologies. This is particularly important for those manufacturers with substantial environmental footprints. These transformative actions are essential in mitigating the environmental and health impacts in the affected regions.