Transport infrastructure, economic growth, and transport CO2 emissions nexus: Does green energy consumption in the transport sector matter?

The moderating role of environment-related technologies in the link between transportation infrastructure, agricultural, and environmental contamination in highly congested countries of the world

Densely populated countries have greater demand for agricultural output, greater vehicle usage, and busier traffic, so these countries devote more agricultural land to agricultural production and invest more in transportation infrastructure, resulting in higher environmental emissions. Most studies in literature assume that environment-related technologies directly diminish environmental contamination, while this study suggests that environment-related technologies indirectly mitigate environmental hazards through interactions with agricultural land use, agricultural value addition, and transportation infrastructure. Thus, this study determines to disclose the influence of agricultural land use, agricultural value added, and transportation infrastructure investment on ecological damage in countries with the highest population density during the period 1990-2022; and the sole moderating effect of environment-related technologies in the association of the proposed regressors with CO2 emissions. Results illustrate that agricultural land use and investment in transportation infrastructure contribute significantly to CO2 emissions, but only in the long term. However, agriculture value addition strongly promotes environmental contamination in both the short and long term. Furthermore, in the long run, the reversed U-designed EKC premise holds only for the top five most populous countries. Environmental contamination can be mitigated through environmentally relevant technologies when interacting with agriculture land use, value addition of agricultural and investment in transportation infrastructure. Finally, (>-1.115) is the estimated threshold level of environment-related technologies, at which agricultural land use, agricultural value added, and transportation infrastructure can significantly improve environmental quality. Policymakers in densely populated countries should prioritize the adoption of environmentally friendly technologies in agriculture and transportation to achieve environmental sustainability.

Dynamic relationships between environment-related technologies, agricultural value added, transport infrastructure and environmental emissions in the five most populous countries

Densely populated countries have higher demand for agricultural products and greater use of fuel and vehicles, resulting in higher environmental emissions, so this study considers transportation infrastructure and the agricultural sector as the two major drivers of environmental degradation in the top five densely populated countries. In a baseline regression, this study first unveils the impact of investments in transportation infrastructure, agricultural value addition, and environment-related technologies on per capita CO2 emissions using CS-ARDL approach from 1990 to 2021 in the five most populous countries. Besides, this study also reveals the typical moderating effect of environment-related technologies in the link between transport infrastructure, agricultural value added and environmental hazards. The results of the baseline model indicate that transport infrastructure and agricultural value added can substantially contribute to per capita carbon emissions in both the short and long term. However, environment-related technologies significantly reduce environmental emissions in both the short and long term. Per capita GDP extensively promotes per capita carbon dioxide emissions, while per capita GDP2 substantially reduces per capita carbon dioxide emissions in the long term rather than the short term, thus authenticating the inverted U-shaped EKC hypothesis for the top five countries with the highest population density. The moderating effect of environment-related technologies shows that the application of environment-related technologies in both transportation and agriculture can alleviate environmental pollution. Finally, the threshold level of environment-related technologies shows that as environment-related technologies move from lower threshold levels (≤ - 1.05) to higher threshold levels (> -1.05), agricultural value added and transportation infrastructure investment significantly improve the reduction of environmental contamination. The goal of environmental sustainability can be ensured by the adoption of environment-related technologies in agriculture and transportation sectors.

Evolutionary game analysis of carbon emission reduction in transportation infrastructure construction under dual regulation

Under the dual regulation of government intervention and environmental constraints, user demand, low-carbon awareness, and the willingness of construction enterprise to reduce carbon emissions are crucial to the realization of low-carbon transportation infrastructure construction. Basing on prospect theory, this paper constructs an evolutionary game model for the government, construction enterprise, and user, explores the stabilization of the three-game players' strategy choices, and discusses the influence of key parameters on the behavior evolution of relevant players through simulation analysis. The results indicate that: the regulatory cost when the government adopts incentives or no incentives is an important factor affecting the strategy choice. The enhancement of incentives by the government can promote the construction of enterprise and the selection of low-carbon transportation infrastructure by user. However, when the benefit of government credibility outweighs the incremental cost of household subsidies, carbon subsidies, and regulation, the government changes its strategy and no longer adopts encouraging strategy. Improving benefits of build low-carbon transportation infrastructure reducing incremental costs, setting a ladder carbon tax rate, increasing carbon tax rate for traditional construction, and decreasing for low-carbon construction is an effective approach to stimulate enterprise to construct low-carbon transportation infrastructure. The user's choice of low-carbon transportation infrastructure strategy is positively correlated with the subsidy received and is less affected by environmental benefits. And the construction enterprise's strategy choice hasn't been influenced by user, which is related to the public service characteristics of transportation infrastructure.

Tailoring Cu-Based Electrocatalysts for Enhanced Electrochemical CO2 Reduction to Alcohols: Structure-Selectivity Relationship

The use of CO2 as a feedstock for the production of carbon-based fuels and value-added chemicals offers a promising route toward carbon neutrality. In this study, two Cu-based electrocatalysts, namely, Cu24/N-C and Cu2/N-C, are successfully prepared by thermal treatment of Cu24 metal-organic polyhedron-loaded zeolitic imidazolate framework-8 (ZIF-8) nanocrystals (Cu24/ZIF-8) and Cu2 dinuclear compound-loaded ZIF-8 nanocrystals (Cu2/ZIF-8), respectively. Extensive structural and compositional analyses were conducted to confirm the formation of Cu nanocluster-loaded N-doped porous carbon supports in both Cu24/N-C and Cu2/N-C and Cu nanoparticles encapsulated by graphitic carbons in Cu2/N-C as well. These two Cu-based electrocatalysts exhibited different behaviors in the electrochemical CO2 reduction reaction (CO2RR). The Cu24/N-C electrocatalyst showed high selectivity for CO production, while Cu2/N-C showed a preference for alcohol generation. The excellent stability of Cu2/N-C over a 30 h continuous electrochemical reduction further highlights its potential for practical applications. The difference in electrocatalytic performance observed in the two catalysts for CO2RR was attributed to distinct catalytic sites associated with Cu nanoclusters and nanoparticles. This research reveals the significance of their structures and compositions for the development of highly selective electrocatalysts for CO2 reduction.

Will advancement in technologies bring fear and damage human employment? Evidence from China's manufacturing industry

Advancement in technologies such as robotic industries and artificial intelligence bring fear among human being that jobs will be substituted by robots. Base on the panel data of 28 China's manufacturing industries, this research analyzed the impact of technical progress bias on employment. First, we calculate the technical progress bias index of 28 industries base on the stochastic frontier model with transcendental logarithm function found 16 industries were toward the skilled labor while the remaining 12 industries were toward the unskilled labor. Second, the empirical results show that technical progress bias has a positive impact on the total manufacturing employment and significant positive effect on the unskilled labor, while no significant impact on skilled labor employment. Third, the threshold effect test proves that if taking industry value-added per capita or R&D capital stock as threshold variable, the threshold about the impact exist, making the impact on skilled labor was insignificant.

Does foreign direct investment influence carbon emission-related environmental problems? Contextual evidence from developing countries across Sub-Saharan Africa

Sub-Saharan African nations face multifaceted environmental problems, especially those associated with carbon discharges. Hence, this study calculates a composite carbon index in the context of 39 developing nations from this region and uses it as a proxy for the carbon emission-related environmental problems they have faced during the 2000-2020 period. This index is estimated by utilizing data regarding annual carbon dioxide discharges, output-based carbon productivity rates, and energy consumption-based carbon intensity levels in the concerned countries. Hence, policy takeaways from this study have critical relevance for the selected sub-Saharan African nations to help them achieve the objectives related to the Sustainable Development Goals agenda and the Paris Accord. Overall, the findings from the econometric analyses verify that more receipt of foreign direct investment initially raises but later on reduces environmental problems. Thus, the nexus concerning these variables depicts an inverse U-shape. Besides, the results endorse that greening the energy consumption structures of the sampled sub-Saharan African countries helps to abate their environmental problems in the long run while financial development aggravates the extent of environmental adversities that take place. Lastly, improving the quality of regulatory agencies enables the Sub-Saharan African nations to further mitigate their environmental problems. Moreover, these aforementioned findings are observed to be heterogeneous across low- and middle-income categories of the selected Sub-Saharan African countries. Furthermore, the heterogeneity of the findings is also confirmed by the outcomes derived from the country-specific analyses. Nevertheless, these nations should attract clean energy-embodying foreign direct investment, make their energy consumption structures greener by amplifying renewable energy adoption rates, introduce green funds to develop their financial sectors, and make their environmental regulatory agencies more transparent with their activities.

The existence of environmental Kuznets curve: Critical look and future implications for environmental management

Against the backdrop of the great challenge of climate change and growing global environmental concerns, this study deals a systematic literature review of research related to Environmental Kuznets Curve (EKC) from 1991 to 2023, details the background, definition, significance, critiques, theoretical foundations and model specifications of EKC, and summarizes the data, variables, econometric methods and findings used in over 100 EKC studies. This study focuses on EKC studies that examine the relationship between energy consumption, economic growth and environmental degradation, with most of the studies reviewed using global pollutants (carbon emissions) to measure the level of environmental degradation. This study found that EKC still has great research potential, and with the development of energy diversification, energy consumption in EKC studies have been further subdivided into renewable or non-renewable energy consumption; innovative EKC studies in the last few years have favoured the use of novel environmental and economic indicators and econometric method, and have validated the existence of EKC at the sectoral level rather than the national level. Finally, the present study summarizes the development and innovations of EKC and provides suggestions for future research aimed at advancing the development of EKC and environmental management.

Industrial agglomeration, FDI, and carbon emissions: new evidence from China's service industry

In the context of economic servitization and low carbonization, the problem of carbon emissions in the service industry is worthy of attention. An essential channel for restraining carbon emissions from the service industry is industrial agglomeration. Based on provincial panel data from 2004 to 2021 in China, this study empirically analyzes the influence of the service industry's agglomeration on its CO2 emissions. The findings indicate that agglomeration significantly reduces the industry's carbon emissions. Next, producer services agglomeration has a significant carbon-reduction effect, whereas non-producer services agglomeration does not. Moreover, service industry agglomeration helps to restrain carbon emissions from the service industry in East China. However, it does not significantly affect carbon emissions in Central or West China. Regarding the moderating effect, foreign direct investment can enhance service industry agglomeration's carbon-reduction effect. Based on the results, relevant policy implications are provided.

The nexus between indicators for sustainable transportation: a systematic literature review

The relationship between indicators for sustainable transportation is a pressing issue that has argued the attention of policymakers, engineers, and academics. The transportation sector plays a crucial role in economic growth, while also having significant environmental consequences. This systematic literature review offers a comprehensive overview of the different research methodologies utilized to estimate the interrelationships between the transport sector, environmental degradation, and economic growth. Our study analyzed 977 citations sourced from Web of Science and SCOPUS, spanning the years 2010 to June 2022. The PRISMA methodology was employed for organizing and identifying articles. After a thorough evaluation, 52 published articles from 25 international journals were selected for further examination. Our findings show that researchers have used a variety of modeling approaches to shed light on this complex issue, with multivariate co-integration techniques, decomposition analysis, and the generalized method of moments being among the most widely used methods in recent years. This review provides perspectives to policymakers and decision-makers, enabling them to create effective energy and environmental strategies for a long-term, sustainable transportation future.

Exposing the environmental impacts of air transportation on the ecological system: empirical evidence from APEC countries

In the trend of globalization, economic and social benefits of air transportation (AIR) are not indisputable. However, AIR's environmental impacts are still a controversial issue. While previous studies had shown that air transportation contributed to air pollution by emitting CO2, lack of studies consider the effects of air transportation on ecological system. Therefore, this study investigates the relationship between air transportation and ecological footprint as well as CO2 emissions in the case of APEC countries, which is leading in the growth rate of air transport activities. Applying regression with Driscoll-Kraay standard errors for a data set from 1992 to 2015, our research provides evidence that: (i) air transportation increases CO2 emissions but this impact is negligible; (ii) air transportation contributes significantly in reducing ecological footprint of APEC countries; and (iii) globalization reduces both CO2 emissions and ecological footprint. In addition, Dumitrescu-Hurlin causality test helps to confirm the bidirectional causality relationship between air transportation and ecological footprint. Meanwhile, unidirectional causality runs from air transportation to carbon emissions. Based on these conclusions, some policy suggestions are given for APEC countries.

Analysis of Carbon Emission Projections and Reduction Potential of Resource-Dependent Urban Agglomerations from the Perspective of Multiple Scenarios-A Case Study of Hu-Bao-O-Yu Urban Agglomeration

The Hu-Bao-O-Yu urban agglomeration is an important energy exporting and high-end chemical base in China, and is an important source of carbon emissions in China. The early achievement of peak carbon emissions in this region is particularly crucial to achieving the national carbon emission reduction targets. However, there is a lack of multi-factor system dynamics analysis of resource-dependent urban agglomerations in Northwest China, as most studies have focused on single or static aspects of developed urban agglomerations. This paper analyses the relationship between carbon emissions and their influencing factors, constructs a carbon emission system dynamics model for the Hu-Bao-O-Yu urban agglomeration, and sets up different single regulation and comprehensive regulation scenarios to simulate and predict the carbon peak time, peak value, and emission reduction potential of each city and urban agglomeration under different scenarios. The results show that: (1) Hohhot and Baotou are expected to reach peak carbon by 2033 and 2031 respectively, under the baseline scenario, while other regions and the urban agglomeration will not be able to reach peak carbon by 2035. (2) Under single regulation scenarios, the effect of factors other than the energy consumption varies across cities, but the energy consumption and environmental protection input are the main factors affecting carbon emissions in the urban agglomeration. (3) A combination of the economic growth, industrial structure, energy policy, environmental protection, and technology investment is the best measure to achieve carbon peaking and enhance the carbon emission reduction in each region as soon as possible. In the future, we need to coordinate the economic development, energy structure optimisation and transformation, low-carbon transformation of industry, strengthen research on carbon sequestration technology, and further increase the investment in environmental protection to make the Hu-Bao-O-Yu urban agglomeration a resource-saving urban agglomeration with an optimal emission reduction.