Urban planning policy and clean energy development Harmony- evidence from smart city pilot policy in China

Does tourism development become an accelerator of low-carbon transition? The moderating role of digital economy and green finance

In the context of global efforts to curb CO2 emissions, identifying new drivers of low-carbon transition has become a pressing task for countries worldwide. However, whether tourism development acts as a catalyst for this transition remains unclear. To address this gap, our study adopted carbon emission efficiency as an indicator to better capture the dynamics of the low-carbon transition. Employing a dynamic SYS-GMM model, this study explored the potential inverted U-shaped relationship between tourism development and low-carbon transition. Moreover, recognizing the growing influence of the digital economy and green finance in fostering sustainable tourism, this study further examined their moderating effects. The results indicate that tourism development initially promotes low-carbon transition, whereas its effect diminishes beyond a certain threshold, following an inverted U-shaped pattern. While both digital economy and green finance amplify the positive impact of tourism development, the digital economy also exacerbates negative externalities. In contrast, green finance plays a mitigating role.

Does smart city construction promote urban green development? Evidence from a double machine learning model

The issue of whether smart city construction (SCC) can promote urban green development (UGD) is controversial. To address this problem, first, a UGD evaluation index system with four dimensions, namely, green production, green living, green growth, and green ecology, is developed in this study to measure the UGD level. Second, the causal relationship between SCC and UGD is examined by using a double machine learning model. Last, the influence mechanism of SCC on UGD is investigated in terms of industrial upgrading, resource allocation, information support, and technological innovation. Panel data from 282 Chinese prefecture-level cities from 2011 to 2021 are used in this study, and several valuable conclusions are drawn. First, the UGD level of the Chinese cities shows an upward trend. Second, SCC can substantially promote UGD and has a positive effect on the green production, green living, and green growth of the Chinese cities. Third, SCC can promote the UGD of the Chinese cities through industrial upgrading, resource allocation, information support, and technological innovation. Last, the effect of SCC on UGD in the Chinese cities displays regional heterogeneity.

Can urban digital intelligence transformation promote corporate green innovation? Evidence from China

Can urban digital intelligence transformation (DIT) facilitate corporate green innovation (CGI)? This research uses the staggered difference-in-differences (DID) approach to study how urban DIT, represented by the Artificial Intelligence Innovation Development Pilot Zones (AIIDPZs), affects CGI. Regression results indicate that urban DIT promotes both the quantity and quality of CGI. Mechanisms analysis reveals that urban DIT promotes CGI by facilitating digital transformation, increasing firms' investment in R&D, and facilitating information sharing. Heterogeneity analysis shows that urban DIT has a more significant effect on promoting green innovation in non-SOEs, industries with lower pollution levels, and enterprises in regions with high intellectual property protection (IPP). This study offers new perspectives on the role of urn promoting green development and provides empirical support for policy-making.

How to improve drought resilience to guarantee regional sustainable development

Drought is a pressing environmental issue with profound socio-economic impacts. Frequent drought disasters around the world have brought huge impacts and challenges, severely constraining the sustainable development of cities. How to improve drought resilience to guarantee regional sustainable development has become a hot research topic. In this study, we developed a comprehensive framework to assess drought resilience in China, analyzing its spatiotemporal evolution characteristics, uncovering the underlying impact mechanisms, and projecting future resilience trends across different regions of the country. Over the past 12 years, the average drought resilience level in China has risen by 14.4 %. Central and eastern coastal provinces demonstrated higher resilience levels, contrasting with the western inland regions' lower resilience. A significant positive spatial correlation was observed in China's drought resilience, with high-value clusters emerging in the southeastern and northeastern regions. Among the sub-resilience dimensions, social resilience had the most substantial impact. The prediction model suggests that the drought resilience level will increase modestly by 6.2 % across provinces, maintaining the spatial pattern of higher resilience in the eastern coastal areas and the southern and northern extremities, with lower resilience in the central region. Our findings underscore the significance of understanding regional variations in drought resilience to inform targeted and efficient policy interventions.

Unveiling the power of unity: A novel examination of regional cooperation in mitigating air pollution

Amidst escalating environmental concerns, regional cooperation has emerged as a potent strategy for environmental preservation. Yet, the potency of such cooperation in curbing air pollution remains largely unexplored and nebulous. Drawing upon a decade-long (2010-2019) new data from the dynamic Guangdong-Hong Kong-Macao Greater Bay Area (GBA), this study seeks to fill these knowledge gaps. Our findings underscore the transformative potential of regional cooperation in mitigating air pollution. By catalyzing technological advancements, fostering structural shifts in businesses, and reshaping land-use patterns, regional cooperation paves the way for a cleaner, healthier environment. A deeper dive into the heterogeneity reveals that "top to bottom" city agreements within regional cooperation frameworks significantly enhance air quality. While institutional and economic collaborations prove instrumental in reducing air pollution, social cooperation appears to have a lesser impact. Research findings indicate that the future will necessitate strengthening formal, institutionalized regional cooperation to address potential challenges posed by environmental pollution.

Does digital infrastructure construction impact urban carbon emission reduction? Evidence from China's smart city construction

As the cornerstone of the digital economy, the construction of digital infrastructure plays a crucial role in promoting China's high-quality economic growth.. Against the backdrop of the "dual-carbon" goals, the development of digital infrastructure will provide new momentum for carbon emissions reduction in urban areas. This study utilizes unbalanced panel data from 277 prefecture-level cities in China between 2008 and 2019, treating the smart city construction as a quasi-natural experiment, to systematically evaluate the impact of the pilot construction of smart city on urban carbon emissions intensity. The research findings reveal that the construction of the smart city has significantly contributed to the reduction of urban carbon emissions intensity, indicating that digital infrastructure contributes to urban carbon emission reduction. The reduction of carbon emissions resulting from smart city construction is particularly significant in the East and Central regions., as well as regions with high financial development levels, regions with high human capital levels and non resource-based cities. The construction of the smart city primarily achieves the reduction of urban carbon emissions intensity through two main pathways: improving the penetration rate of digital infrastructure and enhancing technological innovation capability. Therefore, this study recommends that local governments strengthen the integration and penetration of digital infrastructure with traditional industries, foster urban innovation vitality, and accelerate the transformation towards green and low-carbon cities.

Role of scientific and technological innovations on industrial upgradation in China: A spatial econometric analysis

China is in a phase of high-quality development, where scientific and technological innovations are serving as the primary driving force for its development strategy. This emphasis on innovations is expected to fuel the upgrading of the industrial structure. This study investigates the role of scientific and technological innovations in industrial upgradation in China using spatial econometric analysis. Leveraging the data of 31 provinces of China from 2005 to 2022, we employed a spatial Durbin model to determine the spatial spillover effects of scientific and technological innovations on industrial upgradation. Our findings reveal the significant positive spatial spillover effects, indicating that provinces with higher levels of scientific and technological innovations tend to experience greater industrial upgradation, which in turn contributes to regional economic development. Furthermore, the findings suggest a strong spatial correlation between innovation and the upgrading of industrial structures, indicating that regional innovations have the potential to drive China's industrial upgradation. These results underscore the critical role of scientific and technological innovations in promoting industrial upgradation and regional development in China.

Transportation infrastructure upgrading and green development efficiency: Empirical analysis with double machine learning method

In order to deal with the environmental problems such as pollution emissions and climate change, sustainable development in the field of transportation has gradually become a hot topic to all sectors of society. In addition, promoting the green and low-carbon transformation of China's transportation is also an important issue in the new era. Thus, it is particularly important to correctly identify the green effect of high-speed rail. However, the traditional causal reasoning model faces several challenges such as 'dimensional curse' and multicollinearity. Based on the panel data of 283 prefecture-level cities in China from 2003 to 2019, this study uses the double machine learning model to explore the impact of transportation infrastructure upgrading on the efficiency of urban green development in China. The research shows that the upgrading of transportation infrastructure can effectively improve the efficiency of urban green development by 4%. Service industry agglomeration and green innovation are verified as two mediating channels. Moreover, the synthetic difference in difference model is employed to evaluate the regional impact of high-speed rail, and finds that the regional impact of transportation policies often exceeds the impact of individual cities. We further apply the conclusions of this paper to the research at the micro enterprise level. Goodman-Bacon decomposition and a variety of robustness tests confirm the validity of our conclusions. The study's comprehensive empirical analysis not only validates the positive effects of transportation upgrades on green development, but also offers novel insights into the underlying mechanisms and policy implications of transportation upgrading.

Promoting sustainable development: Revisiting digital economy agglomeration and inclusive green growth through two-tier stochastic frontier model

In the global wave of digitization, digital economic agglomeration, as an emerging model, profoundly impacts the economy, environment, and society. Countries worldwide are formulating strategies and policies to promote the development of digital economic agglomeration, yet they also face challenges of widening digital divide and environmental sustainability. Existing research primarily focuses on the positive effects of the digital economy, with limited assessment of the dual effects of digital economic agglomeration on sustainable development. This study utilizes panel data from 282 Chinese cities between 2011 and 2021, employing a two-tier stochastic frontier model. It reexamines the dual impacts and intrinsic mechanisms of digital economic agglomeration, attempting to capture regional and temporal variations in the dual effects to address this research gap. The study shows that: (1) The positive effect of digital economy agglomeration is much more than the negative effect, resulting in a positive net effect that shows an overall increasing trend with significant regional disparities. (2) Digital economic agglomeration has a significant negative spatial spillover effect, promoting local inclusive green growth while inhibiting inclusive green growth in neighboring cities. (3) Regarding the mediating mechanisms, industrial structure, technological innovation and resource allocation efficiency have positive indirect effects on inclusive green growth, while environmental regulation intensity has a negative indirect effect, and it has a nonlinear effect under the threshold constraint of the mediating mechanisms. This study provides policy insights for promoting inclusive green growth, emphasizing the need to consider regional differences in resource distribution, ecological environment, and social demands. It advocates for the organic integration of the digital economy across different regions, reducing polarization effects, and enhancing diffusion effects.

Sustainable digital transformation path for manufacturing outwards foreign direct investment firms: Gradual or leapfrogging

Digital transformation plays an important role in improving the efficiency of production of enterprises and can provide strong support for green and sustainable development. Compared with domestic enterprises, outward foreign direct investment (OFDI) enterprises have greater access to advanced digital technology. This paper aims to analyze the path selection of green and sustainable production for the digital transformation of manufacturing outward foreign direct investment (OFDI) companies, whether gradual or leapfrogging. However, there is a lack of systemic game mechanisms and numerical simulation methods for heterogeneous enterprises. Based on the analysis of reverse technology spillover intensity of outward foreign direct investment (OFDI) and differences in the absorptive capacity of enterprises, we have proposed the evolutionary game model for different path selection of digital transformation of manufacturing enterprises, due to heterogeneous enterprises under different spillover degrees with numerical analysis methods. The research results show that: (i) Under low reverse technology spillover intensity, all enterprises evolve to a gradual transformation path, and enterprises with weaker absorptive capacity converge faster; (ii) There is a certain threshold for reverse technology spillover. When reverse technology spillover intensity exceeds the threshold, enterprises with stronger absorptive capacity converge to a leapfrog transformation path, but enterprises with weak absorptive capacity converge to a gradual transformation path; (iii) With high reverse technology spillover intensity, all enterprises evolve toward a leapfrog transformation path, and faster convergence happens to enterprises with higher absorptive capacity. The evolutionary game path of digital transformation in manufacturing enterprises is illustrated in Fig. 1.

Obscuring effect of income inequality and moderating role of financial literacy in the relationship between digital finance and China's household carbon emissions

Households have emerged as one of the primary sources for carbon emissions in China, thus posing challenges to the "dual carbon" objectives. Digital finance, an emergent form of industry that fused advanced technology with financial services, had a pronounced impact on household carbon emissions stemming from daily consumption. However, the mechanisms driving this impact have not been adequately examined. Based on micro-level household survey data across 25 Chinese provinces from 2012, 2014, 2016, and 2018, the study identified the chief channels via which digital finance affected household carbon emissions, deriving several key findings. First, digital finance augmented household carbon emissions, presenting a significant negative impact on the climate. Second, due to the existence of "digital divide" between rural and urban areas, the impact of digital finance was more subdued in rural areas. Additionally, the effects of digital finance were more pronounced in the affluent eastern provinces. Third, income mobility obscured the positive relationship between digital finance and household carbon emissions. This is primarily attributed to the urban-rural divide in China; taking into account that urban-to-rural transfers make income distribution more equitable, there is a counterintuitive drop in per capita consumption, thereby suppressing consumption-related carbon emissions. This presented the conundrum of "income distribution equality-consumption negativity". Finally, financial literacy was identified as a crucial positive moderating role, enabling households with high financial literacy to harness the dividends of digital finance, thereby engaging in more diversified consumption activities and intensifying the negative impact of digital finance on carbon emissions. The findings reinforced the pivotal role of digital finance in bolstering efforts to combat climate change and ensuring environmentally-responsible economic advancements.

Regulation of microclimate and shading effects of microalgal photobioreactors on rooftops: Microalgae as a promising emergent for green roof technology

Urban areas remarkably affect global public health due to their emissions of greenhouse gases and poor air quality. Although urban areas only cover 2% of the Earth's surface, they are responsible for 80% of greenhouse gas emissions. Dense buildings limit vegetation, leading to increased air pollution and disruption of the local and regional carbon cycle. The substitution of urban gray roofs with microalgal green roofs has the potential to improve the carbon cycle by sequestering CO2 from the atmosphere. Microalgae can fix 15-50 times more CO2 than other types of vegetation. Advanced microalgal-based green roof technology may significantly accelerate the reduction of atmospheric CO2 in a more effective way. Microalgal green roofs also enhance air quality, oxygen production, acoustic isolation, sunlight absorption, and biomass production. This endeavor yields the advantage of simultaneously generating protein, lipids, vitamins, and a spectrum of valuable bioactive compounds, including astaxanthin, carotenoids, polysaccharides, and phycocyanin, thus contributing to a green economy. The primary focus of the current work is on analyzing the ecological advantages and CO2 bio-fixation efficiency attained through microalgal cultivation on urban rooftops. This study also briefly examines the idea of green roofs, clarifies the ecological benefits associated with them, discusses the practice of growing microalgae on rooftops, identifies the difficulties involved, and the positive aspects of this novel strategy.

The mechanism of China's renewable energy utilization impact on carbon emission intensity: Evidence from the perspective of intermediary transmission

Renewable energy (RE) plays a crucial role in global energy transformation, and a thorough study of the potential impact of RE on regional carbon emissions is of great significance. This is particularly relevant to China, which needs to clarify its path to carbon reduction. Using the sample data of 30 provinces in China from 2000 to 2021, this paper uses the Granger causality test to verify the causal relationship between carbon emission intensity (CEI) and other factors. It builds a mediation effect model on this basis to explore the direct impact effect and indirect transmission path of renewable energy utilization (REU) on CEI. The results show that REU has a one-way causal relationship with CEI. REU can directly and indirectly reduce CEI by improving social wealth and changing the direction of energy investment. In addition, REU indirectly increases CEI through the transmission paths of investment in the energy industry - social affluence and industrial level-social affluence. The CEI is indirectly reduced through the conduction paths of (social affluence-Urbanization rate), (Investment in the energy industry-Urbanization rate), (Industrial level-Urbanization rate), and (Industrial level-Investment in the energy industry). These conclusions will assist policymakers in exploring targeted pathways for low-carbon power development, providing a reference for strategic and sustainable carbon reduction policies.

Evaluating the synergistic effect of digitalization and industrialization on total factor carbon emission performance

Combating climate change and reducing carbon dioxide emissions are serious challenges shared by countries around the world. In the current era, digitalization has a significant impact on CO2 emissions. However, prior studies have not assessed the synergy between digitalization and industrialization on carbon emission performance. The principal component analysis and non-radial directional distance function (NDDF) are used to measure the digitalization and total factor carbon emission performance of Chinese 245 prefecture-level cities from 2003 to 2019. This study establishes a fixed effects model to study the panel data. The findings are as follows: (1) Digitalization can significantly promote Chinese cities' CO2 emission reduction. This result still holds after several robustness checks. (2) The heterogeneity results indicate that digitalization mainly improves central cities' carbon emission performance. Meanwhile, the impact of digitalization is more obvious after 2011. (3) Digitalization improves urban carbon emission performance through energy efficiency, industrial transformation, and technological innovation. (4) It is worth noting that digitalization synergizes with industrialization to improve carbon emission performance in Chinese cities. This study provides empirical evidence and some constructive policy recommendations for the government to push the collaborative development of the digitalization and low-carbon economy.

Experimental Study on Gas-Solid Two-Phase Flow Characteristics of a Vertical Cyclone Combustor System

According to the design and operational parameters of the cyclone liquid slag-discharging boiler, an experimental platform for the cyclone burner was designed and constructed in a cold state based on the principle of similarity. The experimental study investigated the effects of parameters, such as swirl-vane angles, coal concentration, operating parameters, and particle size, on the flow distribution and vertical riser resistance characteristics of the vertical cyclone burner. The results showed that there were differences in flow distribution among the cyclone burners, and the most uniform flow distribution was achieved when the swirl-vane angle of the primary air was 30°. The concentration of pulverized coal significantly influenced the pressure drop in the vertical ascending section, which increased with higher concentrations of pulverized coal. When the concentration of pulverized coal remains constant, the pipeline pressure drop is minimized at a primary air velocity of 7.5 m/s. As the secondary wind speed increased, the pressure drop consistently rose; when the secondary wind speed is 22 m/s, the pressure drop of the pipeline is the maximum; however, excessively high secondary wind speeds were found to be detrimental to the formation of an optimal aerodynamic field in the burner. Furthermore, when the pulverized coal concentration was held constant, materials with larger particle sizes exhibited the highest pressure drop. When the particle size increases from 50 to 150 μm, the pressure drop of the vertical riser segment also increases. Finally, based on the Barth additional pressure drop theory, the pressure drop formula of the vertical riser is fitted by a dimensional analysis method, and the correlation formula of the pressure drop test of gas-solid two-phase flow in the vertical riser is obtained.

Plants' emission behaviors under dual control of pollutant concentration and quantity

Quantity-based and concentration-based limits are two common environmental permitting approaches utilized by government worldwide in environmental management. While existing literature is still unambiguous about roles played by quantity-based versus concentration-based limits in environmental management, it becomes evident that relying exclusively on concentration-based or quantity-based limits to control plant emissions may not necessarily result in improved environmental quality. This paper leverages a unique opportunity arising from a recent reform in China's Pollutant Emission Permit System (PEPS) initiated in 2016 to analyze how the introduction of quantity-based limits in addition to concentration-based limits through the PEPS reform impact emissions at the plant level. Utilizing a unique plant-level continuous emission monitoring system data collected from Shaanxi Province (located in western China), the paper finds a significant reduction in air pollutant emissions as a result of the PEPS reform (nitrogen oxides (NOx) by 39%, sulfur dioxide (SO2) by 15% and particulate matter (PM) by 13%). The heterogeneity analyses show emission reductions in plants differ across those with varying quantity limits specified in their permits, distinct emission ratios and diverse ownership structures. Furthermore, plants that fall under the classified management system with more stringent regulations imposed, especially those operating in high-pollution sectors, situated within industrial parks, or classified as large-sized plants, attain higher pollutant quantity limits. Findings of the paper carry important implications for effective environmental management, particularly within developing countries, and shed some light on carbon emission reduction policies in China.

Environmental, social, and governance (ESG) performance and financial outcomes: Analyzing the impact of ESG on financial performance

BACKGROUND

Environmental Social Governance (ESG) investment had entered a phase of rapid development in the past few decades as most nations had put forward "carbon neutral" initiatives. ESG would receive more attention from the industry and academia in a global environment full of uncertainties. Companies benefit from the sharing of ESG data by improving their brand image, which attracts funding, lowers financing costs, and increases valuation.

PURPOSE

To explore how ESG drives corporate financial performance. Also, the research examines the interrelation of ESG presentation and corporate presentation.

DESIGN

/methodology/approach: Over an interval of 10 years (2011-2020) using a sample of 3332 listed organizations worldwide. The theory of the research is on the basis of stakeholder and transmitting signal theory and multiple regression and categorized regression were applied with STATA 16.0 software.

RESULTS

The study utilizes a large dataset of 24,076 valid observations, providing robust statistical power for the analysis. The study findings proved that ESG performance is positively interrelated with corporate performance (p < 0.01). According to the findings of the study, at 1% of the level related to significance (p < 0.01), the regression coefficient for ESG is considerably positive. Thus, the influence of ESG rating on corporate performance is significant for large-scale companies and insignificant for small-scale companies. The results demonstrate that the positive impact of ESG rating on corporate financial performance is more pronounced in the high risk case than in the low risk case (p < 0.01). The results highlight the importance of ESG performance in today's world. Overall, the study gives precious perception about the interrelation between ESG and corporate financial performance (CFP).

POLICY IMPLICATIONS

The researchers believe that the results of this study are beneficial to companies and governments in the development of environmentally conscious industries since they demonstrate corporate success through ESG. More realistically, the ESG can boost corporate firm performance by enabling businesses to maintain sustainability, establish a solid reputation, win the trust of stakeholders, and contribute to solving national sustainable development issues. Additionally, the researchers believe that the results of this study can boost management effectiveness, which in turn can help firms succeed.

ORIGINALITY/VALUE

In the context of environmentally sensitive industries, this study findings provide empirical insights to the association between the corporate firms success and ESG performance. In addition, the findings provide insights to the business organizations development and the significance of ESG integration in the business organizations.

Cost-benefits analysis of ultra-low emissions standard on air quality and health impact in thermal power plants in China

As China's largest energy infrastructure, thermal power plant consumed approximately half of China's coal over the past decade and threatened air quality, human health and socioeconomic development. Thus, a series of control policies have been implemented to alleviate those impacts in China. Particularly, China has witnessed unprecedented declines in air pollutant emissions from thermal power plants since the ultra-low emissions (ULE) standards were implemented. In contrast, the effect of the ULE policy on air quality, health and cost benefits remains poorly understood. Therefore, this study estimates the improved air quality and associated health and economic benefits under the ULE standards in the thermal power sector by using a measure-specific approach, combining a bottom-up emission inventory, an atmospheric model, a health assessment model and a cost analysis model. The results show that all the control measures lead to reduced air pollution, and renovating pre-existing units (RPU) is the most effective. Compared to without implementing the ULE policy, the population-weighted average PM2.5 and O3 concentrations decreased by 1.50 μg/m3 and 0.87 ppm, and 67,831 premature deaths could be avoided nationally. Furthermore, the results also show the net economic benefits of combining health benefits and costs due to control measures are 109.92 billion Yuan (in 2015 value) in China. The comprehensive results reveal that the health benefits outweigh the direct policy. Based on these empirical findings and the specific circumstances of China, we suggest that RPU should be further promoted to the entire of China, and if necessary, establish a long-term compensation mechanism for inter-provincial interests and institute and enforce comprehensive policies that carefully consider the health impacts of policies. This study provides strong arguments for China's policy-making and considering tightening emission standards for thermal power plants worldwide.

Linking tourist's footprint and environmental tragedy through transportation, globalization and energy choice in BIMSTEC region: Directions for a sustainable solution using novel GMM-PVAR approach

The rising temperature in the world's atmosphere is an outcome strongly linked to man-made manufactured interventions. Recreational activities in the form of tourism are such interventions that can unleash multidimensional negative externalities if not regulated properly. The Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) region has become one of the major hubs for recreational activities in the last few decades. However, the region's tourism-led environmental degradation has received scant attention in the literature. As such, this paper unveils how tourist footprint affects the region's environmental sustainability and explores potential solutions to encourage the tourism industry to be more pro-environmental. We have used the novel GMM-PVAR technique to assess how globalization, transportation, green energy, and economic growth have affected the tourism industry and carbon footprint in the BIMSTEC region from 1990 to 2019. We lean on the empirical outcomes to propose regional sustainable tourism development policies. The GMM-PVAR model indicates that renewable energy, economic growth, and the transportation sector's development positively affect the tourism industry's growth in the region. However, globalization and environmental degradation negatively influence tourists' arrival. Contrarily, transportation services, economic growth, and tourism boost the carbon footprint in the region. Although globalization and clean energy reduce carbon footprint, these indicators are insignificant, indicating that this region is still lagging in renewable energy generation and failed to reap the positive spillovers of globalization. Based on these outcomes, we propose that the region redesign its tourism industry to encourage eco-friendly tourism by leaning more on pro-environmental strategies (i.e., powering the tourism industry through the penetration of renewable energies) and tightening environmental regulations.

How do carbon trading price and carbon tax rate affect power project portfolio investment and carbon emission: An analysis based on uncertainty theory

Responding to the social, economic, and environmental call to resolve current sustainability challenges, the concern about carbon dioxide emission reduction should be incorporated into the power investment decision process. Reflecting the low carbon emission requirement, this paper proposes a new optimization model for power project portfolio selection that simultaneously considers both of carbon emission trading scheme and carbon tax imposition. In this model, the initial investment outlay, the power sale price, the carbon trading price, and carbon tax rate are treated as uncertain variables considering the fast-changing environment and complex market situation. Incorporating the constraint on whether the carbon quota is exceeded into the model, two investment strategies are proposed for investors. Using the proposed model, the impact of the rises in carbon trading price and carbon tax rate on the investor's investment strategy selection and the carbon emission is simulated and analyzed through a case study. When the expected carbon price is 203.50 RMB/tCO2-eq or less, a company should invest based on the strategy that annual emissions exceed the quota to obtain a maximum expected NPV which is larger than 408588 million RMB. When future carbon prices are 352.00, 500.50 and 649.00 RMB/tCO2-eq, the government should impose carbon tax rates of 30, 30, and 40 RMB/tCO2 on a power company, respectively, to obtain carbon emission reduction effect. At last, to see the contrast effect of the results from simultaneous implementation of both carbon trading and carbon tax, the results considering the carbon trading alone or carbon tax alone are discussed, respectively.

A review of applied research on low-carbon urban design: based on scientific knowledge mapping

The construction of low-carbon cities is an essential component of sustainable urban development. However, there is a lack of a comprehensive low-carbon city design and evaluation system that incorporates "carbon sink accounting-remote sensing monitoring-numerical modelling-design and application" in an all-around linkage, multi-scale coupling, and localized effects. This paper utilizes the Citespace tool to evaluate low-carbon city design applications by analyzing literature in the Web of Science (WOS) core collection database. The results reveal that low-carbon cities undergo four stages: "measurement-implementation-regulation - management." The research themes are divided into three core clustering evolutionary pathways: "extension of carbon sink functions," "spatialisation of carbon sink systems," and "full-cycle, full-dimensional decarbonisation." Applications include "Utility studies of multi-scale carbon sink assessments," "Correlation analysis of carbon sink influencing factors," "Predictive characterisation of multiple planning scenarios," and "Spatial planning applications of urban sink enhancement." Future low-carbon city construction should incorporate intelligent algorithm technology in real-time to provide a strong design basis for multi-scale urban spatial design with the features of "high-precision accounting, full-cycle assessment and low-energy concept."

Differences in carbon emissions between the digital economy sectors in China and the USA

In an era of rapid development of digital technologies and dramatic global climate change, digital economy is crucial to achieving the 'carbon peak' and 'carbon neutral' goals. However, less research has been done in the area of indirect carbon emissions in the digital economy sector. Therefore, this study uses an input-output model to calculate the embodied carbon emissions of the ICT (information and communication technology) industry in China and the USA in 2005, 2010 and 2016 from the production and consumption sides. Moreover, a comparative analysis is conducted in terms of the driving factors of carbon emissions and the relationship between emissions and economic benefits in the two countries. The results reveal that emissions are larger on the production side in the USA and on the consumption side in China. For both countries, electricity is the largest upstream sector in terms of emissions. ICT in the USA causes sectoral emissions mainly in manufacturing and services. While China mainly causes sectoral emissions in manufacturing. The US ICT sector is more economically efficient for the same emissions. Regarding drivers, the primary driver of the fall in emissions is a reduction in emission intensity. The increase in emissions driven by final demand is greater in China than in the USA. Finally, the results of the two countries are extended to other developed countries and emerging economies, providing recommendations for reducing carbon emissions in the ICT sector.

The impact of green taxes on green innovation of enterprises: a quasi-natural experiment based on the levy of environmental protection taxes

Green innovation is a strategic choice for Chinese enterprises to achieve in balancing economic performance and environmental benefits. Environmental protection tax (EPT) is the first green tax in China. How to fully leverage the institutional dividends of environmental tax reform to achieve green innovation in enterprises is of great significance for the high-quality development of China's current economy. This study takes the levy of environmental protection taxes as the quasi-natural experiment and uses DID, DDD, PSM-DID and so on to verify the impact of EPT on green innovation. The results show that EPT can improve green innovation through the path of legitimacy pressure and legitimacy management. Notably, the effects are more obvious in enterprises with non-state-owned, low-financing constraints and located in the eastern region. Furthermore, green innovations under the push of environmental protection tax can improve long-term performance, while it has a negative effect on short-term performance. The levy of EPT has the dual dividend effect of economy and environment. Moreover, this study explores the source of the legitimacy pressure and the strategic response of enterprises and provides guidance for government's precise implementation of policies to optimize the role of EPT in green innovation.

Differential impacts of vaccine scandal by ethnic and socioeconomic factors: Evidence from China

Widespread vaccination against important diseases plays a key role for global health security, particularly in the context of the COVID-19 pandemic. However, building and maintaining trust in immunization services remains challenging because of doubts about quality and safety of vaccines. China has periodically faced mounting pressure and even public outrage triggered by incidents of poor-quality vaccines. We aimed to evaluate the impact of the diphtheria, pertussis, and tetanus (DPT) vaccine scandal of 2018 in China and the ensuing misinformation on vaccination, and investigate differential responses to the scandal by ethnic and socioeconomic factors. With data from January 2017 to December 2018 in Sichuan province, China, we used a difference-in-differences (DID) method to compare the changes in the county-level monthly DPT vaccinations against the hepatitis B vaccinations, both before and after the DPT vaccine scandal. We found that the number of DPT vaccinations decreased by 14.0 percent in response to the vaccine scandal and ensuing misinformation. The number of vaccinations in minority regions, under-developed regions, and regions with poor medical resources decreased more than in non-minority regions, developed regions, and regions with good medical resources (24.5 versus 10.1 percent, 17.3 versus 8.3 percent, and 17.0 versus 8.7 percent, respectively). People did more online searching for "Substandard vaccine" and "DPT vaccine" after the scandal, with the socioeconomically advantaged group searching more compared with the socioeconomically disadvantaged group. The results suggest the urgent need to make true information about the vaccine easily accessible over the internet, especially for the socioeconomically disadvantaged groups. Our findings for China can also have implications for immunization service planning for better safeguarding public health in other countries, particularly developing ones.