Nexus Between Financial Development, Renewable Energy Investment, and Sustainable Development: Role of Technical Innovations and Industrial Structure.

Significant challenges confronting China include reducing carbon emissions, dealing with the resulting problems, and meeting various requirements for long-term economic growth. As a result, the shift in industrial structure best reflects how human society utilizes resources and impacts the environment. To meet China's 2050 net-zero emissions target, we look at how technological innovations, financial development, renewable energy investment, population age, and the economic complexity index all play a role in environmental sustainability in China. Analyzing short- and long-term relationships using ARDL bounds testing, we used historical data spanning 1990-2018. According to the study's findings, the cointegration between CO2 emissions and their underlying factors was found. The deterioration of the environment directly results from financial development, increasing economic complexity, and population aging. Technical advancements, investments in renewable energy sources, and changes to the industrial structure all contribute to lower CO2 emissions. Granger causality results were also reliably obtained in this study. According to our findings in the fight against environmental problems, a key tool for meeting long-term sustainability goals is policy prescriptions that use technological innovations, renewable energy investment, and industrial structure.

Introduction

Academics, industry representatives, and policymakers pay growing attention to sustainable development (SD) (Nureen et al., 2022). The discussion on SD has touched on many different topics, but one of the most important is how innovations can help improve sustainability (Majumder et al., 2019). Because both the external environment and the way we live are subject to constant change (see here for more information), innovations are essential components that must be present for businesses, institutions, regions, communities, and countries to implement sustainable practices (Kouhizadeh et al., 2019). The body of academic research agrees that innovative methods should be prioritized when addressing the issue of sustainability (Iqbal et al., 2019). Changes toward a more sustainable world are moving slowly in reality. There are urgent calls for institutions of higher learning and governments to step up their investments and initiatives to find new and creative solutions to our environmental challenges (Huang et al., 2019).

The Brundtland Commission's seminal definition of sustainable growth emphasizes the interdependence between sustainability's financial (Chen et al., 2021; Quan et al., 2021) and environmental aspects. Asikha et al. (2021) suggest that equal consideration should be given to economic, environmental, and communal dimensions when making business and public policy decisions. According to the findings of some studies (Ahmed and Omar, 2019; Adedoyin et al., 2021; Fahria et al., 2021), the discussion of sustainability has expanded beyond the relationship between environmental and economic parameters to include the effects on society as well. Similarly, Chen et al. (2022) acknowledge the need to analyze the complex interactions between all three dimensions. They conclude that the ever-changing nature of sustainability calls for a process of adaptation that requires the active participation of all relevant stakeholders (Geissdoerfer et al., 2018; Deng and Zhao, 2022; Xu et al., 2022). This introductory article and the study contribute to reducing the current knowledge gap in this field. This is because different studies have different definitions of innovation for sustainable development.

China has experienced phenomenal economic growth over the last few decades, thanks to the country's quickening pace of industrialization. China is currently one of the most important manufacturers worldwide. On the other hand, noteworthy economic accomplishments have been accomplished at the expense of the environment and by consuming an excessive amount of energy. Industrial activities account for more than two-thirds of China's total energy consumption, making it the world's major consumer of power and carbon emissions emitter (He X. et al., 2021). Energy efficiency in industrial systems is critical to developing a low-energy, environmentally responsible, and sustainable system.

Major shifts in global energy consumption and industrial structures are taking place as urbanization and industrialization continue to progress and become more advanced (Wu and Zhu, 2021; Lei et al., 2022). The position of Asia as the primary contributor to global energy consumption is shifting (Hou et al., 2019). Changes in energy consumption bring about the improvement of environmental conditions. However, accomplishing this transformation remains challenging due to the difficulty of reorganizing subsidies for the consumption of fossil fuels and supply risks concerning the supply of oil and gas (Falcone et al., 2018). The achievement of long-term reductions in CO2 emissions presents a formidable obstacle. After 3 years of stagnant growth, the world's energy-related carbon dioxide emissions raised by 1.7% in 2017 (Salari et al., 2021). In addition, it is anticipated that they will continue to expand in the coming years, which is a significant departure from the requirements set forth by climate change targets. According to the Fifth Report given by the Intergovernmental Panel on Climate Change (IPCC), greenhouse gases in the atmosphere steadily rise yearly. Since 1750, there has been a 40% increase in the concentration of CO2, which has resulted in levels of CO2 that have never been seen before (Awaworyi Churchill et al., 2020). According to the projections made by the International Energy Agencies, the amount of carbon dioxide released into the atmosphere due to energy use will reach a maximum around the year 2020. However, it is a fact that global carbon emissions, particularly those that result from Asia, will either remain unchanged or even slightly increase by the year 2040. This prediction is based on objective data. In addition, ~95% of the total allowable emissions to meet global climate targets have already been accounted for by current emissions (Xiao et al., 2021). As a result, governments, international organizations, experts, and academics will continue to focus on the issue of carbon emissions and carbon reduction for the foreseeable future. Sustainability at the global and regional levels depends on achieving green ecological development by cutting back on energy use, pollution, and emissions in these areas. Reduced energy use, pollution, and emissions are part of this solution.

One of the most prevalent topics of conversation in contemporary research is the development of new methods for preserving the quality of the environment, cutting carbon dioxide emissions, and raising production levels (Yu et al., 2022). The application of novel concepts constitutes innovation. Product and organizational innovation are distinct subcategories of innovation that can be distinguished from one another (Klarl, 2020). Despite the positive effects of innovation on production growth and cost reduction, it also has a deleterious influence on energy usage and carbon dioxide emission. The most significant benefit that can be reaped from innovation is a cut in carbon dioxide emissions, which can be accomplished without hampering economic expansion (Wang J. et al., 2019). The price of energy can be reduced with the help of recently developed products that use less. To put it another way, increased production can be achieved while maintaining the same level of energy consumption. The topic of energy efficiency is brought to people's attention by research that focuses on how innovation lowers carbon emissions (Ben Cheikh et al., 2021).

The introduction of new technologies has two significant repercussions. The first effect is a reduction in wasted energy. The second effect is that there will be a greater requirement for more energy because the same activity will be carried out using less energy. While reducing carbon emissions and fuel consumption is a top priority, the rebound effect must be properly considered. Blondeau and Mertens (2019) claim that developing countries are particularly susceptible to the problem of a rebound effect. In order to determine if this problem exists in other countries and developing nations, further research must be done.

As a result, the focus of this paper will be on the impact that technological innovations have on the path that technological change takes, and the low-carbon technology will be divided into clean technology and gray technology. Within the scope of this investigation, the following research questions about technological advancements will be posed: (1) Is it possible for TI to develop into a useful tool for guiding technological advancement? (2) Does TI have an effect on economies that produce less carbon? In an effort to answer these questions, this study has contributed to the existing body of research in the four areas listed below, all of which pertain to the association between technological innovation and a sustainable environment. In the first step of this project, we will extend the research that has already been done on technical innovations for low-carbon economies in China. We will answer how this factor can affect the total amount of emissions. This study investigates the link between financial development and sustainable development by using domestic credit to the private sector as a proxy. As a second point, this paper makes new contributions to the existing literature on financial development and sustainable development. Investment in renewable energy sources can cause reductions in carbon emissions; however, which of these two strategies is more effective in bringing down emissions levels? This article attempts to answer the research question does renewable energy investment (REI) reduce carbon emissions? To investigate REI's effect on emissions, we will have a quick conversation about investments in renewable energy. Moreover, to investigate the suggested objectives, this study chose the time period from 1990 to 2018. The data has been selected in recent years due to data availability. Hence this study uses the mentioned time period to deliver its objective. In addition, the ARDL methodology is applied in this study to estimate the concerned objective of the study.

Literature Review

Nexus of Financial Development and Environment Quality

Several studies have observed the link between economic growth and pollution, and what they've found is summarized here. Based on the findings of the studies, empirical literature can be divided into three main subfields (Mutascu, 2018). Carbon emissions have been linked to economic growth in the first section of this discussion. A random-effect model examined financial development in the BRICS countries. When it comes to the stock market, financial openness, the deposit money bank asset-to-GDP ratio, capital account convertibility, financial liberalization, and FDI, researchers found that a decrease in carbon emissions goes hand in hand with a rise in fiscal development. Carbon emissions in 24 transitional economies were studied by You and Lv (2018) using a new random effect model and dynamic GMM. They concluded that freeing the financial system positively affected the environment. Ma et al. (2019) used the cointegration method to observe the carbon emissions of 129 countries. According to their findings, carbon emissions can be reduced by increasing the amount of domestic credit available to the private sector—results from an investigation into the influence of financial development on carbon emissions by Adebayo et al. (2021a) and Ojekemi et al. (2022) were encouraging. Higher loan-to-deposit ratios are linked to lower carbon emissions. In China, the research was conducted.

According to Khan et al. (2019), financial development, specifically domestic credit to the private sector, takes part in reducing carbon emissions in Malaysia. This study's goal was to show that financial growth has a negative effect on carbon dioxide emissions. ARDL was used by Jalalian et al. (2019) to find that financial development, as measured by stock market incomings, total credit, private sector credit, and stock market capitalization, reduced carbon emissions in Pakistan and during the period of financial liberalization. During the time frame under consideration, this was discovered to be true. Liu et al. (2019) used ARDL to study the impact of China's financial development on carbon emissions. Financial development has reduced carbon emissions as measured by the ratio of liquid liabilities and private sector loans to GDP. It was crucial to look at the ratio of private sector loans to GDP to determine whether financial development affected carbon emissions. Financial stability in Pakistan, India, Nepal, and Sri Lanka has been found to improve the environmental quality of these countries, and financial stability unidirectionally causes carbon emissions in these countries. These and other nations are included in the research (Shahbaz and Sinha, 2019; Aydogan and Vardar, 2020).

In addition, Jalalian et al. (2019) used ARDL to investigate the impact of China's financial development on the country's carbon emissions. They concluded that China's financial development has a negative impact on carbon emissions. Zubair et al. (2020) used GMM to examine the influence of financial growth on carbon emissions in China. The investigation showed that the intensity of carbon emissions was reduced when financial development was measured by the ratio of bank loans to GDP, private loans to GDP, and non-private loans to GDP. These ratios were all compared to GDP. Using ARDL, Adams et al. (2020) concluded that domestic credit provided by banks from the private sector to the private sector as part of financial development helps reduce emissions produced by the construction industries in Malaysia. A separate piece of research (Aydogan and Vardar, 2020) investigated the connection between carbon emissions and financial development in Turkey. They concluded that in the short term, at least, financial development leads to lower levels of carbon emissions.

A positive effect of financial development on carbon emissions is reported in the second part of the empirical studies used VECM and ARDL to examine the effects of financial development on carbon emissions in India. They concluded that financial development (credit to the private sector) increases carbon emissions. Aydogan and Vardar (2020) published their findings in Environmental Research and Development Letters. In India, Boutabba (2014) discovered that through the use of ARDL and the Granger causality test, financial development (domestic credit to the private sector) leads to an increase in carbon emissions and a uni-directional causal connection between financial development and carbon emissions. Al-mulali et al. (2015) also examined the effect of China's rapid financial development using the cointegration and causality approach. He discovered that the indicators of rapid financial development are the primary drivers of carbon emissions. According to Nyoka (2019), an increase in financial development—defined as domestic credit extended by banks to the private sector—leads to increased carbon emissions from the transportation, oil, and gas sectors.

Carbon emissions rise when financial depth (the ratio of loans and deposits to GDP) rises, according to a study by Razmjoo et al. (2021) using the system-GMM. The researchers also discovered a U-shaped link between carbon emissions and economic development. Using a system-generalized method of moments, Acheampong (2019) investigated the indirect and direct effects of financial development on carbon emissions for 46 countries in sub-Saharan Africa between 2000 and 2015. The countries in this study were divided into two groups: those with high levels of financial development and those with low levels. According to the study results, financial development, as measured by domestic credit to the private industry, broad money, and domestic credit by banks, all contribute to increased carbon emissions. Carbon emissions aren't affected by foreign direct investment, liquid liabilities, or domestic credit from the financial sector. Although FDI has been found to moderate economic growth, which reduces carbon emissions, it does not moderate power usage, which has no impact on CO2 emissions, according to the study's findings. Contrary to the first three financial development indicators (i.e., broad money), financial development (i.e., domestic credit by banks and the financial sector) regulates energy consumption to increase CO2 emissions. For 122 countries, Razmjoo et al. (2021) used FMOLS and DOLS to observe the impact of financial development on carbon emissions from 1990 to 2014. They found that the overall sample's carbon emissions worsened as financial development progressed. Environmental Research Letters published their findings. According to the research, a decrease in carbon emissions was observed in countries with high incomes; on the other hand, a rise in emissions was observed in countries with low and middle incomes.

The most recent collection of empirical studies found no significant link between the growth of the financial sector and increases in carbon emissions. In their study, Kacprzyk and Kuchta (2020) utilized system-GMM to investigate the impact of a country's financial development level on its carbon emissions in 12 MENA nations. According to their findings, the expansion of financial resources (credit to the private sector) does not influence levels of carbon emissions. A study conducted using OLS and causality analysis (Abokyi et al., 2019) examined the impact of financial development on carbon emissions in 40 European countries. They concluded that financial development, defined as domestic credit provided by banks to private sectors, does not negatively impact carbon emissions. In a separate piece of research, Zubair et al. (2020) used ARDL to examine the relationship between the state of the nation's financial system and the country's total carbon emissions. According to the findings of their study, there is no evidence of a causal connection between the expansion of the domestic credit market to the private sector and increases in carbon emissions. According to Tan et al. (2021) research, domestic credit provided by banks to the private sector as part of financial development has a negligible effect on agriculture emissions in Malaysia's context. According to the findings of Acheampong et al.'s (2019) most recent research, economic growth causes an increase in carbon emissions in Australia, Brazil, and China, while it results in a decrease in carbon emissions in the United States and India.

Nexus of Technical Innovations and Environment Quality

In terms of the pollution caused by carbon dioxide emissions, studies investigating the association between innovation and those emissions have been encouraging. Salari et al. (2021) conducted research in Malaysia covering 1985–2012 to investigate the correlation between technological advances and carbon dioxide emissions. Using causality analysis, researchers found a two-way causality between CO2 emissions and financial growth and between Carbon dioxide emission and technological innovation over the long term. This link between cause and effect can be observed in the short and long term. A more positive outlook for the environment was provided by investing in cutting-edge technologies that were also environmentally friendly (Yuping et al., 2021). Twenty-four countries were studied by Khan and Rana (2021), which looked at the relationship between CO2 emissions and economic development between 1980 and 2010. The study spanned the years 1980–2010. The study found a connection between long-term increases in CO2 emissions and increases in economic growth, but this connection does not exist in the short term. Additionally, it was discovered that technological advances were responsible for a portion of the decrease in CO2 emissions (Awosusi et al., 2022b).

Between 1990 and 2017, Mehmood (2021) found that environmental innovations in the BRICS countries influenced CO2 emissions efficiency and production-based energy usage. The findings of the tests indicate that technological advancements in BRICS states have a substantial impact on the amount of energy consumed and the emissions of carbon dioxide. According to the findings, investments in development and research led to decreased carbon emissions, which was the study's focus. Awosusi et al. (2022a) conducted research to determine the influence of environmental innovations on Italian regions' level of environmental efficacy from 2002 to 2005. The experiential findings demonstrate that improvements in environmental competence are more satisfying in industries with a high level of adoption of environmentally friendly technologies. Pejović et al. (2021) conducted research in the United States covering the years 1963–2010 to investigate the effect of economic growth, technological advancement, and CO2 emissions on each other over the long term. According to empirical research findings, a rise in income is accompanied by a fall in CO2 emissions due to technological advances in production. Increases in revenue and technological advancement can have a detrimental impact on the strength of CO2 emissions. He K. et al. (2021) made an effort to establish whether or not the pursuit of innovation benefits the level of carbon dioxide emissions. Their research used information about research and development and energy usage from China, the European Union, and the United States between 1990 and 2013. The study's findings support the hypothesis that developed countries' expenditure on research and development is positively linked with lower levels of carbon dioxide emissions.

Investment in R&D has been found to be an important factor in both economic growth and the attainment of sustainable development goals (Adebayo et al., 2021b, 2022; Awosusi et al., 2022a). This was a discovery that the National Science Foundation made. Kang et al. (2019) investigated the connection between innovative practices and CO2 emissions in 28 countries members of the OECD from 1990 to 2014. The research concluded that innovation plays a significant role in lowering CO2 emissions in most OECD countries. Luo et al. (2020) conducted research on the primary factors that determine CO2 emissions and the connection between them for France. According to the writers, increasing public investment in energy research and development has decreased CO2 emissions. From 2003 to 2017, Li W. et al. (2021) studied the connection between innovation, economic expansion, and CO2 emissions in the most innovative countries. The United States, India, China, France, Japan, Italy, the Republic of Spain, Korea, and the United Kingdom were all included in the study. According to the findings, many factors can reduce CO2 emissions. These factors include high-tech exports, innovation, R&D expenses, and environmental taxes. Populace size and the price of the solar system are both factors that can increase CO2 emissions.

Işik et al. (2017) conducted research to determine China's high-tech industry had on the country's total CO2 emissions. According to the findings of the tests, sectors contributing to low carbon emissions and energy efficiency make use of advanced technological processes. As a result, it was discovered that the technology industry was successful in lowering CO2 emissions and fostering the transition to a low-carbon budget. Martinell et al. (2021) investigated the agglomeration effect of CO2 emissions and the effect of industrial growth on China's efforts to lower CO2 emissions from 2001 to 2015. Their study covered the period from 1984 to 2016. Considering the data from the patents, it was discovered that factors in China have a beneficial effect on developing new technologies, conserving energy, and reducing CO2 emissions. Piaggio et al. (2017) conducted research on the connection between the amount of electricity used, CO2 emissions, R&D stocks, and economic development for Mediterranean nations from 1990 to 2016. According to empirical research, a one-way causality relationship was seen between CO2 emissions and R&D stocks. Even though robust feedback effects exist between economic growth, CO2 emissions, and electricity consumption, this was the case. Le et al. (2020) conducted research to investigate how innovation and technological investment affect CO2 emissions in OECD countries from 2000 to 2014. The time period covered was from 2000 to 2014. The following are some of the most important conclusions that the authors have reached regarding the connection between CO2 emissions and innovation: There is a mathematically significant inverse relationship between the amount of money spent on R&D and the amount of carbon emissions. A correlation can be considered significant between the number of patents and the amount of carbon emissions. Shen et al. (2021) investigated whether or not domestic innovation in Turkey helps slow the rate of environmental degradation. They looked at the association between innovation and CO2 releases from 1971 to 2013 and found some interesting results. The findings indicate a relationship in the shape of an inverse U between the level of CO2 emissions and the number of domestic patents. On the other hand, there appears to be a non-linear connection between the amount of CO2 emissions and innovation within the country. Anser et al. (2020) investigated the impact of eco-innovation on reducing carbon dioxide emissions in the top twenty countries in terms of refined oil exports between 2007 and 2016. The findings indicate that eco-innovation has a negative effect on carbon dioxide emissions. Researchers (Duro et al., 2020) analyzed the impact that innovation shocks had on CO2 emissions in twenty-six countries members of the OECD between 1996 and 2014. The authors concluded that disruptive innovations have a negative impact on environmental quality. Alternatively, it was emphasized that any decrease in innovation activities and strategies would lead to a rise in CO2 emissions. This point was driven home repeatedly.

Ma et al. (2019) conducted research to investigate the relationship between China's energy consumption rate and its rate of technological advancement in the energy sector from 2005 to 2016. The development of energy technologies and the rate at which they emit carbon dioxide has an inverse U-shaped relationship. Eighteen developed and six developing countries were included in the study (Khan et al., 2019) to investigate the association between innovation, CO2 emissions, and economic development from 1990 to 2016. An examination of panel data reveals a correlation between higher energy usage and CO2 emissions. The authors concluded that innovation had a mixed result. In the G6 countries, innovation leads to a reduction in CO2 emissions, but it leads to a rise in CO2 emissions in the BRICS and MENA countries.

Nexus of Renewable Energy Investment and Carbon Emissions

Administrations have utilized mandatory and incentive mechanisms to boost utility corporations to finance renewable energy. These are the two primary mechanisms that have been utilized (such as subsidies and carbon taxes). In the research that has been done, various obligatory mechanisms have been debated. The mechanism known as the feed-in tariff ensures returns for investors (Cheng et al., 2019). According to the findings of Iqbal et al. (2022), the investor should invest in renewable energy during the present period if the profit will decrease over time; however, the investor should delay investment until a later period if the profit will increase at least somewhat for a later period. Shabir et al. (2022) analyze and contrasts the risks associated with two different pricing mechanisms: the fixed price mechanism and the premium price mechanism. They conclude that a fixed price mechanism can lessen the risks associated with the investment. Both (Raghutla et al., 2021) conducted research on the mechanism known as the renewable portfolio standard. They highlight that the electricity supply must contain a certain percentage of renewable energy under this mechanism. The feed-in-tariff mechanism, which sets a fixed price for electricity, and the renewable portfolio standard mechanism, which requires the utility company to generate a certain amount of renewable energy using mandatory methods, are distinct from the cap-and-trade is a market-based trading system.

Incentives and their associated mechanisms have also been examined in the research. Wang and Zhang (2020) investigate the rationale behind investing in renewable energy by comparing the costs and benefits of producing energy using renewable vs. non-renewable sources. They make the point that a tax on carbon raises the value of renewable energy sources, whereas an increase in carbon price may discourage investment in renewable energy sources. In contrast to Wang et al. (2020), our research demonstrates that an increase in carbon price leads to an increase in investment in renewable energy. This is because renewable energy and conventional energy are interchangeable, whereas, in their paper, they are complementary. Because of this, according to our model, the utility company will be motivated to finance renewable energy whenever the price of carbon goes up. They show that investment in renewable energy is decreased (increased) if the government subsidizes inflexible (flexible) energy sourcing. They focus on how subsidizing conventional energy influences investment in renewable energy. Shahbaz et al. (2020) focus on how conventional energy subsidies influence investment in renewable energy.

Nexus of Industrial Structure and Carbon Emissions

Numerous researchers examined the association between the structure of industries and the amount of energy consumed from various vantage points and depths. According to researchers, adjusting the industrial structure is the primary method of reducing energy intensity (Jing et al., 2018). There have been many studies that have concentrated on the energy intensity of various subindustries (ref). According to Zhang et al. (2014), who studied the relationship between China's industrial structure and energy strength from 1980 to 2006, China ought to improve the utilization efficiency of coal and cut down on the energy it consumes from coal. In their study on the effect of varying conditions on energy intensity, Wang and Feng (2018) utilized a non-linear threshold cointegration method to conduct their research. Wang K. et al. (2019) used 283 cities to investigate how a city's internal industrial structure affects energy intensity at the city level. During China's 12th Five-Year Plan (FYP) Period, Yan and Su (2020) analyzed the driving force behind energy intensity and identified the key sectors considering the critical effects. The researchers (Chai et al., 2021) analyzed the change in energy intensity in China from 1997 to 2015 and concluded that an important driving force behind the decrease in energy intensity was an adjustment to the industrial structure. Because it did not take into account any of the other factors that went into production, energy intensity could not accurately reflect technical efficiency or substitution effects (Lin and Xu, 2020). Researchers started paying attention to the energy efficiency of industrial systems based on multiple inputs and outputs at about the same time (Feng and Wu, 2022). For instance, measured the energy efficiencies of Beijing's industrial sectors from 2005 to 2012 and found that there were differences between the various industrial sectors. Chen et al. (2017) analyzed the non-uniform inputs and outputs of various industrial sectors to determine the energy efficiencies of those sectors. Feng and Wu (2022) found that the structure of the industrial sector was the most important determinant of energy efficiency in the industrial sector.

Scholars have also conducted pertinent research regarding the relationship between the structure of industries and carbon emissions (Xu and Lin, 2016). Numerous studies concluded that the structure of industries played an important part in carbon emissions (Dong et al., 2018). Some researchers investigated how adjusting the structure of industries would affect the amount of carbon emissions. Xiong and Sun (2022) conducted their research on the effect of industry structure utilizing decomposition analysis. The convergence of industrial carbon intensity in China focused on research conducted by Wang et al. (2017). The effects of industrial structure on carbon intensity from city levels in China were analyzed by Wang and Yang (2020), and they concluded that the adjustment of the industrial structure had very little impact on the reduction of carbon intensity. Because carbon intensity was only one indicator of carbon efficiency, researchers started using other methods to study industrial carbon emissions' effectiveness. Du et al. (2019) investigated the effectiveness of the meta frontier non-radial Malmquist method in their research on the efficiency trends of carbon emissions. The authors of the 2013 study (Jia et al., 2019) investigated the effect that alternative energy policies had on the power industry in Europe. Li Z. et al. (2021) developed a new DEA method to evaluate the dynamic changes in the performance of carbon emissions. Tong et al. (2018) developed a method to investigate the carbon efficiencies of China's 30 provinces by combining cross efficiency with the Malmquist productivity index. This method was used to compare the provinces in order to determine which industries are the most effective at reducing their carbon footprint.

Literature Gap

From an empirical point of view, most previous studies (Zhao and Yang, 2020; Amin et al., 2022; Xiong et al., 2022) have investigated the impact of financial development and renewable energy on CO2 emissions have employed either time series or panel data analysis. In addition, only a few studies have concurrently included technology innovation, renewable energy investment and financial development to assess their impact on CO2 emissions. To the best of our knowledge, no studies in the empirical literature have examined this research question that accounts for the concurrent effects of technology innovation, renewable energy investment and financial development on CO2 emissions within the China framework. In addition, from an observational perspective, several research studies on the impact of renewable energy technology innovation and financial development on environmental degradation have utilized either a time-series or panel data analysis. Comparatively, very few studies have used a financial development index, technological innovation, or renewable energy investment to determine the impact that these factors have on CO2 emissions. Therefore, this research fills the gap in the existing research.

Data and Methods

The following section will discuss the variables used in this study, their measurements, and the data sources used. The annual time series data covers CO2 carbon emissions in KT, the economic complexity index, an aging population, financial development, technological innovations, industrial structure, and investment in renewable energy from 1990 through 2018. In addition, the information, along with its units and sources, can be found in Table 1. Moreover, the scatterplot graphs of variables are given in Figures 1–5.

Table 1

Description of variables.

Variable	Unit	Source
Dependent variables
CO2	Carbon emission (Kt)	WDI
Explanatory variables
FD	Financial development (domestic credit to private sector % of GDP)	WDI
TI	Research and Development expenditures (% of GDP)	WDI
IS	Industrial structure percentage of the added value of a third industry to GDP (% of total)	Statistics China
Control variables
ECI	Economic complexity index
REI	Renewable energy investment (USD Billions)	GTREI/ IRENA
PA	Population aging (65+)	WDI

Figure 1

Scatterplots of renewable energy investment vs. CO2 emissions.

Figure 5

Scatterplots economic complexity index vs. CO2 emissions.

Scatterplots of industrial structure vs. CO2 emissions.

Scatterplots of technological innovation vs. CO2 emissions.

Scatterplots of population vs. CO2 emissions.

Econometric Model

In this study, an attempt is made to investigate the long-run association between the chosen variables. We use carbon emissions as our dependent variable. We use the economic complexity index, population aging, financial development, technological innovations, industrial structure, and investment in renewable energy sources as our explanatory variables. The data transformation into logarithmic form is done because it results in more efficient, better, and more consistent outcomes (Baek, 2015). The logarithmic representation of the data makes it possible to obtain smooth data, but it also solves the problem of heteroskedasticity. The ECI is not converted into log form before being used as an index. The model is presented in the following.

By taking its natural log

The letter t denotes the time trend, and the letter denotes the error term. The Economic Complexity Index, or ECI for short, PA stands for “population aging,” REI stands for “investment in renewable energy,” FD stands for “financial development,” TI stands for “technical innovations,” and IS refers to “industrial structure.” CO2 denotes emissions of carbon, and B0 is unchanging.

The descriptive statistics regarding the variables are presented in Table 2. The following table reports the descriptive statistics, including the mean, median, maximum, and minimum values and the standard deviation and probability values. The average rate of population decline is the highest, while the average rate of carbon emissions is the lowest. The table demonstrates that all of the variables follow a normal distribution.

Table 2

Descriptive statistics.

	LCO2	ECI	PA	TI	REI	IS	FD
Mean	1.87469	4.96572	11.28974	8.56974	3.96547	6.85469	7.54128
Median	1.61235	3.85412	9.541326	7.96451	2.96471	5.23897	7.23851
Maximum	7.95644	11.8546	21.8546	14.9657	6.98547	12.8745	10.2314
Minimum	0.89524	0.14569	0.89745	0.98451	0.02374	0.75871	0.63984
Std. dev.	0.9820	0.8456	0.4031	0.3478	0.5641	0.8456	0.4145
Prob.	0.0000	0.0001	0.0000	0.0005	0.0000	0.0000	0.0008

The summary of the correlation matrix is presented in Table 3. The concentration of CO2 has a positive and significant relationship with ECI. Similarly, population aging, investment in renewable energy, and financial development positively correlate with rising carbon emissions. In addition, technological advancements and industrial structure negatively correlate with the variable that is being explained. As a result, no single variable has a high correlation with the variable that is being explained; consequently, we can say that there is no multicollinearity in our chosen variables. Moreover, Figure 6 presents the study plan.

Table 3

Matrix correlation.

	LCO2	ECI	LPA	LTI	LREI	LIS	LFD
LCO2	1
ECI	0.2365	1
LPA	0.7145	0.2345	1
LTI	−0.5641	0.6354	−0.6354	1
LREI	0.6358	0.4123	0.2546	0.6574	1
LIS	−0.6987	0.3265	−0.7356	0.2385	0.7412	1
LFD	0.3987	−0.2385	0.5234	−0.4198	0.4187	0.6981	1

Figure 6

Scheme of study.

Estimation Procedure and ARDL

We use the most advanced method, called Autoregressive Distributed Lag or ARDL bound tests for short. These tests were developed by Pesaran (2015). This method has a number of advantages over other methods, such as the Engle and Granger technique (Citation needed), which is used for two different variables. On the other hand, the Johansen Cointegration (Citation needed) method is utilized for analyses involving more than two variables. Therefore, the Johansen Cointegration model is superior to the Engle and Granger models. Adekoya et al. (2022) developed an extended version of the VAR model. However, for it to be applicable, certain conditions, such as dealing with a large sample size and meeting the pre-conditions for the cointegrated VAR, state that all variables must be integrated in the same order, i.e., I, must be met first (1). The ARDL technique eliminates these problems, but it also has a number of other significant benefits. When dealing with a small sample size, the ARDL cointegration method is preferable to the JJ method. Second, it can be utilized regardless of whether the variables in question are composed entirely of I(0), I(1), or a combination of both I(0) and I(1). Third, it accurately estimates the number of delays in the DGP (Data generating process), especially concerning the transition from the general to the specific process, as Saadaoui (2022) has reported. A straightforward OLS transformation can be used to derive the error correction model from the bound testing method, which brings us to the fourth point. ECM illustrates the mechanism for adjusting from short to long run without compromising the integrity of the long-run data. Fifth, if some endogenous regressors exist, the ARDL approach offers unbiased estimates in the long run. Researchers implement instrumental variables to circumvent the endogeneity problem (s). Nevertheless, there is no such thing as the perfect instrument. Making the model dynamic and introducing the variable (s) lags is the most effective method. The model is made dynamic by using the ARDL approach. Although ARDL can be utilized regardless of whether all variables are stationary at level, i.e., I(0) or I(1), or a mixture of the two (,). However, Ouattara commented that we are unable to use ARDL because the bound testing approach is based on I(0), I(1), or a mixture of these two sets if any of the variables being investigated are stationary at the second difference. As a result, we examine each variable's “unit root” property to ensure that none of the variables should be considered stationary at the second difference. We use ADF (Im et al., 2003) and the Zivot unit root test to accomplish this.

The basic idea behind the autoregressive distributed lag to co-integration approach is that it uses two steps to investigate the long-term relationship between the different variables. First, using the F-statistic, one needs to determine whether or not there is a relationship over the long run between the variables. If the F-statistic demonstrates that cointegration does exist, the next step is to investigate the long-run and short-run coefficients. This method is based on the joint F-statistic, and this approach has no co-integration of the null hypothesis. Im et al. (2003) reported two different types of critical values, which they referred to as lower bounds and upper bounds, respectively. In lower bounds, variables are assumed to be I(0), whereas, in upper bounds, they are assumed to be I(1).

Suppose the calculated F-Statistic is greater than the upper bounds. In that case, this indicates that the null hypothesis of no co-integration has been rejected and that the variables do, in fact, exhibit long-run co-integration. If the calculated F-statistic is less than the lower bounds, then we cannot reject the null hypothesis that there is no co-integration, and we are also unable to move forward with the ARDL model. It is inconclusive if the calculated F-statistic falls somewhere in the middle of the lower and upper bounds. In this particular scenario, Peter Boswijk (1994) reported that using an error correction term will effectively determine the variables' long-term relationship with one another. The long-run relationship among the variables can be confirmed because the error correction term is negative and significant. The critical bounds were determined by Pesaran (2004) are applicable to large sample sizes. Therefore, the results they provide may be biased due to the limited size of the sample. In 2008, Breitung and Pesaran (2008) introduced the same tables for small sample sizes that are helpful for thirty to eighty observations. These tables can be found here. Due to the limited size of our data set, we have chosen to adhere to Breitung and Pesaran (2008) tables. The following error correction models need to be estimated in order to use ARDL, and their mathematical representation will be as follows:

In Equation (3), β0 is constant, β1- β6 are error correction dynamics, Δ is the first difference operator, μt is the white noise error term, and the second part of the equation from δ1 to δ6 characterizes the long-run relationship among the variables in the model. ARDL approach based on Wald F-statistic is applied to check the long-run co-integration among the variables of the concern with the null of no co-integration as H0: Ω0 = Ω1 = Ω2 = Ω3 = Ω4 = Ω5 = Ω6 = 0 and alternative as H1: Ω0≠ Ω1≠ Ω2≠ Ω3≠ Ω4≠ Ω5≠ Ω6≠ 0.

Short-run coefficients must be found after the long-term correlations between variables and the long-term coefficients of the variables have been established. There will thus be a set of short-term models for the variables:

The symbol ECT denotes the error correction term in Equation (10). This term is used to determine if there is a disturbance in the system and how much time it will take for the system to return to its equilibrium path in the long run. The error correction term has a coefficient of 1, which is 1. Other equations can be explained in a manner analogous to that described above. Error correction can be explained for other equations following a pattern very similar to this one. The Cumulative Sum (CUSUM) and Cumulative Sum of Squares provided by Sarkodie and Adams (2018) can determine whether or not the coefficients are stable over the short and long term. In addition, the Granger causality was used in this investigation to look into the association between variables and their causes.

Results and Discussion

Lag Length Selection Criteria

The ARDL method is based on the number of regressions (P + 1) k, where P is the number of maximum lags and K is the variable that displays the number of different factors in each equation. The AIC, the Schwarz information criterion, and the Hannan-Quinn information criterion are the three information criteria that form the foundation of the suitable lag selection procedure. The F-statistic is extremely sensitive to the number of lags present in ARDL. Therefore, to accurately estimate the F-statistic, it is necessary to select appropriate lags, the length of which should be the optimal lag length. Most of the tests, specifically HQ and AIC, are based on our selection for the lag. In addition, Saadaoui (2022) argued that AIC is superior when applied to a small sample size. According to Table 4, the findings indicate that the ideal number of lags between events is 2.

Table 4

Lag selection criteria.

Lag	AIC	SC	HQ
0	4.05896	1.8549	0.8569
1	1.7843	1.4975	1.1178
2	−5.2583*	0.9645	−1.8312
3	−3.2385	−4.8862*	−1.23692*

The

symbol indicates the 10% significance level.

After making sure that we have chosen the right lag, we will calculate the F-statistics, which will be reported in Table 5. It can be seen that the F-statistic is 10.965, which is greater than the upper bounds at 1, 5, and 10% levels of significance. The independent variables are when carbon emissions are taken as the dependent variable, economic complexity index, population aging, financial development, technical innovations, renewable energy investment, and industrial structure. This is because the F-statistic is greater than the upper bounds at all three significance levels. As a result, we are forced to conclude that there is, in the long run, an association between the variables.

Table 5

ARDL bound test.

Significance level	I (0)	I (1)
1%	2.96	4.26
2.5%	2.6	3.84
5%	2.32	3.5
10%	2.06	3.4

Unit Root Test

The unit root test results are presented in Table 6, and the unit root tests ADF and Zivot are utilized in this investigation. This test demonstrates that some variables have cointegration at level, while others have cointegration at the first difference, as indicated by the outcomes of the ADF unit root test. In addition, the structural Zivot unit root test is utilized to investigate the expected breaks in the data provided.

Table 6

Unit root tests.

Variable	ADF			Zivot unit root
	Level	1st difference	Level	Break	1st difference	Break
LCO2	−3.4574*	−7.5685	−3.1189**	1999	−6.1256*	2006
ECI	1.4599	−5.1125*	−5.6895*	2007	−6.4425*	2012
LPA	2.4752	−9.6689*	−4.2285*	2000	−7.5782*	2009
LREI	−3.4234**	−6.7456	−3.6642**	2003	−5.9469*	2010
LFD	−4.5236*	−11.237	−2.8823*	2001	−6.7815*	2008
LTI	2.9645	−6.3674*	−3.1578*	2003	−5.9741*	2009
LIS	−3.8564*	−8.2369	−4.9654**	1995	−7.6985*	2004

The

symbol indicates the 1% significance level.

ARDL Long-Run Results

This investigation into the long-run behavior of economic complexity index, population aging, investment in renewable energy consumption, financial development, technical innovation, and industrial structure with carbon emissions uses the Autoregressive Distributive Lag (ARDL) model. The estimated results are presented in the following Table 7: Within the context of sustainable development in China, the economic complexity index (ECI) is the factor that is being looked at as the primary factor in carbon emissions. The coefficient value is 0.368, which is positively associated with carbon emissions. Since this factor is positively associated with carbon emissions, a change of one unit in this factor would result in a rise in carbon emissions in China of 0.368%. The practice of shifting economies away from farming and toward more modern production and services directly affects the environment, as it encourages exponential growth in the consumption of fossil fuels and significant CO2 emissions. Structural change is also known as “economic restructuring”. This transition necessitates a higher energy consumption, leading to an increase in CO2 emissions and the deterioration of the environment. The increased complexity of the exported goods is one factor contributing to the poor air quality and extensive energy consumption. In a similar vein, the process of industrialization and the transformation of the productive system both contribute to an increase in the demand for energy and the amount of carbon emissions. In recent decades, particular modern production methods have been shown to have a significantly more positive impact on the environment than the methods they have replaced. For example, in the agricultural sector, the conventional method of fertilizing on farms, in which animals supplied manure to pollinate the land, has been replaced by organic fertilizers, which have resulted in significant pollution issues due to the contamination of heavy metals as well as elevated radionuclide concentrations. This method of fertilizing was responsible for causing the land to be pollinated by animals. The findings are consistent with those obtained in previously conducted research such as Vujanović et al. (2021). In addition, in contrast to Fatima et al. (2021), who focused their research on European nations, this investigation determined a capacity for mitigating the negative effects of economic complexity on environmental degradation. This evidence is the primary contribution and represents a highly innovative and fresh approach to the existing body of research. The complexity of the economy may help reduce carbon emissions. As a result, policymakers should consider it when designing economic growth at the national and regional levels, as well as energy and environmental regulation. The productive system within the host economy is what is meant when we talk about a country's economic complexity. Because of this, it has particular effects on the surrounding environment. It is possible to reduce the amount of carbon dioxide released into the atmosphere by properly managing the productive system using mixed baskets and technological innovation. This discovery about the complexity of the economic system is both specific and reassuring.

Table 7

Short run and long run ARDL test.

Variable	Coefficient	Std. error	T-statistics	P-value
ECI	0.36851	0.00256	143.94	0.005
PA	0.65142	0.11364	5.7323	0.000
REI	−0.85243	0.21547	−3.9561	0.000
FD	0.96425	0.07896	12.211	0.001
TI	−0.32987	0.12354	−2.6701	0.000
IS	−0.69451	0.13851	−5.0141	0.005
C	−1.23654	0.89254	−1.3854	0.000
Short run ARDL outcomes
D (ECI)	0.06982	0.00118	59.169	0.0421
D (PA)	−0.23845	0.01123	−21.225	0.000
D (REI)	0.45128	0.123691	3.6484	0.005
D [LREI (−1)]	0.08512	0.004165	20.436	0.047
D (FD)	0.41235	0.12487	3.3022	0.000
D (TI)	1.23654	0.98245	1.2586	0.145
D [TI (−1)]	−0.65234	0.23854	2.7347	0.002
D (IS)	0.02396	0.00012	199.66	0.000
CoinEq (−1)	−0.67452	0.23171	−2.9110	0.002

Source: Author calculation using EViews 10.

Similarly, the elderly population is a significant indicator of the continued viability of the environment. The positive association between population aging and carbon emissions is demonstrated by the coefficient value that has been given. This suggests that a 1% increase in the proportion of older people in the population would result in a 0.6514% increase in emissions, respectively. There is a positive correlation between China's carbon emissions and the country's aging population. Adedoyin et al. (2021), Jabeen et al. (2021), and Ziaei (2022) found positive correlations between the percentage of senior citizens and the amount of carbon emissions. This finding is in line with those findings. Our viewpoint is that China's aging population's way of life is distinctive compared to that of people in other countries, particularly western nations. The elderly tend to live a more frugal lifestyle, opting to move in with their children more frequently and taking fewer vacations. According to Mehmood (2021), seniority has a beneficial effect on energy-saving behavior. On the other hand, the effect of population aging on carbon emissions is relatively insignificant (Mehmood, 2021). The following list of reasons explains why China's aging population currently correlates positively with the country's total carbon emissions. The constant availability of new workers is the primary explanation. Compared to developed nations, China's aging population has only been a reality for a relatively short time (China entered an aging society stage in 2001). The current aging of the population, caused by falling fertility rates and rising life expectancy rates, has not resulted in a relative decrease in the size of the labor force. The percentage of the working-age population is growing in most provinces and at the national level overall. During the sample period of our study, China's demographic gap was still present. The consistent availability of work contributed to the expansion of the economy and increased the amount of carbon emissions. Rising labor supplies are the primary cause of increased carbon emissions in countries that are still economically developing. There is a significant positive correlation between China's aging population and the country's total carbon emissions, primarily attributable to the continuously rising labor force. The second cause is connected to psychological aspects and considerations. Like the aging populations in other countries, the aging population in China is becoming less willing to pay for environmental protection. Others also spotted this pattern (Zaman et al., 2021). As people get older, their willingness to pay for improved environmental quality drops significantly (Saraswat and Digalwar, 2021; Wang et al., 2021). Only one-third of people over the age of 65 would be willing to pay higher gasoline prices to protect the environment compared to those aged 15–24. This indicates that older people are less concerned about the environment than younger people (Qashou et al., 2022). Improving the quality of the environment is a process that takes a relatively long time. It is more likely to improve the standard of living of the population in the future.

More interestingly, the connection between investments in renewable energy and carbon emissions shows an inverse association. A 1% increase in this factor would lead to a 0.852% decrease in environmental deterioration, according to the ARDL estimator. This result can be understood by applying some economic logic to the situation. The implementation of policies for REI will encourage investors to invest more in production that uses renewable energy, which will reflect favorably on the environment's sustainability. This result demonstrates that the company has the potential to increase its profitability by increasing the amount of money it invests in the production of electricity using renewable energy. This finding implies that the government can use REI as an effective mechanism to encourage producers to invest in renewable energy production to replace the production of conventional power. It will produce the least overall carbon emissions from green energy consumption because it must cover both electricity generation costs and carbon dioxide emissions from using conventional energy. Because of this, firms are less likely to use conventional energy, resulting in lower overall carbon dioxide emissions. On the other hand, businesses can invest the most heavily in renewable energy because they can set a low price for electricity to stimulate more demand in the market. It then needs to invest more money in renewable energy sources in order to meet the electricity demand.

In a similar vein, it is believed that the estimated coefficient of financial development has a positive association with carbon emissions. The findings indicate that an increase in this factor by 1% would lead to an increase in environmental damage of 0.964%, respectively. This result can be rationalized in some way. The fact that this variable has a positive coefficient indicates that the financial sectors in China do not allow financial resources for environmental protection and do not support organizations or production units that do not use green technologies. According to Wang et al. (2021), liberalization and financial openness are two factors that encourage research and development projects and international investment. The resulting financial obligations and expenditures are the primary sources of technologies that increase energy-related effectiveness and play an essential role in reducing carbon emissions. Financial resources in an economy are a leading factor in channeling resources to areas where productivity is high, and the nation wishes to promote strategically. This is the role that financial resources play in an economy. In addition, in terms of production factors, financial resources are still relatively scarce in China, whereas labor supply continues to outweigh the demand. According to this point of view, the circulation of financial resources plays a primary part in the circulation of other production factors. The flow of labor is contingent upon the geographic region, the industry, or the investment projects that receive financial resources. Therefore, the destination of the flow of financial resources and the direction in which they are channeled plays an extremely significant role, one that is significantly more significant than the role played by any of the other factors, in the process of optimizing economic structure, economic growth, and carbon emissions. Similarly, in the same vein, financial development is not useful for improving environmental quality in countries where the financial sector is still in its early stages. For instance, Huang et al. (2022) argued such for BRICS, Abbas et al. (2022) for Pakistan, and Yumei et al. (2021) argued in the case of developing regions of China. All of these studies were conducted in Pakistan.

Regarding the coefficient of technological innovations, there is an inverse relationship between the two variables (carbon emissions). It can be deduced from this that a 1% increase in this factor would result in a 0.329% decrease in China's total emissions. This finding indicates that R&D has an inverse relationship with carbon emissions, suggesting that higher authorities in China are increasingly interested in R&D projects that aim to reduce CO2 emissions. Research and development can create novel knowledge, processes, and products thanks to technological advances. According to Feng et al. (2022), the proliferation of innovative technologies can help reduce harmful effects on the environment due to energy consumption usage by improving energy efficiency. This can be accomplished by improving energy utilization. This result is consistent with the findings found in the research of Zhang et al. (2022). It was established that investments in research and development have the potential to stimulate improvements in energy efficiency. According to Zhang et al. (2022), reputable institutions can better direct their efforts toward reducing carbon emissions and, as a result, improve the overall quality of the environment while fostering economic growth. Therefore, in this case, the negative nexus demonstrates the successful implementation of environmentally friendly policies by India's institutions and the government to enhance energy usage efficiency.

There is a possibility that the industrial structure is responsible for a significant portion of the environmental damage. According to the outcomes that have been estimated, this means that an increase in the industrial structure of 1% would result in a decrease in emissions level of 0.329%. This result is not only very interesting but also makes some sense. Developing a more efficient industrial structure is inextricably bound up with economic and demographic factors. Because of this, it is to be anticipated that urban development has resulted in a continuous increase in industrial solid waste despite a relatively slow garbage disposal capacity that lags behind the production of solid waste, which has resulted in a phenomenon known as a “garbage siege” (Anser et al., 2020). As a result of the fact that industrialization is the primary driver of both urbanization and economic development, more pollution is produced during such development processes. As a result of China's relatively high levels of urbanization and the country's relatively low proportion of traditional industries, China's urbanization processes have resulted in less pollution being released into the environment. Even though urbanization has contributed to increased environmental pollution in China, this problem has become less severe as the percentage of the tertiary industry has grown. This may be because of the following reasons: First, as a result of ongoing urbanization, advances in technology, and modifications to industrial policies, the percentage of the economy comprised of the tertiary industry has been steadily growing over the past few decades. An improvement in the industrial structure can also result in decreased reliance on resources and energy in the production processes of businesses, which directly impacts the ecological environment (Waqas, 2021). Second, due to the optimization and upgrading of industrial structure, the percentage of traditional industries with high energy consumption levels, pollution, and emissions has been gradually decreasing. At the same time, resources have been shifted from industries with low utilization efficiency to industries with high efficiency and low levels of pollution. As a result, significant progress has been made in reducing pollutant emissions and enhancing the ecological environment.

Stability Tests

Because there is an association in the long run between the chosen variables, it is now essential to test the robustness of the model. As a result, the various tests are utilized in this study to investigate the serial, correlations, autocorrelation, and other such phenomena. The results of each test are detailed in Table 8 below.

Table 8

Model stability tests.

Test	F-statistics	P-value
Serial correlation test	5.235	0.214
ARCH test	0.9856	0.623
WHITE test	3.1258	0.111
RAMSAY test	1.8521	0.198

After the stability test and long-run outcomes, there is a need to check out causal association among variables. Therefore, this study uses the Granger causality test to investigate the causal effect of one variable on another variable. The results of causality analysis are given in Table 9. The given results found a bi-directional causality between population aging and financial development, which infers that any change in population aging would change the activities of financial institutions and vice versa. It will be meaningful if we say the policies concerning population aging and financial development are working together. Moreover, a two-way causal association was found between industrial structure and technical innovations. This infers that as research development expenditures increase, the industrial structure becomes more developed due to advanced technologies. Similarly, this behavior of the industrial structure can be judged for technical innovations. On the other hand, there was a uni-directional association between environmental degradation and investment in renewable energy, while there has been no evidence for feedback. Likewise, the economic complexity index granger causes environmental quality, financial development, technical innovations, and industrial structure. Moreover, population aging found a one-way causal association between population aging and environmental degradation in China's economy. Likewise, renewable energy investment also causes financial development, and no feedback exists. In the last, the industrial sector granger causes financial development.

Table 9

Granger causality tests.

DV	Type of Granger causality
	Short run (lag)						Long run
	ΔLCO2	ΔECI	ΔLPA	ΔLREI	ΔLFD	ΔLTI	ΔLIS	ECT-1
	F-statistics ( P -values)							t-stat
ΔLCO2	–	1.0478 (0.111)	1.6387 (0.339)	1.24781 (0.005)	2.23458 (0.081)	1.96542 (0.331)	2.41237 (0.852)	−3.3741 (−1.3856)
ΔECI	3.47124 (0.000)	–	1.46871 (0.623)	1.42603 (0.5611)	3.2358 (0.000)	3.6541 (0.000)	5.23659 (0.000)	−1.35468 (−0.5689)
ΔLPA	4.1456 (0.000)	1.45127 (0.125)	–	1.13589 (0.853)	5.91856 (0.000)	1.85461 (0.555)	3.14561 (0.096)	2.52134 (1.1245)
ΔLREI	1.4451 (0.191)	2.5689 (0.212)	1.85121 (0.213)	–	3.98745 (0.005)	1.2345 (0.999)	1.98651 (0.962)	0.65480 (0.9645)
ΔLFD	5.8546 (0.000)	1.8952 (0.121)	4.8546 (0.005)	1.68452 (0.522)	–	1.4456 (0.287)	2.12489 (0.471)	−0.86944 (−1.2341)
ΔLTI	1.6314 (0.962)	2.1245 (0.113)	1.63214 (0.087)	2.8541 (0.418)	1.5236 (0.851)	–	3.96894 (0.005)	−1.56891 (−0.6312)
ΔLIS	1.6396 (0.895)	1.5692 (0.235)	3.6245 (0.412)	2.652 (0.285)	5.3245 (0.000)	7.9852 (0.002)		0.96325 (0.0125)

Conclusions and Policy Recommendations

This study aims to investigate the impact of technological advancements and industrial structure changes on carbon emissions from 1990 to 2018. We research the socioeconomic indicators of China's economy to understand its potential for sustainable development. These determinants have surprising results, and the factors in question are the economic complexity index, the aging population, investments in renewable energy, and the growth of the financial sector. The application of the ARDL bound test allowed for the discovery of these results. Based on this analysis, the following generalizations can be made: Due to an increase in the economic complexity index, China's overall carbon emissions have been climbing steadily from 1990 to 2018. In addition, an aging population and the growth of the financial sector both contribute to an increase in emissions and a decline in the quality of the environment. In a similar vein, the industrial structure, investments in renewable energy, and industrial structure all contributed significantly to the overall quality of the environment. Additionally, the Granger causality test was utilized in this research to investigate the causal association between variables. The results revealed a two-way causal linkage between population aging, financial development, technical innovation, and industrial structure.

Policy Recommendation

In light of the anticipated findings, this research offers recommendations for environmental policy to create a sustainable environment. It is imperative that China put into action strategies that will halt the rise in CO2 emissions—owing to the fact that the economic complexity of the chosen economy is organized in a fashion that promotes the emission of greenhouse gases. The transition in the economy demonstrates a shift from an “energy-intensive economy” to a “technology-intensive economy.” In order to reduce the amount of CO2 emissions in China, structural improvements in the environment may be required. Because an aging population does not significantly contribute to maintaining a sustainable environment, it is essential to reevaluate the policies in question. First, China's population aging (PA) has resulted in the consumption of significant energy resources and has caused significant damage to the natural environment.

Consequently, China's current energy consumption structure needs to be revised to reduce the country's levels of air pollution and increase the effectiveness of energy consumption (Mngumi et al., 2022). To accomplish this goal, the government and businesses will need to collaborate. It is the government's responsibility to develop appropriate policies that will not only direct the implementation of consumption structure upgrades in energy-intensive industries but will also encourage the use of clean energy across the entire country. In the process of developing policies to protect the environment, it is essential to take into account regional variations, such as increasing rates of seniority and the proportion of people employed in service industries (Chien et al., 2021; Hai Ming et al., 2022; Mngumi et al., 2022; Nasir et al., 2022). As a direct result of this, China is in a position to impose stricter environmental regulations and higher business entry barriers.

Undoubtedly, China's rapid economic development significantly contributes to the country's environmental damage. As a result, economic development and financial activities should be centered on enhancing the quality of the environment, and the promotion of forms of financialization that are more environmentally friendly should be a priority. Public and macroeconomic policy development should center on environmentally friendly and sustainable forms of finance. It should be discouraged to allocate financial resources to industries with lower environmental impact efficiency. At the same time, resources should be allocated to industries that positively impact the environment.

Similarly, technological innovations (TI) significantly contribute to environmentally sustainable practices. Based on our empirical research findings on the costs of TI, we have concluded that TI is good for the natural environment. Because the statistics demonstrated very strong and empirically robust results, we can infer with high levels of confidence that TI is essential to the process of addressing environmental challenges. Because of this, it is necessary to direct both public policy and the distribution of resources toward research and development when formulating policies, particularly when attempting to reduce carbon emissions. This will make it easier for us to accomplish our goal of reducing carbon emissions to zero. In addition, it has been suggested that to maintain the structure of the industrial system. Advanced industries need to adjust their development patterns to become green. For a very long time, China's industrialization has been defined by low output, high input, low efficiency, and high consumption. Even after several years of economic development, a significant portion of China's economy comprises secondary industries in many regions. Therefore, a significant step is optimizing inventory stocks and controlling increments at the beginning of transitioning from the nation's traditional model of high energy consumption, high input, and extensive industrial development to one that promotes the development of the green industry. This transition could initially involve optimizing inventory stocks. This supposedly “optimized” inventory will allow China to optimize the production of its already-established industrial enterprises, continuously promote and implement a wide range of innovative technologies and pieces of equipment, and eventually realize the intensive, environmentally responsible development of its industrial enterprises.

Future Research Directions and Limitations

Even though the current research makes it possible to determine solid findings, additional research needs to be conducted using a variety of factors that influence environmental sustainability. These factors include urbanization, trade, foreign direct investment (FDI), globalization, industrialization, population, and so on. In addition to that, this research employed the use of CO2 as a stand-in for environmental deterioration. Therefore, subsequent research ought to make use of various stand-ins for environmental deterioration.

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Author Contributions

All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher's Note

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