A Comparative Study of China’s Carbon Neutrality Policy and International Research Keywords under the Background of Decarbonization Plans in China

Abstract

The impacts of climate change have become a series of important issues in global public health and environmental governance. As a major developing country with carbon emissions, China has actively participated in global climate and public health governance. The international academic research by Chinese scholars on carbon neutrality has gradually shifted from focusing on technological development to focusing on sustainability, green development, a decarbonization plan, public health and environmental governance. This study uses bibliometrics, scientometrics, and policy documents quantification to carry out a comparative study, comparing the keywords of China’s national “carbon neutrality” policies from 2006 to 2021 with the keywords of international research by Chinese scholars, and analyzes the evolution of the academic and political concerns and development measures of China’s carbon neutrality. It is found that in the stages of preliminary development and steady growth, China’s carbon neutrality research and policy portfolio grew in an orderly manner, and the influence of policy and the promotion of academic research gradually strengthened. After 2020, with the outbreak of the COVID-19, national policies and carbon neutrality research began to focus on green development and public health issues, and the intersections of policy keywords and academic keywords increased. Overall, the focus of Chinese scholars on carbon neutrality research and policy is gradually approaching and integrating, and the degree of interaction and integration between academia and politics is increasing. Under the complex situation of China’s decarbonization plans, climate changes, COVID-19, and international political and economic changes, China’s policy design and development model are conducive to public health, green development, and innovation transformation, and building a community with a shared future for mankind.

1. Introduction

At present, the impact of climate change is an important global environmental and public health issue. In recent years, the handling and governance of climate change and the COVID-19 epidemic has gradually become a series of important issues that the world is paying attention to, and many departments from the government to the academic community are paying attention to and studying [1,2,3,4,5]. Starting from the purpose of alleviating the negative influences of blockade policies on economic activities, various countries have successively introduced policies to boost the economy; under the dual influence of the blockade strategy of the epidemic and the economic stimulus policy, the carbon emission trajectory of countries around the world will change significantly in the next few years, and the investment behavior will lock in the growth path of carbon emissions, profoundly affecting the long-term response to global climate change [6,7,8]. Data show that the COVID-19 epidemic has caused a “historic decline” in global carbon emissions, but throughout history, the retaliatory rebound brought about by economic recovery is almost inevitable [8]. Governments around the world have gradually introduced policies on carbon neutrality and the COVID-19 epidemic, paying more attention to the combinations and relationships between them. Meanwhile, many scholars have begun to pay attention to the connections and impacts between climate change, carbon neutrality, and the COVID-19 epidemic [7,8,9].

Liang and collaborators have found that urban air pollution and other environmental problems may easily increase the probability of people’s infection with COVID-19 [9]. Shan and collaborators comprehensively calculated the impact of the epidemic blockade and economic recovery on the carbon dioxide emissions of 79 major countries in the world from 2020 to 2024, trying to effectively capture the direct and indirect effects in the global supply chain caused by COVID-19 epidemic control measures through research models, and reveal the influences of the epidemic on the whole world economy, trade, business, and carbon dioxide emissions [7]. Many scholars and institutions believe that the COVID-19 crisis may lead to the largest decline in global carbon emissions in history, which shows the potential to restore long-term low carbon, but we must also focus on the rebound of carbon emissions after the epidemic has eased, and continue to carry out research and respond to the relationship between carbon emissions, climate change, and COVID-19 [10,11,12]. Gradually, more and more scholars have carried out research on the relationship and impacts of climate change, carbon neutrality, and the COVID-19 epidemic through policy analysis, bibliometrics, and other methods [13,14,15].

To address various environmental governance issues and related political and economic issues triggered by climate change, the governments, United Nations, and other relevant agencies of various countries have been continuously taking measures to encourage countries around the world to reduce greenhouse gas emissions and enhance defense against climate change, environmental issues, the COVID-19 epidemic, and a series of issues, and promote the improvement of global environmental issues and sustainable development through a series of agreements, conventions, and cooperation mechanisms such as the Paris Agreement [5,16,17,18,19]. The IPCC (Intergovernmental Panel on Climate Change) has released many reports to study addressing climate change and related crises, attracting attention from both the political and academic communities [1,20,21,22,23]. Numerous studies and reports from various organizations show that the Earth system has experienced severe climate shocks, and the overall situation is not optimistic due to various environmental governance issues and a series of public health governance issues such as the COVID-19 epidemic [20,21,22,23,24]. Many countries in the world have successively formulated the targets and paths of carbon peak and carbon neutrality and responded to the impacts and challenges brought by climate change and the COVID-19 epidemic through academic research, policy initiatives, and practices on environmental protection and public health governance [1,2,3,4,5,6,20,21,22,23,24].

What are carbon peak and carbon neutrality?

Peak carbon dioxide emissions or carbon peak means that at a certain time, carbon dioxide emissions reach the historical peak, and then stop growing and begin to decline gradually; this indicates the peak point of carbon dioxide emissions, which gradually decreases and adapts to human social and economic development; carbon neutrality means the removal of manmade carbon dioxide to neutralize and balance manmade carbon dioxide emissions globally, which can also be called net-zero carbon emissions [21,22,23,24]. When a country, organization, enterprise, group, or individual wants to achieve carbon neutrality or net zero emission of carbon dioxide, it must completely offset the total amount of carbon dioxide emissions measured within the specified period, thus achieving a balance between the overall quantity of carbon dioxide emissions and the overall quantity of carbon dioxide removal [22,23,24]. Some scholars and the National Public Utility Council have investigated 137 countries that have made carbon neutrality commitments or created initiatives. The overall situation of these countries’ main carbon neutrality targets, policy, and legal aspects is shown in

Table 1. The goals and policy guarantee of carbon neutrality of 137 countries.

Goals of Carbon Neutrality		Policy Guarantee
Target Year	Country	Status	Country
Before 2050	Bhutan and Suriname (Achieved), Uruguay (2030), Finland(2035), Iceland and Austria (2040), Sweden and Germany (2045), etc.	Legal Level	13 countries including Sweden, Denmark, France, Hungary, New Zealand, the UK, etc.
		In Legislation	Fiji, Chile, Spain, Canada, Republic of Korea, etc.
2050	More than 120 countries including the United States, Japan, Canada, New Zealand, Switzerland, Republic of Korea, Norway, etc. (124 of the 137 countries)	Policy Level	More than 120 countries including Norway, Australia, China, Germany, Finland, Iceland, USA, Columbia, etc.
2060	Australia, Singapore, China, Ukraine, Kazakhstan, etc.	Under Discussion	More than 120 countries including Belgium, Greece, Italy, Maldives, Mexico, etc.

Source: According to references [5,24].

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According to Table 1, as of July 2022, Bhutan and Suriname are two countries that have achieved carbon neutrality. Uruguay proposed the idea of achieving carbon neutrality by 2030, while Finland proposed achieving it by 2035. Iceland and Austria are aiming for 2040, and Sweden and Germany around 2045. The carbon neutrality goals of many European countries are generally five years earlier than the previous goals, demonstrating their own national support and ambition [5,24]. According to surveys by scholars and research funded by the National Public Utility Council, among the 137 countries participating in the survey of carbon neutrality goals, more than 120 nations and regions have proposed the idea of achieving carbon neutrality by 2050; this is inseparable from the promotion of the international Carbon Neutral Alliance, and some countries such as Ukraine, Kazakhstan, China, and Australia set the target year at 2060 [5,24]. From the perspective of policy guarantees, in terms of law, only a few countries in the world have implemented legislation for the goal of carbon neutrality, such as Sweden, Denmark, France, and 13 other countries; Chile, Fiji, and other countries have put forward legislative proposals [4,5,6,16,17,18,22,23,24]. At the policy level, more than 20 countries including China, Norway, the United States, and Germany have set climate goals and carbon neutrality goals as official policies, and have issued a series of national policies. However, the commitments made by more than 90 countries such as Belgium and Italy are only at the discussion level, and there are not many effective actions for climate and carbon neutrality [4,5,6,16,17,18,22,23,24].

How to achieve the goal of carbon neutrality and move towards the vision of carbon neutrality is an urgent question for all countries in the world, especially China [16,17,18,19]. Since entering the new century, China has attached great importance to and implemented actions related to global environmental governance and climate change response, and gradually established an increasingly complete supporting policy system and promotion programs at home, making important contributions to promoting the realization of the carbon neutrality goal vision and promoting global climate response and sustainable development [21,22,23,25,26,27,28,29,30]. Many scholars around the world have conducted research on environmental governance and carbon neutrality, and China’s statements, actions, and visions on carbon peaking and carbon neutrality have attracted the attention of the academic community [3,4,5,16,17,18,19,20,21,22,23,30,31,32,33,34,35]. For example, some research reports from the School of Environment at Tsinghua University suggest that China’s carbon neutrality goals are in line with the recognition of many international organizations [36,37]. What is the relationship between the international research of Chinese scholars and the carbon neutrality policy of the Chinese government? In recent years, due to the impact of climate warming, COVID-19, and other factors on China’s carbon neutral development and public health, how to reflect it from scholars’ research and relevant policies, and how to view the role of academic research and policy promotion in China’s environmental governance and public health are a series of issues worthy of attention and exploration.

Scholars worldwide have gradually enriched and diversified their research on climate change and carbon peak carbon neutrality. For example, from the level of international climate governance and global governance, it gradually enriches, deepens, and transitions to national governance, industrial governance, and provincial and municipal regional governance [38,39,40,41,42,43,44]. Some scholars have conducted research on government measures for carbon neutrality, company development and transformation, green practices, low carbon, energy-saving, and environmental protection [45,46,47,48]. Meanwhile, some scholars have gradually increased their research on carbon reduction plans and carbon neutrality from different dimensions and levels of methodology [48,49,50].

Many scholars and teams in China have been engaged in research on climate change, resources and environment governance, environmental economy, and public policy evaluation and sustainable development [31,32,33,34,35,36,37,51,52,53,54,55,56]. Many of the international research achievements of these Chinese scholars are specific research, interdisciplinary scientific research, and comprehensive research related to climate change response, carbon peaking and carbon neutrality in urban governance, new energy, environmental governance, circular economy, renewable energy, biomass reuse, new technology development and application, and many other fields, which have high influence and academic contribution in international exchanges and cooperation, global governance, and domestic and foreign environmental governance [31,32,33,34,35,36,37,38,39,40,41,42,46,47,48,49,51,52,53,54,55,56,57,58,59]. Recently, more and more scholars have carried out policy tool analysis, organizational analysis, evolution analysis, and related research review analysis on China’s exploration and practice in climate change and carbon neutral construction [60,61,62,63,64]. Through the analysis of scholars’ research topics and research hotspots, we can explore the technology accumulation and frontier edge in the area [59]; by quantitatively analyzing the themes and keywords of policies, we can explore the concerns and support of policies in related fields, which is conducive to identifying the top-level design and policy trends of relevant departments [14]. In recent years, some scholars began to compare and analyze the keywords of relevant international research with policy keywords to explore the link between the research objects of academic circles and the government’s policy practice, and there are also some scholars who have conducted comparative analyses of the policies, measures, and practical experiences of China and other countries [65,66,67,68]. Many other scholars have carried out diversified and multi-dimensional research such as analysis and review of relevant research literature evolution, policy release and practice analysis, quantitative analysis of policy text or network text information, and construction of policy mechanism framework or method research framework [69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84]. In fact, there are many papers and monographs on scientometrics, bibliometrics, and quantitative analysis of policy documents in the existing research. In the analysis below, we carry out scientific metrology analysis and quantitative research on policy documents. The innovation of this study lies more in the combination of methods. By comparing research keywords and policy theme keywords, the interaction between academic research and policy promotion can be analyzed more clearly and accurately, which is conducive to China’s carbon neutral construction and sustainable development.

Scholars have conducted literature reviews, quantitative analyses, evolutionary analyses, and policy analyses on climate change response and carbon neutrality construction [3,4,5,60,66,69,70,71,72,73,74]. However, few studies have focused on comparative research between scientific econometric analysis and policy analysis, as well as quantitative analysis of policy literature. Based on this research gap, this article selects research papers from Web of Science related websites and databases as the research object, and searches and downloads policy documents from official websites and policy databases as the research object, to conduct scientific quantitative analysis and policy document quantification. This study explores the development, evolution, research hotspots, and keywords of international research on carbon neutrality by Chinese scholars, and conducts a comparative analysis based on China’s national policy system, action priorities, and themes during the same period. It preliminarily sorts out the interaction and influence between Chinese academia, and explores the similarities and differences, connections, and functional relationships between academic research and policy deployment.

2. Knowledge Map Visual Analysis of China’s Carbon Neutrality International Research

The concept and formulation of mapping knowledge domains or knowledge maps can be traced to a symposium on mapping knowledge domains organized by the NAS (National Academy of Sciences) in America in 2003, and then it was introduced into China in 2005; as a new technology and method of bibliometrics, scientometrics, citation analysis, and visual analysis, it gradually rose and developed rapidly [85,86,87,88]. Synthesizing the research of scholars, knowledge maps are based on the knowledge domain and scientific knowledge, and the object of analysis specifically includes the academic carrier form of scientific knowledge represented by all sample data sources related to the research topic [86,87,88,89,90]. Through the combination of scientific metrological methods such as thematic analysis and citation analysis with computer programming modeling, multivariate statistical analysis, social network analysis, and other methods, the image of the development process and structural relationship of scientific knowledge is displayed [87,88,89,90,91].

We select international research articles on carbon neutrality by Chinese scholars during the period of 2006–2021. In this study, “Chinese scholars” refers to scholars whose academic institutions are Chinese research institutions and whose nationality is Chinese. In the process of paper data collection, screening, and cleaning, we screen the relevant information of scholars one by one to ensure the accuracy and clarity of the data, then carry out the analysis of the paper data, and use the CiteSpace software to draw the knowledge map of China’s carbon neutrality international research keywords [89,90,91]. The Kyoto Protocol came into effect in 2005. In 2006, “carbon-neutral” was evaluated as the word of the year by the New Oxford American Dictionary. Studies on carbon neutrality have become the focus of scholars from all over the world, especially Chinese scholars. Since 2006, the quantity and quality of international research by Chinese scholars has increased. Moreover, in 2007, the State Council of PRC issued the CNCCP (China National Climate Change Program), which is the first national program issued by a developing country to address climate change, demonstrating China’s positive attitude to climate change. Based on the increasing trend of Chinese scholars’ research on carbon neutrality since 2006, we select the relevant international research literature for a period of 15 years from 2006 to 2021 to carry out scientometrics analysis and visual analysis of the knowledge map. We select the WOS database (http://www.isiknowledge.com/, accessed on 1 January 2023) which is relatively comprehensive and highly credible for the sources of Chinese scholars’ international research articles on carbon neutrality, and continue to select the “Web of Science Core Collection” in the database for retrieval, download, and analysis of higher quality articles. We use “carbon neutral*” and other words related to carbon neutrality for example “carbon-neutral”, “carbon neutrality”, “carbon neutral”, and “carbon neutralization” as the search formula, and search for various articles published by scholars from China with these words from 2006 to 2021. After further screening, elimination, and refining, we finally obtain 391 international research articles by Chinese scholars directly related to “carbon neutrality”, which are used as the research objects for our scientometrics and visual analysis.

2.1. The Stage Division, Major Cooperative Countries, Major Discipline Classifications, and Major Research Organizations of China’s Carbon Neutrality International Research Achievements

The scientific metrological analysis and visual analysis of knowledge maps of international research achievements published by scholars in a certain field and country can more clearly explore the academic research interests, popular topics, and frontiers of scholars in a certain field and country, and understand the evolution and development of the focus, popular areas, and frontiers of the field and discipline. It can provide important academic observation and help suggestions for the development of academic field and top-level policy design [87,88,89,90,91]. Carrying out scientometrics analysis and knowledge map visualization analysis of international research results published by scholars in a certain field and country can more clearly explore and understand the evolution and development of the field, the key points, key topics, and frontiers of this field, and provide important academic observations and suggestions for the development of the academic field and the top-down design of policies [87,88,89,90,91]. After refining and analyzing 391 international papers on carbon neutrality research by Chinese scholars, we draw the annual distribution and stage division map of China’s carbon neutrality international research papers, as shown in Figure 1.

Figure 1 shows that the general trend of publications of Chinese scholars’ international research papers on carbon neutrality is increasing yearly. According to the annual number of publications, the cumulative number of publications, the fluctuation growth trend, and the impact of policies, this research divides the development stages of the thesis into three parts: (1) The first stage is the preliminary and decentralized exploration stage (2006–2013). During this period, the cumulative number of published papers fluctuated within 50. China has also begun to gradually participate in the global response to climate change, contributing its own strength. The research popularities and achievements of Chinese scholars have gradually increased. (2) The second stage is the gradual and steady growth stage (2014–2019). During this period, more and more papers were published directly related to carbon neutrality, forming an orderly and rapid growth trend. In December 2015, the United Nations Climate Change Conference formally adopted the Paris Agreement, which defined the global actions and plans to address climate change after 2020. Chinese scholars are paying more and more attention to carbon neutrality research, and relevant research also revolves around national policies and domestic and foreign actions and initiatives. (3) The third period is from 2020 to 2021, which is a period of rapid growth. During this period, the results of international papers on carbon neutrality research by Chinese scholars ushered in an explosive growth, and the cumulative number of directly related results increased rapidly from over 100 to nearly 400. China has issued various policy documents related to carbon peak and carbon neutrality, carried out top-down design and substantive actions, and promoted the deployment and development of various research and activities focused on climate change, environmental management, and achieving carbon neutrality. This period is also known as the new era of carbon neutrality in China.

As shown in

Table 2. The major cooperative countries and regions of China’s carbon neutrality international research (2006–2021).

No.	Countries/Regions	Paper Numbers
1	USA	27
2	Australia	15
3	Pakistan	14
4	England	13
5	Japan	12
6	Turkey	12
7	France	9
8	Germany	8
9	Canada	7
10	Republic of Korea	5

, except for China, according to the number of relevant international cooperation achievements, the countries and regions where China conducts research cooperation in the carbon neutral field mainly include USA (27 articles), Australia (15 articles), Pakistan (14 articles), England (13 articles), Japan (12 articles), Turkey (12 articles), France (9 articles), Germany (8 articles), Canada (7 articles), and Korea (5 articles).

Moreover, India, Malaysia, Saudi Arabia, Scotland, Austria, Romania, Switzerland, Greece, Spain, and other countries and regions are where Chinese scholars have conducted international research cooperation on carbon neutrality.

As shown in

Table 3. The major disciplinary categories of China’s carbon neutrality international research (2006–2021).

No.	Web of Science Categories	Paper Numbers
1	Environmental Sciences	98
2	Energy Fuels	50
3	Physical Chemistry	39
4	Multidisciplinary Materials Science	34
5	Environmental Engineering	32
6	Electrochemistry	26
7	Chemical Engineering	26
8	Green Sustainable Science Technology	25
9	Multidisciplinary Chemistry	23
10	Analytical Chemistry	22

, we conducted a statistical analysis of the Web of Science categories under the Web of Science database for the international research results of Chinese scholars on carbon neutrality retrieved from the database. According to the distribution of the number of articles classified by subject, the top-ranked disciplines in this study are: environmental sciences (98 articles), energy fuels (50 articles), physical chemistry (39 articles), multidisciplinary materials science (34 articles), environmental engineering (32 articles), and other disciplines.

In addition, there are many new disciplines and interdisciplinary subjects such as nanoscience/nanotechnology, economics, public environmental occupational health, biotechnology, applied microbiology, etc.

As shown in

Table 4. The major institutions of China’s carbon neutrality international research (2006–2021).

No.	Institutions (Affiliations)	Paper Numbers
1	Chinese Academy of Science	48
2	University of Chinese Academy of Science (CAS)	21
3	Tsinghua University	19
4	Shandong University	28
5	Xiamen University	26

, the major research institutions that have published more papers on international carbon neutrality research by Chinese scholars are the Chinese Academy of Science (48 articles), the University of Chinese Academy of Science (CAS; 21 articles) Tsinghua University (19 articles), Shandong University (10 articles), and other institutions.

In addition, North China Electric Power University, Qingdao University, Southwest University, Tongji University, Dalian University of Technology, and other universities and institutions have also participated in carbon neutrality research.

2.2. The Keywords and Hotspots Evolution of China’s Carbon Neutrality International Research Achievements

After retrieving, downloading, and refining articles in the database, we carry out the evolution analysis, scientometrics, and visual analysis of keywords and hotspots on the results of international research papers on carbon neutrality in China. Many scholars around the world have found that the keywords and research hotspots of the paper results are the focus and concentrated expression of the research content in academic research, and they can reflect the accumulation of knowledge, popular frontiers, and development trends in a certain discipline, field, and aspect [86,87,88,89,90,91]. We use CiteSpace software (version 5.8. R3) to create and draw the knowledge maps of keywords for Chinese scholars’ international research on carbon neutrality. Through visual analysis, we can explore the cooperation network, research topics, and research key areas of carbon neutrality research, which can further our understanding of the evolution, accumulation, and development of carbon neutrality research in China [86,87,88,89,90,91]. Taking the results of 391 international research papers on carbon neutrality by Chinese scholars as the original data and research objects, two types of knowledge maps of China’s carbon neutrality international research keywords and research hotspots are drawn, namely, a timeline-type knowledge map (Figure 2) and a node-type knowledge map (Figure 3).

Figure 2 and Figure 3 reflect the cooperative network, evolution process, main sub-networks, cooperative clustering, and primary nodes of China’s carbon neutrality international research. The primary nodes are presented in the form of keywords and key research areas, and the co-occurrence of subject words is presented through the connection of networks and sub-networks. On the right side of Figure 2, there are also sub-networks marked with “#” and numbered to indicate cluster names. According to the analysis of Figure 2 and Figure 3 combined with the existing paper data, it can be seen that the keywords and areas with high co-occurrence frequency are “carbon neutrality” (53 times), “climate change” (50 times), “carbon neutral” (48 times), “carbon neutralization” (40 times), “impact” (31 times), “co2 emission” (28 times) times), “economic growth” (28 times), “China” (26 times), “performance” (24 times), “energy” (22 times), “energy consumption” (19 times), “renewable energy” (17 times), etc. According to Figure 2 and the existing literature and policy analysis, it can be seen that with the passage of time and the transition of different stages, after entering the stage of explosive growth in 2020, except for conventional keywords and topics, keywords such as “policy”, “plan”, and “action” that indicate policy promotion, top-down design, and deployment are gradually increasing. In addition, the keywords and research hotspots of comprehensive research, cross-study, and integration of various methodologies such as “system”, “mechanism”, and “evolution” of these mechanisms, systems, evolution, and methodologies are gradually increasing. The main cooperation sub-networks, primary nodes, and other contents are clustered and analyzed, as shown in Figure 3. Using the software, a few research areas and various clusters of about 12 topics can be obtained, such as “#1 carbon neutrality”, “#2 ru particle”, “#2 acoustic emission”, “#3 cng 2020 strategy”, “4# determination”, “#5 carbon steel”, and other clusters and sub-networks.

Through the statistical analysis and knowledge map visual analysis of the results of Chinese scholars’ international research papers on carbon neutrality in 2006–2021, we sort out and summarize the hotspots and keywords evolution of China’s carbon neutrality international research. In the two periods of the preliminary and decentralized exploration stage (2006–2013) and the gradual and steady growth stage (2014–2019), the research theme and hotspots gradually changed from the macro, “carbon neutrality”, “climate change”, “impact”, “CO₂ emission”, to the micro and medium, characteristic “China”, “impact”, “economic growth”, “performance”, “energy consumption”, “renewable”, and “energy”. Finally, during the explosive growth stage (2020–2021), the achievements of international papers on carbon neutrality research by Chinese scholars ushered in an explosive growth. The research themes have gradually focused on the policy and implementation levels of “policy”, “plan”, and “action”, as well as mechanisms and systematization levels such as “system”, “mechanism”, and “evolution”. The research on evolution, methodology, emerging disciplines, and interdisciplinary research has gradually increased, and the relationship between academic research and policy deployment has become more and more closely related.

3. Quantitative Analysis of National Policy Documents of Carbon Neutrality in China

3.1. The Time Series Evolution of National Policies and Initiatives of Carbon Neutrality in China

The research of policy document quantification (also known as “policy text computing” by some scholars) is to integrate quantitative analysis, theoretical methods of computational social sciences, bibliometrics, information metrology, scientific metrology, and other theories and methods in the field of policy analysis, develop quantitative analysis of comprehensive methods, and through a range of information such as cooperative networks, network nodes, issuing institutions, policy keywords, policy evolution, and analysis of elements and relations to explore the timing development and structural evolution of policies [92,93,94,95,96]. Over the years, many scholars and teams in the field of information management and other fields have conducted quantitative research on policy literature in fields such as scientific and technological innovation, education, scientific and technological finance, environmental governance, artificial intelligence, Internet information governance, and other multi-field and multi-type policies, and explored the evolution of policy themes and changes in the relationships between government departments [93,94,95,96,97].

From the official website of the State Council of China, China Government Network (https://www.gov.cn/, accessed on 1 January 2023), the National Development and Reform Commission (https://www.ndrc.gov.cn/, accessed on 10 November 2022) and relevant websites of other national ministries and organizations, we search and obtain a certain number of national policies directly related to carbon neutrality, and according to the theme of carbon neutrality, we continue to search supplement, download, refine, and select some national policy documents data on the PKULAW policy database website (https://www.pkulaw.com/law?isFromV5=1, accessed on 10 November 2022) and the “IPOLICY” policy analysis system website (http://39.105.58.246/ipolicy/, accessed on 1 January 2023) of Center for Science, Technology, and Education Policy (CSTEP), Tsinghua University. Finally, after screening and refining, 239 national policies directly related to carbon neutrality are obtained. Combined with a series of initiatives and positive contributions of Chinese government, this study preliminarily draws a process map of the phase division and chronological evolution of China’s carbon neutrality national policies and major initiatives, as shown in Figure 4.

Based on China’s carbon neutrality national policy data, as well as some positive contributions and substantive initiatives of the Chinese government at home and abroad, we also divided the evolution stages of China’s carbon neutrality national policies and initiatives into three stages with reference to the division of development stages of carbon neutrality paper achievements in Section 2 of this paper, so that we can better carry out comparative analysis of academic research and policy initiatives. As shown in Figure 4, the representative policies and main initiatives are as follows:

First, around the time of the preliminary and decentralized exploration stage (2006–2013), countries around the world and China successively adopted some policies and initiatives. In 1997, countries signed the Kyoto Protocol, and agreed to reduce carbon emissions from 2005. In 2005, the Kyoto Protocol came into effect. In 2007, the State Council of PRC issued the China National Climate Change Program (CNCCP), which is the first national program issued by a developing country to address climate change, demonstrating China’s positive attitude to combatting climate change. In 2009, Chinese leaders attended the Copenhagen Conference and the high-level meeting of the Climate Change Conference. China has always promoted the formation of the Copenhagen Accord, and actively participated in adhering to the dual track system of the United Nations Framework Convention on Climate Change and the Kyoto Protocol. In 2013, China released the National Climate Change Adaptation Strategy, the first strategic plan specifically for climate change adaptation, and formulated the key adaptation tasks according to the impacts of climate change in various fields and the basis of adaptation work.

Second, during the gradual and steady growth stage (2014–2019), China’s carbon neutrality policies and initiatives began to increase and be paid attention. In December 2015, the United Nations Climate Change Conference formally adopted the Paris Agreement, which defined the global actions and plans to address climate change after 2020, and set the long-term goal of carbon neutrality. Since then, more and more governments have translated the goals of the “Paris Agreement” into national strategies and policies and put forward the vision of net zero emissions. In 2015, Chinese leaders attended the Paris Conference and delivered important speeches, demonstrating China’s determination to actively achieve carbon neutrality, strive to achieve a win-win situation, and achieve common human development.

Third, around the period of the explosive growth stage (2020–2021), China entered a new era of carbon neutral policy release, and a number of national policies were issued in a centralized manner, forming a systematic and comprehensive “1 + N” policy system. The Chinese government has also become more and more deeply integrated into the independent contribution and active construction of the global climate change response, environmental governance, carbon peaking, and carbon neutrality target actions.

3.2. The Quantitative Analysis of National Policies of Carbon Neutrality in China and the Comparative Analysis of Policy and Research Keywords

Policy documents quantification, or policy text computing, is a new way of interpreting policy texts, including content analysis, network structure analysis, relationship analysis between issuing organizations, discourse analysis, consistency analysis, etc. [91,92,93,94,95]. Many scholars use the co-occurrence of keywords in policy literature to carry out quantitative analysis and visual analysis, to show the evolution of relevant policy themes and keywords in different periods, the relationship with other themes and keywords, and other content, as well as the number of network connections and co-occurrence times to reflect the relevance, importance, and other information and content of policy themes [92,93,94,95,96,97]. This study is based on 239 policy text data points used to carry out co-occurrence analysis of policy themes and keywords of China’s carbon neutrality national policy at different stages, and combined with the keywords of international carbon neutrality research, comparative research and supplementary discussion are carried out. We use VOSviewer (version 1.6.19) to screen and clean up the policy literature data, and then draw the keywords co-occurrence map of China’s carbon neutrality national-level policies.

As shown in Figure 5, this study integrates the preliminary and decentralized exploration stage (2006–2013) and the gradual and steady growth stage (2014–2019) of China’s carbon neutrality national policy development. Because these two stages are the gradual and orderly growth of China’s carbon neutral policies and measures, they have certain similarities, growth and continuity in scale. The focus of policies and measures in these two periods has a certain degree of continuity and overlap. The policy themes and keywords in these two periods are derived from the main keywords such as “climate change” and “global warming”. China’s national policies are largely deployed, designed, and implemented based on the global response to climate warming and climate change, as well as domestic environmental governance. For example, in 2007, China released the “China National Climate Change Program” (CNCCP), which is the first national-level project released by China. We also find that the policies of these two periods are integrated and are mainly divided into two relatively large clusters of policy themes and keywords: The first cluster is the keyword cluster based on “carbon neutrality” macro and meso policies. The co-occurrence keywords include “carbon neutrality”, “carbon peak”, “low-carbon policy”, “environmental protection”, “green development”, “Paris Agreement” and other macro and meso carbon neutrality policies, environmental protection, and governance policy-level keywords, as well as keywords such as “carbon neutral community”, “carbon neutral project”, “climate monitoring”, and other mesoscopic and specific carbon neutral governance and engineering levels. The second cluster is based on the policy themes and keywords of industry and industrial environmental regulation, environmental governance, and carbon neutral action. The co-occurrence keywords include “energy conservation”, “infrastructure”, “industrial system”, “carbon emission market”, and so on.

In 2013, China released the National Climate Change Adaptation Strategy, the first strategic plan specifically for climate change adaptation, and formulated the key adaptation tasks according to the impacts of climate change in various fields and the basis of adaptation work. In 2015, China submitted to the United Nations the “Strengthening Action on Climate Change—China’s National Independent Contribution”. China has always focused on climate change and environmental governance, and has regarded green and low-carbon development as an important strategy and approach for the construction and development of ecological civilization for a long time in the future. A series of actions have been taken, making important contributions to addressing global climate change. Government departments and organizations actively implement “China’s National Plan for Addressing Climate Change”, “Twelfth Five-Year Plan for Greenhouse Gas Emission Control”, “Twelfth Five-Year Plan for Energy Conservation and Emission Reduction Comprehensive Work Plan”, “Twelfth Five-Year Plan for Energy Conservation and Emission Reduction”, “2014–2015 Energy Conservation, Emission Reduction and Low-Carbon Development Action Plan” and “National Climate Change Plan (2014–2020)”, accelerate the implementation of the “National Strategy for Adaptation to Climate Change”, focus on improving the ability to respond to extreme climate events, and make positive progress in adapting to climate change in key areas. The capacity building to deal with climate change is further strengthened, and the “China’s Special Action on Climate Change Science and Technology” is implemented, and the scientific and technological support capacity is enhanced.

In these two periods, the keywords of scholars’ research and the key points of national policies have shown a relatively alienated relationship from the beginning. With the increase of academic research papers and policy initiatives, they began to have a great degree of overlap and interaction and became closer. In addition, it is also found in the study that after the relevant epidemic situation in COVID-19 began to appear in 2019, the government began to introduce some preliminary policy measures.

As can be seen from the co-occurrence diagram of policy keywords in Figure 6, after China’s carbon neutrality policy entered an explosive growth stage, policy themes and main keywords entered a very diverse and rich new era. In addition to co-occurrence keywords such as traditional, comprehensive, and macro “carbon neutrality”, “carbon peak”, “climate change”, “environmental protection”, and “sustainable development”, there are also keywords related to substantive actions carried out around various fields and industries. For example, the keywords “energy conservation” related to the green and low-carbon transformation of energy, “industrial system” related to the carbon peaking action in the industrial field, “low-carbon city” related to the carbon peaking action of urban and rural construction, “green transportation” and “new energy vehicle” related to green and low-carbon actions in transportation, “circular economy” and “green finance” related to circular economy’s contribution to carbon reduction actions, and “technological innovation” and “technology R&D” related to green and low-carbon technological innovation actions have been successively presented. During this period (2020–2021), policies and measures related to climate change, energy transformation, carbon neutral development, and COVID-19 epidemic prevention and control were intensively introduced and implemented.

The “1 + N” policy system of carbon neutrality in China mentioned here in this study is shown in

Table 5. China’s carbon peak and carbon neutrality “1 + N” policy system.

1	Date	Department	Policy Document
Top-Down Design	24 October 2021	The Central Committee of CPC, The State Council	Opinions of the Central Committee of CPC and the State Council of China on Completely, Accurately and Comprehensively Implementing the New Development Concept and Doing a Good Job of Carbon Peak and Carbon Neutrality
	26 October 2021	The State Council	Carbon Peak Action Plan by 2030
N series	Date	Department	Policy Document
Green and Low-Carbon Transformation of Energy	22 March 2022	National Development and Reform Commission, National Energy Administration	The 14th Five Year Plan for Modern Energy System
	23 March 2022	National Development and Reform Commission, National Energy Administration	Medium and Long-Term Plan for the Development of Hydrogen Energy Industry (2021–2035)
Energy-Saving, Carbon-Reducing, and Efficiency-Increasing Actions	24 January 2022	The State Council	Comprehensive Work Plan for Energy Conservation and Emission Reduction in the “14th Five-Year Plan”
	3 February 2022	National Development and Reform Commission, Ministry of Industry and Information Technology, Ministry of Ecology and Environment, National Energy Administration	Implementation Guide for Upgrading Energy Conservation and Carbon Reduction in Key Fields of High Energy Consumption Industries (2022 Edition)
Carbon Peak Action in the Industrial Field	20 January 2022	Ministry of Industry and Information Technology, National Development and Reform Commission, Ministry of Ecology and Environment	Guiding Opinions on Promoting High Quality Development of Iron and Steel Industry
	11 February 2022	National Development and Reform Commission	Implementation Guide for Upgrading Energy Conservation and Carbon Reduction in Cement Industry
	28 March 2022	Ministry of Industry and Information Technology, National Development and Reform Commission, Ministry of Science and Technology, Ministry of Ecology and Environment, Ministry of Emergency Management, National Energy Administration	Guiding Opinions on Promoting the High Quality Development of Petrochemical Industry in the 14th Five-Year Plan
	12 April 2022	Ministry of Industry and Information Technology, National Development and Reform Commission	Guiding Opinions on High Quality Development of Chemical Fiber Industry
	12 April 2022	Ministry of Industry and Information Technology, National Development and Reform Commission	Guiding Opinions on High Quality Development of Industrial Textile Industry
Carbon Peak Action in Urban-Rural Construction	17 November 2021	Ministry of Agriculture and Rural Affairs	Guiding Opinions on Expanding Multiple Functions of Agriculture and Promoting High Quality Development of Rural Industry
	6 January 2022	Ministry of Housing and Urban-Rural Development	The Action Plan for Promoting the Development of Urban and Rural Construction in the Yangtze River Economic Belt in the “14th Five-Year Plan”
	6 January 2022	Ministry of Housing and Urban-Rural Development	The Action Plan for Ecological Protection and High quality Development of Urban and Rural Construction in the Yellow River Basin in the “14th Five-Year Plan”
	1 March 2022	Ministry of Housing and Urban-Rural Development	The 14th Five-Year Plan for Scientific and Technological Development of Housing and Urban Rural Construction
Green and Low Carbon Actions in Transportation	1 March 2022	Ministry of Transport, National Railway Administration, Civil Aviation Administration of China, State Post Bureau	Implementation Opinions on Promoting the High Quality Development of Transportation in Central China in the New Era
Carbon Reduction Action Supported by Circular Economy	1 July 2021	National Development and Reform Commission	The “14th Five-Year Plan” of Circular Economy Development Plan
Green and low -carbon technical innovation Green Low Carbon Science and Technology Innovation Action	Unpublished	Green low carbon science and technology innovation action is one of the “Top Ten Actions for Carbon Peak”. Give full play to the supporting and leading role of scientific and technological innovation, improve the system and mechanism of scientific and technological innovation, strengthen innovation capability, and accelerate the green low-carbon scientific and technological revolution. It includes improving the innovation system and mechanism, strengthening the construction of innovation capacity and personnel training, strengthening the basic research of application, and accelerating the research and development, promotion, and application of advanced and applicable technologies.
Consolidation and Improvement of Carbon Sequestration Capacity	31 December 2021	National Forestry and Grassland Administration	Guidelines for Validation and Certification of Forestry Carbon Sequestration Projects
	21 February 2022	Ministry of Natural Resources	Economic Value Accounting Method of Marine Carbon Sink
The Green Low Carbon National Action	7 May 2022	Ministry of Education	Work Plan for Strengthening the Construction of Higher Education Talent Training System with Carbon Peak and Carbon Neutrality
Cascade Orderly Carbon Peak and Carbon Neutrality Actions in Different Regions	The specific implementation policies of each province and city were introduced in the form of strategic guidance documents, safeguard support documents, local laws and regulations, etc.
Safeguard and Support Policy	14 December 2021	China Development Bank	Implementing Green Low Carbon Finance Strategy to Support Carbon Peak and Carbon Neutrality Action Plan
	15 March 2022	Ministry of Ecology and Environment	Accounting Methods and Reporting Guidelines for Greenhouse Vapor Emissions of Enterprises Power Generation Facilities (Revised in 2022)
	30 April 2022	National Development and Reform Commission	Announcement on Clarifying the Behavior of Operators in the Coal Field to Raise Prices
	18 August 2022	Ministry of Science and Technology, National Development and Reform Commission, Ministry of Industry and Information Technology, Ministry of Ecology and Environment, Ministry of Housing and Urban-Rural Development, Ministry of Transport, Chinese Academy of Sciences, Chinese Academy of Engineering, National Energy Administration	Implementation Plan for Supporting Carbon Peak and Carbon Neutrality by Science and Technology (2022–2030)

Source: According to references [25,26,27,28,29,30].

.

Among them, “1” refers to a top-down design, and two documents are the top-down design documents of carbon peak and carbon neutrality, which run through the two stages of carbon peak and carbon neutrality; “N” refers to a series of sub policies under the top-level design policy, as well as subsequent branch policies at all levels and parts. The two top-level policies mentioned are the “Opinions on Completely Accurately Implementing the New Development Concept and Doing a Good Job in Carbon Reaching Peak and Carbon Neutrality” (“Opinions”, 24 October 2021) and the “Action Plan for Carbon Peaking by 2030” (“Plan”, 26 October 2021). The dual-carbon top-down design documents set the main goals for 2025, 2030, and 2060. Among them, the “Opinions” puts forward 31 key tasks from 10 major aspects, which play a leading role in the dual carbon policy system. The “Plan” identifies 10 major actions for carbon peaking and clarifies the roadmap and construction plan for the dual-carbon goal. After the introduction of the “1” top-down design, the “N” policies are successively introduced at the central level, including implementation policies for industries in key fields and various support and guarantee policies. In addition to the central government, the specific implementation policies of the provinces also belong to N policies, which are issued in the form of strategic guidance documents, guarantee supporting documents, and local regulations. This research mainly sorts out the national policies issued at the central level, as shown in Figure 5.

From the quantitative analysis and visual analysis of international research keywords and key research areas in Section 2, it can be seen that during the period of explosive growth, China’s national policies related to carbon neutrality have also ushered in very rapid growth. There has been a giant leap in quantity and quality. There is a deeper linkage effect and interaction between Chinese scholars’ academic research on carbon neutrality and policy measures. There are many cooperative studies by Chinese scholars who have untangled and analyzed China’s carbon neutrality goals, policies, and measures from different perspectives and fields [4,5,16,17,18,19,20,21]. Other researchers and practitioners have utilized various new methods and combinations of methods to study paper and policy texts on carbon neutrality research [62,63,64,69,82]. There are also many scholars who have carried out extensive international collaborative research on carbon neutrality with scholars around the world [3,36,37,38,39]. At present, many studies are gradually carried out under the “1 + N” policy system of China’s dual carbon strategy, and the introduction of many policies and implementation of measures have drawn on the research and suggestions of scholars. On the whole, this period has continued to the present, and the relationship between academic research and policy practice has become closer, and the cooperation network and interaction mechanism under the theme of carbon neutrality have become more and more perfect.

4. Discussion

This study first determined the stage division, major cooperative countries, major discipline classifications, and major research organizations of China’s carbon neutrality international research achievements, and continued to conduct quantitative analysis and knowledge graph visualization analysis on the evolution of keywords and key topics of Chinese researchers’ carbon neutrality international research achievements. This study found that in these periods of the initial decentralized exploration stage (2006–2013) and the gradual growth stage (2014–2019), the international research theme of carbon neutrality gradually transitioned from the macro “carbon neutrality”, “climate change” to the distinctive micro and medium-sized “China”, “performance”, “energy consumption”, and other key research areas and keywords. Finally, during the explorative growth stage (2020–2021), the achievements of Chinese scholars’ carbon neutral international papers ushered in an explosive growth, and the research topics gradually focused on the policy and implementation level of “policy”, “plan”, and “action”, as well as the mechanism and systematization level of “system”, “mechanism”, and “evolution”. Until now, the research on evolution, methodology, emerging disciplines, and cross disciplines has gradually increased, and the relationship between academic research and policy deployment has also become closer.

Subsequently, this study carried out the evolutionary analysis of policy issuance and implementation of measures, and the quantitative analysis of national-level policy literature research on China’s carbon neutrality. It was found that China’s carbon neutrality policies and initiatives achieved gradual and orderly growth in the preliminary and decentralized exploration stage (2006–2013) and the gradual and steady growth stage (2014–2019) of China’s carbon neutrality policy development, and the focus of policies and initiatives in these two periods had a certain degree of continuity and overlap. For example, the policy themes and keywords in these two periods are derived from the main keywords such as “climate change” and “global warning”, and China’s national policies were deployed, designed, and implemented to a large extent on the basis of global response to climate change, as well as domestic environmental governance. Since China’s carbon neutrality policy stepped into the explosive growth stage in 2020, the policy themes and keywords have entered a new era of great diversity and richness. In addition to traditional, comprehensive, and macro keywords and themes such as “carbon neutrality”, “carbon peak”, “climate change”, “environmental protection”, and “sustainable development”; there are also policy themes and keywords related to substantive actions in various fields and industries. After entering the new era of carbon neutrality, China initially formed a “1 + N” policy system, which is an organic combination of a set of top-down design policies and a series of supporting policies in various fields and industries.

China has been working actively and prudently toward the goals of reaching peak carbon emissions and carbon neutrality. Reaching peak carbon emissions and achieving carbon neutrality will mean a broad and profound systemic social economic transformation. China has also been actively involved in global governance of public health and environmental protection in response to climate change and the COVID-19 epidemic.

With the progress of scientific metrology and quantitative research on policy literature, scholars have gradually begun to conduct comparative research on key research topics, research frontiers, and policy documents’ focuses and keywords [90,91,92,93,94,95,96,97,98]. This study is different from traditional technical reports and review articles and is closer to a comparative analysis paper in the fields of scientific metrology and policy literature quantification in recent years [91,92,93]. Due to the large number of English articles published by Chinese scholars on this topic, and many domestic journals in China generally having English versions, we selected English articles from a larger and more representative number of Chinese scholars as the research object to conduct a comparative analysis between the focus of government documents and practical measures and the key research areas of scholars in the context of climate change and the recent COVID-19 pandemic. The theme of this study is relatively macro and has certain limitations. The specific relationship and impact between climate change, the COVID-19 epidemic, and carbon neutrality are not thoroughly discussed. In the next step of research, it is necessary to conduct in-depth and specific research on the interaction and impact in this area.

In recent years, the Vanke School of Public Health, Tsinghua University, and School of Environment, Tsinghua University, as well as other universities and research institutions have successively held a series of fora and conferences to discuss the relationships and impacts of COVID-19, environmental health, sustainable development, and other aspects, with good outcomes. Our authors’ team also organized and participated in some relevant meetings and research when preparing the paper. For example, we joined forces with the Ministry of Ecology and Environment of PRC, Tsinghua University, Shandong University, and other institutions to investigate the relationships between COVID-19 and environmental health in Sichuan Province, Xinjiang Uygur Autonomous Region, Hebei Province, Beijing City, Tianjin City, and other provinces and cities in China. On the whole, researchers from relevant institutions believe that the COVID-19 epidemic is closely related to environmental health, and the good governance of the epidemic and emergencies is conducive to the scientific and sustainable development of environmental health.

5. Conclusions

In the first part of the article, scientific metrology and knowledge graph visualization analysis methods are used to analyze international research papers related to carbon neutrality. In the second part of the article, we use the method of policy literature to analyze the relevant policies and carry out a comparative study in combination with key research topics. It is found that in the two periods of China’s carbon neutrality international research and national policy development—the preliminary and decentralized exploration stage (2006–2013) and the gradual and steady growth stage (2014–2019)—the overlap between international research keywords and policy theme keywords is increasing, and the intersection between the two is increasing. With the increase of scholars’ research, international cooperation, and exchanges, and the promotion of China’s positive carbon neutrality policies and initiatives, more and more academic key research areas and policy themes intersected, and the interactions were gradually enhanced. In the explosive growth period of China’s carbon neutrality international research and national-level policy development (2020–2021), with the outbreak of the COVID-19 epidemic, relevant academic research and policy initiatives shifted from focusing on technical and industrial issues to paying more attention to public health issues such as the governance of COVID-19. Meanwhile, the quality and quantity of policy measures and academic research have been increasing and becoming more diversified.

In general, with the alleviation of COVID-19, the recovery of the world and China’s economy, and the orderly progress of China’s green development, the overall research of Chinese scholars on environmental governance and carbon neutrality is increasingly focused and linked with national policy themes, and the interaction between scholars and politicians is increasing. In recent years, with China’s active participation in global environmental governance and public health in tackling climate change and preventing and controlling the COVID-19 epidemic, relevant academic research and policy design practices have been carried out in a scientific and orderly manner.