General Secretary Xi Jinping has repeatedly emphasized that China’s carbon dioxide emissions will peak before 2030, and the country will strive to achieve carbon neutrality before 2060. Activities related to industrial production and energy consumption are the main sources of carbon dioxide production. Vigorous promotion of carbon emission reduction in the industrial and energy fields is key to the successful implementation of new environmentally friendly development concepts, and to accelerate the construction of a modern industrial system, which in turn will help achieve carbon peaking, and then carbon neutrality. The old industrial cities have made historical and significant contributions to the formation and improvement of an independent and complete industrial system and national economic system in China, and have been indispensable in the post opening-up reform era, and during the current wave of modernization.

The old industrial city, as a basic unit, still faces many difficulties and challenges with the existing institutional mechanisms, policy systems, and governance methods. The past problems remain prominent and cause difficulties for the old industries to adapt to the requirements of the industrial green and low-carbon transformation. Through an in-depth study of the adjustment and transformation of old industrial cities, in the face of today’s good conditions, this paper aims to help accelerate the reform of high-quality economic development and promotion of green and sustainable development of the industrial economy. Promoting regional coordination and complementarity in order to reduce carbon emissions and pollution, are important to the success of building a beautiful, more affluent, healthier society. The policy of adjustment and reconstruction of old industrial bases across the country can be considered a starting point to achieving the environmentally friendly targets.

2. De-Industrialization

Old industrial cities were once the engines that drove rapid economic development in Europe and the USA. “De-industrialization” in the developed countries led to a severe recession. Similarly, due to market system changes, or the over-specialization of industries, old industrial cities will become prominent in developing countries, which will cause serious ecological and environmental problems ^[1]. How to promote carbon and pollution reduction, especially the green transformation of old industrial cities, with the goal of creating a sustainable “two-oriented society”, is a globally challenging task. Due to the characteristics of the industrial development cycle, it is harder to achieve green transformation in old industrial cities ^[2]. They may suffer from resource curse disadvantages that limit their ability to adapt to economic changes, and can cause serious air pollution problems ^[3]. In terms of the transformation path, old industrial cities have stronger needs than other regions. Trade unions, enterprises, and political figures with greater influence can promote regional green and low-carbon transformation and give play to the comparative advantages of emerging industries ^[4]. Steel production and heavy manufacturing dominated many of the cities in Pennsylvania. Therefore, the Pennsylvania Steel Authority was founded to address the city’s economic development needs. Strategies employed by the Authority included innovative regional connectivity mechanisms and issuance of early warnings to factories about closures and layoffs ^[5]. The prosperity of the old Austrian industrial area was based on steel and metal products, but it gradually declined due to a high degree of specialization and weak adjustment capacity; the area recovered through the optimization of regional innovation networks and indirect policy forms ^[6]. Due to the “industrial lock-in effect”, the competitiveness of traditional Czech industrial zones has declined. Through a low-carbon economy and industrial transformation, the Czech government actively develops modern industries (ICT industry and software industry), which increase the value of the green economy, and stimulate production and employment in low-carbon industries ^[7]. The French industrial sector promoted sustainable development by introducing a regional cluster plan to reverse its declining industries ^[8]. The revitalization of the traditional German shipbuilding industry has benefited from policy support and guidance on the development of emerging industries, and multi-level governance from the regional development environment ^[9]. The old industrial city of Lowell in the USA has accelerated the creative reuse of industrial heritage, and has actively improved the ecological environment of the city to promote the development of new tourism ^[10]. The key to the transformation of economic development in old industrial cities lies in the transformation of institutional paradigms. The dynamic characteristics of institutions have broad application prospects because of their unique utility. The process of urbanization and industrialization in China differs from that of Western countries. The analysis of evolution elasticity theory shows that the economic growth rate and industrial structure of old industrial cities can be differentiated ^[11]. Based on the life cycle theory, and taking the old industrial cities as the research object, the rationalization level of the industrial structure is not found to be high, the economic benefits of most enterprises are marginal, the land is largely idle, the industrial products are at the middle and low end of the value chain, and the innovation capacity is insufficient. The advantages of traditional industries such as iron and steel are weakened, the clean and low-carbon service industry is underdeveloped, the adjustment of industrial structure is slow, and the degree of integration between the service industry and the manufacturing industry is insufficient ^[12]. The transformation of old industrial cities often carries a serious loss for the young and high-quality labor force, and the burden of an aging labor force becomes more serious. This imbalance in industrial structure leads to structural unemployment, and social security becomes overwhelmed ^[13]. Shenyang City in Liaoning Province is a heavy industrial city, and the relationship between per capita GDP and carbon emissions is still coupled; the expected decoupling has not yet occurred ^[14]. As a typical industrial city, China’s Tianjin has more capital investment in industrial infrastructure than real estate, resulting in the largest carbon footprint. Since the early 2000s, Tianjin’s consumption-based carbon emissions due to capital formation have grown rapidly, reaching 72.9%, far exceeding Beijing and Shanghai in China ^[15]. The single-type old industrial base demonstration area in China, the effect of industrial structure transformation and upgrading, is not good, and the endogenous driving force for transformation and development is also weak ^[16]. Therefore, the transformation of industrial cities in the future should comprehensively deepen reforms, emancipate ideas, and create a stable policy environment. Old industrial cities should break down the institutional barriers that hinder its revitalization and focus on new economic services and high-end industrial modernization. The old industrial cities should accelerate towards a high-end low-carbon service-oriented economy and increase the added value of industrial green products ^[17].

3. Policy Introduction and Theoretical Mechanism

3.1. Policy Introduction

Achieving carbon peaking and carbon neutrality are necessary to solve the outstanding problems of resource and environmental constraints, and to ensure sustainable development, in turn nurturing China’s lucid waters and lush mountains. China’s “Notice of the State Council on Printing and Distributing the Action Plan for Carbon Peaking Before 2030” identified the need to establish an economic system of green, low-carbon, and circular development by 2025. The Notice also specifies that carbon dioxide emissions per unit of GDP will drop by 18% compared to 2020, and that substantial progress will have been made in the comprehensive green transformation of economic and social development, with carbon dioxide emissions reaching a peak and achieving stable and moderate declines by 2030. The government encourage key fields such as energy, industry, transportation, and construction to formulate special plans for peaking, and promote key industries such as steel, building materials, nonferrous metals, chemicals, petrochemicals, electric power, and coal to put forward clear peaking goals and formulate peaking action plans. By 2060, the goal of carbon neutrality will be successfully achieved, and a green, low-carbon, and cyclical economic system and a clean, low-carbon, safe, and efficient energy system will be fully established, creating a new realm of harmonious coexistence between man and nature. Old industrial cities face dual pressures in the process of carbon reduction due to their own unique realities. The proportion of traditional industries is still relatively high, and it is increasingly difficult to tap the potential of energy conservation. The coal-biased energy structure, inefficient energy utilization, and low utilization of clean energy remain apparent. The lack of advanced technology reserves, the shortcomings of energy-saving and efficiency-enhancing technological innovation, the tight time window for carbon peaking and carbon neutralization, and the arduous task of realizing the green and low-carbon transformation of old industrial cities, are the unwanted features that still dominate old industrial cities. In order to promote energy conservation, emission reduction, and the sustainable development of old industrial cities, the reform plan for renovating these cities should focus on transforming the mode of economic growth and promoting sustainable development. The government focusing on transforming the mode of economic growth and promoting sustainable development, focusing on the new competitive advantage of re-engineering the industry, taking promoting green and low-carbon development, and enhancing innovation support capabilities as an important focus, promote the comprehensive, coordinated, and sustainable development of old industrial bases, building it into an important new low-carbon industrial base for the country and a key growth pole for the high-quality development of the regional economy.

3.2. Conduction Path

By considering the success rate of the measures taken by 94 old industrial cities after the implementation of the adjustment and renovation policy, their transmission path is proposed. Representative cities in the eastern region (Zibo City, Shandong Province, China), central region (Changzhi City, Shanxi Province, China), and western region (Baiyin City, Gansu Province, China) were then selected for case analysis.

3.2.1. Green Innovation Capability

Industrial green innovation. The continuous innovation of urban intelligent green manufacturing technology can help transport an industry to the high end of the value chain, change the existing unsustainable technology and production system, and improve the level of informatization and automation of the manufacturing industry. The government can deepen the degree of coupling between the innovation chain and the industrial chain; increase the transformation of innovation achievements and the research and development, as well as the application of green and low-carbon cutting-edge technologies; accelerate the upgrading of low-carbon products and technologies; and form new manufacturing processes and equipment that are efficient, energy-saving, environmentally friendly, and recyclable, building a green zero-carbon manufacturing system, thereby greatly reducing carbon emission intensity. Industrial technological innovation can broaden the depth and breadth of the development and utilization of renewable clean energy and promote a revolution in energy consumption. Industrial green innovation also reduces excessive dependence on fossil fuels, optimizes energy industry structure and energy use ways, and improves the efficiency of the optimal allocation of energy industrial cities. The government accelerate the conversion of old and new kinetic energy in cities, and continuously overcome key energy-saving technologies in major energy-consuming fields of industry, so as to reduce total carbon emissions from the source ^[18]. Environment for innovation activities. An environment conducive to innovative scientific research and the construction of innovative service networks plays an increasingly important role in carbon emission reduction. Scientific research includes technological projects in the fields of energy conservation and environmental protection, low-carbon production, and clean energy, and forces and/or motivates enterprises to develop advanced production technology. The people in old industrial cities participate in and popularize the practice of green production and life, actively advocating green, low-carbon, and simple lifestyles in the whole society, and indirectly reduce the scale of carbon emissions ^[19].

3.2.2. High-End Industry Agglomeration

Efficient division of labor. Emerging high-end industrial clusters can reduce production and trade costs through the specialized division of labor and advantageous resource endowments, in turn effectively promoting business exchanges between enterprises. This will help reduce the volatility of demand for green and low-carbon products, deepen the division of labor in the industrial chain, and promote the extension of the industrial chain towards high added value ^[20]. Element sharing. The agglomeration of high-end industries is conducive to promoting the effective allocation of production factor resources and recycling urban infrastructure. Element sharing helps to reduce the transportation distance, expenditure cost, and time search cost in old industrial cities. Element sharing can improve the government’s treatment and utilization efficiency of pollutants, reduce the decentralized consumption of energy, improve the utilization efficiency of energy and elements, and thus promote the rapid reduction of urban carbon emissions. Spillover effect. The complementary effect of the modern low-carbon industry and its related industries will produce increasing returns to scale, resulting in the multiple effects of urban collaborative innovation, cutting-edge ideas, and spillover enhancement effects. The spillover effect will help to enhance the rooting and cohesion of the low-carbon industry, and increase the communication, interaction, and cooperation between enterprises and other related industries. The diffusion of urban clean technology will accelerate, and upstream and downstream enterprises will be promoted through exchanges and interaction along the industrial chain. In addition, other companies will benefit from the agglomeration of high-end low-carbon industries ^[21].

3.2.3. Ecological Governance

Firstly, ecosystem protection and restoration can significantly increase the coverage of natural vegetation, prevent soil erosion and dust storms, increase soil fertility, expand the total amount of forest and grass resources, maintain biodiversity, and effectively improve regional air quality. Ecological governance can change local albedo, turbulent energy, and mitigate natural disaster losses. Ecological governance can promote the enhancement of the carbon sequestration and carbon absorption capacity of forests and wetlands, and effectively reduce the total carbon emissions of cities. Afforestation programs that promote increased terrestrial carbon storage are an important means of helping to gradually reduce atmospheric CO₂ emissions ^[22]. The research on forest carbon sinks of Peking University also shows that for every cubic meter of forest growth, it absorbs about 1.8 tons of carbon dioxide on average, especially in the peak season of tree growth, the forest can absorb 1.6 kg of carbon dioxide per square meter per day. The United Nations Intergovernmental Panel on Climate Change estimates that the global forest carbon storage will exceed 11,000 tons. In order to achieve carbon neutrality, cities require conservation as well as sustainable management to increase carbon sink. Therefore, old industrial cities must formulate policies against deforestation and deforestation, promote scientific research on carbon sinks, actively build forest parks, and promote afforestation activities ^[23]. Research on the forest carbon sinks of Peking University also shows that for every cubic meter of forest growth, an average of 1.8 tons of carbon dioxide are absorbed; the forest can absorb 1.6 kg of carbon dioxide per square meter per day during the peak season of tree growth. Secondly, the expansion of the regional green area can optimize the urban ecological space pattern, enrich the urban connotation and functional quality, and continue to attract new workers. Profiting from their industrial heritage resources, cities can provide a high-quality creative environment and atmosphere through exhibitions and projects, creating green and low-carbon development ecological places, tourist attractions, and idyllic scenery complexes. Ecosystem protection will help cities fundamentally transform their original industrial structure of high energy consumption, high pollution, and high emission industries, realizing the integrated and diversified development of primary, secondary, and tertiary industries, continuously improving the “green content” of emerging industries, and accelerating the realization of low carbonization ^[24].

4. Conclusions and Policy Recommendations

4.1. Conclusions

The implementation of the old industrial city adjustment and renovation policy is a major project initiated by the Party Central Committee and the State Council to revitalize the green space and low-carbon transformation of old industrial cities. This paper uses data from 2006 to 2019 to obtain samples of 94 old industrial cities. Using the samples, this paper firstly analyzes the impact of the adjustment and renovation policies on the green space and carbon levels in old industrial cities, and then further analyzes the effective mechanism, decoupling model, and environmental hypothesis. The following conclusions are drawn:

(1)

Overall, the adjustment and renovation policies can produce a positive low-carbon and carbon-reduction effect, with an average reduction of about 0.068 units of carbon emissions. Compared with the average value, the implementation of the policy can reduce the urban carbon emissions by an average of about 310,670 tons. The policy implementation can effectively promote carbon reduction and pollution reduction in the middle quantile. There is no significant evidence that policy implementation leads to the transfer of pollution from old industrial cities to neighboring cities. The phenomenon of “blaming the neighbors” for serious pollution has not occurred, and thus the implementation of the policy can realize low-carbon regional development.

(2)

The adjustment and renovation policies of old industrial cities have had a distinct and negative effect on pollution reduction and carbon reduction for sample cities in the eastern and western regions, large cities, and cities connected to high-speed rail.

(3)

On the basis of summarizing excellent Chinese cases and conducting empirical estimates, it is found that after policy implementation, the innovation and improvement of urban green quality, the expansion of high-end industrial agglomeration scale, and the increase in ecological environment reconstruction are important mechanisms to reduce urban carbon emissions.

(4)

There is a significant “inverted U-shaped” CO₂ EKC in old industrial cities, but the “N-shaped” curve hypothesis does not hold. There are quite a few old industrial cities that have yet to cross the turning point of the EKC.

(5)

During the implementation of the policy, in 2013, about 62% of the old industrial cities showed a state of relative decoupling and absolute decoupling. As the years pass, the trend of an increasing fluctuation of this ratio becomes more prominent, thus reversing the rapid growth of carbon dioxide in old industrial cities.

4.2. Policy Implications

Based on the empirical results and conclusion analysis, the following policy recommendations are put forward: First, the city government should rationally design a dynamic path for carbon emission reduction to achieve absolute decoupling between economic growth and carbon emissions. City governments should fully integrate carbon peaking and carbon neutrality goals into medium- and long-term planning for economic and social development, and clarify the goals and outcomes of carbon reduction and carbon reduction tasks. City governments should cross the inflection point of the CKC curve as soon as possible; vigorously support cities with endowment conditions, key industries, and key enterprises to take the lead in peaking carbon emissions; and should not implement campaign-style carbon reduction. The government of the old industrial city should strengthen the top-level system design and promote the participation of diversified subjects, such as the government, society, and public, to realize the linkage of carbon emission reduction from top to bottom. Second, the government should take various measures to achieve green and low-carbon development. The government should strengthen the leadership of cutting-edge innovation in the industrial base, cultivate compound green and low-carbon talents, implement key core technology innovations, cultivate green and low-carbon emerging industries, promote cross-sector and cross-industry collaborative innovation, and accelerate industrial low-carbon transformation and digital transformation. The government should further increase the proportion of renewable energy production and consumption, and provide an important guarantee for the construction of a zero-carbon green energy system. The government should cultivate advantageous high-end industrial clusters; improve the coverage of regional communication infrastructure; strengthen regional division of labor and efficient cooperation; broaden the rational flow of production factors and channels; strengthen the coupling and linkage of green and low-carbon industries; and promote the advanced industrial foundation of industrial cities, the specialization of industrial division of labor, and the modernization of industrial chains. The government should speed up the transformation of the original extensive and high-carbon development mode; strengthen the restoration and management of the geological environment and vegetation coverage; enhance the ability to conserve water sources and soil; and realize the coordination and unity of the economic, ecological, and social benefits of resource development. Third, the government should build a cross-regional environmental coordination mechanism. The government should compile and apply a negative list for environmental access; implement an implementation plan for coordinating joint prevention, joint governance, and comprehensive governance; promote the simultaneous coordination of environmental regulations in adjacent areas; and strengthen the industrial division of labor and complementary advantages. The government should break the administrative level restrictions; build a cross-regional pollution-reduction and carbon-reduction coordination mechanism, and a cooperation platform; and achieve regional high-efficiency and integrated governance. The government should focus on the environmental effects of policy reforms in the central region cities, cities without high-speed rail, small cities, and medium-sized cities.