1.1. Background
Economic development is largely achieved through energy consumption. At present, energy consumption is still dominated by fossil energy consumption. While energy consumption promotes economic growth, it also causes a large amount of greenhouse gas emissions. The global warming problem caused by energy consumption has attracted widespread attention [
1]. Therefore, whether the decoupling of economic development and energy consumption can be realized has become the an important issue to scholars in various countries [
2]. As the world’s largest developing country, China has become the world’s second largest energy consumer. In 2018, China’s energy consumption reached 4.62 billion tons of standard coal, accounting for 24% of global energy consumption [
3]. Moreover, China is facing a more severe double test of economic transformation along with energy conservation and consumption reduction. No country is willing to reduce energy consumption at the expense of economic development, so it is particularly important to study whether China’s economic growth and energy consumption are decoupled and the driving factors that lead to decoupling.
China has significant regional differences in terms of energy consumption levels, economic development and technological upgrading. Therefore, it is particularly important to explore decoupling of energy consumption by region. The Qinghai-Tibet Plateau region is a special regional unit in western China. Its special geographical location and climate make the region rich in natural resources, and it also faces the most prominent problems of ecological environment degradation and herder poverty. Because of its particularities, scholars have done little research into the economic development and energy consumption of the Qinghai-Tibet Plateau. Therefore, in solving the problem of the relationship between energy consumption and economic growth, the Qinghai-Tibet Plateau is an extremely urgent and generalizable region to draw information from. To explore the decoupling relationship between energy consumption and economic development in the Qinghai-Tibet Plateau region, and to analyze the influencing factors that cause changes in energy consumption, certain data can provide support for energy conservation and consumption reduction in the region, and provide experience and reference for regions with similar characteristics around the world, so as to jointly realize sustainable development worldwide.
1.2. Literature Review
Decoupling originates from the field of physics, meaning that a response relationship between two or more physical quantities with corresponding relationships does not exist. Currently, the methods of decoupling analysis mainly include The Organization for Economic Co-operation and Development (OECD) decoupling model, changes in the amount of comprehensive analysis, Tapio elastic model, based on decoupling analysis complete decomposition technology, differential regression coefficient method and quantitative analysis method [
4,
5,
6]. For example, Abbas et al. [
7] used an autoregressive lag (ARDL) bound test to study the relationship between household energy use and economic development in Pakistan from 1972 to 2017. Because the differential regression coefficient method and econometric analysis method require relatively more data samples, while other methods are not accurate in their classifications of decoupling degrees, the Tapio elastic analysis method can further improve the objectivity and accuracy of decoupling analysis. The main methods used to analyze the influencing factors of energy consumption decoupling include the factor decomposition method, coefficient analysis method, equation method, causal method and other methods [
8,
9,
10]. Compared with other methods, the factor decomposition method is widely used due to its simple calculations and low data-size requirements. Among them, the LMDI method is the most widely used because it does not generate residuals and can effectively deal with zero-value problems. Thus, the Tapio model and the LMDI approach are often used to assess decoupling and drivers between economic growth and energy consumption. For example, Jana et al. [
11] quantitatively evaluated the relationship between economic development and energy consumption in V4 countries from 1991 to 2015 using the Tapio model. The results showed that most V4 countries are in a state of strong decoupling. Rocio [
12] used the Tapio model to analyze the decoupling degree of energy consumption in Colombia from 2000 to 2015. Wang et al. [
13] discussed decoupling in developing countries through a comparative analysis of the decoupling between economic growth and energy consumption in China and India. Lin et al. [
14] studied the decoupling between China’s economic development and energy consumption, and the results showed that it was mainly determined by secondary industries. In the research on decoupling of energy consumption, most scholars have analyzed it from the perspective of energy-related carbon emissions and the driving factors affecting decoupling. Engo et al. [
15] used the Tapio model to explore the decoupling of energy-related CO
2 from economic growth in the Cameroon transport sector between 1990 and 2016. The results showed that the growth rate of CO
2 is lower than the economic growth rate, which is mainly weakly decoupled. Wang et al. [
16] used Tapio and LMDI models to study the degree of decoupling between China’s economic development and energy-related carbon emissions and the driving factors of carbon emissions. The results showed that the factors restricting decoupling include the carbon coefficient effect, economic structure effect, labor force input effect and investment effect. Xie et al. [
17] also used the Tapio and LMDI models to analyze the factors influencing the decoupling of CO
2 emissions from GDP in China’s power industry, and they found that economic scale and electrification were the two main factors inhibiting it. Li et al. [
18] predicted that the decoupling relationship between China’s CO
2 emissions and economic development would become stronger between 2015 and 2030. Dong et al. [
19] examined Chinese economic growth and energy-related CO
2 emission decoupling driver forces from the perspective of spatial and temporal heterogeneity, and the results indicated that the influences of energy structure, energy intensity, industrial structure and technological progress in most regions were positive in the decoupling index, and are prompting weak decoupling to develop in most parts of China to develop.
In addition to analyzing the degree of decoupling between economic development and energy consumption at the national level, scholars have also discussed decoupling at the regional level. For example, Xu et al. [
20] studied the relationship between economic growth and carbon emissions during the urbanization of the Pearl River Delta, and Zhong et al. [
21] analyzed the relationship between economic growth and energy consumption in the Beijing-Tianjin-Hebei region. Similarly, Wang and Yang [
22] used the LMDI and Tapio models to analyze the decoupling relationship between industrial development and economic growth in the Beijing-Tianjin-Hebei region from 1996 to 2010. The results showed that most years demonstrated weak decoupling. Chen et al. [
23] studied the relationship between energy consumption and economic development in Macau from 2000 to 2013. The results showed that Macau has gone through four decoupling stages: expanded negative decoupling, weak decoupling, extended negative decoupling and strong decoupling. Shi et al. [
24] used the decoupling index to study the relationships between economic growth and energy consumption in China’s provinces. The results showed that North China, Northeast China and East China are in a state of strong decoupling. Wang et al. [
25] combined the Tapio model with the LMDI model to conduct a comparative study on the decoupling of carbon emissions from economic growth in transportation sectors in some provinces in eastern, central and western China. Studies showed that the decoupling degree of transport carbon emissions in the eastern, central and western regions were different, and that the driving factors for carbon emissions were similar. Wen and Zhang [
26] used the LMDI and Tapio models to analyze the influencing factors and decoupling statuses of energy industry carbon emissions in Liaoning province. The results showed that the changes in energy intensity and energy technology were opposite to the changes in industrial carbon emissions. Zheng et al. [
27] combined the LMDI and Tapio models to study the degree and driving factors of carbon emission decoupling in Shijiazhuang. The results showed that energy intensity was the most important driving factor affecting carbon emissions. Wang et al. [
28] directly compared the decoupling status and driving factors of the transportation industry in four municipalities under the central government of China, and concluded that Beijing was in a weak decoupling status, Shanghai and Tianjin were in a strong decoupling status and Chongqing changed from decoupling to negative decoupling. They determined that an energy-saving effect was the main driving factor behind the decoupling in these four cities.
In a large number of studies on the degree and drivers of decoupling between economic development and energy consumption, some further efforts to evaluate decoupling drivers have been made. For example, Etem et al. [
29] evaluated the decoupling process of Turkey and found that Turkey did not make or had made weak decoupling efforts in most cases, and that the biggest factor that had made decoupling efforts was energy intensity. Li et al. [
30] also found that energy intensity had made the biggest contribution to decoupling through an analysis of Central Asia. Wang et al. [
31] studied the status and efforts of urban carbon emission decoupling in different industrial stages in China, and concluded that cities in different industrial stages showed different decoupling states, driving forces and effects. However, to achieve energy conservation and emission reductions, efforts must be made to improve urban energy structures, energy efficiency and industrial structures. Yan et al. [
32] studied the status and efforts of carbon emission decoupling in China’s transportation sector from 1991 to 2015, and the study showed that only in 1991–1995, 2005–2010 and 2010–2015 was there effective work to mitigate carbon emissions.
The research methods and driving factors related to the decoupling of energy consumption and economic development are summarized in
Table 1, which is based on the above analysis and summary. Through literature analysis, most scholars have analyzed decoupling degrees at the levels of nations or regions from the perspective of energy-related carbon emissions, although few papers have studied energy decoupling directly. At the regional level, more studies have focused on more-developed regions, the results of which are not of significance to less-developed regions. Therefore, the present study chose the Qinghai-Tibet Plateau region to represent underdeveloped regions, employing the LMDI and Tapio models, decoupling state analysis and the driving factors of energy consumption and economic development to gather data. Furthermore, by using the decoupling effort model, this paper evaluated the degree of decoupling effort of each decoupling driver force. Finally, based on the results, energy consumption and economic development in Qinghai-Tibet plateau are proposed.