انتشار گازهای گلخانه ای در چین 2007: تجزیه و تحلیل موجودی و داده ستانده

For greenhouse gas (GHG) emissions by the Chinese economy in 2007 with the most recent statistics availability, a concrete inventory covering CO2, CH4, and N2O is composed and associated with an input–output analysis to reveal the emission embodiment in final consumption and international trade. The estimated total direct GHG emission amounts to 7456.12 Mt CO2-eq by the commonly referred IPCC global warming potentials, with 63.39% from energy-related CO2, 22.31% from non-energy-related CO2, 11.15% from CH4 and 3.15% from N2O. Responsible for 81.32% of the total GHG emissions are the five sectors of the Electric Power/Steam and Hot Water Production and Supply, Smelting and Pressing of Ferrous and Nonferrous Metals, Nonmetal Mineral Products, Agriculture, and Coal Mining and Dressing, with distinctive emission structures. The sector of Construction holds the top GHG emissions embodied in both domestic production and consumption, and the emission embodied in gross capital formation is prominently more than those in other components of the final consumption characterized by extensive investment in contrast to limited household consumption. China is a net exporter of embodied GHG emissions, with emissions embodied in exports of 3060.18 Mt CO2-eq, in magnitude up to 41.04% of the total direct emission.

Among the largest carbon dioxide emitters in the world (IEA, 2009), China has been considered responsible for two thirds of the global increase in anthropogenic carbon dioxide emissions of 3.1% in 2007 (Yan and Yang, 2010). Though the Chinese government has committed to cut the carbon dioxide emission per unit of gross domestic product (GDP), by 40–45% by 2020 against the 2005 level (Xinhua net, 2009), in the future the total amount of carbon dioxide emissions in China is expected to increase further, due to the projected lasting economic growth and increase in energy demand and household consumption. Non-CO2 emissions are also remarkably important, as illustrated by the global inventory for 2004 with CH4 comprising 14.3% of the total anthropogenic GHG emission (IPCC, 2007). According to the Initial National Communication on Climate Change of China (INCCCC, 2004), the GHG emission inventory for China 1994 reported that China’s GHG emissions in 1994 totaled 3650 million tons of CO2 equivalent (CO2-eq), of which CO2, CH4, and N2O contributed 73.05%, 19.73%, and 7.22%, respectively. Only considering the CO2 emissions cannot reflect the real situation and full-scale picture of China’s GHG emissions, especially in terms of sectoral structure and embodiment in final demand and international trade, and inclusive account of all the main GHG emissions in China remains to be carried out with more strength consistent with recent socio-economic development. The direct anthropogenic GHG emissions in China have been widely explored. Early in 2005, China produced 2.2 billion tons of coal which represents 37% of total coal production in the world and accounts for 75.9% and 70% of China’s total primary energy production and consumption, respectively (Cui, 2007). Over the years, the coal dominated energy and power structure has instigated a large number of studies on CO2 emissions from fuel combustion in China (e.g., IEA, 2009, Ji and Chen, 2010, Liu et al., 2007, Peters et al., 2006, Wei et al., 2007, Yan and Yang, 2010, Zhang, 2000 and Zhang et al., 2009). Notably, the calculation procedure provided in Peters et al. (2006) has been followed by Xu et al. (2009) and Yan and Yang (2010) in composing Chinese CO2 emission inventories. Meanwhile, China is the largest producer of rice grain with the world’s second-largest area of rice paddies and has a flourishing livestock production with a rapid increase in livestock numbers and the largest meat and egg yields in the world. In recent years, many empirical studies have focused on the estimation of CH4, and N2O emissions from agricultural activities (e.g., Cai, 1999, Cao et al., 1995, Guo and Zhou, 2007, Huang et al., 2006, Liu et al., 2000, Song et al., 1996, Verburg and Denier, 2001, Wang, 2001, Xing and Yan, 1999, Yamaji et al., 2003, Yan et al., 2003, Zheng et al., 2004, Zhou et al., 2007 and Zou et al., 2010), fugitive CH4 emissions from coal mining (e.g., Bibler et al., 1998, Li and Hu, 2008, Yang, 2009, Yuan et al., 2006 and Zheng, 2002), and total CH4 emissions in China (e.g., EPA, 2006, Khalil et al., 1993, Wang et al., 1993, Zhang and Chen, 2010a and Zhang et al., 1999). Many concrete efforts have been made to account GHG emissions from other sources such as waste treatment (e.g., Gao et al., 2006, Hou et al., 2006 and Xu, 1997). In particular, GHG emission inventories of China in 1994 (INCCCC, 2004), 2005 (Cai, 2009 and Chen et al., 2010), and 2006 (Zhang and Chen, 2010b) have been provided. Input–output embodiment analysis which facilitates a deeper appreciation of the sectoral total emission requirements in terms of both the direct, visible and indirect, hidden emission costs (Leontief, 1970 and Miller and Blair, 2009), has been popular as a main frontier method for benchmarking GHG emissions embodied in final consumption and international trade, as indicated by the rapid increase in the number of studies using different input–output models for several single countries (e.g., Andrew and Forgie, 2008, Chung et al., 2009, Ghertner and Fripp, 2007, Lenzen, 1998, Limmeechokchai and Suksuntornsiri, 2007, Mäenpää and Siikavirta, 2007 and Weber and Matthews, 2008) as well as multiple countries and regions (e.g., Chen et al., 2009, Lenzen et al., 2007, Liu and Wang, 2009, Peters and Hertwich, 2008, Weber and Matthews, 2007, Wiedmann, 2009 and Wiedmann et al., 2007), especially in CO2 emissions with a single country framework due to its empirical applicability (e.g., for Japan see Kondo and Moriguchi, 1998; for Brazil see Machado et al., 2001; for Denmark see Munksgaard and Pedersen, 2001; for Spanish see Labandeira and Labeaga, 2002, Roca and Serrano, 2007 and Sánchez Chóliz and Duarte, 2004; for Sweden see Kander and Lindmark, 2006; for Italy see Mongelli et al., 2006; for Norway see Peters and Hertwich, 2006; for Turkey see Tunç et al., 2007). As to China’s GHG emissions, much of the existing research has applied the input–output model to perform embodiment analysis of CO2 emissions. Prominent studies about China’s CO2 emissions were conducted by Weber, Peters and their colleagues in their series work (e.g., Guan et al., 2008, Guan et al., 2009, Peters et al., 2007 and Weber et al., 2008). Peters et al. (2007) analyzed the effects of changes in China’s technology, economic structure, urbanization, and lifestyles on CO2 emissions. According to them, 32% of China’s emission was embodied in exports and 34% avoided by imports in 2002. Weber et al. (2008) first presented a systematic study on the contribution of exports to China’s CO2 emissions during 1987–2005. Around one-third of Chinese emissions were estimated due to production of exports in 2005 (Weber et al., 2008). Guan et al. (2008) assessed the driving forces of China’s CO2 emissions from 1980 to 2030 are the household consumption, capital investment and growth in exports. Wang and Watson (2007) valuated the net exports as up to 23% of the total CO2 emissions in China in 2004. Zhang (2010) adopted the Ghosh input–output model to investigate supply-side structure effect on production-related carbon emissions in China from 1992 to 2005. Lin and Sun (2010) reported that China is a net exporter of CO2 emissions in 2005. Using 1997 input–output table and purchasing power parity index, Yan and Yang (2010) estimated that 10.03–26.54% of China’s annual CO2 emissions are embodied in China’s exports, in contrast to only 4.40–9.05% in China’s imports during 1997–2007. The CO2 emissions embodied in bilateral trade such as China–Japan (Liu et al., 2010), China–US (Shui and Harriss, 2006, Xu et al., 2009 and Guo et al., 2010), China–UK (Li and Hewitt, 2008) were also studied. The embodiment of all the main GHG emissions in terms of CO2, CH4, and N2O, both distinctively and as a whole, in the Chinese economy by its statistical industrial sectors and final use categories have been systematically accounted by Chen and his fellows in their multi-scale ecological input–output analysis of environmental emissions and resources use: in his doctoral dissertation Zhou (2008) presented two sets of databases for embodiment intensity of GHG emissions, one for Chinese economy 1992 under the Material Product System (MPS) for planed economies of the socialist Soviet style and another for Chinese economy 2002 under the System of National Accounts (SNA) for marketing economies; Chen et al. (2010) accounted the GHG emission embodiment in Chinese economy 2005; Zhou et al. (2010) provided the GHG embodiment intensity in the regional urban economy of Beijing 2002. The target of the present work is to present a GHG emission inventory by economic sector in 2007 covering main emission sources including energy production, fuel combustion, industrial processes, agricultural activities, waste treatment, etc., and to systematically reveal the GHG emission embodiment in final consumption and international trade of the Chinese economy, with the most recently available input–output table and relevant environmental resource statistics.

A concrete GHG emission inventory of Chinese economy 2007 is presented to cover all the main anthropogenic sources of CO2, CH4, and N2O, and a detailed input–output analysis for the GHG emission embodiment in final consumption and international trade is carried out. The estimated total direct GHG emission amounts to 7456.12 Mt CO2-eq by the commonly referred IPCC global warming potentials, with 63.39% from energy-related CO2, 22.31% from non-energy-related CO2, 11.15% from CH4 and 3.15% from N2O. The non-CO2 emissions of CH4 and N2O amount to 1066.50 Mt CO2-eq, as one seventh of the total GHG emission. Prominently, the CH4 emission of 831.45 Mt CO2-eq is in magnitude higher than the amount of energy-related CO2 emissions of some developed countries in the same year of 2007, such as 523.0 Mt of UK, 572.9 Mt of Canada, and 798.4 Mt of Germany (IEA, 2009). The essential importance of methane mitigation has been stressed by Zhang and Chen (2010a). On the sectoral basis, the five primary sectors of the Electric Power/Steam and Hot Water Production and Supply, Smelting and Pressing of Ferrous and Nonferrous Metals, Nonmetal Mineral Products, Agriculture, and Coal Mining and Dressing are responsible for 81.32% of the total GHG emissions with different GHG emission structures. The sector of Electric Power/Steam and Hot Water Production and Supply is the largest GHG emitter with 36.90% of the total GHG emission, mainly due to CO2 emissions from coal combustion to produce electricity. The two sectors of Smelting and Pressing of Ferrous and Nonferrous Metals and Nonmetal Mineral Products are the main emitters of non-energy-related CO2, contributing 14.73% and 13.79% of the total GHG emission, respectively. The sector of Agriculture, accounting for 9.20% of the total, has massive CH4 and N2O emissions. CH4 is the dominated GHG emission in the sector of Coal Mining and Dressing, contributing 6.69% of the total GHG emission. In general, the demands of coal-electricity and heavy industrial products such as steel and cement determine the structure of emission embodiment to an essential extent. Embodied GHG emission intensities in most manufacturing and service sectors are highly related to the direct CO2 emission from fuel combustion in the sector of Electric Power/Steam and Hot Water Production and Supply. The sector of Construction holds the top GHG emissions embodied in both domestic production and domestic consumption. Household consumption is responsible for 24.45% of the total GHG emission embodied in the final demand. However, the GHG emission embodied in gross capital formation, 42.22% of the total embodied emission, is the largest in the final demand categories. China is a net exporter of embodied GHG emissions, with a remarkable share of direct emission induced by international trade. The GHG emission embodied in China’s exports is 3060.18 Mt CO2-eq, in magnitude up to 41.04% of the direct domestic emission. China’s textile products, industrial raw materials, and primary machinery and equipment products exports have a significant impact on embodied GHG emissions. Much more effort has to be made to adjust industrial structure characterized by the exports of low value added products at the expense of the environment. Meanwhile, with the huge international trade surplus, as 261.83 billion US dollars in 2007 (CSY, 2008), increasing import of industrial products in China will help to avoid GHG emissions in domestic production, and the developed countries such as U.S. need to encourage the export of high advanced technology to China for global emission reduction and mitigation (Shui and Harriss, 2006, Zhang, 2007 and Zhang, 2009).