在哥本哈根世界气候变化大会上,我国向世界承诺2020年单位国内生产总值的二氧化碳排放量比2005年下降40％~45％。本文在对已有研究成果进行系统梳理的基础上,分析了影响我国碳排放的主要因素,核算了主要减排途径的碳减排潜力,提出了至2020年我国发展低碳经济的基本框架。研究发现,碳排放强度与产业结构演化之间存在倒U字形曲线关系,发展模式转变和产业结构调整取得实质性成效是实现2020年减排目标的前提。此外,工业技术节能、建筑节能和道路交通节能也还都有一定的潜力。在不同情景下,工业技术节能对实现2020年减排目标的贡献程度在12%~14%之间,建筑节能和增加非化石能源规模分别可以起到10%左右的贡献,道路交通节能的贡献率在2%~3%之间。

At the 2009 United Nations Climate Change Conference at Copenhagen, China announced its target of CO₂ emission reduction, i.e. by 2020 the amount of CO₂ emission per output unit (GDP) will drop by 40%-45% compared to that in 2005. The target will be incorporated into China's long term socio-economic planning. Towards such a target, there have been two distinct viewpoints in China. While some scholars tend to consider it quite easy, others argue that it is hard to achieve the target as China is still in the middle of rapid industrialization and urbanization. Based on existing literature and research, in this paper, we will first examine the factors affecting CO₂ emission in China, and then analyze the potentials of major ways of CO₂ emission reduction, and lastly propose a sketch map of low-carbon economic development. We try to argue that there exists a reversed U-shaped relationship between the amount of CO₂ emission per output unit (carbon intensity) and industrial structure. Carbon intensity rises with economic growth at the early stage of industrialization, and decreases after going to the peak at the middle stage of industrialization. By employing a multiple regression, we find that the change of carbon (energy) intensity in the last 15 years in China can be well explained by two factors, i.e. the share of the tertiary industry in GDP and the share of high energy-consumption sectors in total value-added of the second industry (including thermal-power, metallurgy, chemical and construction materials). In 2002-2008, the tertiary share in GDP in China rose little while that of high energy-consumption sectors rose significantly, which resulted in an upturn of carbon intensity of economic output in China. Such "abnormal" can be partly attributed to China's development pattern of being a world factory of low-end commodities. Thus, we tend to argue that China might not be able to fulfill the 2020 target of CO₂ emission reduction if it did not make a visible progress in changing the development pattern and industrial restructuring. That is, adjustment of industrial structure is a major way of fulfilling the 2020 target, which may contribute around 61.5%~67.2% of carbon intensity reduction. Besides, energy saving via technical measures and innovation in sectors like industries (13% of contribution), buildings (10%) and transportation (3%) can make significant contribution to fulfilling the target. Lastly, the development of non-fossil energy is another important path of low-carbon growth, which can contribute about 10% to carbon intensity reduction.