本文采用2007年的中国投入产出表和能源统计数据,比较了国内外在测算贸易隐含碳中主要应用的三种方法:直接排放测算法、基于完全需求系数和完全消耗系数的测算方法。结果发现:①除了能源生产加工部门(如石油加工业等)的完全需求碳排放强度明显小于其完全消耗碳排放强度外,其余行业的完全需求碳排放强度和完全消耗碳排放强度都是比较接近的,二者具有很强的相关性;②直接净出口隐含碳(7.50Mt)〈完全消耗净出口隐含碳(277.30Mt)〈完全需求净出口隐含碳(408.95Mt)。从投入产出模型的原理上来看,基于完全需求系数和基于一次能源行业完全消耗系数的计算方法都反映了对于能源的间接消耗,其结果应该比较接近,本研究实际计算结果也证明,在非能源行业两种计算结果具有比较高的相关性,但是由于目前只能得到统一的能源产值-实物转换系数,从而导致在能源行业基于完全消耗系数计算的碳排放强度远大于基于完全需求系数计算的结果,再加上中国是能源进口大国,这样就进一步扩大了两者计算结果的差异。
International trade is an important factor influencing the greenhouse gas emissions of nations. Describing the situation of embodied carbon emissions in Chinese international trade is important when responding to international negotiation and obtaining greater development rights in the future. Based on the input-output table for 2007, 42 sectors, and energy production and consumption data, we compared the direct emissions calculation method, total demand emissions calculation method and total consume emissions calculation method for carbon emission intensity in international trade. The results show that in addition to the total demand carbon emission intensity of energy sectors (such as the oil processing industry) was significantly less than total consumption carbon emission intensity. For other sectors total demand intensity and consumption intensity were similar. Direct carbon emissions embodied in net exports (7.50 Mt) were less than total consumption carbon emissions embodied in net exports (277.30 Mt) and less than total demand carbon emissions embodied in net exports (408.95 Mt). In theory, the carbon embodied based on total demand emission intensity and total consumption emission intensity should be equal; however, due to data limitations we only obtained an average value-physical conversion coefficient of energy (primary energy production divided by its total output). Given that the energy sector consumes more energy and the price of energy for them is lower than for other sectors, the carbon intensity of energy departments based on the total consumption coefficient was bigger than carbon emission intensity based on total demand coefficient. China is a major importer of energy, thus the difference between import carbon emissions (total demand and total consume coefficients) was expanded. The export carbon emission results were similar in 2007 when measured using these two methods. The carbon emissions of net exports we calculated based on the total demand intensity was larger than