最优增长路径下的中国碳排放估计

Integrated Projection of Carbon Emission for China under the Optimal Economic Growth Path

从能源消费、水泥生产和森林碳汇3个方面对中国未来的碳排放进行了较为全面的估计。其中,能源消费碳排放是在能源—经济框架下利用经济动力学模型对最优经济增长路径下的能源需求进行预测得到的,同时考虑了能源结构的演化及不同能源品种在碳排放系数上存在的差异;水泥生产碳排放则是在对水泥产量预测的基础上进行的,认为水泥产量与城市化进程存在一定的联系,而城市化进程遵循"S曲线"发展规律;森林碳汇是通过引入CO2FIX模型,分别对原有森林与新增可造林的固碳能力进行估算,最终合成了中国未来的净碳排放曲线。结果发现,能源消费碳排放在2031年达到高峰,为2637MtC,对应的人均GDP低于OECD国家的实证经验;人均排放高峰出现在2030年,为1.73tC/人,远低于美国欧盟和日本2006年水平;水泥生产碳排放增长放缓,2050年控制在254MtC左右,占工业总排放的12%;森林碳汇至2050年可累计吸收6806.2MtC,年吸收量逐渐下降;净排放也于2033年达到峰值,为2748MtC。

This paper performed a comprehensive projection of carbon emission through 2050 from the aspects of energy consumption,cement production process and forest carbon sink.Emission from energy consumption is estimated under the energy-economy framework by introducing the economic dynamics model and forecasting the energy demand on the optimal growth path,meanwhile the evolution of energy structure and the variation of carbon contents among energy types are also considered.Emission from cement production is projected on the basis of the forecast of cement output,which is deemed to be relative to urbanization process,while the latter follows the traditional S-curve development law.The estimation of forest carbon sink capability,involving the existing and newly afforested one,is conducted by employing the CO2FIX model.Eventually,all the three carbon sources or sink are composed to obtain the net carbon emission.Our results indicate that carbon emission from energy consumption peaks in 2031,with an emission of 2637 MtC （Million tons of Carbon equivalent） and the GDP per capita in that year is lower than the empirical experience of OECD countries;while the per capita energy-induced emission peaks in 2030,with a volume of 1.73 tC,which is far behind the US level of 2006 and still lower than the EU and Japan level of 2006.Besides,emission from cement production demonstrates a slow-down growth trend,and its emission is confined within 254 MtC,which is equivalently 12% of gross emission （here it refers to those emitted from energy consumption and cement production）.Accumulated forest carbon sink is able to absorb 6806.2 MtC CO2 through 2050,but the annual absorption is dropping gradually.It is estimated that the net emission of CO2 will peak in 2033,which is 2748 MtC.