中国における工業セクターの二酸化硫黄排出構造に関する地域間比較

抄録

An index decomposition analysis method is adopted to quantitatively evaluate the contribution of various factors to the amount of sulfur dioxide emissions from 29 regions (province and large cities) of China during the period 1993-2003. Four factors are adopted for this analysis output of the secondary industries (manufacturing and energy industries), efficiency of coal combustion, sulfur content of coal, and rate of desulfurization. Considering the development of China's national policy for air pollution control, period of the analysis is divided into four phases: Phase I (1993-1995), Phase II (1995-1997), Phase III (1998-2001), and Phase IV (2001-2003). Patterns of increase or decrease of the emission from the previous phase are very different among the regions.

A cluster analysis of the 3 factors excluding of output of the secondary industries and 29 regions resulted in four types: energy efficiency lowering type, coal quality improving type, desulfurization developing and coal quality lowering type, and energy efficiency improving type. During the Phase I, many regions are categorized as energy efficiency lowering type, but few regions are categorized as the type after Phase I. Regions of coal quality improving type had significantly decreased the emissions during Phase I, II and III despite of increase of industrial output. Regions of desulfurization developing and coal quality lowering type increased the emission throughout the four periods, indicating that development of desulfurization was unable to substantially reduce the emissions. During Phase II, many regions are categorized as energy efficiency improving type, indicating energy saving contributed to the reduction of the emissions during this period.

While factors affecting the amount of the emissions are different among the regions and phases, lowering coal sulfur content seem to have been selected as the measure of sulfur dioxide emission reductions prior to adoption of desulfurization equipment. Energy intensity has been improving throughout the four periods, but was unable to offset the emission increase due to the increasing industrial output.