Comprehensive evaluation of industrial CO2 emission (1989-2004) in Taiwan by input-output structural decomposition

Taiwan currently emits approximately 1% of the world's CO2--ranking it 22nd among nations. Herein, we use the input-output (I-O) structural decomposition method to examine the changes in CO2 emission over a 15-year period. By decomposing the CO2 emission changes into nine factors for the periods of 1989-1994, 1994-1999, and 1999-2004, we have identified the key factors causing the emission changes, as well as the most important trends regarding the industrial development process in Taiwan. The 5-year increment with the largest increase of CO2 emission was that of 1999-2004, due to the rapid increase of electricity consumption. From the decomposition, the industrial energy coefficient and the CO2 emission factors were identified as the most important parameters for the determination of the highway, petrochemical materials, iron and steel, the commercial sector, and electric machinery as the major sources of increased CO2 emission during the past 15 years. From 1989 to 2004, the level of exports and the level of domestic final demand were the largest contributors to the increase in the total increment of CO2 change. During 1989-2004, the industrial energy coefficient and CO2 emission factors, being minimally significant during 1989-1994, became extremely important, joining the domestic final demand and the level of exports factors as the major causes of the increase increment of CO2. This indicates a heavy reliance upon high-energy (and CO2) intensity for Taiwanese industries; therefore, continuous efforts to improve energy intensity and fuel mix toward lower carbon are important for CO2 reduction, especially for the electricity and power generation sectors. Relevant strategies for reducing carbon dioxide emissions from major industries are also highlighted.