Factor decomposition and the decoupling effect of carbon emissions in China's manufacturing high-emission subsectors

The manufacturing industry makes the greatest contribution to China's carbon emissions, so reducing emissions among its high-emission subsectors is important to achieve China's overall reduction goals. Innovation is crucial to the green transformation and development of high-emission subsectors. Previous studies have hardly considered the effect of innovation factors on carbon emissions and decoupling of high-emission subsectors. This study incorporated innovation factors into the GDIM (generalized dividing index method) and DEI (decoupling effort index) models and decomposed them into three variables, the innovation input scale, innovation input carbon intensity, and innovation input efficiency, in order to compare the impact of different factors on carbon emissions and decoupling of high-emission subsectors. This approach expands the application scope of the GDIM method and helps to formulate the green transformation policies of the high-emissions manufacturing sector. The results were as follows. (1) The innovation input scale is the primary factor leading to the increase in carbon emissions. The cumulative increase of carbon emissions in the high-emission sectors from 1995 to 2019 was 3.45 billion tons. Innovation input carbon intensity is the primary factor that inhibits the carbon emissions growth. (2) There were significant differences in the degree of decoupling between the high-emission sectors in manufacturing in different periods. The decoupling effect of the manufacture of non-metallic mineral sector was the best; it achieved strong decoupling in 2015–2019, with the DEI reaching 2.17. (3) Decoupling efforts with regard to the carbon intensity of outputs and innovation inputs are the key factors that determine the decoupling of economic growth and carbon emissions in the high-emission subsectors of the manufacturing industry. • Factor decomposition and the decoupling effect of carbon emissions in manufacturing. • The GDIM and DEI are combined to identify the drivers of decoupling. • Most high-emission sectors of manufacturing are weakly decoupled or not decoupled. • The carbon intensity of the output and innovation inputs are key factors. • This study contributes to targeted interventions towards low-carbon manufacturing.