Effects of decoupling of carbon dioxide emission by Chinese nonferrous metals industry

We adopted the refined Laspeyres index approach to explore the impacts of industry scale, energy mix, energy intensity and utility mix on the total carbon dioxide emissions from the Chinese nonferrous metals industry for the period 1996–2008. In addition, we calculated the trend of decoupling effects in nonferrous metals industry in China by presenting a theoretical framework for decoupling. As the results suggest, Chinese nonferrous metals industry has gone through four decoupling stages: strong negative decoupling stage (1996–1998), weak decoupling stage (1999–2000), expensive negative decoupling stage (2001–2003) and weak decoupling stage (2004–2008). We have analyzed the reasons for each phase. Generally speaking, the rapid growth of the industry is the most important factor responsible for the increase of CO2 emissions, and the change in energy mix was mainly due to the increased proportion of electric energy consumption that has contributed to the increase of CO2 emissions. Reduction of energy intensity has contributed significantly to emissions decrease, and the utility mix effect has also contributed to the emission decrease to some extent.