Determining factors and diverse scenarios of CO2 emissions intensity reduction to achieve the 40-45% target by 2020 in China - a historical and prospective analysis for the period 2005-2020

The Chinese government committed to reduce its national CO2 emissions intensity by 40-45% until 2020 in response to climate change. This paper quantitatively evaluates the performance of CO2 emissions reduction over the period 2005-2020 from the historical and prospective perspectives by using a combination of decomposition analysis and scenario analysis, aiming to provide suggestions about how to achieve the target in key emissions reduction fields. Unlike traditional index decomposition methods, this paper incorporates the total energy conversion efficiency effect into the model, and further decomposes it into a final energy mix effect and a final energy conversion efficiency effect by a multilevel decomposition procedure, allowing to measure the contributions of primary energy structure low-carbonization, the final energy mix electrification, and the energy conversion efficiency improvement. The results show that the carbon intensity could decline over the period 2005-2020 by 47.8%, 50.9%, 48.0%, 44.5% and 47.5% in the Business as Usual, S1, S2, S3 and S4 scenarios, respectively. This shows that the 40-45% target is very likely to be achieved. The final energy intensity effect is always the most important driving factor, causing carbon intensity to decrease by 24.0% and 22.1%, again respectively, from 2005-2012 to 2012-2020. Moreover, the energy conversion effect was another major driver during 2005-2012. The Chinese government needs to make more efforts to adjust the industrial structure, which could cause carbon intensity to decrease by 3.6% during 2012-2020, and to adjust the primary energy mix, which could cause carbon intensity to decrease by 7.1% during 2012-2020. (C) 2016 Elsevier Ltd. All rights reserved.