From carbonization to decarbonization?—Past trends and future scenarios for China's CO2 emissions

Along the lines of the Kaya identity, we perform a decomposition analysis of historical and projected emissions data for China. We compare the results with reduction requirements implied by globally cost-effective mitigation scenarios and official Chinese policy targets. For the years 1971–2000 we find that the impact of high economic growth on emissions was partially compensated by a steady fall in energy intensity. However, the end – and even reversal – of this downward trend, along with a rising carbon intensity of energy, resulted in rapid emission growth during 2000–2007. By applying an innovative enhanced Kaya-decomposition method, we also show how the persistent increase in the use of coal has caused carbon intensity to rise throughout the entire time-horizon of the analysis. These insights are then compared to model scenarios for future energy system developments generated by the ReMIND-R model. The analysis reaffirms China's indispensable role in global efforts to implement any of three exemplary stabilization targets (400, 450, or 500 ppm CO2-only), and underscore the increasing importance of carbon intensity for the more ambitious targets. Finally, we compare China's official targets for energy intensity and carbon intensity of GDP to projections for global cost-effective stabilization scenarios, finding them to be roughly compatible in the short-to-mid-term.

► An extended Kaya-decomposition is applied to historical data and ReMIND-R scenario results for China.
► Reversing a historic trend, energy intensity has increased in recent years.
► The contribution of coal in increasing carbon intensity and emissions has been constant in the past.
► Decarbonization becomes increasingly important with increasingly ambitious climate targets.
► Chinese targets for carbon intensity of GDP are in line with a 450 ppm CO2-only stabilization scenario.