A review of Chinese CO2 emission projections to 2030: the role of economic structure and policy

The projections of 89 scenarios from 12 different models for the CO2 emissions of China to 2030 are reviewed, along with wider examinations of lessons from the history of energy forecasting in OECD countries, and of the Chinese macroeconomic situation.Even by 2030, emissions in the scenarios span a factor of almost 2.5, indicating significant range and uncertainty. Statistical analysis of Kaya components suggests the carbon intensity of energy supply to be the strongest determining factor. However, most scenarios assume that industry(1) continues to account for more than 50% of total final energy demand. This is in contrast both to historical examples, which have consistently shown economies shifting from energy-intensive industrial bases to service-based structures as income per capita rises, and to recent Chinese policy statements, which reflect a similar ambition. It is also highly salient that major failures in energy and emissions projections can frequently be accounted for in retrospect by failures to anticipate such major economic structural shifts.In conclusion, while the future trajectory of Chinese emissions remains profoundly uncertain, the potential for a significant Chinese macroeconomic transition and its implications for the scale and structure of energy demand will be a crucial factor, to which energy-climate models must pay far more attention.Policy relevanceThe dramatic growth of Chinese emissions since 2000 has become a major factor in global emission prospects and the international political agenda. Many models project rapid continued emissions growth, but an apparent halt in Chinese emissions in 2014 has amplified debate. Projections and policy need to recognise fundamental uncertainties in emission prospects, because in addition to energy/climate-specific policies, they depend on the progress in Chinese macroeconomic reforms, which are poorly represented in the models we survey. Global projections, the international process, and the design of China's own policies (most obviously, its national cap-and-trade system) need to cope with the possibility of continued growth to peaking in 2030 (the central commitment in China's Intended Nationally Determined Contribution), but must also be prepared to exploit and encourage the possibilities of low-carbon development and much earlier peaking.