International trade has become the fastest growing driver of global carbon emissions, with large quantities of emissions embodied in exports from emerging economies. International trade with emerging economies poses a dilemma for climate and trade policy: to the extent emerging markets have comparative advantages in manufacturing, such trade is economically efficient and desirable. However, if carbon-intensive manufacturing in emerging countries such as China entails drastically more CO2 emissions than making the same product elsewhere, then trade increases global CO2 emissions.

China is the world's largest emitter of carbon dioxide, accounting for one-quarter of the global total in 2013. Although the country has successfully lowered the rate of emissions from industry in some cities through improved technology and energy-efficiency measures, rapid economic growth means that more emissions are being added than removed. Without mitigation, China's CO2 emissions will rise by more than 50% in the next 15 years.

The magnitude and growing annual rate of growth of China's carbon emissions make this country the major driver of global carbon emissions and thus a key focus for efforts in emissions mitigations. This report presents independent data on China's carbon emissions from 1950–2012, and provides a basis to support mitigation efforts and China's low-carbon development plan.

China committed itself to reduce the carbon intensity of its economy (the amount of CO2 emitted per unit of GDP) by 40–45% during 2005–2020. Yet, between 2002 and 2009, China experienced a 3% increase in carbon intensity, though trends differed greatly among its 30 provinces. Decomposition analysis shows that sectoral efficiency gains in nearly all provinces were offset by movement towards a more carbon-intensive economic structure.