As the global climate change problem becomes increasingly serious, the global climate negotiation process becomes more complex and pressure increases on China to reduce its carbon emissions. The challenge of reducing carbon emissions has become a focus of the international community. The polices in developed countries aimed at reducing nationally produced CO₂ emissions may result in the relocation of emission-intensive industries to poor countries with less stringent policies. This often leads to a simple relocation of emissions and to an absolute increase of emissions, owing to less advanced technology in developing countries, and a failure to meet global greenhouse gas emission reduction targets. For a country like China with a very large territory, carbon emission relocation between sub-national regions may also lead to failure of the entire national carbon reduction effort. To overcome this difficulty, input-output technology-based research on consumption-based carbon emission accounting and carbon emissions embedded in trade are important aspects in the field of carbon emission study.
This study is a contribution to that literature. Following the latest related research, this paper constructs a model to calculate the carbon transfer embedded in trade between sub-national regions by use of input-output tables. It then takes China as an example, to examine the change of carbon transfer embedded in trade by 17 sectors in eight main regions of the country, in 1997 and 2007. First, we find that the region with the highest economic development level always has high per capita product-based emissions and high per capita consumption-based emissions. This is in contrast to that of the global scale, in which developed countries generally have low product-based emissions with high consumption-based emissions. Second, influenced by national development and natural resource use strategies, the middle and eastern regions are the largest net exporters of carbon emissions. In the northwest region in particular, there are about 67 million tons net carbon, which account for 33.64% of its direct emissions in 2007, transferred from other regions such as the southeast coastal and Beijing-Tianjin areas. Compared with 1997, emissions in 2007 showed a big change of carbon emission transfer in China, in terms of both magnitude and region. The change has an overall trend of increasing carbon emission transfer from the southeast coast to western China. Specifically, the northwest region has become the biggest carbon net transfer-in region, and the Beijing-Tianjin and southeast coastal areas are always the main net transfer-out regions. The increase of embedded carbon transfer from southeast China to the middle and western regions caused by southeastern exports is the most obvious. To continue the globalization process and implementation of the western China development strategy, the role of the middle and western regions as suppliers of raw and processed materials becomes increasingly important, as trade expands on the southern and eastern coasts. As a result, there must be more carbon emissions "transferred" in the future, from the western and central regions to the southern and eastern coastal areas. Therefore, adjusting the export and investment structure of eastern China and establishing an improved regional carbon reduction policy should be thoroughly considered by administrators in China.