Spatio-temporal changes and root-cause identification for embodied carbon emissions based on production and consumption in China's Yangtze River Economic Belt.

The Yangtze River Economic Belt (YEB) is at the centre of China's economy and development. Its regional carbon emissions account for about 36.9% of the country's total carbon emissions, and thus, there is an urgent need to sustain the development of a low-carbon economy. However, the complex patterns of embodied carbon flows arising from multi-scale trade in such a megaregion are often ignored in carbon environmental governance. This study incorporates a megaregion into an environmentally extended multi-regional input-output (EEMRIO) framework and identifies the drivers of production and consumption-based carbon emissions using four measures through structural decomposition analysis (SDA). The results show that (1) the YEB strengthens inter-provincial trade links while reducing international trade links; (2) there is obvious carbon transfer in multi-scale trade in the YEB, with a corresponding transfer of responsibility for carbon reduction occurring; and (3) consumption volume and carbon intensity are the main drivers and inhibitors of the increasing carbon emissions, respectively, and the optimisation of production structure and consumption structure are effective ways to control production-based carbon emissions (PBEs) and consumption-based carbon emissions (CBEs), respectively. This study extends the research scale of "national-provincial-city" to a megaregion. Studies based on multiple trade scales would provide additional insights to understand the carbon reduction responsibilities of megaregions and help achieve coordinated regional carbon reductions.