Analysis Of Embodied Carbon Emissions Flows And Carbon Reduction Targets Allocation From The Perspective Of Ecological Networks

After more than 30 years of reform and development,China's economy has maintained a long-term high-speed growth rate and has become the second largest economy in the world.However,with the rapid economic growth,China has become the world's most energy-consuming country since 2013.China consumed 52% of the world's coal,13.9% of oil and 6.7% of the world's coal in 2017 natural gas.One of the most essential discussions in 21 st century is how can the global community work together to deal with the threat of climate change by keeping global temperature rise within a reasonable range in this century.Many efforts have been made to reach a consensus that every country and individual on the planet takes some level of responsibility for reducing carbon emissions.China has become the world's largest carbon emitter since 2006,which accounting for nearly 29% of global emissions in 2017.As a responsible country,China has set a target of reaching its emissions peak before 2030,reducing its greenhouse emissions intensity of its GDP by 60%-65% over 2005 level by 2030 in Paris Agreement.However,the Pair Agreement are mainly focused on distribution of differentiated responsibilities in the national level.China is a country with substantial differences in economic development,energy consumption mix,resources and technologies,as well as development path at provincial level.Therefore,China's provinces have different potential and degrees of difficulty to carry out carbon emission reduction(CER)requirements.In addition,interprovincial trade,with a large amount of embodied carbon emissions,has become the fastest growing driver of China's total carbon emissions.Owing to the differences in economy,technological development and energy efficiency,it is important for China to strength coordination and cooperation among different provinces,which could help China to achieve its national CER commitment.The prerequisites for this cooperation and coordination are fairly allocating the national targets to each province.In order to allocate the CER task at the provincial level,policy makers should take the diversity and complexity of China into consideration.Direct carbon emissions can only explain a part of the reduction task,because various immediate goods are generated and traded across the whole production life cycle.Policy that is based only on the absolute amount of production-based direct carbon emissions lacks an understanding of provincial carbon emission transfers.Considering the large volumes of interprovincial carbon emissions trade,consumption-based accounting can perform better in providing the actual features and responsibility for carbon emissions that a certain province should take.The concept of ECE,based on the consumption-based perspective,is introduced in this paper.Considering that the initial allocation of CER tasks may significantly influence the sharing of emission burden,reasonable emissions reduction policies should be constructed to promote fairness and relatively decrease the costs of emissions reduction,which is crucial for realizing the commitment that China announced in the Paris Agreement.In this paper,ecological network analysis(ENA),combined with a multi-regional input-output model(MRIO),is adopted to build an ecological network of embodied emissions across 30 provinces,which is constructed to account for the carbon emission characteristics of each node(province),the carbon flow among nodes and the ecological relations among the nodes.Firstly,through the single-area input-output model and the multi-region input-output model,we calculate the embodied carbon emission characters in each province,and get the data of interprovincial embodied carbon emission flows.Secondly,combining with the ecological network analysis model,China's overall ecological network system is constructed.From the perspective of consumers,the specific relationships among different provinces are determined,and the amount of responsibility that a certain province should take quantified,with respect to the embodied carbon emission(ECE)flows from interprovincial trade.Finally,through the model of carbon emission reduction marginal cost and the carbon consumption characteristics of each node,the emission reduction costs of each node are obtained,and the emission reduction responsibility assumed from the producer's perspective is estimated.Overall,in this paper,the MRIO and ENA model are used to obtain detailed interprovincial ECE flows and the relationships between all 30 provinces in China's ECE ecological system.These results provide comprehensive information about ECE flows and ecological relationships between them,which help us to quantitatively analyze the responsibility a certain province should take and then establish fair allocation policies.On one hand,from producer perspective,the different emission reduction costs are used to design reasonable emission reduction mechanism.Efforts should be made to promote emission reductions with practical policies,solve emission reduction problems with minimum economic cost and enhance efficiency.On the other hand,based on the data of ECE and the interprovincial relationships,a relatively fair CER plan is established,which could increase fairness.The developed provinces could take their CER responsibility through transferring more advanced technologies,counselling program of carbon reduction programs and appropriate financial support to underdeveloped provinces.By industrial upgrading of science and technology and structural adjustment of industries,underdeveloped provinces could reduce the absolute amount of carbon emissions and fulfill their responsibility of reducing emissions.