Water-Energy-Carbon Nexus In China’s Trade Network:An Analysis With Multi-regional Input-Output Paradigm

The consumption of water and energy as well as carbon emission caused by human are composed three vital impacts on the natural environment.Meanwhile,China is the largest carbon emitter and energy consumer,and one of country with most serious water shortages.Excessive consumption of water and energy as well as large amounts of carbon emission have caused many environmental problems.Resource and environmental issues related to water,energy,and carbon have led to a drop in human well-being,worsen ecosystem health,and hindered economic development.Thereby,it is significant to understand water-energy-carbon(WEC)nexus in China.The aim of this study is to clarify the WEC nexus in China.First,the temporal and spatial distribution of water resource exploitation,energy consumption and carbon emission are analyzed.After that,the water footprint(WF),energy footprint(EF)and carbon footprint(CF)as well as virtual transfer of water,energy and carbon are discussed in this study based on the multi-regional input-output(MRIO)method.Moreover,the driving factors of changes of water,energy and carbon footprints are explored.Finally,the WEC nexus in provincial production,transfer and consumption processes are quantitative descripted.Findings of this study are expected to assist government in decreasing the environmental footprints and achieve sustainable development of China.Results are as follows:(1)The exploration on temporal and spatial distribution of water resource exploitation,energy consumption and carbon emission find that China’s water resources exploitation,energy consumption and carbon emission show continuous rising from 2002-2012,the national rising rate of water resources exploitation,energy consu1ption,and carbon emission are 7.79 billion m3/y,267.54 million t ce/y,and 603.9 million t CO2/y,respectively.In addition,China’s population and national GDP also show a rising trend,with a population and GDP growth rate of 7.58 million/y and 3.5778 billion yuan/y,respectively.In terms of resource utilization efficiency,per capita water resources exploitation,energy consumption and carbon emissions rise,while water consumption,energy consumption and carbon emissions per 10,000 yuan of GDP fall.Moreover,the primary industry dominates the exploitation of water resources(65%),and the secondary industry dominates total energy consumption and carbon emissions(accounting for 71%and 85%,respectively).(2)The discussion of WF,EF and CF as well as virtual water,energy and carbon transfer of the entire industry sector in China’s provincial scale based on MRIO shows that Guangdong,Jiangsu and Shandong present higher WF.Shandong,Jiangsu and Henan present higher EF.Shandong,Jiangsu and Hebei present higher CF.In addition,provinces with the highest per capita WF,EF and CF are Xinjiang,Qinghai and Ningxia,respectively.Fixed capital formation and urban consumption are the main components of China’s WEC footprint,while inventory changes account for a relatively small proportion of China’s WEC footprint.The WEC footprint of China mainly rely on internal supply,and the external footprint account for less than 50%in most provinces.Sectors with the highest proportions of WF,EF and CF are the agricultural sector,the metal products and processing sector,and the power sector,respectively.Besides,the magnitudes of direct water,energy and carbon consumption coefficients of each sector vary greatly.The northwest region is the main virtual water exporter,and the northern coastal region is the largest virtual energy carbon exporter.Generally,China’s virtual water,energy and carbon flow from North to South.(3)The exploration of the driving factors of variation of WF,EF and CF based on the structural decomposition analysis(SDA)in 2002-2012 shows that The WF of most of provinces generally decreases firstly and then increases,while EF and CF continue increase.From 2002 to 2007,per capita final use and resource intensity contribute most to the changes of WF,with contribution rates of 20.9%and-33.3%respectively.For EF,per capita final use and production structure contribute most,with contribution rates are 53.2%and-10.3%respectively.For CF,per capita final use and carbon emission intensity contribute most,with the contribution rates are 56.0%and-13.6%respectively.From 2007 to 2012,per capita final use and resource intensity contribute most to the changes of WF,with contribution rates of 58.1%and-47.7%,respectively.For EF,per capita final use and final use structure contributed the most,with the contribution rates are 58.0%and 7.9%,respectively.For CF,per capita final use and final use structure contribute most,with the contribution rates are 56.1%and 9.3%,respectively.(4)The analysis of the WEC nexus shows that the amount of water exploitation,energy consumption,and carbon emissions of provinces and industry sectors are highly correlated,and these correlations are guessed related to population and GDP.Provinces with large water resources exploitation,large energy consumption and high carbon emissions usually have larger populations and higher GDP.Category 1 as well as categories 2 and 3 present opposites in W-E and W-C nexuses.The net water and energy transfers are significantly positive correlated in category 1,while both sides are negative correlated in categories 2 and 3.Sectors with higher direct consumption coefficients usually account for a larger proportion in the total amount of water,energy and carbon transfer.WEC footprint shows consistency in the proportion of external footprint.In addition,WF,EF and CF of different provinces are highly positively correlated.Finds of this study are expected to capture the WEC nexus of China and subsequently to be delivered to sustainability suggestions.