Supply-side drivers of phosphorus emissions from phosphorus supply chains in China

Human activities interfere with natural Phosphorus(P)cycles by introducing increased levels of P emissions to air,land,and water.A supply-side analysis of P supply chains and associated P emissions can provide insights into underlying economic activities and transitions responsible for human-induced P emissions.Taking the China's Mainland as the case,this study constructs time-series physical input-output tables to describe P supply chains during 1949-2012.Subsequently,it identifies critical products and influencing factors of P supply chains enabling P emissions to the environment(including air,land,and water)from the supply perspective.The results show that phosphate rock,an important initial supplier of P from natural environment to China’s P supply chain,was responsible for 86%of P emissions in 2012.Moreover,food crops and livestock are important initial suppliers of P from soil to China’s P supply chain,through cultivation and pasturing,respectively.From 1949 to 2012,the change in primary input level was the largest driver of P emission increments,followed by changes in population,emission intensity,and primary input structure.On the contrary,changes in production structure reduced P emissions.These findings could support supply-side policy decisions on P emission control.