Phosphorus Flows in China. Physical Profiles and Environmental Regulation

The substantial shifts in the structure of domestic phosphorus (P) throughput, during a crucial period of social and economic transitions, brings forth a challenge for curbing the extensive eutrophication of surface waters in China. The lack of an overall knowledge on the societal metabolism of P has contributed to the absence of eutrophication policy and efficient measures in China. Therefore, it is vital to reflect on the fundamental economic and environmental characteristics of physical P flows, in order to reinvent ecologically rational solutions for a successful eutrophication control in China.This study develops a comprehensive research approach for inquiring into the societal P cycles within China. The methodology, combining a substance flow analysis (SFA) approach and an environmental policy evaluation method, starts with a quantitative analysis of the entire life cycle of societal P metabolism. Subsequently, it identifies the critical P flows with crucial environmental consequences and then relates them to an evaluation of the environmental policies directed at these P flows. The Dianchi Basin, one of the national key environmental protection watersheds, has been selected as a case study area, both for characterizing the social P metabolism and for evaluating the policies to reduce eutrophication.Two static SFA models for national (PHOSFLOW) and regional (PHOSFAD) P regimes have been developed, respectively, for quantitatively estimating unknown but critical flows. These models reveal how a nation or a region extracts P from nature, metabolizes it via various economic activities, and finally excretes P as waste into the environment. The analysis of the P metabolic structure in general shows a clear form: the societal P metabolisms, both within the national and local economies, have developed into a once-through system where P is mobilized in large quantities from nonrenewable rocks and subsequently leaks into either the (natural or cultivated) soil or surface water. In analyzing the ecological restructuring of China, that is, examining the environmental effectiveness and economic efficiency of critical P flows throughout time, it was found that China has become more efficient in the use of P materials over the last two decades, measured per unit of national economic growth. But the absolute quantities of these P flows have increased, which is of course especially relevant for the environment.The SFA models were deliberately modified by applying a set of data processing principles and new data series. While the updated P fluxes of the static SFA models are arguably better reflecting their counterparts in the natural cycle, the process itself has demonstrated a gradual increase in the knowledge on societal P cycles. The modification also facilitates anormative (re)formulation ofthe main findings of these SFA models. This has enabled an understanding of the similarities and differences of the physical characteristics of P throughput between the national and the local economies: 1) the local P throughput in Dianchi Basin was basically export-oriented while relying on domestic reserves; 2) the local P fluxes were more intensivein quantitycompared to those at the national level; 3) the import and export of agricultural goods was, in general, balanced at both the national and local levels, except for the crop trading in Dianchi Basin; 4) the increasingly widespread cultivation of vegetables and flowers in Dianchi Basin resulted in an intensive application of P fertilizer; 5) the large-scale feedlots and farms in Dianchi Basin did less harm to the environment than the small family-scale units; 6) the physical configurations of P flows associated with urban and rural residents were mostly similar, the exception being the urban sewage system, which proved more efficient in terms of P removal in Dianchi Basin.The SFA models enable the identification of critical P flows that should be the central object of concern for environmental policy and regulation. The P flows associated with intensive livestock, urban centralized sewage systems and P-detergents are the appropriate candidates for this concern.These flows also have the attention of environmental authorities in contemporary China.In order to assess how and to what extent the environmental policies have successfully (re)directed these P flows to generate environmental benefits for eutrophication control, a policy evaluation framework proposed by the European Environment Agency (EEA) is applied. This methodology facilitates a systematic investigation into both the policy design in terms of the relevance of policy objectives and the policy implementation with regard to evaluating issues of economic efficiency, environmental effectiveness and overall social impact.The evaluated environmental policies contain two main societal responses to P- caused eutrophication: an endeavor to prevent P from flowing into waterbodies, and an attempt to reduce P use at the household level. The end-of-pipe approaches that remove P from effluent do not necessarily result in a reduction of P input or an increase in P recycling, both of which are underlying propositions of an ecologically rational eutrophication policy. At the same time, the current and potential environmental effects of these approaches in terms of P outflow reduction are limited, due to a large number of economic, social and institutional barriers. The ban of P-detergents - a source-control strategy - could considerably reduce the P input in the economy. As reduced P consumption results in the introduction of substitute materials, this policy could lead to undesired negative environmental impacts. In this way, the P control approach at source could become less promising. Furthermore, the P-detergent ban, like the other two end-of-pipe strategies, relies mainly on government-oriented regulatory measures, while other measures, especially market-based economic incentives, are to a large extent ignored.The application of the approach and methodology of this studyproves its innovative value forChina. First, this researchproducestwo P flow models and a normative evaluation of three clusters of P-related environmental policies, which can be understood as an innovation in contemporary research on P in China.The comprehensive insight to P flows, at both national and local levels,provides a scientific basis for strengthening and further developing the eutrophication control framework. Second, by introducing the substance flow analysis method and the policy evaluation method into China, thisthesisoffers a promising research paradigmfor reflecting on the fundamental societal material cycles, which is particularly important for the ongoing campaign of establishing a circular economy in China.