Sustainability assessment and causality nexus through ecosystem service accounting: The case of water purification in Europe

The paper builds on the Supply and Use Tables module within the System of integrated Environmental and Economic Accounts - Experimental Ecosystem Accounts (SEEA EEA) developed by the UN. We explore the evolution of Supply and Use Tables from the System of National Accounts (SNA) to the System of integrated Environmental and Economic Accounts - Central Framework (SEEA CF) and then to the SEEA EEA, and we propose a further extension: we propose that ecosystem types should be treated as accounting units able to produce, consume and exhibit changes in regeneration and absorption rates. The implications are first explained in the methodological section and then shown in the application where the water purification service is tested against two major policy issues: sustainability assessment (we show how to assess whether the ecosystem service is used sustainably by comparing the quantification of potential and actual flow) and causality nexus (we quantify the connection between the value of agricultural production and that of the ecosystem service used). The paper highlights how the overall outcomes change when considering different scales. A contrast emerges, for example, between the positive balance at the continental scale, where water purification services appear to be used sustainably (thanks to the high potential flow of Northern European countries) and the negative balance of almost all European countries when considered at a national scale. Taking advantage of the experimental opportunities offered by operating with external satellite accounts, we are able to show how the proposed complementary tables could support policy action.