Importing terrestrial biocapacity: The US case and global implications

Human societies depend for their survival on goods and services provided by both local and global ecosystems. For most of history, people used mainly local resources. Increasingly, however, globalization and trade enable consuming populations everywhere to support themselves on the output of distant ecosystems. This is potentially problematic because of global change and because the spatial separation of material production (including resource exploitation) from consumption eliminates the direct negative feedback that normally occurs when people dependent on local ecosystems degrade those ecosystems. With spatial separation comes psychological separation. Modern consumers remain generally unconscious of their growing reliance on biophysical goods and services produced half a world away and see no connection between their consumer lifestyles anti distant ecological consequences. The purpose of this paper, therefore, is to raise a cautionary flag about unfettered trade and to show the value of accounting for trade-related physical flows and their impacts on natural capital in sustainability analyses. Using the United States as an example, we present an analytical method that can locate and measure the ecosystem area embodied in any population's imports of renewable resources. We quantify U.S. imports from specific countries around the world; we estimate the area of terrestrial ecosystems in those countries devoted to consumers in the U.S. and we highlight both increasing U.S. imports and their potential impact on extra-territorial ecosystems. This method creates indirect (conceptual) feedback between consumption and ecosystems integrity which we hope will partially replace the physical feedback neutralized by globalization. Such analyses can help generate public and decision makers' awareness of both their dependence and their impacts on, distant natural capital stocks. This in turn should increase interest in establishing improved co-management regimes to maintain the stability and reliability of such now obligatory relationships. (C) 2009 Elsevier Ltd. All rights reserved.