The real wealth of nations: Mapping and monetizing the human ecological footprint

Abstract

The earth provides myriad ecosystem services or ‘benefits’ that enable and enhance human existence. Humanity, in turn, imposes myriad environmental impacts or ‘costs’ on the earth. We explore the idea of mapping these ‘costs’ and ‘benefits’ using proxy measures. We set the total value of the world's ecosystem services to be equal to the total cost of anthropogenic environmental impacts at fifty trillion dollars (roughly the global GDP in the year 2000). A global representation of ecosystem service value is mapped at 1 km 2 resolution using Net Primary Productivity (NPP) as a proxy measure of ecosystem service value (‘benefit’). A similar global representation of environmental impact is mapped using pavement (i.e., anthropogenically created impervious surface area or ISA) as a proxy measure of ‘cost’. Subtracting the 50 trillion mapped onto ISA from the 50 trillion mapped onto NPP produces a 1 km 2 resolution map of those areas where: (1) human imposed costs exceed naturally supplied benefits, resulting in an ecological deficit, (2) human costs balance with environmental benefits and (3) environmental benefits exceed human costs, resulting in an ecological surplus. Mapping this ecological balance produces a spatially explicit and monetized representation of ecological sustainability that can be aggregated to national, sub-national, and regional levels. Aggregations of this map at the national level are compared with other national measures of biophysical sustainability such as the Global Footprint Network's ‘Eco-Deficit’. An additional benefit of this approach is that the national values derived from this difference map suggest a starting point for discussions of the dollar values and costs of both under and over consumption of ecosystem services on the part of the nations of the world.