Trading spaces: Calculating embodied Ecological Footprints in international trade using a Product Land Use Matrix (PLUM)

Nations import and export biophysical resources. With many ecosystems worldwide under mounting stress, countries may be increasingly interested in knowing the extent and origin of their ecological imports and dependencies. In this paper the Ecological Footprint is used as a tool to measure the biophysical (as opposed to financial) value of international trade flows. This paper attempts to answer the following question: How large of an Ecological Footprint does a given country exert inside the borders of each of its trading partners? Records in the UN COMTRADE bilateral trade database are multiplied by a matrix of per-product Footprint yield coefficients to translate from values in dollars and tonnes to units of hectares. The results show that the largest interregional flows are from Latin to North America, and from North America to Asia-Pacific. Grouping countries by GDP, high and middle income countries appear in Footprint terms to trade predominantly with other high and middle income countries and much less with low income countries.