10.18130/V3SJ67
O'Bannon, Clark
Clark
O'Bannon
University of Virginia
Carr, Joel
Joel
Carr
University of Virginia
Seekell, David
David
Seekell
University of Virginia
Globalization of agricultural pollution due to international trade
Copernicus Publications on behalf of the European Geosciences Union
2014
Article
2014
All rights reserved (no additional license for public reuse)
Almost 90% of freshwater resources consumed
globally are used to produce plant and animal commodities.
Water-scarce countries can balance their water needs by importing
food from other countries. This process, known as
virtual water transfer, represents the externalization of water
use. The volume and geographic reach of virtual water transfers
is increasing, but little is known about how these transfers
redistribute the environmental costs of agricultural production.
The grey water footprint quantifies the environmental
costs of virtual water transfers. The grey water footprint
is calculated as the amount of water necessary to reduce nitrogen
concentrations from fertilizers and pesticides released
into streams and aquifers to allowed standards. We reconstructed
the global network of virtual grey water transfers
for the period 1986–2010 based on international trade data
and grey water footprints for 309 commodities. We tracked
changes in the structure of the grey water transfer network
with network and inequality statistics. Pollution is increasing
and is becoming more strongly concentrated in only a handful
of countries. The global external grey water footprint, the
pollution created by countries outside of their borders, increased
136% during the period. The extent of externalization
of pollution is highly unequal between countries, and
most of this inequality is due to differences in social development
status. Our results demonstrate a growing globalization
of pollution due to virtual water transfers.
University of Virginia