Sustainable solutions to water-food security through virtual water trade!

Abstract:

Ensuring food needs of the growing population with limited water resources is a major challenge. Freshwater scarcity has been increasing at an alarming rate due to climate change and socio-economic development and threatening crop production at the local and global scale. According to the state-of-the-art virtual water trade (VWT) concept, many countries could offset their limited and uneven distribution of water resources through international trade of food commodities. This concept potentially promotes regional and global water and food security. However, local water renewals and socio-economic norms are not considered in the vast majority of virtual water trade studies. Alberta is a Canadian Prairie province that exports cereal and agri-food to over a hundred countries, and is among the major breadbaskets in the world. To assess how considerations of local water renewal affect VWT strategies, we simulated yield, water demand, and VWT of rainfed and irrigated cereals (wheat, barley, and canola) using the physically process-based Soil and Water Assessment Tool (SWAT). We analyzed historical and future VW exports from Alberta. Our projections revealed that the annual average export potential of VW might reach ~138 billion m³ through the export of cereal grains and other processed foods. This export potential outweighs the total historical provincial water yield of 66 billion m³ and counts for 47% of total historical precipitation. This water supply-demand imbalance presents potential risks to other major economic sectors, thereby demanding for a significant reduction in agricultural production, resulting in a significant cutback in the global food supply. The results of this study reveal that projection of VWT at international levels without consideration of local economic norms and water renewals, may be erroneous and the implication for future water sustainability may be misleading.