The water footprint of food waste: case study of fresh mango in Australia

In many parts of the world, freshwater is already a scarce and overexploited natural resource, raising concerns about global food security and damage to freshwater ecosystems. This situation is expected to intensify with the FAO estimating that world food production must double by 2050. Food chains must therefore become much more efficient in terms of consumptive water use. For the small and geographically well-defined Australian mango industry, having an average annual production of 44,692 t of marketable fresh fruit, the average virtual water content (sum of green, blue and gray water) at orchard gate was 2298 l kg−1. However, due to wastage in the distribution and consumption stages of the product life cycle, the average virtual water content of 1 kg of Australian-grown fresh mango consumed by an Australian household was 5218 l. This latter figure compares to an Australian-equivalent water footprint of 217 l kg−1, which is the volume of direct water use in Australia having an equivalent potential to contribute to water scarcity. Nationally, distribution and consumption waste in the food chain of Australian-grown fresh mango to Australian households represented an annual waste of 26.7 Gl of green water and 16.6 Gl of blue water. These findings suggest that interventions to reduce food chain waste will likely have as great or even greater impact on freshwater resource availability as other water use efficiency measures in agriculture and food production.