PNNL

Abstract

With a rapidly expanding population and climate change having an impact, pressures on food production systems are expected to increase in coming decades. To meet current demand, it is estimated that over one third of the earth’s land surface is used as cropland or pastures (FAO, 2016b). Although management intensification, such as increasing fertiliser application rates (FAO, 2014b), has led to more productive systems, much of this has been at the expense of the environment, including increasing greenhouse gas (GHG) emissions such as nitrous oxide (Alexandratos and Buinsma, 2012). Management strategies that aim to achieve high N use efficiencies (Wang et al., 2017) and closing of crop yield gaps have been proposed as ways of alleviating pressures on food production systems (Foley et al., 2011; Mueller et al., 2012). However the net benefits these strategies is predicated on environments that are not resource limited. The aim of this study, therefore, is to combine the projections of changes in water scarcity with the projected areas of future agricultural land, to identify the potential regional vulnerabilities of agricultural land and food production to water scarcity. By combining global maps of projected cropland and pasture area with an ensemble of water scarcity projections, we aim to quantify the risks that water scarcity could pose to land-based food production in 2050. An in-depth analysis is also undertaken for specific food commodities: maize, rice, wheat, vegetables, fruit and pulses on croplands, and cattle production systems t on grasslands.