2.2 Food Supply and Demand
2.2.1 Predictions
Over the last 50 years, total food supply has increased almost threefold, whereas the world’s population has only increased twofold, a shift that has been accompanied by significant changes in diet related to economic prosperity (Keating et al. 2014). Over the last 25 years, the world’s population increased by 90% and is expected to reach the 7.6 billion mark in the first half of 2018 (Worldometers). Estimates of increased world food demand in 2050 relative to 2010 vary between 45% and 71% depending on assumptions around biofuels and waste, but clearly there is a production gap that needs to be filled. In order to avoid a reversal in recent downward trends undernourishment, there must be reductions in food demand and/or fewer losses in food production capacity (Keating et al. 2014). An increasingly important reason for rising food demand is per capita consumption, as a result of rising per capita income, which is marked by shifts towards high protein foods, particularly meat (Ehrlich and Harte 2015b). This trend creates further pressures on the food supply chain, since animal-based production systems generally require disproportionately more resources, both in water consumption and feed inputs (Rask and Rask 2011; Ridoutt et al. 2012; Xue and Landis 2010). Even though the rate of increasing food demand has declined in recent decades, if current trajectories in population growth and dietary shifts are realistic, global demand for agricultural products will grow at 1.1—1.5% per year until 2050 (Alexandratos and Bruinsma 2012).
Population growth in urban areas has put pressure on land that has been traditionally used for soil-based crops: demands for housing and amenities continue to encroach on prime agricultural land and raise its value well beyond what farmers could make from cultivation. Close to 54% of the world’s population now lives in urban areas (Esch et al. 2017), and the trend towards urbanization shows no signs of abating. Production systems that can reliably supply fresh foods close to urban centres are in demand and will increase as urbanization increases. For instance, the rise of vertical farming in urban centres such as Singapore, where land is at a premium, provides a strong hint that concentrated, highly productive farming systems will be an integral part of urban development in the future. Technological advances are increasingly making indoor farming systems economical, for instance the development of LED horticultural lights that are extremely long lasting and energy efficient has increased competitiveness of indoor farming as well as production in high latitudes.
Analysis of agrobiodiversity consistently shows that high- and middle-income countries obtain diverse foods through national or international trade, but this also implies that production and food diversity are uncoupled and thus more vulnerable to interruptions in supply lines than in low-income countries where the majority of food is produced nationally or regionally (Herrero et al. 2017). Also, as farm sizes increase, crop diversity, especially for crops belonging to highly nutritious food groups (vegetables, fruits, meat), tends to decrease in favour of cereals and legumes, which again risks limiting local and regional availability of a range of different food groups (Herrero et al. 2017).