The challenge of feeding 9–10 billion people equitably and sustainably

SUMMARY The present paper reviews some of the high-level challenges facing the global food system over the next 40 years, drawing in particular on the UK Government's Foresight Report on the ‘Future of Food and Farming’, to set the scene for discussions about the sustainable use of nitrogen in agriculture. It reviews the likely demand and supply pressures on the food system, and the pressing requirements to improve sustainability and address the needs of the world's poorest. It argues that the food system is entering a period of radical change, led particularly by growth in demand, which requires action on food production, diet, waste and efficiency, and governance. A key challenge on the supply side is sustainable intensification – producing more from the same amount of land with fewer and less profound negative effects on the environment. Increasing the efficiency of nitrogen fertilizer application will be critical for increasing yields while reducing the many major environmental consequences of leaching and run-off.