According to 400 scientific experts who have spent the past four years probing the future on behalf of the World Bank and UN Food and Agriculture Organisation, agriculture is going to mean vastly more to civilisation than merely tucker on the table. The world's two billion farmers are the guardians of much of what is left of the natural landscape, holding in their hands the fate of thousands of threatened species as well as the world's remaining forests. Agriculture uses three-quarters of the world's fresh water. Its run-off has degraded Earth's main rivers, estuaries and even seas. It occupies 40 per cent of the world's free land surface. It is responsible for 30 per cent of global greenhouse emissions. And it represents seemingly intractable poverty, disadvantage and suffering. That is the true cost of the cheap food many of us still enjoy. For the time being.