842 million people in the world are poorly nourished and 2.1 billion are overweight
Gathering in the harvest is a job far removed from the methods of the 1940s. Instead of choking dust and relentless noise from binders and steam-driven threshing machines, today farmers can sit inside the air-conditioned cab of a diesel-fuelled combine harvester.
Farmers get a real-time read out of the yield and use it to programme fertiliser applications the next year. Wheat yield in Britian is around 7-10 tonnes per hectare - in the 1950s it was 3-4 tonnes.
Today a 1,000 hectare high-tech arable farm needs only three full time workers, together with barns full of modern machinery and chemicals. In the 1950s much smaller farms would have produced a mix of meat, milk and field crops - and employed 13 people.
Across Britain, the agricultural workforce has shrunk to a fifth the size it was 50 years ago - all the result of technology.
Where we once had one style of farming, we now have many. Organic farming has increased greatly in recent years but only accounts for about 4% of farms in the UK.
By contrast, highly intensive farming helps produce the sheer volume of food that the world needs - but at a cost. Some hedgerows have been pulled up. Wild plants and animals on farmland have declined, in number and diversity.
The environmental cost
Though agriculture covers 70% of the UK’s land area, we import much of our food. We have developed cosmopolitan tastes and lost all sense of seasonality.
Supermarkets may source food more cheaply from overseas and our climate limits what we can grow. For most of us, our average weekly food basket at the supermarket comes from all around the world.
Weighing up the costs and benefits of that is very difficult. The environmental cost of transporting the food to the UK is high but it does generate income for growers, often in poorer nations. In some countries. however, it may also use their scarce water resources.