The Challenge in a Nutshell

This image neatly summarises the challenge of food sustainability.
Our planet currently supports 6.6 billion people, each of whom need something to eat and drink every day.
Vast amounts of food are grown and produced around the world, but it cannot always be grown where the people are most highly concentrated. In cities, where populations are highly concentrated, most people do not have the space to grow food for themselves or their communities, and rely on food that is transported from farming areas. Because of the demand for large quantities of food, intensive farming practices have developed over the last 60 years or so. Intensive farming produces high yields of crops, but often causes environmental degradation such as chemical pollution, erosion, soil depletion, salinity. The need to transport food also raises problems of resource use and pollution.
So the problem is that under current conditions, we are not balancing human needs with environmental needs, to the point that the health and possibly survival of the planet is under threat. The challenge is to find sustainable means of meeting our food needs, while looking after our natural systems so that they can continue to support us.
Every human being can play a role - whether it is by growing some of our own food, or reducing the amount of food we consume (or waste), and especially by being aware of the ecological and social impacts of some of the food products we buy and making different choices to minimize that impact.