What is sustainable agriculture?

We all want to eat food that is produced sustainably. But it's not at all clear what that means in practice. Fundamentally, agriculture can be regarded as sustainable if it can continue to meet human needs whilst avoiding irreversible harm to the planet. The human needs are not just food, but include employment, leisure, social cohesion and the many ecosystem services provided by agricultural land that benefit people, including regulating water quantity and quality, carbon storage, maintaining landscapes of cultural and spiritual value, and providing homes for wildlife. Agriculture causes harm to the planet from habitat loss, carbon emissions, and pollution of air and water. Meeting these challenges is tough now, but it will only become more difficult as the human population rises and climate change becomes more difficult to cope with.