Feeding the world sustainably.

• Author: Da Silva, Jose Graziano

The 1992 Earth Summit in Rio de Janeiro was memorable for its landmark agreements to guide sustainable development worldwide. The first principle of the 1992 Rio Declaration on Environment and Development states: "Human beings are at the centre of concern for sustainable development. They are entitled to a healthy and productive life in harmony with nature." Twenty years later we have yet to deliver on this fundamental principle--too many people in this world are still not living healthy and productive lives in harmony with nature. Approximately 925 million people are suffering from hunger. We cannot call development sustainable if one out of every seven persons is left behind. At the same time there is hunger, which is senseless in a world that already produces enough food to feed everyone. Hundreds of millions more suffer from obesity and related medical problems.

It follows that eradicating hunger and improving human nutrition must be central to the Rio+20 debate. The upcoming United Nations Conference on Sustainable Development can and should provide the impetus for the world to feed itself more sustainably and more equitably.

The starting point must be the awareness that agricultural systems, which include non-food as well as food products, livestock, fisheries, and forestry, are the main source of food and income for most of the world's poor and food-insecure people, around 75 per cent of whom live in rural areas. Further, the millions of people that manage agricultural systems--from the very poorest to commercial producers--constitute the largest group of natural resource managers on the face of the earth.

Thus, agriculture is at the heart of the solution of the sustainability issue, contributing from the environmental, economic, and social sides. If we improve agricultural and food systems, we can improve the livelihoods and health of people, and produce healthier ecosystems as well. The dominant agricultural model we inherited from the Green Revolution of the 1960s, with its emphasis on a narrow range of crops and its heavy use of chemicals, energy and capital, cannot meet the challenges of the new millennium.

Cereal production doubled between 1960 and 2000, but at a huge cost. Collateral damage includes land degradation and deforestation, over-extraction of groundwater, emission of greenhouse gases, loss of biodiversity, and nitrate pollution of water bodies.

As well as affecting the environment and contributing to climate change...