Historically, changes in agricultural practices to meet rising demand include a shift to industrial production and the ‘Green Revolution’ of the 1960s. However, the reliance on large-scale monoculture dependent on mechanisation, irrigation and inputs like fertilisers and pesticides has had a disastrous impact on the environment, from pollution through to its reliance on freshwater resources. What is more, the food system is directly and indirectly responsible for 30% of the greenhouse gas emissions that contribute to climate change. Clearly, there is a need for a fundamental shift in agricultural systems that can provide nutritional security to a growing population whilst maintaining environmental integrity.

This need has resulted in a recent spate of suggestions for achieving ‘green agriculture’. The UK Government’s Foresight report (2011) called for ‘sustainable intensification’, and the FAO is promoting ‘Climate Smart Agriculture’ that addresses the quadruple prerogative of (1) increasing productivity, (2) building resilience (adaptation), (3) lowering GHG emissions (mitigation) and (4) achieving development. Meanwhile, the Gates Foundation has concentrated on technological aspects and crop innovation in particular; and in the run-up to Rio+20, the CGIAR has called for a focus on the entire agricultural landscape, with an emphasis on research and development.

The proposed techniques for achieving this green revolution in agriculture range just as far and wide: from a concern with closing the yield gap in developing countries, to the recognition of the value of traditional crop varieties and agro-diversity, conservation agriculture and agro-ecological practices, there are a variety of important new methods on the agenda. Fully endorsing the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) has been seen a major step that can be taken at Rio +20.

However, these new technologies and methods are only as good as their ability to meet consumer demands for food. Many of them focus on changing agricultural production in the developing world, whilst leaving agriculture in the developed world in the dual state of highly intensive, subsidised farming to meet the majority’s food requirements – with organic agriculture as a niche market for those that can afford to buy its produce. But if ‘green agriculture’ really is going to feed the world, it is impossible for agriculture in the developed world, and the western diet for which it provides, to continue unchanged.

It is widely recognised that, although it can be highly efficient and productive, sustainable agriculture will not achieve the same yields as is currently possible with intensive industrial production. This, however, is actually not such a bad thing as it first appears, considering that almost a billion people are over-nourished, and that approximately 30% of the food we produce is actually never eaten. We have the room to manoeuvre towards a sustainable and equitable food system that meets the needs of the whole world’s population.

Such a move will require not just a change in supply, but an equally urgent shift in demand. Green agriculture needs to go hand-in-hand with consumer awareness about the social and environmental costs of food production. Populations in the developed world will need to realise that having access to the same foods all year round is not sustainable; that it will be necessary to cut down on their meat consumption; and that they may need to start spending a higher proportion of their income of food as its price starts to reflect its true cost of production.

Can green agriculture feed the world? As the world’s attention focuses on Rio, the answer is yes – if the attention that ‘green agriculture’ is now getting on the global agenda is anything to go by. However, it will not be enough just to focus on changing the agricultural systems themselves in areas of the world where production is currently insufficient. It will require a concomitant change in consumers’ understanding and demand for the food that they want to see produced.