Next month, we will all gather again in Rio de Janeiro to work out what went wrong 20 years ago and consider solutions that we have dismissed.
Children who were 12 years old during the first Rio summit, in 1992, might now be quickly approaching the end of their life expectancy in some countries. But what if smallholder farmers had been at the centre of the debate 20 years ago?
At the International Fund for Agricultural Development (IFAD) - the United Nations' agency focused on rural development - we believe there can be no green economy without "green" agriculture.
Agriculture is a key economic and development sector in all countries across the globe, recognised by world leaders for boosting gross domestic product (GDP). If done sustainably, agriculture can provide a significant opportunity for the 1.4 billion people living in extreme poverty to improve their lives, and cater to the food security needs of the world's more than 925 million malnourished people.
In addition, climate-smart and simple technologies can help poor smallholder farmers to build their resilience and mitigate risks associated with climate change.
IFAD and its partners have been working to ensure that innovation and investment in agriculture - and more importantly in the world's 500 million small farms - lead to long-term sustainability.
ORGANIC FAIR-TRADE COCOA
In Sao Tome and Principe, for example, IFAD has helped turn around the dying smallholder cocoa sector after the collapse of world market prices in the late 1990s.
By setting up public-private partnerships with overseas buyers of organic fair-trade cocoa of high quality, the project helped small farmers establish export cooperatives and achieve stable and significantly improved incomes.
Smallholder families participating in the programme have seen their yearly income increase, on average, from a level 25 percent below the poverty line to 8 percent above it. One particularly successful producer used the profit from organic cocoa production to set up a small roadside shop that his wife runs, generating even greater profit.
This initiative was coupled with organising small farmer groups and training them in organic and conservation agriculture, solar drying, integrated pest management and other environmentally sustainable practices.
Smallholder farmers have untapped growth potential. The message IFAD will take to the upcoming conference in Rio is that we must explore this potential by transforming smallholder farmers into empowered business women and men.
This transformation requires adopting new approaches that are competitive, sustainable, sufficiently diversified and within the carrying capacity of natural ecosystems. By helping smallholders in integrating and developing "green value chains", we offer them an opportunity to sustainably harvest not only food, but also economic, social and environmental benefits.
For instance, a new initiative in Sierra Leone is aiming to develop markets for high-quality organic, fair-trade cocoa. The project will rehabilitate a cocoa plantation abandoned during the war.
Prices for good-quality certified cocoa are less susceptible to market fluctuations, and this encourages further investment and assures sustainability. In addition to the extra income provided by intercropped plants, cocoa agroforestry systems will support greater biodiversity and avoid land degradation and erosion caused by slash-and-burn farming.
Smallholder farmers have immense potential to contribute to a green economy and to sustainable growth in general. To do that successfully, they need enabling environments and support such as improved access to land, water and markets, financial services, adequate technologies and technical assistance.
In this respect, promoting the role of women and youth as farm entrepreneurs is particularly crucial. We have the means, we have the knowledge, and now we need the collective will. If we don't act now, we risk going back in another 20 years to acknowledge the failure of choices.
Naoufel Telahigue and Rami Abu Salman are Regional Environment and Climate Specialists at the International Fund for Agricultural Development (IFAD). IFAD is co-organising Agriculture and Rural Development Day on June 18 ahead of the Rio+20 Summit in Rio de Janeiro.