The world’s population is growing and its climate is changing—at the same time, its land and water resources are running out. Two recent events at the United Nations Conference on Sustainable Development (Rio+20) put a spotlight on how agriculture can keep up with these challenges.

Elinor Ostrom’s death on 12 June, just days before the Rio+20 conference, is an enormous loss. But her life’s work offers many lessons for the deliberations, decisions and path to progress at and after Rio.

Food insecurity poses a daunting challenge to the G20’s goals of global economic growth and development. The impacts of high and volatile food prices in 2007-2008 and 2010-2011 remain widely visible, as seen during the 2011 Horn of Africa food crisis. Since 2001, commodity price volatility has been at its highest level in 50 years. This volatility can serve to reduce investments in agriculture, discourage long-term planning, reduce agricultural productivity, and decrease global food stocks.

Some experts believed that by 2010, up to 50 million “environmental refugees” would flee their lands due to the dramatically negative effects of climate change. Such claims, however, are not based on the actual responses of households and communities to climate change but on broad estimates of the number of people “at risk” from the changing climate.