This month's Global development podcast looks ahead to the Rio+20 talks and asks what they may mean for sustainable development.

The discussion looks back 20 years to see where this all began, explores arguments for a "green economy" (a key conference theme) and the role of business in sustainable development, and considers what is at stake for the People's summit.

To debate these issues, John Vidal is joined in the studio by Claire Melamed, the head of the growth and equity programme at the ODI, a thinktank on international development and humanitarian issues; Hannah Stoddart, head of economic justice policy at NGO Oxfam and Andrew Raingold, executive director of the Aldersgate Group, an alliance of leaders from business, politics and society working for a sustainable economy.

Joining the podcast on the telephone are Anil Naidoo from the council of Canadians and co-facilitator of the water thematic group at the People's summit, and Saleemul Huq, senior fellow at the International Institute for Environment and Development.