In the run-up to June’s Rio+20, the Natural History Museum is running an interesting-looking series of web-based debates on the following topics:

• Ecosystem economics – can we put a price on nature? 25 January 2012.
• Beyond GDP – how can we measure progress? 22 February 2012.
• Green cities in a green economy – how to pioneer a sustainable transition? 14 March 2012.
• Food security – how do we feed 9 billion people in 2050? 11 April 2012.

A panel of experts, chaired by Richard Black, the BBC’s environment correspondent, will discuss these issues. See here for more information.