Rio+20: Agreement criticised for being 'far too weak'

Negotiators have agreed a text to be approved by world leaders meeting this week in Rio in a summit intended to put society on a more sustainable path.

However, environment groups and charities working on poverty issues have already criticised the agreement as being far too weak.

The Rio+20 gathering comes 20 years after the Earth Summit, also held in the Brazilian city.

David Shukman reports.

Report features Daniel Mittler, Greenpeace