 The format of "Saving Planet Earth" was something of a departure for the Unit, using celebrities not normally associated with natural history programmes rather than selecting a familiar face from its pool of specialists.The season began with a special hour-long programme on BBC One entitled "Sharing Planet Earth", a clarion call for action to conserve nature, presented by David Attenborough.It was followed by nine documentaries broadcast nightly over the course of a fortnight, in which celebrities investigated the plight of endangered species.