As world leaders gather in Brazil, Prince William tells them they must urgently work together to prevent further climate change. But how much can be achieved with the leaders of some of the world’s largest CO2 emitters - the US, China, Russia and India - absent from the meeting? Also on the programme: top Democrat Nancy Pelosi announces her retirement after nearly four decades in the US Congress; and the actress Pauline Collins, best known for her roles in 'Upstairs Downstairs' and 'Shirley Valentine', has died at the age of 85. We speak to her friend and co-star Tom Conti.