David Attenborough and Barack Obama face-to-face in TV interview

In unexpected turn of events, US president interviewed naturalist during visit to White House in May - though Attenborough asks toughest questions

It sounds like a scenario from a fantasy dinner party: the most powerful man on the planet interviewing one of the world's most beloved naturalists about his life story, about climate change and the future of life on Earth.

But in May, it has emerged, this encounter did happen, when Barack Obama invited Sir David Attenborough to the White House for a televised discussion - in which he, the US president, was to ask the questions of the broadcaster, not the other way round.