Sir David Attenborough on global warming
Sir David Attenborough's new series Frozen Planet looks at life at the North and South Poles.
Sir David says he is back on screen in the seven-part series to express his "personal view" on the effects of global warming.
Frozen Planet starts on 26 October at 21:00 BST on BBC One
Richard Bacon broadcasts Monday to Thursday 14:00 to 1600 on BBC Radio 5 live.
To hear more Radio 5 live highlights, please visit the best bits (www.bbc.co.uk/5live/bestbits) page.