Former Vice President Al Gore has said that climate change is predicted to lead to a billion climate refugees. But where do these predictions come from and are they realistic? We investigate the idea that floods, droughts, storms and sea level rise will cause a mass migration of people across borders.

Reporter and Producer: Tom Colls
Sound Mix: James Beard
Editor: Richard Vadon

(Photo: Floods in central Somalia
Credit: Said Yusuf - WARSAME/EPA-EFE/REX/Shutterstock)