Ice and the Sky: the cold truth about climate change

The French glaciologist Claude Lorius talks about a new documentary that tells how the Antarctic surveys of his team alerted the world to the threat posed by carbon emissions

Claude Lorius sits on a rocky outcrop and gazes pensively across a vast, white vista. Next to him a penguin patters past, hesitates and plops into the icy water. It is hard to tell who is most at home.

One of the most poignant moments in Luc Jacquet's breathtaking documentary, Ice and the Sky (La Glace et le Ciel), it is a beautiful scene of quiet contemplation. But then Lorius, 83, has much to reflect on. Fresh-faced and eager, he set out during the International Geophysical Year, nearly 60 years ago, a pioneer on one of the ambitious scientific expeditions to study Antarctica - a poorly mapped continent labelled with little more than "here be dragons". "It's hard to describe the fervour gripping my shipmates and I," he recalls in the film.