But, speaking after it emerged that a number of overseas broadcasters were not buying the last episode of BBC documentary series Frozen Planet which deals with climate change, Sir David said it was “perfectly possible” to tell the story of the Antarctic and Arctic without talking about global warming.
And he said it was the “right and prerogative” of other broadcasters to decide what they showed.
“What the series tries to do is look at all aspects of what is happening at the Poles,” he said.
But he added: “What happens in the Antarctic and what’s happening at the Poles is going to have a huge effect.
“If the Greenland ice cap melts, London could be in danger of flooding.
“We know enough about the atmosphere to realise that these are key places.”
The veteran broadcaster and naturalist added: “What is happening at the Poles is having huge significance on us, and we are affecting what is happening at the Poles.”