David Spiegelhalter

A look at three key numbers that clarify the important questions on climate change, giving a unique perspective on what we know about the past, present and future of our climate.

Risk Factor begins with filmmaker Robert Lang expressing confusion about his personal risks and the societal risks that seem to threaten us all. Which risk factors are truly dangerous? And which ones don’t matter? To gain insight, he decides to go on a journey to meet the world’s top risk experts.