Defining The Decade - The Heat is On

Edward Stourton tries to make sense of a decade in which history has been put on fast forward. There has been a revolution in the way we communicate, widespread alarm about the planet's very survival and a challenge to the world order. What does it mean for the way we live as we head into 2010? Back in the year 2000, the world's leaders didn't seem to be troubled by the notion of global warming, so what has changed?