Sandy was a climate change warning. Obama must now take the stage and fulfil the promise of hope the world needs.

I first met Nelson Mandela when I was in my late 20s, in 1993. I was helping facilitate an African National Congress (ANC) workshop to plan its media strategy. I went down to meet him for the first time and you know me I got stupid... I just choked. I said, "Hello Madiba, it's a real honour to meet you," and I couldn't get another word out.

Struggles only move forward when decent men and women step forward and say, 'enough is enough and no more.'

The struggle to avert catastrophic climate change is bigger than all the other struggles, whether it is slavery, democracy struggles, the woman's right to vote, and so on I would argue that if what is at stake is securing life as we know it, then there can be no bigger struggle that we face.

Sandy was a climate change warning. Obama must now take the stage and fulfil the promise of hope the world needs.

The city of Copenhagen is a climate crime scene tonight, with the guilty men and women fleeing to the airport in shame. World leaders had a once in a generation chance to change the world for good, to avert catastrophic climate change. In the end they produced a poor deal full of loopholes big enough to fly Air Force One through.

[Nelson] Mandela was very keen not to be understood as an exceptional person.