I was 15 years old when I first heard the name Mandela, or Madiba, as he is fondly known in Africa. In apartheid South Africa he was public enemy number one. Shrouded in secrecy, myth and rumour, the media called him 'The Black Pimpernel'.

This week we saw progressive business and faith leaders making strong commitments that are moving ahead of what world leaders promised today. The leaders of major economies must be bolder than they were today in providing a vision for 100% renewable energy for all.

There is no definition of terrorism and there is still the reality that one person's terrorist is another person's freedom fighter.

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.

I think even though he [Nelson Mandela] was feted and praised as he was, he always was at pains to say, I'm a human being.

I've come across a lot of people in my life who talk about poverty and talk about the poor, but you rarely have a sense that it matters to them to the point at which they will be willing to sacrifice something.

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