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.

Currently, we allow our political and business leaders to get away with murder. Now is the time to change that. We need direct liability for those who are destroying our future and this planet. We need fast, profound and systemic change. History only moves forward when courageous people get up and act. That's why I support this citizens' initiative to recognise ecocide as the crime it is.

Nelson's Mandela own sense of himself was a very humble reading, [different] from how the world read him. And, quite often, you had the sense that he was not comfortable with all the accolades that would be.

Whenever anybody called Nelson Mandela a saint, he would say: "If by saint you mean a sinner who is trying to be better, then I'm a saint."

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.

My final advice for young people is to not wait for leadership from adult politicians. Step forward today, because our current leaders are denying the dire reality we are facing. Leadership can come form anywhere.

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'.