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.

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.

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.

One of the things that I noticed with my own eyes was Nelson Mandela ability to engage with kings and queens and heads of state on the one hand, and his ability to engage with ordinary people, equally comfortably.

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.

Investing one cent more in oil, coal and gas is investing in the death of society, and the in the death of our children.