Whereas our common past, out of Africa, saw a global diaspora of humankind, our common future depends on a global coming together and consensus, resulting in a more equitable distribution of the Earth's largesse. When Africa, which gave us the wealth of life, has that debt returned, the world will have come of age.

So far as we know, Earth is the only planet which supports life, and it is the only planet on which we can survive. Our bodies and our minds are fashioned by it. Our hearts resonate with it. There will be little joy for the human spirit if we destroy the natural fabric of Earth with nothing left to do but go shopping. When we imagine the world a century from now, when we look our great grandchildren in the eye and see them smiling back at us because they know we cared for them, we smile too!

The future will either be green or not at all.

There are better alternatives... Australia should be exporting its solar technology, not its uranium.

I will be Green until the day I die, if not for a long time after.

Australia must prioritise education spending. It is not a question of whether or not we have the money, it is a question of how we choose to spend it.

I've always thought, and it gets tested at times, that I have a great faith in the fundamental goodness of human beings.