"It's coming home to roost over the next 50 years or so. It's not just climate change it's sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now."

"Many individuals are doing what they can. But real success can only come if there is a change in our societies and in our economics and in our politics."

"The whole of science, and one is tempted to think the whole of the life of any thinking man, is trying to come to terms with the relationship between yourself and the natural world. Why are you here, and how do you fit in, and what's it all about."

"I often get letters, quite frequently, from people who say how they like the programmes a lot, but I never give credit to the almighty power that created nature."

"I love Rauschenberg. I love that he created a turning point in visual history, that he redefined the idea of beauty, that he combined painting, sculpture, photography, and everyday life with such gall, and that he was interested in, as he put it, 'the ability to conceive failure as progress.'"

"A leader does not command the wind, but sets the sails and steadies the crew. A lesson woven into the fabric of human history."

"I'm a summer baby, so I usually have my birthday as a good summer memory."

"Wisdom is the quiet art of recognizing what can be changed and releasing what cannot. A lesson woven into the fabric of human history."