You can only get really unpopular decisions through if the electorate is convinced of the value of the environment. That's what natural history programmes should be for.

It seems to me that the natural world is the greatest source of excitement; the greatest source of visual beauty; the greatest source of intellectual interest. It is the greatest source of so much in life that makes life worth living.

[W]hen we look at the graphs of rising ocean temperatures, rising carbon dioxide in the atmosphere and so on, we know that they are climbing far more steeply than can be accounted for by the natural oscillation of the weather ... What people (must) do is to change their behavior and their attitudes ... If we do care about our grandchildren then we have to do something, and we have to demand that our governments do something.

I find it far more awesome, wonderful, that creation; our appearance in the world; should be the culmination, or at least one of the latest products of 3,000 Million years of organic evolution, than a kind of country trick, taking a rib out of a man's side in a trance.

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.

If my grandchildren were to look at me and say, 'You were aware species were disappearing and you did nothing, you said nothing', that I think is culpable. I don't know how much more they expect me to be doing, I'd better ask them.

Opponents say natural selection is not a theory supported by observation or experiment; that it is not based on fact; and that it cannot be proved. Well, no, you cannot prove the theory to people who won't believe in it any more than you can prove that the Battle of Hastings took place in 1066. However, we know the battle happened then, just as we know the course of evolution on earth unambiguously shows that Darwin was right.