The correct scientific response to something that is not understood must always be to look harder for the explanation, not give up and assume a supernatural cause.

The fact is that no species has ever had such wholesale control over everything on earth, living or dead, as we now have. That lays upon us, whether we like it or not, an awesome responsibility. In our hands now lies not only our own future, but that of all other living creatures with whom we share the earth.

The future of life on earth depends on our ability to take action. Many individuals are doing what they can, but real success can only come if there's a change in our societies and our economics and in our politics. I've been lucky in my lifetime to see some of the greatest spectacles that the natural world has to offer. Surely we have a responsibility to leave for future generations a planet that is healthy, inhabitable by all species

I think we're lucky to be living when we are, because things are going to get worse.

There are some four million different kinds of animals and plants in the world. Four million different solutions to the problems of staying alive.

As far as I'm concerned, if there is a supreme being then He chose organic evolution as a way of bringing into existence the natural world... which doesn't seem to me to be necessarily blasphemous at all.

In the West, that's what's happening. The birth rate has been dropping steadily and still is. But there is still a vast amount of the world where that's not the case. And that is where the big population growth is taking place.