Anyone who believes in indefinite growth in anything physical, on a physically finite planet, is either mad—or an economist.

Education is not a matter of getting facts and sowing them within brains, but that it is an attitude of mind that you teach children to find out for themselves

Every 10 years, an area the size of Britain disappears under a jungle of concrete.

Homo sapiens is a compulsive communicator. Look at the number of people you see walking around talking on mobile phones. We seem to have an infinite capacity for communicating and being communicated with. I’m not sure how admirable it is, but it certainly demonstrates that we are social organisms.

I am besotted with birds of paradise. Watching them display is the most extraordinary thing I’ve ever seen in my life.

I don’t like rats but there’s not much else I don’t like. The problem with rats is they have no fear of human beings, they’re loaded with foul diseases, they would run the place given half the chance…

I grew up in Leicestershire, in Leicester, which is on the Jurassic, and it’s full of lovely fossils. Ammonites, belemnites, brachiopods—very beautiful. How did they get there, in the middle of the rocks, in the middle of England, and so on? And I had the collecting bug, which I still have, actually, which is the basis of so much of natural history, really, and so much of science. And so collecting all these things, and discovering what they were, and how they lived, and when they had lived, and all that, was abiding fascination to me from the age of I suppose about eight. And I still feel that way, actually.

I have never really had dreams to fulfil…. You just want to go on looking at these ecosystems and trying to understand them and they are all fascinating. To achieve a dream suggests snatching a prize from the top of a tree and running off with it, and that’s the end of it. It isn’t like that. … What you are trying to achieve is understanding and you don’t do that just by chasing dreams.

I have no doubt that the fundamental problem the planet faces is the enormous increase in the human population. You see it overrunning everywhere. Places that were very remote when I went there 50 years ago are now overrun.

I often get letters … from people who say … I never give credit to the almighty power that created nature. … I reply … “Well, it’s funny that the people, when they say that this is evidence of the Almighty, always quote beautiful things … orchids and hummingbirds and butterflies and roses.” But I always have to think too of a little boy sitting on the banks of a river in west Africa who has a worm boring through his eyeball, turning him blind before he’s five years old. And I … say, “Well, presumably the God you speak about created the worm as well,” and now, I find that baffling to credit a merciful God with that action. And therefore it seems to me safer to show things that I know to be truth, truthful and factual, and allow people to make up their own minds about the moralities of this thing, or indeed the theology of this thing.

I think every child born on this planet up to the age of about four or five is fascinated by the natural world. If they aren’t it’s because we deprive them of the opportunity. Over half the world’s population is urbanised and the thought that some children may grow up not looking at a pond or knowing how plants grow is a terrible thing. If you lose that delight and joy and intoxication, you’ve lost something hugely precious.

I thought existing zoo programmes were really not doing animals justice. They all looked like oddities, like bizarre stage things, when, really, in their own environment, they are wonderful answers to very complex questions.

If I were working in astrophysics I would find it quite hard to explain to people what I was doing. Natural history is a pretty easy thing to explain. It does have its complexities, but nowhere do you speak about things that are outside people’s experience. You might speak about a species that is outside their experience, but nothing as remote as astrophysics.

If my legs give up, they give up. But in that case I could sit and do programmes about amoebas—Micro Monsters, perhaps. What else do you want to do? Sit by the fire and read yesterday’s newspaper?

If we [humans] disappeared overnight, the world would probably be better off.

If you want to achieve conservation, the first thing you have to do is persuade people that the natural world is precious, beautiful, worth saving and complex. If people don’t understand that and don’t believe that in their hearts, conservation doesn't stand a chance. That’s the first step, and that is what I do.

If you’re telling a story, it’s very tempting to personalise an animal. To start with, biologists said this fascination with one individual was just television storytelling. But they began to realise that, actually, it was a new way to understand behaviour–following the fortunes of one particular animal could be very revealing and have all kinds of implications in terms of the ecology and general behaviour of the animals in that area.

In a great number of programmes I’m not a scientist—I’m simply a commentator. So I should claim no virtue for the fact that [people] seem to trust me, if that is indeed the case. It’s simply that I very seldom talk about something they can’t see. If I say a lion is attacking a wildebeest, they can see it is; if I were to say something about a proton, it might be different.

In my position you can’t go out and just say, “I think,” because it’s a very serious thing. So if you get up and say climate is changing because of CO2 emissions, you better bloody well be right.

In my view, the proper attitude of a public-service broadcaster is that it should attempt to cover as broad as possible a spectrum of human interest and should measure success by the width of those views. There shouldn’t be all that large a number of gaps in the spectrum; and a major element in the spectrum is scientific understanding. The fact that it doesn’t necessarily get as big an audience as cookery is of no consequence.

In the 1940s when I did my natural sciences degree in zoology it was very much laboratory-based. … I was not keen on the idea of spending the rest of my life in the lab. I also don’t think I would have been particularly good at it. I don't think I have as analytical a mind or the degree of application that one would need to become a first-rate research scientist.

In the early days of dealing with climate change, I wouldn’t go out on a limb one way or another, because I don’t have the qualifications there. But I do have the qualifications to measure the scientific community and see what the consensus is about climate change. I remember the moment when I suddenly thought it was incontrovertible. There was a lecture given by a distinguished American expert in atmospheric science and he showed a series of graphs about the temperature changes in the upper atmosphere. He plotted time against population growth and industrialisation. It was incontrovertible, and once you think it’s really totally incontrovertible, then you have a responsibility to say so.

In the past, you wouldn’t have had any problem in getting a countryman to explain the difference between a blackbird and a song thrush, but you might have that difficulty with a kid now. Equally, if you asked a chap about gorillas in the 19th-century, he wouldn’t have heard of the creatures, but today an urban boy knows all about them.

It is very difficult not to be excited by 10,000 king penguins.

It wasn’t the finches that put the idea [of natural selection] in Darwin’s head, it was the tortoises. The reason he didn’t use the tortoises [in writing On the Origin of Species] was that, when he got back, he found he didn’t have localities on the tortoise specimens. Here the great god, the greatest naturalist we have records of, made a mistake. His fieldwork wasn’t absolutely perfect.

It’s important natural history isn’t seen as something that is “out there”, which you have to travel to. It’s right there in your garden. Public awareness of the natural history of the world as a whole has never been as great. But it’s important to know about species close to home.

I’m not an animal lover if that means you think things are nice if you can pat them, but I am intoxicated by animals.

Kids like their fossils. I’ve taken my godson fossil-hunting and there’s nothing more magical than finding a shiny shell and knowing you’re the first person to have seen it for 150 million years.

Looking down on this great metropolis, the ingenuity with which we continue to reshape our planet is very striking. It’s also sobering. It reminds me of just how easy it is for us to lose our connection with the natural world. Yet it is on this connection that the future of both humanity and the natural world will depend.

Nature doesn’t sit still. Things and individuals are changing, dying and new things are coming. They’re all stories.

One of the great achievements of the 1950s and 1960s was a [TV] series called Your Life in Their Hands, which dealt with medical science. It presented the scientific evidence for the connection between tobacco and cancer, against the entrenched opposition, all of which you can quite easily imagine. … The “television doctor” … presented the evidence of the connection between the two over and over again on television. A lot of people tried to stop it, but he carried on. It ruined his career, I suspect, in the medical sense, but he stuck to his guns. It’s one of early television’s badges of honour.

People are not going to care about animal conservation unless they think that animals are worthwhile.

The beauty of natural history programmes is that you can be straightforward and fascinate the 7s and the 70s. If you just present it as it is, all kinds of people of all ages and all educational backgrounds love it. That’s the joy of natural history—it’s a godsend for blokes like me.

The biggest animal that has ever lived on our planet: a blue whale. … It’s far bigger than even the biggest dinosaur. Its tongue weighs as much as an elephant. Its heart is the size of a car. And some of its blood vessels are so wide that you could swim down them.

The great heroes and heroines of our society are of course the teachers, and in particular the teachers of kids in their first years. Once a child has been shown what the natural world is, it will live with them forever.

The whole biological community needs to be talking to one another so that people can get a comprehension of the turmoil in which our planet is involved at the moment, which is a biological turmoil above anything else.

There are three times as many people in the world as when I started making television programs 56 years ago. It is frightening. We can’t go on as we have been. We are seeing the consequences in terms of ecology, pollution, space and food production.

There is a huge disconnect. Those living in the most urbanised areas don’t see a wild thing from one day to the next—unless it’s a pigeon or a rat. If you lose the connection with nature, you lose a source of great pleasure.

We are a plague on the Earth. 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.

We tried to transform Tarmac playgrounds into places with pools, and earth where children could grow things. Now the Government is saying we need more classroom space so the schools are building them on the very nature habitats we’ve been working to provide.

We’re suffocating ourselves by cutting things down. And the awful thing is that the knowledge is there. Fifty years ago when we exterminated things, we did it without realising. Now there’s plenty of evidence of what it is we’re doing, and yet we keep on doing it.

We’re very safety conscious, aren’t we? [In 1989,] I did a programme on fossils, Lost Worlds, Vanished Lives, and got a letter from a geologist saying, “You should have been wearing protective goggles when you were hitting that rock. Fragments could have flown into your eye and blinded you. What a bad example you are.” I thought, “Oh, for goodness sake...”

When I was a boy, I could cycle out of town and be in fields in ten minutes. I knew where the birds’ nests and badger setts were. Now children’s mothers would tell them they need someone to go with them, to make sure they weren’t molested by a sexual deviant.

When I was about 13, I cycled from Leicester to the Lake District and back again, collecting fossils and staying in youth hostels. I was away for three weeks, and my mother and father didn’t know where I was. I doubt many parents would let children do that now.

Yes, we have to [do more to prioritise animals and the environment over human activity]. There are whole areas—the rainforest, for example—that have to be protected for the animals and for the whole of the climate of the planet. That’s a priority if ever there was one.

You can’t [have pets], when you go away filming for weeks, [but] I have great crested newts in the pond, and a darling robin that comes in the kitchen.

You would be surprised at the number of academics who say things like ‘I didn’t realise what a sponge was until I saw a programme of yours’.

You’ve got to be fairly solemn [about the environment]. I mean the mere notion that there are three times as many people on Earth as there were when I started making television. How can the Earth accommodate them? When people, including politicians, set their faces against looking at the consequences—it’s just unbelievable that anyone could ignore it.

[A key to success] is being able to talk to camera without a teleprompter. … If you believe something and want to make clear what you are talking about, you ought to be able to articulate it without a teleprompter.

[Am I vegetarian?] No. If you understand about the natural world, we’re a part of the system and you can’t feed lions grass. But because we have the intelligence to choose… But we haven’t got the gut to allow us to be totally vegetarian for a start. You can tell by the shape of our guts and the shape of our teeth that we evolved to be omnivores. We aren’t carnivores like lions but neither are we elephants.

[At my secondary school] if you were very bright, you did classics; if you were pretty thick, you did woodwork; and if you were neither of those poles, you did science. The number of kids in my school who did science because they were excited by the notion of science was pretty small. You were allocated to those things, you weren’t asked. This was in the late 1930s/early 1940s … Science was seen as something more remote and less to do with everyday life.

[Boundless curiosity.] That’s what being alive is about. I mean, it’s the fun of it all, making sense of it, understanding it. There’s a great pleasure in knowing why trees shed their leaves in winter. Everybody knows they do, but why? If you lose that, then you’ve lost pleasure.

[If I were to be reincarnated] I would come back as a sloth. Hanging from a tree, chewing leaves sounds great.

[My dream dinner guest is] Charles Darwin. It’s an obvious answer, but it’s the truth. Think of any problem and before you start theorising, just check up whether Charles Darwin mentioned it in one of those green books sitting on your shelf. Whether it’s earthworms, human gestures or the origin of species, the observations that man made are unbelievable. He touched on so many subjects. Then, Alexander von Humboldt, the last polymath. There was no aspect of the natural world that he wasn’t curious about or didn’t write about in Kosmos, an extraordinary book.

[Perfecting a script is] verbal carpentry. … That's what my speciality is, really, and always has been. If you can use four words instead of five that’s good.

[Watching natural history programs] brings a solace you can’t describe in words. It’s because we’re part of it fundamentally…. In moments of great grief, that’s where you look and immerse yourself. You realise you are not immortal, you are not a god, you are part of the natural world and you come to accept that.