Each [pelican] has already survived many perils in its young life. As a chick, it fought battles with its brothers and sisters and won. - David Attenborough

Sinking beneath the waves is a very surreal experience. Your first instinct is to hold your breath. At night, the reef is a ghostly world. Tiny shrimplike creatures dance in the lights. ... with little light, there is a lot less colour. But this is still a magical place.

In the south west of India lies the long narrow coastal state of Kerala. Most of its thirty-two million inhabitants live off the land and the ocean, a rich tropical ecosystem watered by two monsoons a year. It's also one of India's most crowded states - but the population is stable because nearly everybody has small families... At the root of it all is education. Thanks to a long tradition of compulsory schooling for boys and girls Kerala has one of the highest literacy rates in the World. Where women are well educated they tend to choose to have smaller families... What Kerala shows is that you don't need aggressive policies or government incentives for birthrates to fall. Everywhere in the world where women have access to education and have the freedom to run their own lives, on the whole they and their partners have been choosing to have smaller families than their parents. But reducing birthrates is very difficult to achieve without a simple piece of medical technology, contraception. m35s09-m38s21

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.