Do we really require so many gardening programmes, makeover programmes or celebrity chefs?

I'm no longer sceptical. I no longer have any doubt at all. I think climate change is the major challenge facing the world.

Its about cherishing the woodland at the bottom of your garden or the stream that runs through it. It affects every aspect of life.

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

We keep putting on programmes about famine in Ethiopia; that’s what’s happening. Too many people there. They can’t support themselves — and it’s not an inhuman thing to say. It’s the case. Until humanity manages to sort itself out and get a coordinated view about the planet it’s going to get worse and worse.

An understanding of the natural world and what's in it is a source of not only a great curiosity but great fulfillment...

The truth is: the natural world is changing. And we are totally dependent on that world. It provides our food, water and air. It is the most precious thing we have and we need to defend it.