Patrick Barkham

We've seen and demonstrated enormous successes with saving individual species, particularly charismatic predators and mammals towards the top of the food chain.

We've seen tiger populations double.

in India over the past decade thanks to focused conservation efforts.

The gorillas that David, of course, famously filmed in Life on Earth numbered 250 in Rwanda in the 70s.

Poaching had decimated them.

And today, the population in the national park where he filmed them is more than 600.

Here in the UK, species of butterfly like the large blue, which became extinct in the year that Life on Earth was broadcast, have been brought back from extinction.

And Britain actually has a larger large blue butterfly population than any other country in the world now.

And by saving individual species, we not only inspire and galvanize people, but we often are saving a particular habitat or an ecosystem.

So it is important to see all the successes and what we're doing, but obviously set them in the frame of ongoing challenges.

Well, the invisible side of the legacy is, as you say, in the hearts and minds of all the people who have watched Attenborough programmes and been inspired not simply to act, but make their careers, their life's work, one of acting to save species or help the planet.

And so that's a very real legacy.

And he carries so much authority that people really do listen.

And they include world leaders and politicians desperate to be seen to be doing the right thing when gently admonished by David Attenborough.

It's hard to put our finger on how much action has been down to him but certainly specifically last summer he released a film Ocean that was incredibly successful at cinemas in Britain and around the world and that highlighted very graphically for the first time the devastation caused by bottom trawling and I know that David Attenborough had very specific ambitions there to see that practice banned.

It hasn't been yet but there's certainly

more of a movement now to curtail it and constrain it than ever before.

I think he will look at his own work and the astonishing number of glorious programmes that tell amazing stories about the natural world.

And I don't see how he would not consider that a life's work well spent.

My gosh, he's a model and an inspiration for all of us in terms of how to tackle old age.