Patrick Barkham

In 1926, the planet's human population was 2 billion.

Today, it's 8.2 billion.

In terms of carbon emissions, parts per million, back in 1926, it was approximately 305 parts per million.

And today, it's up to 430.

And of course, the thing that's really transformed is our levels of consumption in the first world and the impact that's had on the planet.

Roughly half of all the destruction of forests in human history has happened over the course of Sir David's lifetime.

That's an area larger than the size of China.

We have since 1971.

a 73% decline in the average populations of monitored vertebrates.

Among invertebrates, it's less certain, but certainly in Britain there's good data.

Since 1970, there's been a 37% decline in invertebrates found on farmland.

And that's the honest picture of the last 100 years.

It's just astonishing to think of the losses that have occurred over his lifetime.

And those losses are continuing, but...

There is some hope too, and a lot has changed for the better over the course of certainly the last 50 years of David's life.

We've seen the birth of conservation in Sir David's lifetime.

The Wildlife Trust actually celebrate their 100th birthday a few weeks before David's 100th birthday, so...

The conservation movement in Britain was essentially born in the same year as David Attenborough.

And I mean, one of the things we've touched on is David's own influence on conservation science.

It's virtually impossible to meet a conservation scientist anywhere in the world who won't cite David Attenborough as one of their influences and sources of inspiration.