Hello and welcome, I'm Justin Rolatt.

And this is episode four of a Geochemical History of Life on Earth on the BBC World Service.

This is the series looking at what lessons we humans should clean from the last four

billion years of evolution about the folly of meddling with our planet's chemistry.

This week we look at the great flourishing of life that rose up from the ashes of the

meteor that wiped out the dinosaurs 66 million years ago.

The flourishing produced the wealth of mammals, birds, flowers and insects we know today.

And eventually it also produced us.

But as new arrivals on the scene are we humans about to bring this golden era to an untimely

end with a catastrophe of our own making.

For we're conducting a giant experiment with our planet's chemistry filling her atmosphere

and oceans with carbon dioxide.

We know this is transforming the Earth's climate but to fully appreciate the gravity of

what we're doing we need to look back over these last 66 million years because it is

a period that shows just how variable the world's climate can be.

These are fossil collections of an apple and a few metres in.

So these great cabinets hold thousands of fossils.

Can we just open a door around them and have a quick peek?

I'm taking a peek at the vast hidden treasure trove of fossils in London's Natural History

Museum.

It's all about our largest and oh my what's this?

If I open a random drawer these are toe bones of Wolley Rhinothorus from the last

...