Hello and welcome to the History Hour Podcast from the BBC World Service with me Max Pearson,

the past brought to life by those who were there.

This week a special edition looking at moments that shaped our relationship with the environment

over the past century.

Coming up, the scientific pioneer who revealed why our climate was changing.

Well, it didn't look like a stock market record flickering up and down.

It had this amazing regularity. This was all of

humanities exhaust building up in the atmosphere and he was seeing that. Superimposed on the natural

breathing of the planet. Also the moment when the UK had a nuclear accident in the 1950s.

It was in a big shed with about 10 feet of concrete between me and the reactor which was burning underneath.

The man who fed the world...

Dr Borlogg saved a billion lives.

And I think it's probably true.

Now that those lives have been saved, we have to sustain the earth.

We'll also remember the Nobel Prize winning Kenyan environmentalist Wangari Methai.

Something very drastic was going wrong with our environment.

Water was no longer clean as I knew it.

The soil was disappearing.

So I told the women, let us plant trees.

And why Mexico banned cars for one day a week.

The smog hangs like a shroud over the city,

slowly poisoning the 20 million inhabitants. Just breathing is like

...