Geographer, historian and author Jared Diamond has said he is "cautiously optimistic" the world will be able to tackle the existential threats it faces such as climate change.

Over the last 50 years the world has had a good "track record" in tackling global issues, he told Hardtalk’s Stephen Sackur.

"The chances are better than even that we will succeed but it is dicey and it will take work, particularly it's going to take political will, which is the ingredient that is deficient at the moment," he said.

You can see the Hardtalk interview in full on Thursday 30 May 2019 on BBC World News and the BBC News Channel and after on BBC iPlayer (UK only).