International bestselling author, Ian McEwan, joins Simon and Matt for a chat about his new novel 'What We Can Know'.

Optimistic manifesto? Or a cautious tale?

In the first half of the book, we learn about a lost poem - which is at the heart of the novel - as this is ultimately a book about a quest.

As well as poetry, they talk about renewable energies being on the rise and the positive conversations around climate change.

'you only have to stop doing bad things to nature, for it to push back quickly'

Here's more on the book:

2014: A great poem is read aloud and never heard again. For generations, people speculate about its message, but no copy has yet been found.2119: The lowlands of the UK have been submerged by rising seas. Those who survive are haunted by the richness of the world that has been lost.Tom Metcalfe, a scholar at the University of the South Downs, part of Britain's remaining archipelagos, pores over the archives of the early twenty-first century, captivated by the freedoms and possibilities of human life at its zenith.When he stumbles across a clue that may lead to the great lost poem, revelations of entangled love and a brutal crime emerge, destroying his assumptions about a story he thought he knew intimately.