Yuval Noah Harari: Technology is humanity's biggest challenge

In 2014, Yuval Noah Harari's life changed completely. The little-known academic was thrust into the international literary spotlight when his book on the history of humans from the discovery of fire to modern robotics, Sapiens, was translated into English. Then-US President Barack Obama said the book gave him a new perspective on "the core things that have allowed us to build this extraordinary civilisation that we take for granted". It went on to sell more than eight million copies worldwide. "I still see myself as a historian," says Harari. "I don't think that historians are experts in the past, historians are specialists in change and how things change and we learn the nature of change by looking at the past."