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.' 'The real question is what is happening right now What can we learn from the past about the future changes And what we should be doing or thinking today' In his next book, Homo Deus, Harari delved into how the growth of big data, artificial intelligence (AI) and biotechnology could radically alter and divide human society, perhaps ending the species altogether. The same themes appear in his latest work, 21 Lessons for the 21st Century, which collects essays, talks and responses to his readers. 'What I see today in the world is that people are overwhelmed by information, misinformation, by distraction and they don't realise often what the most important challenges are. I see my job as trying to bring more clarity to the public discussion.' 'There are three big challenges facing human kind in the 21st century,' says Harari. 'They are nuclear war, climate change and technological disruption, especially the rise of artificial intelligence (AI) and bioengineering. This will change the world more than anything else. 'Nuclear war and climate change we can hopefully prevent, so these are changes we try to avoid. But technological disruption and especially AI and bioengineering are bound to happen