Humanity has reached a critical moment. Our world is unsettled and rapidly changing, and we face existential risks over the next century. Various prospects for the future – good and bad – are possible. Yet our approach to the future is characterised by short-term thinking, polarising debates, alarmist rhetoric and pessimism. In this short, exhilarating book, renowned scientist and bestselling author Martin Rees argues that humanity’s future depends on our taking a very different approach to thinking about and planning for tomorrow.