This is an important book. At a time when the credibility of politicians has fallen to new depths one would hope that there is more appetite for books that are realistically bleak in their outlook. Defiant Earth does not pander to mainstream demands for optimism, leadership, creativity and economic growth. Now that climate change is so alarmingly real in its effects, and the world has got the Donald it so probably deserves, it is time to get real. As Clive Hamilton explains, it is time for a thorough rethink.