Amitav Ghosh’s The Great Derangement: Climate Change and the Unthinkable is a tract for the times, a polemic against the political inertia of the international order and its disorders. But for all the urgency of its case, it’s a measured and judicious, soberly annotated exposition. This is a short book with a long reach, digging deep into not just the causes of climate change — fossil fuel energy systems, deforestation, the demands of accelerating population growth — but also how we choose to perceive it, the ways we audit and still marginalise it. The title’s “derangement” is what history will judge as our failure to engage with the depth and range of global warming. Derangement? Well, the “leader of the free world”, in one of his proto-presidential geopolitical insights, declared that climate change is a merely a hoax perpetrated by the Chinese government.