Verso Books, 2018 Climate Leviathan is a jarring, dissatisfying read. Its best arguments are left undeveloped. What should have been tangential points are expanded upon in bland, circuitous detail. Its central proposition is not supported by strong evidence. It promises a new political theory, but its conclusions are vague, hesitant and almost painfully schematic. The core argument of authors Geoff Mann and Joel Wainwright is that a liberal capitalist supra-national world state or “sovereignty” is a likely way that the capitalist system will adapt to runaway climate change and other ecological breakdowns. They call this outcome the Climate Leviathan. Mann and Wainwright write about the Climate Leviathan as a warning. It poses a future “new imperial hegemony” where a single state or handful of powerful states attain global hegemony and “seize command, declare an emergency, and bring order to the Earth, all in the name of saving life.”