In Climate Leviathan, Mann and Wainwright address the political implications of climate change by theorizing four possible planetary futures: Climate Leviathan as capitalist planetary sovereignty, Climate Mao as non-capitalist planetary sovereignty, Climate Behemoth as capitalist non-planetary sovereignty, and Climate X as non-capitalist non-planetary sovereignty. The authors of the present article agree that the depth and scale of destabilizations induced by climate change cannot be navigated justly from within the present social-political-economic system. We disagree, however, on which of the non-capitalist orientations (...) is better suited for generating viable alternatives to the worst dystopian futures. The article thus stages a debate to elucidate the theoretical and political divergence between Climate X and Climate Mao. (shrink)