Japanese philosopher Kohei Saito reveals how nothing but a transformation of our economic life can save us from climate collapse. If we are to avoid the most terrible political prospects of climate change, the future must belong to degrowth communism, a fair and humane existence within the limits of nature. Karl Marx himself reached this breakthrough at the end of his life. Now that we are entering our own end-game, we must grasp Marx's final lesson before it is too late. The endless acceleration of capital has run out of road. We must slow down.