The social relation of capital, as we all know, is a contradictory one. These contradictions, though stemming from capitalism's internal laws of motion, extend out to phenomena that are usually conceived as external to the system, threatening the integrity of the entire biosphere and everything within it as a result of capital's relentless expansion. How to understand capitalism's ecological contradictions has therefore become a subject of heated debate among socialists. Two crucial issues in this debate are: (1) must ecological crisis lead to economic crisis under capitalism?, and (2) to what extent is there an ecological contradiction at the heart of capitalist society?This article can also be found at the Monthly Review website, where most recent articles are published in full. Click here to purchase a PDF version of this article at the Monthly Review website.