This paper aspires to analyze the impact of climate change litigation on the form of private law and, in so doing, to provide a contribution to the understanding of the transformative potential and limits of private law. I argue that, because of its distinctive features, climate change litigation has anti-systemic potential: more precisely, I advance that it is anti-systemic in its form because it contradicts the rationale of capital accumulation. This finding is surprising and needs to be inquired: indeed, it is usually impossible to use private law in an anti-systemic way, because the legal form, even in the age of monopoly capitalism, reproduces the commodity form. I contend that this outcome is possible because climate change litigation breaks the homology between commodity form and legal form. Developing this argument, I make three distinct contributions. First, I demonstrate that the legal form of climate change litigation is not compatible with the rationale of capital accumulation. Second, in order to assess how and why this finding is original in relation to private law, I widen the focus to private law in general and analyze what usually prevents private law from having anti-systemic potential. I argue that the commodity form theory of law, as elaborated by Pašukanis, is a powerful theory to explain the stability of the private law system. However, the transformations of the global capitalist systems, and in particular monopolization, seem to undermine some of the pillars upon which this theory is built: it therefore necessitates an update. To do so, I develop a theoretical framework to conceptualize and understand the transformations of European private law systems that have been unfolding for some decades, that I tentatively label as private law for the age of monopoly capitalism (PLAMC). I will then demonstrate how the underlying rationale of the commodity form theory of law is still operating even in this context. Finally, assessing climate change litigation against this theoretical framework, I contend that it departs from the rationale of PLAMC and that in these cases the legal form does not replicate the commodity form: this rare dissociation makes possible its antisystemic potential.