Worldwide, over a thousand lawsuits are launched about legal responsibility for climate change, including eight in European private law. This development imposes the question how these courts should decide upon such cases, given their role in the multi-level legal order of European private law. Climate change litigation is controversial; many believe that the environment as a problem belongs to the political domain, subject to the peopleā€™s power rather than to the discretion of a single court. Climate change confronts us with a tension between law and politics. To grasp this tension, the book assesses what are the boundaries of democratically legitimate judicial law-making in European private law. This book builds on, but ultimately departs from political theory developed by JĆ¼rgen Habermas on deliberative democracy. It reconstructs the tension that captures Justitia, between democratic demands of the Peopleā€™s Power and claims concerning the protection of Mother Earth. The departure from Habermas centres on the observation that our current understanding of deliberative democracy suffers from serious deficits, as analysed by inter alia Dryzek and Pickering. That is, environmental problems typically affect at least three groups not included in the democratic decision-making process: (i) people abroad, (ii) future generations, and (iii) non-human entities like animals, plants and ecosystems. The book analyses the European private law climate cases, and shows how they push for an environmental constitutionalism inclusive towards these groups. The climate cases are signalling a growing legal consensus that the environment is a constitutional matter, which deserves judicial protection against democratic majorities.