The aim of this paper is to question the utilitarian hegemony in recent discussions about global climate change by defending the possibility of a contractualist alternative. More particularly, I will raise and try to answer two questions. First: How can we justify principles of climate justice? As opposed to the utilitarian concern with maximizing general welfare, a contractualist will look at the question whether certain principles are generally acceptable or could not reasonably be rejected. Second: What do we owe to (...) future generations in these matters? Three principles of climate justice are suggested: a sufficiency principle securing basic human rights, a principle of justice giving each generation a right to realize its conception of justice, and a principle of reciprocity requiring us to take responsibility for the reception of benefits and the causation of harm. (shrink)