The purpose of this article is to map the relationships of various moral arguments for action on climate change to each other in a particular case rather than to explore any single argument in depth or to make any abstract claims about the priorities among the arguments themselves. Specifically, it tries to show that “historical responsibility”, that is, responsibility (moral or legal) for past emissions, is very important, although not quite in the way usually argued, but that it is not by itself determinative. Other, independent considerations also greatly matter, although it happens that as a matter of fact all considerations strongly tend to converge towards the same conclusions about which states are responsible to act in order to slow climate change. “Historical responsibility” is shown to involve both contribution to, or causation of, climate change and benefit from climate change. Other factors that play roles in this case are ability to pay, the no-harm principle, and the duty to preserve the physical pre-conditions of human life.