How should we think of the relationship between the climate harms that others will suffer in the future and our current emissions activity? Who does the harming? Which harms are attributable to which agents? We can ask these questions of both individual agents and groups. I begin by considering individual actions, asking what harms they do, what factors need to be taken into account in order to assess their moral significance, and what moral judgements are supported by this assessment. I conclude that an assessment of this kind does not clearly support the conclusion that the carbon-emitting actions of individual agents are morally wrong. However, this still leaves us with the harms that are attributable to carbon-emitters considered collectively, and our actions as members of this group. The paper’s overall conclusion is that it is morally wrong for individuals not to offset their own personal carbon emissions. This conclusion, I argue, is supported not by facts about the actual or expected harm associated with one’s own individual energy-consuming activity, but from the participatory relationship one stands in to what we do together.