This paper explains that there are two kinds of beneficiaries of international efforts to tackle climate change, only one of whom (unfair beneficiaries) is argued to come under an obligation to join such efforts and do a fair share according to the principle of fairness. For this argument, it is discussed that the problem of climate obligation is such that a theory of climate obligation, in addition to a theory of climate justice, is required for an actual imposition of the (...) obligation mentioned earlier. Having briefly introduced the principle of fairness with the focus on its basic idea, this paper makes a distinction between fair and unfair beneficiaries, the latter of which is argued to be identified as the right climate obligation bearers. Furthermore, four advantages of identifying climate obligation bearers in terms of unfair beneficiariesare pointed out. (shrink)