Bearing the Weight of the World: On the Extent of an Individual's Environmental Responsibility

To what extent is any individual morally obligated to live environmentally sustainably? In answering this, I reject views I see as constituting two extremes. On one, it depends entirely on whether there exists a collective agreement; and if no such agreement exists, no one is obligated to reduce her/his consumption or pollution unilaterally. On the other, the lack of a collective agreement is morally irrelevant, and regardless of what others are doing, each person is obligated to limit her/his pollution and consumption to a level that would be sustainable if everyone were to act in this way. I argue that the truth is somewhere between these, but that a very precise specification of the extent of one's responsibility is impossible. Roughly, what can be said is that each individual ought constantly to strive to do more than she/he does currently and to push her/himself into new, uncomfortable territory, though no one is obligated to martyr her/himself for an environmental cause.