In an ecologically constrained world, both the global North and the global South need to consider new obligations and limits. A basic commitment to social justice requires that the claims of the poor, chiefly residing in the South, take precedence over the claims of the rich, chiefly residing in the North. The scope for further growth to contribute to well-being in affluent regions is quite limited, so the costs to the North of reducing growth may be modest—especially if a new economy is organized to provide the economic basis of a good life based on precepts other than more, more, and still more. While recognizing a priority for the poor imposes obligations on the North, this recognition cannot be a license for the South to replicate the wasteful disregard for ecosystem boundaries or the claims of the disadvantaged that has characterized growth in the North.