There is considerable uncertainty about how tightly ecology constrains planetary growth. Given this uncertainty, prudence dictates a conservative approach that takes limits to growth seriously. 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 North may have to accept an actual reduction in conventional measures of standard of living to create ecological space for Southern growth. At any rate, 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 that has characterized growth in the North. Nor ought the South to countenance the wanton disregard for the claims of the disadvantaged that has allowed large islands of Northern poverty to continue to exist in oceans of Northern wealth.
This Perspective was written by Stephen A. Marglin of Harvard University. It draws from the consensus statement of a 2010 workshop, “The challenge of sustainability: towards Rio+20”, organized by the United Nations Division for Sustainable Development, which was endorsed by the following attendees (in alphabetical order): Frank Ackerman, Lois Barber, Peter Brown, Robert Costanza, Paul Ekins, Marina Fischer-Kowalski, Maja Göpel, Tim Jackson, Ashok Khosla, Nebosja Nakicenovic, Paul Raskin, William Rees, Wolfgang Sachs, Juliet Schor, Gus Speth, Peter Victor, and Ernst von Weiszäcker, many of whom contributed to the text.