You could argue that the status quo is not sustainable socially, because an unjust society will not long endure. That is more a hope than a demonstrated fact. You could also argue, and with more evidence, that the status quo is not environmentally sustainable; indeed, that is the origin of the “sustainability” slogan. But changes can be made within the present system to cope with problems such as environmental degradation and global warming. Nor is it inevitable that such changes will be socially just.

Certainly “sustainable” means sustainable, physically and environmentally, in the long run. But what does “in the long run” mean? How long is that, and who is to determine it? Never mind Lord Keynes’ “in the long run, we will all be dead.” We may be dead, but our children and their children will live. Two quite separate problems arise here, one social and political, the other scientific.

The Social Problem

The costs of moving towards environmental sustainability will not be born equally by everyone. In conventional economic terms, different people have different discount rates for the same cost or benefit. Meeting higher environmental standards increases costs; some will profit from supplying the wherewithal to meet those standards. Others, not able to pay for them, will have to do without. Thus, the effects of income inequality are likely to be aggravated by the raising of environmental standards in this way. This problem is evident when it comes to the issue of atomic power plants in developing countries that have no other available sources of energy, or in the rain-forest disputes in South America. Similar issues are raised in the environmental justice movement in the United States. Better environments for some will be at the expense of worse environments for others, as waste disposal sites, air pollution, and water contamination, are moved around. Even when there is a solution that improves conditions for some without hurting others, the benefits will be unevenly distributed.

The Scientific Problem

Our knowledge is limited, and the further out into the future we wish to project it, the more the uncertainties grow. Malthus calculated, with the best scientific knowledge of his day, that food production would not sustain a world population much beyond its size at that time. Since then, world population has increased more than five-fold, and is better nourished and lives longer. We know we need to deal with the problem of global warming, and we know that relying on technological fixes is dangerous. Those two propositions should lead us to scale down certain activities linked to growth, and to seek substitutes for others. They mandate adoption of specific policies to achieve specific goals by specific actors in a specific timetable. But absent those specific policies, long-range concerns do not help very much in making decisions about shorter-range questions.

Not Just Environmental

In any event long-term environmental considerations are not the only long-term considerations that need to be taken into account. Matters that have both short- and long-range implications include: social justice, economic development, international relations, democracy, democratic control over technological change, and globalization. For a given policy to be desirable, it should meet the constraints of sustainability in each of these dimensions.

Environmental sustainability seems at first blush to be the most “objective,” the most inescapable, of all these constraints. If humankind dies off, the game is over. But may that not also be said of freedom, democracy, or tolerance? Since none of these deaths will be one-shot catastrophes, is the danger of environmental degradation a greater danger in the long run than war, fascism, poverty, hunger, or disease?

Environmental Justice

In practice “sustainability” had its origins in the environmental movement and in most usage is heavily focused on ecological concerns. But why, given limited resources and limited power to bring about change, are efforts thus focused? I would suggest that the environmental movement is a multi-class, if not upper- and middle-class movement, in its leadership, financing and politics. While the environmental justice movement is making a substantial contribution to both social justice and environmental protection, the environmental movement as a whole often proclaims itself to be above party, above controversy, seeking solutions from which everyone will benefit, and to which no one can object. How nice it would be if we could find such a program we could all rally around, and escape the unpleasant business of facing conflicting interests, having to deal with the unequal distribution of power, the necessities of redistribution, and the defeats that accompany the victories? No wonder “sustainability” is an attractive slogan! But if our goal is redistribution of wealth or opportunity, sharing power or reducing oppression, sustainability does not get us far. All uses of the sustainability concept are not subject to the criticisms I have made. One leading definition is that of the World Commission on Environment and Development (1987): “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”

Fine. Clearly here the goal is “meeting needs,” and the remainder, making it sustainable, is a constraint on the appropriate means to be used. Other formulations focus on the “carrying capacity of supporting ecosystems,” an elusive concept. To the extent that sustainability requires the review of policies designed today to meet the needs of today in such a way that they do not make things worse in the future, it is an important concept, though for planners it is not a very new one. Among those devoted to the concept, there is also an important debate about the relationship between growth and development, a difficult issue conceptually and one viewed very differently in the developed as against the developing world. So the discussion of sustainability can make a real contribution to advancing the understanding of policy alternatives and their implications.

The pursuit of sustainability is a delusion and snare to the extent that we call for “sustainable” activities that are of universal benefit; activities that everyone, every group, and every interest will or should or must accept in their own best interest. It is a delusion to think that only our ignorance or stupidity prevents us from seeing what we all need to do. Indeed, a just, humane, and environmentally sensitive world will in the long run be better for all of us. But getting to the long run entails conflicts and controversies, issues of power and the redistribution of wealth. The “sustainability” slogan hides these conflicts instead of revealing them.