PLANNING FOR SUSTAINABILITY
In recent years there has been much interest among planners in the matter of planning for sustainable development. In the United States part of the interest is homegrown, and part comes from Great Britain, the Netherlands, and other nations in Western Europe where much higher population densities give many planning questions a sense of greater urgency. Most discussions of planning for sustainable development hark back to a 1987 report of the World Commission on Environment and Development—also known as the Brundtland Commission, after the name of its Chair, Gro Harlem Brundt- land, who was then prime minister of Norway. In its report the Commission defines sustainable growth as follows:
Sustainable development is development that meets the needs of the present
without compromising the ability of future generations to meet their own
That is a very general statement, and much thought and argument have been devoted since then to defining exactly what it means. On the surface it may be taken to have a simple environmental meaning. For example, in regard to forestry, it may mean not cutting more board feet of timber in one year than the forest can grow in one year. However, with the passage of time, sustainability has come to be defined more broadly. Although there is no single, unambiguous definition for sustainable development, a very rough, general agreement appears to have emerged in the past decade or so. Most writers define sustainable development planning as planning that addresses three overall goals in a coordinated manner. These goals are environmental quality, social equity, and economic development, easily remembered as the three "Es."18
The environmental requirement is readily understood as meaning planning for development that does not degrade the quality of the environment from one time period to the next. However, it should be understood that determining exactly what constitutes degradation is not always so easy. For example, suppose years of farming have thinned the topsoil somewhat in a particular area, but, at the same time years of fertilizer use have increased the nitrate and phosphate content of the soil.
Experts might disagree about whether, on balance, the soil is now better or worse than it was.
Social equity is more ambiguous. Most proponents of sustainable development take it to mean greater equality of wealth and more opportunity for poorer and less advantaged people. To defend the idea that social equity ought to be included in the concept of sustainable development, one might argue that over the long term, any social or economic system must achieve a satisfactory degree of equity or the internal stresses generated by inequity will render it unstable. Whether that is really true may be argued. There is no question that inequity and the perception of inequity have been at the root of many social and political upheavals such as the French or the Russian Revolutions. On the other hand, there have been inequitable systems that have shown remarkable stability. The caste system of India strikes most Westerners and many Indians as grossly inequitable. But the social and economic order upon which the system rests has shown great stability over many centuries and is only now changing at a moderate pace under many pressures of modernity. One may even argue that some social and economic systems may become unstable as they become more equitable, because that change expands people's perspectives and whets their appetite for more change ("the revolution of rising expectations"). The point that equity is a prerequisite for long-term stability may be argued either way. The skeptic may contend that equity has been added as a criterion, not because it is intrinsically necessary for sustainability, but because those who argue for planning for sustainability also, as a group, favor more egalitarian systems—that equity has been tacked on much as a rider is tacked onto a bill in Congress.
It may be argued that at times, sustainability goals and equity goals may be in conflict, just as environmental and equity goals may be in conflict (see Chapter 15). Therefore, planning for sustainable development should address such conflicts. But that is a separate argument from the question of whether equity issues are inherently part of the question of sustainability. However, regardless of argument and counterargument, equity is now firmly ensconced as one of the three main elements of the term sustainability as commonly used in the planning profession.
If one accepts equity as a key element in planning for sustainability, then the requirement for economic development makes considerable sense. If equity concerns make it desirable to redistribute a certain amount of wealth, that goal will be easier to achieve if average wealth is growing than if it is stable. In a steady-state situation, any redistribution of wealth would necessarily be a zero-sum game and would meet powerful resistance.19 This observation is no more profound than saying that it is easier to be generous if you are wealthy than if you are poor.
In principle the idea of planning for sustainable development may be applied at any scale ranging from the municipality, or perhaps even a part of a municipality, up to the planet itself. Actions to promote sustainable development at one geographic scale will inevitably have effects on the environment at other geographic scales. Then, too, what looks sustainable or not sustainable at one scale may look different at another scale. For example, the development of Manhattan (the most densely populated urban place in the United States) may look very bad from a sustainable development perspective, if viewed solely at a municipal scale. Most of the natural environment has been paved or built over; the original land form has been substantially changed; creeks, streams, and marshy areas have been filled in; and biodiversity has been vastly reduced.
On the other hand, when viewed from a larger geographic perspective, Manhattan looks environmentally virtuous. The 1.54 million people living on Manhattan's 22.7 square miles have much less environmental impact than would the same number of people if spread out over, say, 750 square miles (at a typical suburban density of 2,000 people per square mile). Transporting one person to work by subway consumes considerably less energy than transporting one person to work by car. It takes less energy to heat one apartment than it does to heat one single-family house. Fewer trees must be cut down to build one high-rise apartment than would have to be cut down to build single-family houses for an equivalent number of residents.
The amount of impervious cover is one aspect of environmental impact. Manhattan has 508 miles of streets. Multiply that by 5,280 (the number of feet in a mile). Then divide that figure by the population of Manhattan, around 1,540,000. The result is that there is approximately 1.7 feet of street length per Manhattan resident. Contrast that with how many feet of street there would be per resident on a suburban street of single-family houses built on 100-foot-wide lots. Thus, in considering sustainable development, one may come to very different conclusions depending on whether one thinks in terms of what happens at a particular location on the map or whether one thinks in terms of accommodating a specific number of people or a specific amount of economic activity.
With all of the preceding caveats, we turn now to planning for sustainable development in a single municipality.