is recognized as the tragedy of the commons. In view of the above, it is necessary to
clarify points of contact between the sustainability of the global environment and the
sustainability of mankind by individual city unit and to manage these points of
contact by artificially linking them with economic and social activities of the
respective cities.
However, it is inappropriate to apply existing sustainability indices to the contexts
of today’s cities because no index simultaneously fulfills the three conditions: strong
sustainability, distinction between absolute and relative assessments, and leakage
effects (Mori and Christodoulou 2012). Therefore, we have developed a City
Sustainability Index (CSI) that satisfies these three conditions. The purpose of this
chapter is to provide a conceptual framework of this CSI and a definition of
sustainability on which it is predicated and to show provisional results of assessments of megacities based on a prototype of this CSI. An important point to note
regarding the use of the term “city sustainability” in this chapter is that it does not
simply mean that a city itself or cities themselves have the potential to continue to
exist. If an event or condition that has a serious impact on the global environment
eventuates and results in the unsustainability of other areas, the city or cities causing
that impact will be considered unsustainable even if they themselves may be able to
survive. In other words, sustainability is clearly not a term that describes cities per se;
it is a term for considering the sustainability of mankind or the global environment in
the context of the behaviors of individual cities.
9.2 Sustainability
What is sustainability? Sustainability is not a general term that has a clear definition
or application; it is a technical term in the process of evolving. Out of necessity, it
has come to be used to consider the conflict between human economic activities and
the limitations of the global environment, and the definition and content have
changed and evolved. It is perhaps appropriate to assume that discussion of the
details of sustainability is still ongoing at present in relation to various analytical
objectives. This section will briefly review typical discussions where the relationship
with sustainability appeared strong prior to the release of the Brundtland Report in
1987. It will then review the notion of sustainability considering this report, focusing
on academic papers.
As an argument on mankind confronting the limitations of its environment, I
would like to start the discussion with the Malthusian theory of population (Malthus
2005). Based on a theory that refutes the notion that population will grow geometrically on the grounds that food production supporting population increases only
mathematically due to limitations of the area of land available, Malthus indicated
that any increase in food production for the most part would be immediately offset
by population growth and that the working class would always suffer extreme
poverty. While Malthus did not use the word sustainability, the circumstances he
described presented a conflict between population growth and environmental
9 The City Sustainability Index (CSI): How Should the Sustainability of. . .
165
clarify points of contact between the sustainability of the global environment and the
sustainability of mankind by individual city unit and to manage these points of
contact by artificially linking them with economic and social activities of the
respective cities.
However, it is inappropriate to apply existing sustainability indices to the contexts
of today’s cities because no index simultaneously fulfills the three conditions: strong
sustainability, distinction between absolute and relative assessments, and leakage
effects (Mori and Christodoulou 2012). Therefore, we have developed a City
Sustainability Index (CSI) that satisfies these three conditions. The purpose of this
chapter is to provide a conceptual framework of this CSI and a definition of
sustainability on which it is predicated and to show provisional results of assessments of megacities based on a prototype of this CSI. An important point to note
regarding the use of the term “city sustainability” in this chapter is that it does not
simply mean that a city itself or cities themselves have the potential to continue to
exist. If an event or condition that has a serious impact on the global environment
eventuates and results in the unsustainability of other areas, the city or cities causing
that impact will be considered unsustainable even if they themselves may be able to
survive. In other words, sustainability is clearly not a term that describes cities per se;
it is a term for considering the sustainability of mankind or the global environment in
the context of the behaviors of individual cities.
9.2 Sustainability
What is sustainability? Sustainability is not a general term that has a clear definition
or application; it is a technical term in the process of evolving. Out of necessity, it
has come to be used to consider the conflict between human economic activities and
the limitations of the global environment, and the definition and content have
changed and evolved. It is perhaps appropriate to assume that discussion of the
details of sustainability is still ongoing at present in relation to various analytical
objectives. This section will briefly review typical discussions where the relationship
with sustainability appeared strong prior to the release of the Brundtland Report in
1987. It will then review the notion of sustainability considering this report, focusing
on academic papers.
As an argument on mankind confronting the limitations of its environment, I
would like to start the discussion with the Malthusian theory of population (Malthus
2005). Based on a theory that refutes the notion that population will grow geometrically on the grounds that food production supporting population increases only
mathematically due to limitations of the area of land available, Malthus indicated
that any increase in food production for the most part would be immediately offset
by population growth and that the working class would always suffer extreme
poverty. While Malthus did not use the word sustainability, the circumstances he
described presented a conflict between population growth and environmental
9 The City Sustainability Index (CSI): How Should the Sustainability of. . .
165