1.3 Megacities and Global Environment
Cities cannot become independent of other areas, such as other cities, rural areas,
hinterland, agricultural areas, natural areas, and so forth. They are highly reliant on
hinterland and natural areas beyond boundaries for the supply of various types of
environmental resources and ecosystem services, as well as the disposition of
wastes, sewage, and any pollutants; thus, they have a negative impact on the global
environment as an open system (Camagni et al. 1998; Rees 2001; Munda 2006).
Many cities have developed through a long history of interaction with their surrounding areas. The natural environment and ecology in cities merely play a
marginal and complementary part in the maintenance of the bio-natural status of
urban systems (Bithas and Christofakis 2006). In addition, consumption in cities
imposes an enormous burden on the environment, even far away from them. This
impact is called the leakage effect. We cannot consider the relationships between
cities and the global environment without taking leakage effects into account (Mayer
2008; Graymore et al. 2010). People can consume resources beyond the local
carrying capacity through trade, and this over-consumption has a negative impact
on the global environment because all the ecological accounts must globally balance
as a whole (Daily and Ehrlich 1992).
When it comes to considering the impact of human activities in megacities on the
global environment, we need to consider three issues: our tendency to put too much
weight on socioeconomic prosperity, lack of long-term vision, and externality and
resilience. First, as mentioned above, cities are focusing on socioeconomic prosperity rather than environmental protection and preservation, although we need to take
the triple bottom line (environmental, economic, and social dimensions) into consideration. We might tend to put more weight on what we can perceive easily or
directly. In line with this, we have dealt with environmental problems that more
directly affect us in cities: local pollution. However, we have accumulated an
environmental burden globally while we enjoy socioeconomic prosperity, and we
are currently at the stage of paying the price in terms of the global environment
(Meadows and Randers 2012).
Second, we have difficulties developing a long-term vision that covers at least
1000 years, although many definitions of sustainability include equity between
current and future generations (Gasparatos et al. 2008; Baumgärtner and Quaas
2010). In order to realize equity between generations, it is necessary to maintain a
constant level of ecosystem functions and services. However, many economic
activities pursue the maximization of short-term returns and do not have the vision
of keeping human sustainability in the long term. One of the symbols of the myopia
is positive discounting of future values. We need to ask how we can always consider
such a long-term vision of sustainability, even in cities at a local level.
Third, environmental issues are problems of externality and resilience. Human
activities in cities have a negative impact on the environment beyond their boundaries without any controls of market mechanisms, and the accumulated impact has
deprived ecosystems of resilience. The total external costs imposed by cities are
1 Megacities as a Global Center of Sustainability Issues: Overview of the Book
7
Cities cannot become independent of other areas, such as other cities, rural areas,
hinterland, agricultural areas, natural areas, and so forth. They are highly reliant on
hinterland and natural areas beyond boundaries for the supply of various types of
environmental resources and ecosystem services, as well as the disposition of
wastes, sewage, and any pollutants; thus, they have a negative impact on the global
environment as an open system (Camagni et al. 1998; Rees 2001; Munda 2006).
Many cities have developed through a long history of interaction with their surrounding areas. The natural environment and ecology in cities merely play a
marginal and complementary part in the maintenance of the bio-natural status of
urban systems (Bithas and Christofakis 2006). In addition, consumption in cities
imposes an enormous burden on the environment, even far away from them. This
impact is called the leakage effect. We cannot consider the relationships between
cities and the global environment without taking leakage effects into account (Mayer
2008; Graymore et al. 2010). People can consume resources beyond the local
carrying capacity through trade, and this over-consumption has a negative impact
on the global environment because all the ecological accounts must globally balance
as a whole (Daily and Ehrlich 1992).
When it comes to considering the impact of human activities in megacities on the
global environment, we need to consider three issues: our tendency to put too much
weight on socioeconomic prosperity, lack of long-term vision, and externality and
resilience. First, as mentioned above, cities are focusing on socioeconomic prosperity rather than environmental protection and preservation, although we need to take
the triple bottom line (environmental, economic, and social dimensions) into consideration. We might tend to put more weight on what we can perceive easily or
directly. In line with this, we have dealt with environmental problems that more
directly affect us in cities: local pollution. However, we have accumulated an
environmental burden globally while we enjoy socioeconomic prosperity, and we
are currently at the stage of paying the price in terms of the global environment
(Meadows and Randers 2012).
Second, we have difficulties developing a long-term vision that covers at least
1000 years, although many definitions of sustainability include equity between
current and future generations (Gasparatos et al. 2008; Baumgärtner and Quaas
2010). In order to realize equity between generations, it is necessary to maintain a
constant level of ecosystem functions and services. However, many economic
activities pursue the maximization of short-term returns and do not have the vision
of keeping human sustainability in the long term. One of the symbols of the myopia
is positive discounting of future values. We need to ask how we can always consider
such a long-term vision of sustainability, even in cities at a local level.
Third, environmental issues are problems of externality and resilience. Human
activities in cities have a negative impact on the environment beyond their boundaries without any controls of market mechanisms, and the accumulated impact has
deprived ecosystems of resilience. The total external costs imposed by cities are
1 Megacities as a Global Center of Sustainability Issues: Overview of the Book
7