enormous on a global scale, but the impact of an individual city is quite small, even
in the case of megacities. Even the largest city has a population of about 30 million,
accounting for only 0.5% of the world’s population. Just considering the sustainability issues of an individual city, we may think that it is unnecessary to cope with
external costs on the global environment. Some researchers point out that cities are
eco-efficient (Martínez-Zarzoso and Maruotti 2011; Dodman 2009). However, the
total impact of cities in the world cannot be ignored (MEA 2005; IEA 2008; IPCC
2014).
We need to clarify the mechanisms connecting cities with the limitations of the
global environment, considering planetary boundaries (global environmental thresholds) (Rockström et al. 2009; Steffen et al. 2015). To the best of our knowledge
however there has been no research output that provides a whole picture of these
mechanisms. Grimm et al. (2008) depict a big picture that shows the connections
between human drivers and global environmental changes. In this picture, the main
cause of the negative impacts on the environment is human social and economic
activity. They are majorly conducted in cities and megacities. We need to do further
research in order to understand mechanisms connecting human activities in cities
with changes in the global environment profoundly because environmental devastation should be avoided. By examining the dynamic links between megacities and
their surrounding local and global environment in the context of the discussion of the
urban interaction sphere, we can analyze the relationships between the two from a
holistic point of view. This holistic view will enable us to provide a solution to
trade-off problems among stakeholders. We need to develop holistic inter- and
transdisciplinary approaches in the study of megacities and to overcome several
methodological and technical challenges. Some of the methodological challenges
come from the fact that most academic disciplines today are too specialized and
separate from each other. In this respect, some experts with different expertise have
contributed to this book in order to develop a foundation for such a holistic
perspective. Results of these studies can help us propose and develop sustainable
urban systems with appropriate backup systems for megacities.
1.4 Overview of this Book
The main theme of this book is the prospect of sustainable megacity futures by
taking the diversity of megacities into consideration. The ultimate purpose is to work
together to find a philosophy for living wisely in megacities. Wise lifestyles in a
megacity could become one of the most important factors for accomplishing global
sustainability. However, such ways of life are not immediately self-evident. We must
discover and clarify them, based on the wisdom of the past and discussions about
interactions between cities and the environment.
In this book, we detected 18 megacities whose population size is equal to or more
than ten million. The definition of cities, including megacities, and the method of
specifying urban boundaries were created by us. Most of the megacities are in
8
S. Muramatsu and K. Mori
in the case of megacities. Even the largest city has a population of about 30 million,
accounting for only 0.5% of the world’s population. Just considering the sustainability issues of an individual city, we may think that it is unnecessary to cope with
external costs on the global environment. Some researchers point out that cities are
eco-efficient (Martínez-Zarzoso and Maruotti 2011; Dodman 2009). However, the
total impact of cities in the world cannot be ignored (MEA 2005; IEA 2008; IPCC
2014).
We need to clarify the mechanisms connecting cities with the limitations of the
global environment, considering planetary boundaries (global environmental thresholds) (Rockström et al. 2009; Steffen et al. 2015). To the best of our knowledge
however there has been no research output that provides a whole picture of these
mechanisms. Grimm et al. (2008) depict a big picture that shows the connections
between human drivers and global environmental changes. In this picture, the main
cause of the negative impacts on the environment is human social and economic
activity. They are majorly conducted in cities and megacities. We need to do further
research in order to understand mechanisms connecting human activities in cities
with changes in the global environment profoundly because environmental devastation should be avoided. By examining the dynamic links between megacities and
their surrounding local and global environment in the context of the discussion of the
urban interaction sphere, we can analyze the relationships between the two from a
holistic point of view. This holistic view will enable us to provide a solution to
trade-off problems among stakeholders. We need to develop holistic inter- and
transdisciplinary approaches in the study of megacities and to overcome several
methodological and technical challenges. Some of the methodological challenges
come from the fact that most academic disciplines today are too specialized and
separate from each other. In this respect, some experts with different expertise have
contributed to this book in order to develop a foundation for such a holistic
perspective. Results of these studies can help us propose and develop sustainable
urban systems with appropriate backup systems for megacities.
1.4 Overview of this Book
The main theme of this book is the prospect of sustainable megacity futures by
taking the diversity of megacities into consideration. The ultimate purpose is to work
together to find a philosophy for living wisely in megacities. Wise lifestyles in a
megacity could become one of the most important factors for accomplishing global
sustainability. However, such ways of life are not immediately self-evident. We must
discover and clarify them, based on the wisdom of the past and discussions about
interactions between cities and the environment.
In this book, we detected 18 megacities whose population size is equal to or more
than ten million. The definition of cities, including megacities, and the method of
specifying urban boundaries were created by us. Most of the megacities are in
8
S. Muramatsu and K. Mori