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L. T. Molina et al.
With appropriate planning, dedicated scientific research, robust emissions control
policies, and effective access to advanced technologies and financial support, these
urban centers also have the opportunity to manage the growing population sustainably while reducing atmospheric pollution and its impacts.
21.1 Introduction
Megacities, typically defined as urban agglomerations with more than 10 million
inhabitants, are now a common phenomenon in many regions around the world. As
of April 2018, 55% (4.3 billion) of the global population (7.8 billion) reside in urban
areas. The world’s urban population is projected to increase 2.5 billion by 2050 due
to population growth and high urbanization rate, with almost 90% of this increase
occurring in Asia and Africa. Currently there are 33 megacities in the world; this
is projected to increase to 43 by 2030, with most of them in the developing regions
[16]. While most of the world’s urban population still lives in cities of fewer than
10 million inhabitants, many of these cities are growing faster than the megacities.
The concentrations of people and their activities have resulted in higher demand
for energy and consumption of fossil fuels, leading to atmospheric pollution that
affects public health, causes regional haze and acid deposition, and alters the earth’s
climate. On the other hand, as centers of economic growth, higher education and
technology innovation, these urban centers also offer opportunities to manage the
growing population sustainably and reduce the atmospheric pollution and its impacts.
Air pollution in megacities and large urban centers is strongly influenced by
topography, meteorology, and a wide array of natural and anthropogenic sources
including industrial activities, residential combustion, solvents use and transport,
among others. The sources of emissions vary substantially among megacities, notably
by geographical region. For example, the transport sector accounts for most of the
emissions in megacities and large urban centers in Europe and the Americas, whereas
emissions from Asia and Africa are largely from residential biofuel use [1]. Mexico
City, Mexico and Santiago, Chile are presented as examples of urban centers that
have been active in managing their air quality. Both cities have demonstrated the
types of environmental problems experienced by large urban centers, encountered
similar challenges, and have been successful in implementing emissions reduction
strategies.
21.2 Mexico City Metropolitan Area
The Mexico City Metropolitan Area (MCMA) extends over 7600 km
2 and is home
to more than 21 million inhabitants, making it the largest metropolitan area in North
America and one of the largest in the world. With an altitude of 2240 m a.s.l., an
opening to the Mexican Plateau to the north, and a mountain gap to the southeast,
L. T. Molina et al.
With appropriate planning, dedicated scientific research, robust emissions control
policies, and effective access to advanced technologies and financial support, these
urban centers also have the opportunity to manage the growing population sustainably while reducing atmospheric pollution and its impacts.
21.1 Introduction
Megacities, typically defined as urban agglomerations with more than 10 million
inhabitants, are now a common phenomenon in many regions around the world. As
of April 2018, 55% (4.3 billion) of the global population (7.8 billion) reside in urban
areas. The world’s urban population is projected to increase 2.5 billion by 2050 due
to population growth and high urbanization rate, with almost 90% of this increase
occurring in Asia and Africa. Currently there are 33 megacities in the world; this
is projected to increase to 43 by 2030, with most of them in the developing regions
[16]. While most of the world’s urban population still lives in cities of fewer than
10 million inhabitants, many of these cities are growing faster than the megacities.
The concentrations of people and their activities have resulted in higher demand
for energy and consumption of fossil fuels, leading to atmospheric pollution that
affects public health, causes regional haze and acid deposition, and alters the earth’s
climate. On the other hand, as centers of economic growth, higher education and
technology innovation, these urban centers also offer opportunities to manage the
growing population sustainably and reduce the atmospheric pollution and its impacts.
Air pollution in megacities and large urban centers is strongly influenced by
topography, meteorology, and a wide array of natural and anthropogenic sources
including industrial activities, residential combustion, solvents use and transport,
among others. The sources of emissions vary substantially among megacities, notably
by geographical region. For example, the transport sector accounts for most of the
emissions in megacities and large urban centers in Europe and the Americas, whereas
emissions from Asia and Africa are largely from residential biofuel use [1]. Mexico
City, Mexico and Santiago, Chile are presented as examples of urban centers that
have been active in managing their air quality. Both cities have demonstrated the
types of environmental problems experienced by large urban centers, encountered
similar challenges, and have been successful in implementing emissions reduction
strategies.
21.2 Mexico City Metropolitan Area
The Mexico City Metropolitan Area (MCMA) extends over 7600 km
2 and is home
to more than 21 million inhabitants, making it the largest metropolitan area in North
America and one of the largest in the world. With an altitude of 2240 m a.s.l., an
opening to the Mexican Plateau to the north, and a mountain gap to the southeast,