340 Big pictures
Megacity transportation for the huge population also poses numerous prob-
lems, from streets clogged with pedestrians, bicycles, and vehicles (Beijing,
Calcutta) to underground rail systems periodically subject to flooding (New York,
Osaka, Moscow). An extensive area of high-vehicle-density and traffic jams is char-
acteristic (Los Angeles, Sao Paulo, Tokyo). Megacities produce huge amounts of
CO 2 contributing to global climate change. These giant cities have giant eco-
logical footprints (Chapter3). Within their nations, megacities are all dynamic
centers for economic growth, social groups and institutions, politics and govern-
ment, transportation, culture, jobs, and opportunity. Finally, megacities serve as
powerful magnets attracting more people.
Megacities in developing countriesare somewhat distinctive. A relatively high
proportion of urban poor and an abundance of informal housing (squatter set-
tlements) are characteristic. Effective urban infrastructure, such as public trans-
port, clean water supply, and gas/electricity, only serves portions of the metro
area. For example, sewage treatment serves a quarter of the people in Calcutta
and Dhaka. Because low-lying areas are largely covered with development, floods
commonly cause major problems.
Also, megacities in developing countries are normally prime centers of indus-
trial production. Atmospheric particulate pollution, resulting from coal burning,
industrial production, and other sources (e.g., fecal particles, dust from upwind
soil erosion) tends to be severe. Public health problems are rampant. Street trees
are relatively sparse overall, and parks may be invaded by squatters. Effective
zoning surrounding the metro area is limited, so land uses are intermixed at a
relatively fine scale. This in turn degrades or eliminates water and biodiversity
values that depend on large semi-natural patches (Chapter4).
On the other hand,megacities in developed nationstend to expand outward in
alow-density form associated with extensive auto usage and thus cover much
larger and more distant areas. This process may produce aggregations of build-
ings around numerous villages, towns, and small cities scattered across the
land (London), or result in massive sprawl of houses on relatively large lots
(Los Angeles, New York). Both patterns also create an extensive fine-scale road net-
workacross the land, with an extensive use of cars and trucks thereon. Building
sprawl, road network, and vehicle use, when combined, cause extensive habitat
loss and habitat degradation.
Megacities in developed nations also are more likely to be financial than ind-
ustrial centers. Urban liveability or quality of life is often considered to be a goal
(Costanzaet al.2006). A relatively high priority is given to investment in clean
watersupply (sometimes transported from a relatively distant forested drainage
basin), sewage treatment, a separate pipe system for stormwater drainage and hu-
man wastewater, solid waste disposal (transported to distant sites), controls
on air pollutants, controls on water pollutants, and the establishment and