Plan Now to Avoid Megacities Nightmare
Mario Molina, professor of chemistry at MIT, was awarded the Nobel
Prize in 1999 for his work on atmospheric chemistry and stratospheric
ozone depletion. He also is director of a joint MIT-Harvard Project on
Megacities, using Mexico City as the case study. He spoke with NPQ recently.
NPQ | By the middle of this century, there will be 50 "megacities"
in Asia alone, each with a population of 20 million or more. If the pollution
is bad now, what will it be like when the whole planet has gone urban?
Won't these cities, in effect, be gigantic bonfires heating up the climate?
MARIO MOLINA | Large population concentrations plus economic growth
will mean not only widespread pollution, but also an increasing lack of
mobility because of congestion. Unless action is taken now to plan the
growth of these areas before they reach megastatus, the health of millions
will be at stake, particularly in the developing regions of Asia and Latin
America, where there is little pollution control of any kind.
But the problem extends beyond the direct health and mobility costs to
the actual inhabitants of these megacities. As you suggest, with so many
megacities dotting the planet, their collective output of carbon dioxide
and other gases will further contribute to climate change. Their chemical
emissions will further deplete our protective ozone layer.
Moreover, we now know that pollution drifts across the Earth, worsening
the "background" air quality in places far from the source of
the pollutants. This will only increase as a result of larger and larger
cities in the Northern Hemisphere, meaning, for example, that in the future
California may not be able to meet its strict clean-air standards because
of "background" pollution that has drifted across the Pacific
from Asia. Background air quality is already detectably worse in Europe.
Clearly, the cost for society will be much less if we act now to design
cleaner and more efficient urban systems rather than trying to cope with
the health and clean-up costs, not to speak of the economic losses, after
Solving the serious problem of air pollution requires an approach that
integrates science, technology and politics. It is not just a matter of
understanding physical and chemical processes, but also an ability to
balance economic, social and technological factors, to make decisions
in the face of uncertain and incomplete data, and to educate and involve
the public to ensure their acceptance of pollution control policies.
For example, in the United States high taxes to cut down consumption of
gasoline are politically unviable, whereas they are more acceptable in
Europe. In India, the government had to back down in its effort to close
small industries that were polluting because of the uproar over job loss.
Dealing with the social issues involved is every bit as important to solving
the problem as understanding the science.
NPQ | Los Angeles has made great strides in reducing air pollution.
Even Mexico City, where fetuses have famously been found to have toxic
levels of lead in their blood from the air their mothers breathe, has
begun to improve. What is the key to these changes?
MOLINA | In both cases, the key element was government regulation,
primarily requiring the use of unleaded gasoline and catalytic converters
in all new cars. Most cities in developing countries, including China,
do not include these items on their planning agenda.
While some components of pollution in Mexico City have improved, we still
face the problem of particulate matter that enters the lungs and smog
that comes from gas fumes, nitrogen oxide and light mixing at our high
California has begun to take the further, more difficult step of regulating
such decentralized lifestyle activities as backyard barbecues and requiring
more use of water-based instead of oil-based paints. Although the transportation
sector is still the main culprit, when cities grow to millions of inhabitants,
every act involving a chemical or creating particulate pollution adds
Clearly, the next step must be a shift to cleaner cars that are energy
efficient, such as hybrid fuel or electric cars. A small number of people
are already buying these automobiles, but to have a significant impact
on climate change and pollution, their use must be widespread-which means
they must be required by governments.
Even so, with cleaner cars than we have today, the temptation to have
more and more cars can make the situation worse in an absolute sense.
What is essential is to have a well-integrated plan that makes a city
work efficiently and cleanly, including through well-designed public transportation
Without question, more innovative thinking is required to link the use
of clean cars (and the powerful attraction of individual mobility) with
public transportation. One such idea, for example, involves the sharing
of inexpensive electric cars to go the relatively short distances to and
from public transportation sites.
NPQ | The Chinese government still has a central-planning apparatus
intact. Perhaps it ought to require not only catalytic converters and
unleaded fuel but, within a reasonable time frame, hybrid fuel cars?
MOLINA | While some parts of the Chinese government have been receptive
to pleas for planning ahead, the dominant view is worrisome: China just
wants to build cheap cars so more people can have them. Mexico used to
have this policy until the last president, Ernesto Zedillo. Car manufacturers
in Mexico built two sets of cars-one for export and one for the domestic
market. The ones for Mexico were a little cheaper but much dirtier. In
the future, all cars being made in Mexico will abide by cleaner standards.
China and other developing countries ought to follow a more enlightened
policy of adopting standards in sync with the US with some years' lag.
After all, they have a great advantage: They don't have to invest in creating
clean-fuel car technology but only need to purchase or manufacture the
cars. It is really essential that they look ahead at these options before
they build out their megacities and are trapped in a pollution nightmare.
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