Geoscience Reference
In-Depth Information
af
uent West to developing nations, from the United States to Mexico for instance,
where used vehicles are more affordable.
54
Governments in the developed world have begun to include performance and
fuel ef
ciency standards for automobiles in Clean Air Acts to obtain breathable air
for their citizens, and to monitor air quality in urban centres in an attempt to meet
internationally agreed standards, such as those published by the World Health
Organisation.
55
However, there has been a much slower adoption of controls on
exhaust emissions in the highly congested cities of the developing world. During
the early 1990s, for example, national air quality standards were violated in Mexico
City over 300 days every year (despite regular monitoring). Like Los Angeles,
hemmed in by mountains Mexico City
cult to
disperse. A pollution reduction scheme which prohibited cars with odd and even-
numbered licence plates being driven in the city on particular days was ineffective,
as many people switched vehicles or even plates. More recently, vehicle inspections
twice a year and tax incentives to use cleaner fuels and new technologies, such as
catalytic converters, have begun to reduce Mexico City
'
s photochemical smog was dif
s ozone levels.
56
While a
'
great deal of progress has been made, its 4 million cars
—
especially older vehicles
—
s atmospheric pollution, and peak ozone
levels still regularly exceed recommended limits.
In most parts of the world vehicle pollution has mainly been seen as a scienti
are still responsible for most of the city
'
c
or technological problem, to be solved by the development of cleaner fuels, more
ef
cient engines and catalytic converters to reduce harmful exhaust emissions,
rather than a social and legal one. The World Health Organisation has recently
warned that vehicle exhausts are a major contributor to more than million premature
deaths worldwide every year from urban outdoor air pollution. At present there are
around 1 billion motor vehicles on the world
'
s roads, and by 2030 this
gure may
double as a result of China
ts of
reducing emissions using cleaner technologies may be greatly diminished by sheer
weight of numbers, as low-cost cars such as the Indian Tata motor company
'
s and India
'
s rapid economic growth. The bene
'
s Nano
are changing the way millions of people travel in the developing world.
57
At ground level, then, ozone is a pollutant that adversely affects human health
and the environment. However, about 90 % of all ozone is found high in the
stratosphere (between 10 and 50 km above the earth
s surface), where it shields life
on the planet from harmful ultraviolet (UV) radiation. Since 1930, when the DuPont
company began to manufacture the
'
uorocarbons
(CFCs) under the trade-name Freon, the stratospheric ozone layer has been under
invisible assault. Chloro
rst of the family of chloro
uorocarbons like Freon made the widespread use of
54
Papaioannou and Sapounaki-Drakaki (
2001
), McNeill (
2000
) and United Nations Environment
Programme and Organisation for Economic Cooperation and Development (
1999
).
55
Robinson (
2005
).
56
Jacobson (
2002
), Lezema (
2004
) and United Nations Environment Programme and Organi-
sation for Economic Cooperation and Development (
1999
).
57
Elsom (
1992
), World Health Organisation, Health and Environment Linkages Initiative (HELI)
(
2013
) and Sperling and Gordon (
2010
).
