Coastal
Mega-Cities In
For A Bumpy Ride
By Srabani Roy
30 March, 2007
Inter
Press Service
NEW YORK - About
643 million people, or one-tenth of the world’s population, who
live in low lying coastal areas are at great risk of oceans-related
impacts of climate change, according to a global research study to be
released next month.The study, by researchers at Columbia
University’s Center for International Earth Sciences Information
Network and the London-based International
Institute for Environment and Development, is the first
of its kind. The researchers identified populations, particularly urban
populations, at greatest risk from rising sea levels and more intense
storms due to climate change.
“Of the more than 180
countries with populations in the low-elevation coastal zone, 130 of
them — about 70 percent — have their largest urban area
extending into that zone,” said Bridget Andersen, a research associate
at CIESIN, in a statement.
“Furthermore, the world’s
largest cities — those with more than five million residents —
have on average one-fifth of their population and one-sixth of their
land area within this coastal zone.”
The study, which will be
published in the peer-reviewed journal Environment and Urbanization,
assesses the risks to populations and urban settlements along coastal
areas that are less than 10 meters above sea level, referred to as the
low-elevation coastal zone, or LECZ. Although globally this zone accounts
for only two percent of the world’s land area, it contains 10
percent of the world’s population and 13 percent of the world’s
urban population, the study found.
The 10 countries with the
largest number of people living in this vulnerable, low-elevation zone,
include in descending order: China, India, Bangladesh, Vietnam, Indonesia,
Japan, Egypt, the United States, Thailand and the Philippines.
Cities such as Dhaka, Shanghai
and Mumbai are some of the most susceptible to coastal, climate-related
hazards such as floods, storms and cyclones. And the rapid urbanization
occurring in these cities — especially in China, which has growing
special economic zones along its coasts — will continue to attract
more and more people.
“On average, coastal
cities are growing 20 percent faster than any other cities in the world
and they have 10-15 percent higher densities than other cities,”
Sharad Shankardass, spokesperson for the U.N.’s agency for human
settlements, UN-Habitat, told IPS. “Of the 20 mega-cities in the
world, 15 of them are coastal.”
The study found that 75 percent
of people living in the vulnerable low-elevation zone and two-thirds
of the world’s urban population are in Asia. In conjunction with
the findings of the CIESIN-IIED study, 11 of the 15 coastal mega-cities
listed by UN-Habitat in 2005 are in low-medium income countries. The
study found that 14 percent of the population of least developed countries
live in the LECZ, compared to only 10 percent in wealthier countries.
Twenty-one percent of the
urban populations in least developed countries live in this zone. In
richer countries belonging to the Organization for Economic Cooperation
and Development, this number drops to 11 percent. Human settlements
in lower income countries with limited resources are, therefore, significantly
more vulnerable to climate-related hazards.
“It is very clear in
my mind that poor countries will have a disproportionate burden,”
Deborah Balk, a project investigator and co-author of the study, told
IPS, “particularly those with large deltaic regions.”
In fact, of the top 10 countries,
Bangladesh, Egypt and Vietnam have a large proportion of their populations
living within the LECZ: 46, 38 and 55 percent respectively. The Bahamas,
the Netherlands, and Suriname have well over 70 percent of their populations
living in the LECZ.
The study was partially funded
by the Swedish International Development Corporation Agency and the
Danish International Development Agency, both of which have programs
in urban environmental issues. Researchers overlaid geographic data,
the most recently available census data, and information on urban settlements,
to produce maps showing the populations and land area in the LECZ for
244 countries. The information was then summarized by country, region
and income category.
The study makes it clear
that sea levels are not expected to rise anywhere near the 10 meters
of the low-elevation zone. The fourth Intergovernmental Panel on Climate
Change report estimated that sea levels are likely to rise in the range
of 22-34 centimeters between 1990 and the 2080s. This level could be
significantly higher with accelerated melting of the Greenland and polar
ice sheets, the study noted.
Although small island states
have the largest share of land in the low-elevation zone (16 percent),
and would, therefore, be most likely to be affected by sea-related hazards,
they tend to have less of their population living in the zone. Balk
attributed this to the fact that people living on such islands are more
adapted to coastal hazards and tend to live further inland.
“The study demonstrates
how critical an issue this is from a global perspective — it is
certainly not just one for small island states,” Gordon McGranahan,
head of the human settlements group at IIED and co-author on the study,
told IPS.
According to Tanya Imola,
spokesperson for the international association of local governments,
ICLEI, many cities have started implementing environmental programs
to address climate change and to curb their overall carbon footprint.
Initiatives include improvements to public transportation, recycling
programs and energy efficiency. But only a few cities have started thinking
about how to address the effects of sea level rise and other ocean-related
hazards.
The authors of the CIESIN-IIED
study categorize three types of responses to address these risks: migration,
mitigation and modification. Both McGranahan and Balk agreed that these
strategies have a long lead time.
UN-Habitat and the U.N. Environment
Program have initiated joint projects to address these issues, but UN-Habitat’s
Shankardass pointed out that “we are still in the early stages
of establishing a realistic strategy for intervention and implementation
for cities that will be directly affected by climate change.”
Of utmost importance, McGranahan
noted, is to start working with national and local authorities engaged
in urban and environmental issues, and for them to start making commitments
to these types of strategies now.
“Ultimately, adaptation
has to be negotiated locally, and so we want to combine this sort of
global analysis with local engagement,” he told IPS.
Copyright 2007 IPS - Inter
Press Service
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