11.2.4.6. Potential Impacts and Coastal Zone Management
As outlined in IPCC (1998), climate-related stresses in coastal areas include
loss and salinization of agricultural land resulting from changes in sea level,
likely changes in the intensity of tropical cyclones, and the possibility of
reduced productivity in coastal and oceanic fisheries. Table
11-9 lists estimates of potential land loss resulting from sea-level rise
and the number of people exposed, assuming no adaptation (Mimura et al., 1998;
Nicholls and Mimura, 1998). These estimates of potential land loss and populations
exposed demonstrate the scale of the issue for the major low-lying regions of
coastal Asia. The results are most dramatic in Bangladesh and Vietnam, where
15 million and 17 million people, respectively, could be exposed given a relative
change in sea level of 1 m (Brammer, 1993; Haque and Zaman, 1993)—though
it should be recognized that a 1-m sea-level rise is at the extreme range of
presently available scenarios. Nonetheless, these examples demonstrate the sensitivity
of coastal areas to climate change impacts and unsustainable utilization of
resources in these areas. The impacts could be exacerbated by continued population
growth in low-lying agricultural and urban areas (Nicholls et al., 1999). At
the same time, adaptation strategies will alter the nature of the risk and change
the socially differentiated nature of the vulnerability of populations living
in hazardous regions. Response strategies that are based solely on tackling
the physical parameters of risks from sea-level rise and tropical cyclones have
been shown in some circumstances to enhance the vulnerability of certain parts
of the population—usually those with least ability to influence decisionmaking
(Blaikie et al., 1994; Hewitt, 1997; Mustafa, 1998; Adger, 1999b).
| Table 11-9: Potential land loss and population exposed
in Asian countries for selected magnitudes of sea-level rise and under no
adaptation measures (modified from Nicholls and Mimura, 1998; Mimura et
al., 1998). |
 |
| |
Sea-Level Rise
|
Potential Land Loss
|
Population Exposed
|
| Country |
(cm)
|
(km2)
|
(%)
|
(millions)
|
(%)
|
|
| Bangladesh |
45
|
15,668
|
10.9
|
5.5
|
5.0
|
| |
100
|
29,846
|
20.7
|
14.8
|
13.5
|
| India |
100
|
5,763
|
0.4
|
7.1
|
0.8
|
| Indonesia |
60
|
34,000
|
1.9
|
2.0
|
1.1
|
| Japan |
50
|
1,412
|
0.4
|
2.9
|
2.3
|
| Malaysia |
100
|
7,000
|
2.1
|
>0.05
|
>0.3
|
| Pakistan |
20
|
1,700
|
0.2
|
n.a.
|
n.a.
|
| Vietnam |
100
|
40,000
|
12.1
|
17.1
|
23.1
|
|
Human activities, including protection facilities themselves, aggravate the
vulnerability of the coastal regions to climate change and sea-level rise. There
are complex interrelationships and feedbacks between human driving forces and
impacts, on one hand, and climate- and sea level-induced changes and effects
on the other (IPCC, 1996). At the interface between ocean and terrestrial resources,
coastal ecosystems undergo stress from competing multi-usage demands, while
having to retain their functional diversity and resilience in the face of global
environmental change (Bower and Turner, 1998). To enhance coastal resilience
and facilitate adaptation, integrated management of coastal zones must take
into account the multiple resource demand and variety of stakeholders, as well
as natural variability, recognizing the importance of the institutional, cultural,
and historical context (Klein and Nicholls, 1999).
Integrated coastal zone management (ICZM) is an iterative and evolutionary
process for achieving sustainable development by developing and implementing
a continuous management capability that can respond to changing conditions,
including the effects of climate change (Bijlsma et al., 1996). Essentially,
ICZM is a cooperative effort on the part of coastal zone stakeholders that results
in a "win-win" outcome. ICZM already has been developed and implemented
in some Asian countries for the allocation of environmental, sociocultural,
and institutional resources to achieve conservation and sustainable multiple
use of the coastal zone (Sato and Mimura, 1997). Since the 1970s, the Philippines
has formulated programs and projects on coastal management, covering fishery
and mangrove reforestation (Perez et al., 1999). Mangrove rehabilitation has
been recommended to mitigate climate impacts in coastal zones of Vietnam (Tri
et al., 1998). Since the 1960s, a groundwater withdrawal/pumping-back system
has been carried out to mitigate ground subsidence in Shanghai and Tianjing.
Fishing in certain seasons has been banned and the annual quality of fish catch
restricted in the coastal zone of China (ESD-CAS, 1994). Sri Lanka conserves
coastal tourism resources by using ICZM principles (White et al., 1997). Coastal
natural conservation parks have been established in Bangladesh, Thailand, China,
and other countries (Sato and Mimura, 1997; Allison, 1998). However, land ownership
and management responsibility issues in Bangladesh have inhibited coastal zone
management. Similarly, privatization and decentralization of storm protection
systems in Vietnam have created a vacuum for strategic management and increased
the potential impacts of climate variability (Adger, 1999b, 2000).
Given that many potential climate change impacts on coastal zones feature irreversible
effects, surprise outcomes, and unpredictable changes, the appropriate policy
response should be to maximize flexibility and enhance the resilience and adaptation
potential of these areas (Pritchard et al., 1998). By contrast, coastal management
in Asia to date more often than not has been dominated by policies that have
sought to buffer socioeconomic activities and assets from natural hazards and
risks via hard engineering protection (Chua, 1998).
|