Transcript Patrick Nunn

AIACC Asia Regional Workshop
Session C2: Water Resources,
Watersheds, Coasts (Bangkok, 26.3.03)
Vulnerability and Adaptive
Capacity in the Archipelagoes
of the South Pacific
Patrick D. Nunn
The University of the South Pacific
Organisation of this Talk
• Overview of the South Pacific
archipelagoes
• Water resources – vulnerability and
adaptive capacity
• Watersheds - vulnerability and adaptive
capacity
• Coasts - vulnerability and adaptive
capacity
• Future work/prospects
Part 1:
Overview of the South
Pacific archipelagoes
Overview of South Pacific island
vulnerability
• Comparatively large
ratios of coast
length to land area.
• Comparatively
remote and difficult
of access.
• Comparatively high
dependence of
people on locally
available food
sources.
Overview of South Pacific island
adaptive capacity
• Large area of highly
vulnerable coastal
lowland.
• Comparative smallness of
land areas limits withinisland relocation.
• Most practical
environmental decisionmaking is at community
level.
• Lifestyle options limited.
Part 2:
Water resources –
vulnerability and adaptive
capacity
Pollution
Vulnerability –
Increasing
demands
(agricultural,
urban, waste,
industrial,
marine)
Pollution
Adaptive capacity
–
More effective
environmental
legislation,
improved public
awareness
Shortage
• Vulnerability –
– Natural droughts
– Infrastructural
maintenance
Shortage
• Adaptive capacity –
– Improved public
awareness
– Improved forecasting
– Improved
management
Part 3:
Watersheds – vulnerability
and adaptive capacity
Natural landscape change
Vulnerability –
Natural
processes,
exacerbated by
changes in
climate and
climate
extremes
Natural landscape change
Adaptive
capacity –
Many
settlements can
move fairly
easily, hard
engineering
solutions often
prohibitively
costly.
Human-induced land degradation
Vulnerability – inland populations
increasing and likely to increase further as
coastal populations are displaced. Many
inland landscapes degraded from millennia
of agricultural use and burning.
Human-induced land degradation
Adaptive capacity – low in many island countries
because island land areas are small. Crop strains more
suited to upland than lowland areas, and more tolerant
of warmer wetter conditions need to be developed.
Part 4:
Coasts – vulnerability and
adaptive capacity
Melanesia, 1860s?
Shoreline
protection
Cm
HONOLULU TIDE-GAUGE RECORD
10
5
0
-5
-10
-15
1900
1920
1940
Years AD
1960
1980
Coasts - vulnerability
•
•
•
•
•
Low-lying
Unconsolidated
Permeable
Subject to storms
Locations of most
settlements, most
infrastructure, most
revenue-generating
enterprises
(including tourism)
Consequence of 20thcentury sea-level rise:
inundation and
salinisation of coastal
lowlands.
Bruun Rule
Consequence of
20th-century sealevel rise: shoreline
erosion along
sandy coastlines.
On-site adaptation
where possible
Out-migration where onsite adaptation impossible
Coastal vulnerability – the
seawall mindset
• Most government
and community-level
decision makers
believe in remedying
short-term problems
rather than
addressing the likely
long-term effects.
Coastal vulnerability – the
seawall mindset
• Most long-term
solutions are being
driven by NGOs
although
governments
commonly pay lipservice to such
sustainable
solutions.
Coasts – adaptive capacity
Accommodation
Coasts – adaptive capacity
Protection
Coasts – adaptive capacity
Retreat inland
Coasts – adaptive capacity
Retreat upslope
Part 5:
Future work/prospects
Cm
120
100
Sea-Level Rise,
AD 1800-2100
1992a High (+91 cm)
80
1992a Best (+51 cm)
60
40
1992a Low (+19 cm)
20
Extrapolated level
0
1800
2000
1900
Year AD
2100
TONGATAPU ISLAND, KINGDOM OF TONGA
Denselypopulated
areas
N
0
10
km
TONGATAPU ISLAND, KINGDOM OF TONGA
Land area less than
5 m above sea level
Denselypopulated
areas
N
0
10
km
Sea-level rise
• Probable sea-level rise
over the next 100 years
will see some parts of
the Pacific disappear,
many others
significantly reduced in
habitable area.
• The geography of the
Indo-Pacific region will
change.
In atoll nations, the
effects of future
sea-level rise are
certain to produce
environmental
refugees.
Coral-reef death
• Increased oceansurface
temperatures over
the next 100 years
will kill many of the
world’s coral reefs.
Aims of AIACC Project (S)IS09
• Improve models for vulnerability and
adaptation assessment in the Pacific Islands
region.
• Develop the capacity of Pacific Island nations
to plan more effectively for future climate
change.
• Develop and trial methods of assessment
which are transferable to other island regions.