Mekong ARCC Climate Change
Impact and Adaptation Study for
natural and agricultural systems
Jeremy Carew-Reid,
ICEM – International Centre for Environmental Management
www.icem.com.au
September 2012 Hanoi
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Assessing climate change threats to agriculture and
subsistence livelihoods
Climate
changes
Hydrological
changes
Agricultural
zones
Commercial
crops
ICEM, 2012
Subsistence
crops
Aquaculture
Ecological
zones
Species “zones”
Traditional
crops
Livestock
Crop wild
relatives
Adaptation options
NTFPs
Wild fish
catch
Wildlife
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Agro-ecological systems and climate change vulnerability continuum
ICEM, 2012
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Transition from subsistence to
commercial agriculture
Industrialization, rural-urban migration
Small
holdings
Labour
intensive
Land
consolidation
Increased
capital
intensity
Low
capital
intensity
Subsistence
Intermediate
Commercial
farms and
plantations
Commercial
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Climate change shifts
Regular climate
1. Geographic shifts – change in area of suitability
2. Elevation shifts (for highly restricted habitats and
species) – change in (i) location and (ii) elevation
3. Seasonal shifts – change in (i) yields, (ii) cropping
patterns
Extreme events
4. Extreme event shifts
 Micro – eg flash flooding and soil loss in uplands
 Macro – eg saline intrusion in Delta; cyclone landfall
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Geographic shift
Original extent of
natural habitat
Shift in zone of suitability
for habitat and crops
Paddy rice
and
commercial
crops
Remaining
natural habitat
pockets
Subsistence crops and NTF
collection
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ICEM, 2012
Identifying climate change “hot spots” – i.e. highly
vulnerable areas
• High exposure:
 significant climate change relative to base conditions
 exposure to new climate/hydrological conditions
• High sensitivity:




limited temperature and moisture tolerance range
degraded and/or under acute pressure
severely restricted geographic range
rare or threatened
• Low adaptive capacity



Poor connectivity
Low diversity and tolerances
Homogenous systems
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Climate change
hot spot rainfall
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Climate change
hot spot Temperature
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Industrial and
commercial
crops and
climate change
hotspots
Lowland rice
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upland rice
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rubber
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Coffee (coffea canephora)
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cassava
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Maize
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17
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Sensitivity assessments:
climate tolerances
Optimal growing conditions: Mean annual maximum temperature
Sensitivity assessments:
climate tolerances
Optimal growing conditions: mean annual precipitation
Trends in commercial crops with
climate change
• Rubber: Projected increases in temperature and precipitation
would open upland areas for rubber cultivation.
• Coffee plantations would suffer from changes in rainfall patterns
and/or excess rainfall in the highland areas (especially Arabica).
• Cassava: Relatively resistant to drought so would become a
substitute in rain fed agricultural systems in drier areas BUT
would have reduced suitability in high rainfall areas.
• Sweet potato and key root crops not well suited to higher
rainfall and soil moisture conditions and higher temperatures
• Soybean would suffer from higher temperatures - shift to higher
elevation may be required.
• Bananas and mangoes: increases in temperature and
precipitation would open upland areas for cultivation
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Rice
Rice cultivation and extreme flooding
• Extreme floods will be more common in rice based
production systems in Lowland Cambodia and the
Mekong Delta.
• Flood would have a larger impact where agriculture is
intensified, with high yielding rice varieties less
resilient to flood than traditional ones.
• Investment in intensive rice cultivation will become
more risky
• Other commercial crops such as fruit and vegetables
are less resilient to flood than rice.
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Rice
Rice cultivation and sea level rise
• A 30 cm rise by 2050 with increased flood extent,
depth and duration will result in a loss of 193,000 ha
of rice area in the Mekong Delta.
• Agriculture will be severely constrained by increased
saline intrusion in the dry season and longer flood in
the rainy season.
• The double and triple cropping system commonly
used in the Mekong Delta might not be possible.
• Climate change will change the occurrence of plant
disease and pests such as fungus and moulds,
viruses, nematodes and a range of insects.
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Thank you
Jeremy Carew-Reid,
ICEM – International Centre for Environmental
Management
www.icem.com.au
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