Mekong ARCC Climate Change Impact and Adaptation Study for Natural and Agricultural Systems This presentation from the International Centre for Environmental Management (ICEM) about the Mekong ARCC project was given by ICEM's director Jeremy Carew-Reid at the World Bank-sponsored Second Global Conference on Agriculture, Food Security and Climate Change, held in Hanoi, Vietnam from 3-7 September 2012. The presentation focuses on the Mekong ARCC assessments and findings regarding climate change threats to agriculture and subsistence livelihoods. It addresses the significant transition from subsistence to commercial agriculture in the region. Commercial cropping has doubled in the last 20 years, particularly with the growth in production of rubber and cassava. The presentation provides recommendations from the Mekong ARCC assessments focusing on food production, advocating that food production will need to grow by 25% in the next 15 years just to supply local populations. The presentation highlights 'hot spots' in terms of rainfall and temperature changes, and illustrates potential implications for the location of industrial and commercial crops. The presentation focuses on the Se San catchment area, and notes some key changes which have implications for rice cultivation in the context of more extreme flooding and sea level rise.

1. 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 1a

2. Climate
changes
Hydrological
changes
Agricultural
zones
Ecological
zones
Species “zones”
Commercial
crops
Subsistence
crops
Traditional
crops
Aqua-
culture
Crop wild
relatives
NTFPs Wild fish
catch
Adaptation options
WildlifeLive-
stock
Assessing climate change threats to agriculture and
subsistence livelihoods

3. Agro-ecological systems and climate change vulnerability continuum
3

4. 4
Transition from subsistence to
commercial agriculture
Intermediate Commercial
Land
consolidation
Increased
capital
intensity
Small
holdings
Labour
intensive
Low
capital
intensity
Commercial
farms and
plantations
Subsistence
Industrialization, rural-urban migration

5. 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

6. Geographic shift
Paddy rice
and
commercial
crops
Shift in zone of suitability
for habitat and crops
Original extent of
natural habitat
Remaining
natural habitat
pockets
Subsistence crops and NTF
collection

7. 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

8. Climate change hot spot -
rainfall

9. Climate change hot spot -
Temperature

10. Industrial and commercial
crops and climate change
hotspots

11. Lowland rice
Se San Basin – existing land use suitability

12. upland rice
Se San Basin – existing land use suitability

13. rubber
Se San Basin – existing land use suitability

14. Coffee (coffea canephora)
Se San Basin – existing land use suitability

15. cassava
Se San Basin – existing land use suitability

16. Maize
Se San Basin – existing land use suitability

17. Climate change (precipitation in 2050) in the Se San catchment

18. Climate change (temperature in 2050) in the Se San catchment

19. Optimal growing conditions: Mean annual maximum
temperature
Sensitivity assessments: climate tolerances

20. Optimal growing conditions: mean annual precipitation
Sensitivity assessments: climate tolerances

21. 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

22. 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.

23. 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.

24. Jeremy Carew-Reid
ICEM – International Centre for Environmental Management
www.icem.com.au