Task 2: Mekong ARCC Climate Change Adaptation and Impact Study

Mekong ARCC Climate Change Impact and Adaptation Study for natural and agricultural systemsJeremy Carew-Reid, ICEM International Centre for Environmental Managementwww.icem.com.au

September 2012 Hanoi1a

Assessing climate change threats to agriculture and subsistence livelihoods2ICEM, 2012

Agro-ecological systems and climate change vulnerability continuum3ICEM, 20124

Agriculture is market driven, linked to the international demand and foreign investment. The boom of rubber and cassava is symptomatic of a very reactive private sector, with increasing cultivated area, private sector concessions and intensification of the production. The production of the major crops has doubled in the last 20 years.Food production will need to grow by 25% in the next 15 years just to supply local populations.

4Climate change shiftsRegular climateGeographic shifts change in area of suitabilityElevation shifts (for highly restricted habitats and species) change in (i) location and (ii) elevationSeasonal shifts change in (i) yields, (ii) cropping patternsExtreme eventsExtreme event shiftsMicro eg flash flooding and soil loss in uplandsMacro eg saline intrusion in Delta; cyclone landfall5Geographic shift

6ICEM, 2012Identifying climate change hot spots i.e. highly vulnerable areasHigh exposure: significant climate change relative to base conditionsexposure to new climate/hydrological conditionsHigh sensitivity:limited temperature and moisture tolerance rangedegraded and/or under acute pressureseverely restricted geographic rangerare or threatenedLow adaptive capacityPoor connectivityLow diversity and tolerancesHomogenous systems

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Climate change hot spot - rainfall9

Climate change hot spot - TemperatureIndustrial and commercial crops and climate change hotspots

Lowland rice11

upland rice12

rubber13

Coffee (coffea canephora)14

cassava15

Maize1617

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Optimal growing conditions: Mean annual maximum temperatureSensitivity assessments: climate tolerances

Optimal growing conditions: mean annual precipitationSensitivity assessments: climate tolerances

Trends in commercial crops with climate changeRubber: 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 temperaturesSoybean 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 cultivation21Rice cultivation and extreme floodingExtreme 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 riskyOther commercial crops such as fruit and vegetables are less resilient to flood than rice.

22RiceRice cultivation and sea level riseA 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.

23RiceThank you

Jeremy Carew-Reid, ICEM International Centre for Environmental Managementwww.icem.com.au

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