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

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

Wildlife Live-

stock

Assessing climate change threats to agriculture and

subsistence livelihoods

Agro-ecological systems and climate change vulnerability continuum

3

4

Transition from subsistence to commercial agriculture

Intermediate Commercial

Land consolidation

Increased capital

intensity

Small holdings

Labourintensive

Low capital

intensity

Commercial farms and

plantations

Subsistence

Industrialization, rural-urban migration

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

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

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

Climate change hot spot -

rainfall

Climate change hot spot -

Temperature

Industrial and commercial

crops and climate change

hotspots

Lowland rice

Se San Basin – existing land use suitability

upland rice

Se San Basin – existing land use suitability

rubber

Se San Basin – existing land use suitability

Coffee (coffea canephora)

Se San Basin – existing land use suitability

cassava

Se San Basin – existing land use suitability

Maize

Se San Basin – existing land use suitability

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

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

Optimal growing conditions: Mean annual maximum

temperature

Sensitivity assessments: climate tolerances

Optimal growing conditions: mean annual precipitation

Sensitivity assessments: climate tolerances

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

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.

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.

Jeremy Carew-Reid

ICEM – International Centre for Environmental Management

www.icem.com.au