N n n il n

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

Year

Figure 5. Extent of forest fire destruction in Philippines (1978-1999).

5.4.1.4. Impacts of Climate Change on Philippine Forest Resources. In the case of Philippine forestry sector, no simulation studies have been made yet, although there is now an on-going 3-year integrated assessment of watersheds. The initial vulnerability assessment done was based on the current projections and IPCC assessment reports for Asia and two national studies (that of Thailand and of Sri Lanka) because of resource constraints. Results of the related regional and national studies were used as analogues of the potential impacts of future climate change on Philippine forests. Changes expected to happen in Philippine forests include the likelihood of the expansion of its rainforests as temperature is expected to increase substantially, along with modest increase in precipitation in many areas which already get excessive moisture. On the other hand, the generally increasing trend in precipitation especially during the wettest months will possibly cause serious soil erosion and flood problems in currently denuded forests and watersheds which are dominated by grasses. This could exacerbate the declining productivity of these denuded watersheds and the downstream areas that act as repository of silt transported by surface runoff and streamflow. However, in areas where temperature is expected to increase significantly but rainfall is projected to remain unchanged or even decrease, the expected loss in forested areas may be small. This, however, may lead to the loss of a few species of plants and animals that can significantly erode the biodiversity in these areas and also in the forest in the adjacent areas. And because climate change could exacerbate the loss of local biodiversity already brought about by other pressures through extinction and inhibition of re-immigration from adjacent areas, the greatest impacts are on those whose subsistence depends on the goods and services these forest resources provide.

Additionally, the increase in the frequency of drought/floods due to changes in El Niño will likely render many areas currently under cultivation unfit for agricultural

production. Population growth and shrinking arable lands could increase the pressure of forested areas to be converted, thereby challenging the protection of the remaining natural forests. Grasslands and other areas dominated by shrub and shrub species could become more vulnerable to fire with the increase in temperature and the inadequate increase or even marked decrease and rainfall. This could be further aggravated by any prolonged dry periods which are bound to happen during El Niños. Frequent fires could make these areas more difficult to rehabilitate.

Any changes in temperature and precipitation may result in the outbreak of pests and diseases. This can significantly change the species composition, structure and functions of forest ecosystems in ways similar to the disturbances that come about through forest destruction by man.

5.4.2. Malaysia

Malaysia sits on the South China Sea at the center of Southeast Asia. The country is crescent-shaped, starting with Peninsular Malaysia (West Malaysia) and extends to another region, Sabah and Sarawak (East Malaysia), located on the island of Borneo. The total area of Malaysia is approximately 330,000 km2, with most of it island of Borneo. Peninsular Malaysia comprises approximately only 40% of the total area.

Peninsular Malaysia is located entirely within the equatorial zone. It had 82% of the nation's population in 1990. Economic activity accounted for 84% of Malaysia's gross domestic product in 1987, and 74% of Malaysian land in agricultural use was in Peninsular Malaysia in 1990. Tree crops represent the principal agricultural land use in Peninsular Malaysia. Rubber, oil palm, coconut, and cacao accounted for 83% of the area devoted to agriculture in 1988. Agriculture (including forestry and wood products) is a major sector of Peninsular Malaysia's economy and is important on a global scale as well. Malaysia is the world's largest producer and exporter of natural rubber, palm oil, and tropical logs and sawn wood.

Malaysia's climate is hot and humid with relative humidity ranging from 80 to 90%, except in the highlands. The temperature averages from20to 30 °C throughout the year. The tropical climate is experienced year-round with the rainy season varying on the coasts of Peninsular Malaysia. The west coast has its rainy season from September through December with the east coast (and Sarawak and Sabah) experiencing it from October through February. East Malaysia (the northern slopes) gets up to 5080 mm of rain a year versus West Malaysia's 2500 mm. There exists the possibility of drought in West Malaysia (i.e., Peninsular Malaysia which is the major agricultural area) although the weather disaster of Malaysia is floods.

There are forests covering over half of Malaysia, with notable tropical forests in Sabah and Sarawak. Deforestation is a problem the country is dealing with due to logging and hydroelectric projects.

5.4.2.1. Climate Change and Variability in Malaysia. Like many countries in the world, temperature records in Malaysia in the last 50 years have shown warming trends (see Figure 6). Climate change may bring about an increase in the frequency

TABLE VIII Climate change scenarios for Malaysia

2020 2040 2060

TABLE VIII Climate change scenarios for Malaysia

2020 2040 2060

Northern hemisphere summer

Changes in temperature

+0.3to + 1.4 °C

+0.4to + 2.4 °C

+0.6to + 3.4 °C

Changes in rainfall

-0.4 to +14%

-0.7 to +23%

-1.0 to +32%

Northern hemisphere winter

Changes in temperature

+0.4 to +1.9 °C

+0.7 to +3.2°C

+ 1.0 to +4.5 °C

Changes in rainfall

-4.0 to +7.0%

-7.0 to +12%

-10 to +17%

28.4 28.2 28.0 27.8 27.6 o° 27.4 2 27.2 I 27.0 o 26.8 EE 26.6 £ 26.4 26.2 26.0 25.8 25.6 25.4

51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01

year

—b— Mean Temp-Lnear Regression Linei

Figure 6. Temperature records in Malaysia in the last 50 years.

and intensity of extreme weather events, such as, drought, storms and floods. There is still, however, insufficient data to determine whether the frequency of extreme events has indeed increased. It has been observed that, since 1977, there have been more frequent ENSO warm phase episodes. This behavior, especially the persistent warm phase from 1990 to mid-1995, was unusual in the last 120 years and significantly influenced rainfall in Malaysia.

Table VIII is the climate change scenarios for Malaysia. Generally, the temperature will increase; rainfall may increase probably, but there exists possibility of some decreases. The impacts of climate change on Malaysia agriculture are estimated based on the combinations of higher temperature and increasing rainfall, and higher temperature and decreasing rainfall.

5.4.2.2. Impacts of Climate Change and Variability on Malaysia Agriculture. Most of the materials for this case study are drown from the Malaysia initial National Communication as an output of the UNDP/GEF Project: Enhancement of Technical

51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01

year

Figure 6. Temperature records in Malaysia in the last 50 years.

Capacity to Develop National Response Strategies to Climate Change.

(1) Impacts on rubber. Rubber flourishes in a tropical climate with a high mean daily air temperature of between 25 and 28 °C and high rainfall exceeding 2000 mm per year. Even distribution of rainfall with no dry seasons exceeding 1 month and at east 2100 h of sunshine per year are ideal conditions for growing rubber. The following impacts of climate change on rubber are expected:

• If the mean daily air temperature increases by 4.5 °C above the mean annual temperature, more dry months and hence more moisture stress can occur. A crop decrease of 3-15% due to drought conditions is projected if mean annual temperature increases to 31 °C. The degree of yield decrease will be dependent on clonal susceptibility, as well as the length and severity of the drought.

• Based on the above climate change scenario, some states may experience a reduction in production. It is projected that 273,000 ha of land, or 15% of current rubber land, may be affected. With the availability of higher yielding clones and improved cultural practices, this impact, however, may be minimized.

• If rainfall increases, loss of tapping days and crop washout occur. As a result, yielding losses can range from 13 to 30%. Thus, if the number of rain days were to increase, then most parts of the country will suffer from rainfall interface with tapping.

• If sea level rises by 1 m, low-lying areas may be flooded. Rubber cultivation in these areas would not be possible.

Table IX shows the projected rubber yield in relation to climate change over time.

(2) Oil palm. Oil palm is best suited to a humid tropical climate in which rain occurs mostly at night and days are bright and sunny. For optimum yield, minimum monthly rainfall required is around 1500 mm with absence of dry seasons, and an evenly distributed sunshine exceeding 2000 h per year. A mean maximum temperature of about 29-33 °C and a mean minimum temperature of 22-24 °C favor the highest bunch production.

• A high mean annual temperature of 28-31 °C is favorable for high production. If these higher temperatures lead to drought conditions, however, an estimated 208,000 ha of land or 12% of the present oil palm areas would be considered marginal-to-unsuitable for oil palm cultivation, particularly in drought-prone areas.

• Increased rainfall favors oil palm productivity unless it leads to flooding. With an anticipated sea level rise of 1 m, an estimated 100,000 ha of area, currently planted with oil palm, may be deemed unsuitable and would have to be abandoned.

TABLE IX Projected rubber yield with climate change

Year 2020

CO2(ppm)

400

400

400

Temperature Increase °C

0.3

0.85

1.4

Rainfall change (%)

+ 14%

1.26

1.26

1.23

+7%

1.44

1.44

1.42

+0.4%

1.60

1.60

1.60

0%

1.60

1.60

1.60

-0.4%

1.60

1.60

1.60

-7%

1.55

1.55

1.54

-14%

1.46

1.46

1.44

Year 2040

CO2(ppm)

600

600

600

Temperature Increase °C

0.4

1.4

2.4

Rainfall change (%)

+23%

1.42

1.42

1.42

+ 11%

1.53

1.53

1.53

+0.7%

1.80

1.80

1.80

0%

1.80

1.80

1.80

-0.7%

1.80

1.80

1.80

-11%

1.69

1.69

1.69

-23%

1.53

1.53

1.49

Year 2060

CO2(ppm)

800

800

800

Temperature Increase °C

0.6

2

3.4

Rainfall change (%)

+32%

1.40

1.40

1.40

+15%

1.58

1.58

1.58

+1%

2.00

2.00

2.00

0%

2.00

2.00

2.00

-1%

2.00

2.00

1.82

-15%

1.80

1.78

1.72

-32%

1.60

1.60

1.52

Table X shows the projected oil palm yield in relation to climate change. It can be seen that a decrease in rainfall affects yield significantly. (3) Cocoa. Although cocoa is planted in areas where annual rainfall is in the range of 1250-2800 mm, it prefers areas where annual rainfall is in the range of 1500-2000 mm and the number of dry months is three or less. It should not be

TABLE X

Projected oil palm yield with climate change

TABLE X

Projected oil palm yield with climate change

Year 2020

CO2(ppm)

400

400

400

Temperature Increase °C

0.3

0.85

1.4

Rainfall change (%)

+ 14%

21.5

21.5

21.5

+7%

23.0

23.0

23.25

+0.4%

22.5

22.5

22.75

0%

22.0

22.0

22.0

-0.4%

22.0

22.0

22.0

-7%

17.6

17.6

17.0

-14%

15.4

15.4

15.4

Year 2040

CO2(ppm)

600

600

600

Temperature Increase °C

0.4

1.4

2.4

Rainfall change (%)

+23%

24.0

24.0

24.0

+11%

25.0

25.0

25.0

+0.7%

24.5

24.5

24.5

0%

24.0

24.0

24.0

-0.7%

23.5

23.5

23.0

-11%

19.2

19.2

18.7

-23%

15.6

15.6

14.9

Year 2060

CO2(ppm)

800

800

800

Temperature Increase °C

0.6

2

3.4

Rainfall change (%)

+32%

26.0

26.0

26.0

+ 15%

27.0

27.0

26.0

+1%

26.0

26.0

25.0

0%

26.0

26.0

26.0

-1%

24.0

24.0

22.0

-15%

18.0

18.0

15.6

-32%

14.3

14.3

13.0

planted in areas with annual rainfall below 1250 mm, unless irrigation is provided. Areas with annual rainfall exceeding 2500 mm are also not favorable as it reduces yield by 10-20% due to water logging. Besides, the excessive rainfall causes high disease incidence, especially Phytophthora and pink diseases.

• Most of the cocoa-growing areas have maximum temperature ranges of 30-32 °C and minimum temperature of 18-21 °C. The temperatures in Malaysia is within this range throughout the year. The temperatures exceeding 32 °C may resultin moisture stress, leading to yield of 10-20%.

• Based on these considerations, the states that experience a distinct dry season are marginal areas for cocoa cultivation. Irrigation is required in these areas if cocoa is to be cultivated.

• Some areas, which register high rainfall, are not suited for cocoa cultivation due to the high incidence of diseases. This can result in yield loss of more than 20%.

• With climate change, a high incidence of drought is expected to reduce yield. On the other hand, excessive rainfall with reduced insolation can also result in low yields. In addition, under such weather conditions, a high incidence of fungal diseases such as vascular streak disease and black pod can depress yields.

Table XI shows that cocoa yield is sensitive to both excessive and reduced rainfall. In both cases, the yield is decreased.

(4) Rice. Rice constitutes 98% of total cereal production in Malaysia. Generally, long periods of sunshine are favorable for high rice yields. Growth is optimal when the daily air temperature is between 24 and 36 °C. The difference between day and night temperatures must be minimal during flowering and grain production.

Climate change can affect rice production in the following ways:

• Grain yields may decline by 9-10% for each 1 °C rise in temperature.

• If drought conditions are prolonged, the current flooded rice ecosystem can not be sustained. It may be necessary to develop non-flooded and dry land rice ecosystem to increase the level of national rice sufficiency.

National food security may thus be threatened in both cases. Table XII shows that rice yield is sensitive to climate change.

5.4.2.3. Impacts of Climate Change on Forestry. Table XIII shows the impacts of climate change on forests in Malaysia by examining its physiological process, geographical distribution and biodiversity.

(1) Physiology of the forest. Several climate variables such as air temperature, moisture availability and the concentration of ambient CO2 have direct effects on forest physiology, depending on the species, location, nutrient levels of the soil and the other environmental conditions. Current scientific understanding indicates that elevated CO2 concentrations may lead to increased biomass growth by as much as 40%, resulting from stimulated photosynthesis, leading

TABLE XI Projected cocoa yield with climate change

Year 2020

CO2(ppm)

400

400

400

Temperature Increase °C

0.3

0.85

1.4

Rainfall change (%)

+ 14%

1.86

1.59

1.54

+7%

2.10

1.85

1.79

+0.4%

3.10

2.65

2.56

0%

3.10

2.65

2.56

-0.4%

3.10

2.65

2.56

-7%

2.79

2.39

2.30

-14%

2.79

2.39

2.30

Year 2040

CO2(ppm)

600

600

600

Temperature Increase °C

0.4

1.4

2.4

Rainfall change (%)

+23%

1.55

1.33

1.02

+ 11%

2.17

1.86

1.44

+0.7%

3.10

2.65

2.05

0%

3.10

2.65

2.05

-0.7%

3.10

2.65

2.05

-11%

2.79

2.39

1.85

-23%

2.48

2.12

1.64

Year 2060

CO2(ppm)

800

800

800

Temperature Increase °C

0.6

2

3.4

Rainfall change (%)

+32%

1.33

1.25

0.95

+15%

1.59

1.50

1.14

+1%

2.65

2.50

1.90

0%

2.65

2.50

1.90

-1%

2.65

2.50

1.90

-15%

2.39

2.25

1.71

-32%

1.59

1.50

1.14

to in increased concentrations of CO2 inside the leaves. On the other hand, higher CO2 level may reduce the nitrogen to carbon ration in plant tissue that may affect the rate of litter breakdown. Trees in the forest also respond positively to temperature increase; the temperature and primary productivity

TABLE XII Projected rice yield with climate change

Year 2020

CO2(ppm)

400

400

400

Temperature Increase °C

0.3

0.85

1.4

Rainfall change (%)

+ 14%

6.15

5.81

5.59

+7%

6.65

6.31

6.09

+0.4%

7.20

6.86

6.64

0%

7.20

6.86

6.64

-0.4%

7.20

6.86

6.64

-7%

6.67

6.38

6.18

-14%

6.19

5.90

5.71

Year 2040

CO2(ppm)

600

600

600

Temperature Increase °C

0.4

1.4

2.4

Rainfall change (%)

+23%

7.34

6.94

6.54

+11%

8.20

7.80

7.40

+0.7%

9.04

8.64

8.24

0%

9.04

8.64

8.24

-0.7%

9.04

8.64

8.24

-11%

8.05

7.69

7.34

-23%

6.96

6.65

6.35

Year 2060

CO2(ppm)

800

800

800

Temperature Increase °C

0.6

2

3.4

Rainfall change (%)

+32%

8.62

8.06

7.50

+15%

9.83

9.27

8.71

+1%

10.96

10.4

9.84

0%

10.96

10.4

9.84

-1%

10.96

10.4

9.84

-15%

9.32

8.84

8.37

-32%

7.45

7.07

6.69

are positively correlated by this and depend on the availability of water, which is in turn is dependent on rainfall distribution.

(2) Forest distribution. Given the temperature and CO2 concentration projections of some global climate models, the expansion of upland forest by 5-8% may be expected. This would however be nullified by a loss between 15 and 20% of mangrove forests located along the coastline as a result of sea level rise. The

TABLE XIII

Impacts of climate change on forests in Malaysia

Process/habitat

Impacts

Physiological process

Up to 40% increase in biomass growth due to increase in

photosynthesis processes

Forest distribution/habitat

Upland tropical rainforest

Expansion of suitable forest areas by 5-8%

Mangrove forest

Reduction in mangrove area by 15-20% due to sea level rise

Forest plantation

Minimal impacts due to its limited area

Increased susceptibility to pest and infestation of diseases

Increased fire occurrence

problem of climate-change-induced disease infestation in forest plantation species may also occur.

Forest biodiversity. Tropical forests in Malaysia are rich in diversity, and therefore, the impacts of climate change on biodiversity are of great concern. The change in the climate has likely effects on species composition of the forest, but marked variations are expected due to local effects of soil and topography. Given the intricate interrelationships between plant and animal species in tropical forests, the impact on any species will have inevitable consequences for other species as well.

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