The Impact of Climate Change on the Hydro-Climate of Malaysia Based on IPCC Fifth Assesment Report.

Coastal Region 10

Coastal Region 11

Coastal Region 12

Figure 6.2 - Time series plots of the annual accumulated rainfall during the historical (1970-
2000) and the projected future (2010-2100) conditions for 12 coastal regions in Peninsular
Malaysia. Future conditions are in terms of the individual projections and the ensemble
average of the projections.

129

a)

b)

Figure 6.3 - a) Long-term mean of the annual rainfall (mm) during the historical period (1970-
2000), the early 21st century (2011-2040), the middle 21st century (2041-2070), and the late
21st century (2071-2100), and b) the change in the long-term mean of the annual rainfall from
the historical period, to the early, middle, and late 21st century for 13 watersheds and 12
coastal regions in Peninsular Malaysia.

130

Table 6.1 - Long-term mean of the annual rainfall (mm) during the historical period (1970-
2000), the early 21st century (2011-2040), the middle 21st century (2041-2070), and the late
21st century (2071-2100), and b) the change in the long-term mean of the annual rainfall from
the historical period, to the early, middle, and late 21st century for 13 watersheds in Peninsular
Malaysia.

Long-term mean Change from Historical period
Early Mid
Watershed Hist (2011- (2041- Late Early Mid Late
(1970- 2040) 2070) (2071-
Batu Pahat 2000) 2063.08 2134.17 2100) (2011- (2041- (2071-
Dungun 1994.53 4356.62 4563.34 2207.50
Johor 3973.79 2543.27 2641.91 4607.98 2040) 2070) 2100)
Kelang 2416.47 2550.41 2610.56 2743.03
Kelantan 2410.20 3493.96 3660.42 2671.83 68.55 139.65 212.97
Kemaman 3245.74 3242.52 3379.14 3695.36
Kuantan 3014.69 3171.16 3317.23 3404.77 382.83 589.55 634.19
Linggi 2998.12 2086.30 2141.20 3318.53
Muar 1989.25 1867.48 1932.56 2206.87 126.80 225.43 326.56
Muda 1787.95 3243.10 3425.38 1974.02
Pahang 2895.70 2551.97 2637.66 3532.82 140.22 200.36 261.64
Perak 2438.94 3234.09 3378.68 2641.04
Selangor 2948.80 2949.91 3049.85 3423.65 248.22 414.67 449.61
2723.82 3117.80
227.83 364.45 390.08

173.04 319.11 320.41

97.05 151.96 217.62

79.53 144.61 186.07

347.40 529.68 637.12

113.03 198.72 202.09

285.30 429.88 474.85

226.09 326.03 393.98

131

Table 6.2 - Long-term mean of the annual rainfall (mm) during the historical period (1970-
2000), the early 21st century (2011-2040), the middle 21st century (2041-2070), and the late
21st century (2071-2100), and b) the change in the long-term mean of the annual rainfall from
the historical period, to the early, middle, and late 21st century for 12 coastal regions in
Peninsular Malaysia.

Long-term mean Change from Historical period
Early Mid
Coastal Hist (2011- (2041- Late Early Mid Late
Region (1970- 2040) 2070) (2071-
2000) 2100) (2011- (2041- (2071-
Coastal 3116.67 3294.18
Region 1 2870.61 3392.32 2040) 2070) 2100)
Coastal
Region 2 246.06 423.57 521.71
Coastal
Region 3 3472.41 3822.11 4006.12 4087.31 349.71 533.71 614.91
Coastal
Region 4 2815.49 3025.16 3143.79 3202.37 209.67 328.30 386.88
Coastal
Region 5 2604.94 2764.15 2884.89 2969.25 159.20 279.94 364.31
Coastal
Region 6 2331.90 2403.53 2484.85 2577.29 71.63 152.95 245.39
Coastal
Region 7 2114.00 2149.60 2243.75 2328.05 35.60 129.75 214.05
Coastal
Region 8 1870.01 1909.57 1977.78 2037.41 39.56 107.76 167.40
Coastal
Region 9 2149.56 2254.30 2317.35 2390.71 104.74 167.79 241.15
Coastal
Region 10 2163.70 2253.66 2294.14 2379.14 89.96 130.44 215.44
Coastal
Region 11 2628.29 2844.24 2924.93 3016.88 215.95 296.65 388.59
Coastal
Region 12 2850.34 3117.52 3262.36 3398.16 267.18 412.02 547.82

2066.39 2236.36 2370.14 2554.13 169.97 303.75 487.74

6.1.2. Sabah and Sarawak
Time series plots of annual accumulated rainfall during the historical (1970-2000) and the
projected future (2010-2100) conditions for subregions of Sabah (Beaufort, Beluran, Kota
Kinabalu, Kudat, Lahad Datu, Pitas, Sandakan, Sg Abai, Sg Kalabakan, Sg Kalumpang, Sg
Labuk, Sg Padas, Sg Papar, Sg Segama, Sg Sinsilog, Sg Sugut, Sg Tuaran, Sipitang, Southern
Sabah, Tawau, Trusan Kinabatangan) and Sarawak (Batang Balingian, Batang Baram, Batang
Kemena, Batang Kerian, Batang Lawas, Batang Lupar, Batang Mukah, Batang Oya, Batang
Rajang, Batang Sadong, Batang Samarahan, Batang Saribas, Batang Tatau, Batang Terusan,
Northern Sarawak, Sg Limbang, Sg Sarawak, Southern Sarawak) are presented in Figures 6.4

132

and 6.5, respectively. Future conditions are presented in terms of individual projections (for
RCP2.6, 4.5, 6.0, 8.5) and the ensemble average of the projections. In general, the ensemble
average of the annual rainfall gradually increases during the 21st century over each of the 39
subregions although the annual rainfall in each of the 16 projections has large fluctuations.

Figure 6.6 and Tables 6.3-6.4 show the long-term mean of the annual rainfall (mm) during the
historical period (1970-2000), the early 21st century (2011-2040), the middle 21st century
(2041-2070), and the late 21st century (2071-2100), as well as the change in the long-term
mean of the annual rainfall from the historical period, to the early, middle, and late 21st
century for each of the 39 subregions in Sabah and Sarawak.

In comparison to the historical period, the change in the long-term mean annual rainfall over
the subregions of Sabah varies from 9.9 percent in Southern Sabah to 20.9 percent in Sg
Sinsilog in the early 21st century, from 14.6 percent in Southern Sabah to 29.3 percent in Sg
Sinsilog in the middle 21st century, and 19.7 percent in Southern Sabah to 35.8 percent in Sg
Sinsilog in the late 21st century. In comparison to the historical period, the change in the long-
term mean annual rainfall over the subregions of Sarawak varies from 3.3 percent in Batang
Sadong to 13.1 percent in Batang Lawas in the early 21st century, from 5.3 percent in Batang
Sadong to 16.4 percent in Sg Limbang in the middle 21st century, and 8.1 percent in Batang
Sadong to 22.9 percent in Northern Sarawak in the late 21st century.

The long-term mean annual rainfall values for the 39 subregions are always higher in the early,
middle, and late 21st century when compared to those in the historical period.

Beaufort

133

Beluran

Kota Kinabalu
Kudat
Lahad Datu

134

Pitas
Sandakan
Sg Abai
Sg Kalabakan

135

Sg Kalumpang
Sg Labuk
Sg Padas
Sg Papar

136

Sg Segama
Sg Sinsilog
Sg Sugut
Sg Tuaran

137

Sipitang

Southern Sabah

Tawau

Trusan Kinabatangan

Figure 6.4 - Time series plots of the annual accumulated rainfall during the historical (1970-
2000) and the projected future (2010-2100) conditions for subregions in Sabah. Future
conditions are in terms of individual projections and the ensemble average of the projections.

138

Batang Balingian
Batang Baram
Batang Kemena
Batang Kerian

139

Batang Lawas
Batang Lupar
Batang Mukah
Batang Oya

140

Batang Rajang
Batang Sadong
Batang Samarahan
Batang Saribas

141

Batang Tatau
Batang Terusan
Northern Sarawak
Sg Limbang

142

Sg Sarawak

Southern Sarawak

Figure 6.5 - Time series plots of the annual accumulated rainfall during the historical (1970-
2000) and the projected future (2010-2100) conditions for subregions in Sarawak. Future
conditions are in terms of the individual projections and the ensemble average of the
projections.

143

a)

b)

Figure 6.6 - a) Long-term mean of the annual rainfall (mm) during the historical period (1970-
2000), the early 21st century (2011-2040), the middle 21st century (2041-2070), and the late
21st century (2071-2100), and b) the change in the long-term mean of the annual rainfall from
the historical period, to the early, middle, and late 21st century for each of the 39 subregions
in Sabah and Sarawak.

144

Table 6.3 - Long-term mean of the annual rainfall (mm) during the historical period (1970-
2000), the early 21st century (2011-2040), the middle 21st century (2041-2070), and the late
21st century (2071-2100), and b) the change in the long-term mean of the annual rainfall from
the historical period, to the early, middle, and late 21st century for subregions in Sabah.

Long-term mean Change from Historical

period

Subregions in Sabah Hist Early Mid Late Early Mid Late
(1970- (2011- (2041- (2071-
Beaufort 2000) 2040) 2070) 2100) (2011- (2041- (2071-
Beluran 3578.40 3957.95 4129.44 4399.00
Kota_Kinabalu 2810.12 3307.79 3552.19 3750.67 2040) 2070) 2100)
Kudat 2975.67 3358.72 3525.82 3822.79
Lahad_Datu 2554.44 2938.88 3145.61 3336.94 379.55 551.04 820.60
Pitas 2605.87 2894.03 3021.64 3201.87
Sandakan 2972.82 3486.08 3742.96 3917.98 497.66 742.07 940.55
Sg_Abai 2589.43 3010.10 3153.22 3343.66
Sg_Kalabakan 6335.08 7161.09 7553.85 7868.75 383.05 550.15 847.13
Sg_Kalumpang 2652.73 2961.05 3096.69 3222.46
Sg_Labuk 2420.49 2699.14 2825.44 2974.59 384.44 591.17 782.50
Sg_Padas 2707.49 3093.89 3293.66 3463.59
Sg_Papar 2711.42 3010.32 3112.43 3250.79 288.16 415.77 596.00
Sg_Segama 5607.51 6353.47 6539.26 6786.24
Sg_Sinsilog 2728.64 3036.18 3144.62 3301.39 513.26 770.14 945.16
Sg_Sugut 3392.75 4102.53 4388.04 4606.02
Sg_Tuaran 3725.19 4252.61 4537.55 4728.53 420.66 563.79 754.23
Sipitang 3405.57 3799.26 3970.86 4212.60
Southern_Sabah 4226.82 4785.42 4911.67 5162.74 826.01 1218.77 1533.67
Tawau 3285.46 3611.72 3765.17 3932.73
Trusan_Kinabatangan 2242.97 2469.50 2580.89 2692.02 308.32 443.96 569.73
2665.17 2996.83 3146.77 3293.54
278.65 404.96 554.10

386.40 586.16 756.10

298.90 401.01 539.37

745.95 931.75 1178.72

307.54 415.98 572.75

709.78 995.29 1213.27

527.42 812.36 1003.35

393.69 565.30 807.04

558.61 684.86 935.92

326.25 479.71 647.27

226.53 337.91 449.05

331.66 481.60 628.37

145

Table 6.4- Long-term mean of the annual rainfall (mm) during the historical period (1970-
2000), the early 21st century (2011-2040), the middle 21st century (2041-2070), and the late
21st century (2071-2100), and b) the change in the long-term mean of the annual rainfall from
the historical period, to the early, middle, and late 21st century for subregions in Sarawak.

Long-term mean Change from Historical
period
Subregions in Hist Early Mid Late
Sarawak (1970- (2011- (2041- (2071- Early Mid Late
2000) 2040) 2070) 2100) (2011- (2041- (2071-
Batang_Balingian 2981.56 3252.03 3379.02 3532.39 2040) 2070) 2100)
Batang_Baram 4195.21 4633.49 4740.59 4879.27 270.47 397.46 550.83
Batang_Kemena 4437.94 4933.38 5076.94 5214.21 438.28 545.39 684.06
Batang_Kerian 3174.95 3384.30 3461.93 3624.05 495.45 639.00 776.27
Batang_Lawas 4272.18 4831.58 4963.24 5212.94 209.35 286.98 449.09
Batang_Lupar 3237.92 3395.95 3431.61 3513.95 559.40 691.06 940.75
Batang_Mukah 3096.99 3383.68 3485.12 3623.18 158.03 193.69 276.02
Batang_Oya 2846.68 3080.89 3159.08 3294.97 286.70 388.14 526.19
Batang_Rajang 4064.65 4397.63 4509.66 4629.66 234.21 312.39 448.28
Batang_Sadong 3126.25 3230.80 3292.54 3378.19 332.98 445.01 565.01
Batang_Samarahan 3269.95 3416.05 3521.33 3663.70 104.55 166.29 251.95
Batang_Saribas 3281.06 3481.31 3544.18 3654.19 146.09 251.38 393.74
Batang_Tatau 4676.66 5120.52 5273.37 5377.64 200.25 263.12 373.13
Batang_Terusan 3391.67 3813.29 3904.49 4040.92 443.86 596.71 700.98
Northern_Sarawak 2917.44 3248.07 3393.90 3585.72 421.62 512.82 649.26
Sg_Limbang 3350.27 3766.54 3898.05 4034.48 330.63 476.46 668.29
Sg_Sarawak 3551.70 3783.82 3904.26 4055.83 416.27 547.78 684.21
Southern_Sarawak 3733.71 4043.34 4224.35 4502.18 232.12 352.56 504.13
309.63 490.63 768.47

146

6.2. Air temperature
6.2.1. Peninsular Malaysia
Time series plots of annual average air temperature during the historical (1970-2000) and the
projected future (2010-2100) conditions for 13 watersheds (Batu Pahat, Johor, Muda, Kelang,
Kelantan, Linggi, Muar, Pahang, Perak, Selangor, Dungun, Kemaman, and Kuantan) and 12
coastal regions in Peninsular Malaysia are presented in Figures 6.7 and 6.8, respectively.
Future conditions are presented in terms of individual projections for five GCMs and four
emission scenarios RCP2.6, 4.5, 6.0, 8.5, and for the ensemble average of the projections. The
ensemble average of the annual average air temperature gradually increases during the 21st
century over each of the watersheds and coastal regions although the annual air temperature
in each of the 16 projections has large fluctuations.

Figure 6.9 demonstrates the long-term mean of the daily minimum, average, and maximum
air temperature (oC) during the historical period (1970-2000), the early 21st century (2011-
2040), the middle 21st century (2041-2070), and the late 21st century (2071-2100), as well as
the change in the long-term mean of the daily minimum, average, and maximum air
temperature from the historical period, to the early, middle, and late 21st century for each of
13 watersheds and 12 coastal regions in Peninsular Malaysia.

Tables 6.5-6.6 show the long-term mean of the daily average air temperature (oC) during the
historical period (1970-2000), the early 21st century (2011-2040), the middle 21st century
(2041-2070), and the late 21st century (2071-2100), as well as the change in the long-term
mean of the daily average air temperature from the historical period, to the early, middle, and
late 21st century for each of 13 watersheds and 12 coastal regions in Peninsular Malaysia.

The long-term mean of daily minimum air temperature gradually increases toward the late
21st century over each of the watersheds and coastal regions of Peninsular Malaysia. In
comparison to the historical period, the change in the long-term mean daily minimum air
temperature over the 13 watersheds in Peninsular Malaysia varies from 0.70oC in Selangor to
0.73oC in Linggi in the early 21st century, from 1.34oC in Kelang to 1.41oC in Kelantan in the
middle 21st century, and 1.92oC in Kelang to 2.00oC in Kelantan in the late 21st century. In
comparison to the historical period, the change in the long-term mean daily minimum air
temperature over the 12 coastal regions in Peninsular Malaysia varies 0.67oC in Coastal

147

Region 9 to 0.72oC in Coastal Region 2 in the early 21st century, from 1.31oC in Coastal
Region 9 to 1.38oC in Coastal Region 2 in the middle 21st century, and 1.89oC in Coastal
Region 9 to 1.96oC in Coastal Region 2 in the late 21st century.

The long-term mean of daily average air temperature gradually increases toward the late 21st
century over each of the watersheds and coastal regions of Peninsular Malaysia. In comparison
to the historical period, the change in the long-term mean annual average air temperature over
the 13 watersheds in Peninsular Malaysia varies from 0.70oC in Perak to 0.77oC in Johor in
the early 21st century, from 1.31oC in Selangor to 1.37oC in Johor in the middle 21st century,
and 1.87oC in Selangor to 1.93oC in Johor in the late 21st century. In comparison to the
historical period, the change in the long-term mean annual average air temperature over the
12 coastal regions varies from 0.69oC in Coastal Region 11 to 0.77oC in Coastal Region 6 in
the early 21st century, from 1.29oC in Coastal Region 11 to 1.37oC in Coastal Region 5 in the
middle 21st century, and 1.85oC in Coastal Region 10 to 1.92oC in Coastal Region 5 in the
late 21st century.

The long-term mean of daily maximum air temperature gradually increases toward the late
21st century over each of the watersheds and coastal regions of Peninsular Malaysia. In
comparison to the historical period, the change in the long-term mean daily maximum air
temperature over the 13 watersheds in Peninsular Malaysia varies from 0.68oC in Perak to
0.84oC in Johor in the early 21st century, from 1.23oC in Muda to 1.40oC in Johor in the middle
21st century, and 1.77oC in Muda to 1.93oC in Johor in the late 21st century. In comparison
to the historical period, the change in the long-term mean daily maximum air temperature over
the 12 coastal regions varies 0.69oC in Coastal Region 11 to 0.84oC in Coastal Region 6 in the
early 21st century, from 1.29oC in Coastal Region 11 to 1.37oC in Coastal Region 5 in the
middle 21st century, and 1.85oC in Coastal Region 10 to 1.92oC in Coastal Region 5 in the
late 21st century.

148

Batu Pahat
Johor
Muda

149

Kelang
Kelantan
Linggi

150

Muar
Pahang
Perak

151

Selangor
Dungun
Kemaman

152

Kuantan

Figure 6.7 - Time series plots of the annual average air temperature during the historical (1970-
2000) and the projected future (2010-2100) conditions for 13 watersheds in Peninsular
Malaysia. Future conditions are in terms of individual projections and the ensemble average
of the projections.
Coastal Region 1

Coastal Region 2

153

Coastal Region 3
Coastal Region 4
Coastal Region 5

154

Coastal Region 6
Coastal Region 7
Coastal Region 8

155

Coastal Region 9
Coastal Region 10
Coastal Region 11

156

Coastal Region 12

Figure 6.8 - Time series plots of annual average air temperature during the historical (1970-
2000) and the projected future (2010-2100) conditions for 12 coastal regions in Peninsular
Malaysia. Future conditions are in terms of individual projections and the ensemble average
of the projections.

157

a) Long-term mean of daily minimum
Daily average
Daily maximum

158

b) Change in the 30-year mean of daily minimum

Daily average

Daily maximum

Figure 6.9- a) Long-term mean of the daily minimum, average, and maximum air temperature
(oC) during the historical period (1970-2000), the early 21st century (2011-2040), the middle
21st century (2041-2070), and the late 21st century (2071-2100), and b) the change in the 30-
year mean of the daily minimum, average, and maximum air temperature from the historical
period, to the early, middle, and late 21st century for 13 watersheds and 12 coastal regions of
Peninsular Malaysia.

159

Table 6.5- Long-term mean of the daily average air temperature (oC) during the historical
period (1970-2000), the early 21st century (2011-2040), the middle 21st century (2041-2070),
and the late 21st century (2071-2100), and b) the change in the long-term mean of the daily
average air temperature from the historical period, to the early, middle, and late 21st century
for 13 watersheds of Peninsular Malaysia.

Long-term mean Change from Historical period
Early Mid
Watershed Hist (2011- (2041- Late Early Mid Late
(1970- 2040) 2070) (2071-
Batu Pahat 2000) 25.29 25.89 2100) (2011- (2041- (2071-
Dungun 24.52 24.11 24.72 26.43
Johor 23.37 25.10 25.70 25.28 2040) 2070) 2100)
Kelang 24.33 25.28 25.88 26.25
Kelantan 24.56 23.76 24.37 26.43 0.77 1.37 1.91
Kemaman 23.02 24.98 25.59 24.93
Kuantan 24.23 24.95 25.56 26.14 0.74 1.35 1.91
Linggi 24.20 25.42 26.02 26.11
Muar 24.67 25.16 25.74 26.58 0.77 1.37 1.93
Muda 24.41 24.77 25.38 26.29
Pahang 24.06 24.53 25.14 25.94 0.72 1.32 1.87
Perak 23.80 23.66 24.27 25.70
Selangor 22.95 24.85 25.45 24.84 0.74 1.36 1.91
24.14 26.01
0.74 1.35 1.91

0.75 1.36 1.91

0.76 1.35 1.91

0.74 1.33 1.88

0.72 1.32 1.88

0.73 1.34 1.90

0.70 1.32 1.89

0.71 1.31 1.87

160

Table 6.6- Long-term mean of the daily average air temperature (oC) during the historical
period (1970-2000), the early 21st century (2011-2040), the middle 21st century (2041-2070),
and the late 21st century (2071-2100), and b) the change in the long-term mean of the daily
average air temperature from the historical period, to the early, middle, and late 21st century
for 12 coastal regions in Peninsular Malaysia.

Coastal Hist Long-term mean Late Change from Historical period
Region (1970- (2071-
2000) Early Mid 2100) Early Mid Late
Coastal (2011- (2041- (2011- (2041- (2071-
Region 1 2040) 2070) 2040) 2070) 2100)
Coastal
Region 2 24.57 25.29 25.89 26.44 0.72 1.32 1.87
Coastal
Region 3 23.83 24.57 25.19 25.74 0.74 1.36 1.91
Coastal
Region 4 24.59 25.33 25.94 26.49 0.75 1.35 1.90
Coastal
Region 5 24.42 25.17 25.77 26.32 0.75 1.35 1.89
Coastal
Region 6 24.65 25.42 26.02 26.57 0.77 1.37 1.92
Coastal
Region 7 24.87 25.64 26.23 26.78 0.77 1.36 1.91
Coastal
Region 8 24.88 25.65 26.24 26.79 0.76 1.36 1.91
Coastal
Region 9 24.77 25.51 26.10 26.65 0.74 1.33 1.89
Coastal
Region 10 25.06 25.78 26.38 26.93 0.71 1.32 1.87
Coastal
Region 11 24.47 25.17 25.77 26.32 0.69 1.29 1.85
Coastal
Region 12 24.70 25.39 25.99 26.56 0.69 1.29 1.86

24.89 25.61 26.21 26.76 0.73 1.33 1.88

6.2.2. Sabah and Sarawak

Time series plots of annual average air temperature during the historical (1970-2000) and the
projected future (2010-2100) conditions for the subregions of Sabah (Beaufort, Beluran, Kota
Kinabalu, Kudat, Lahad Datu, Pitas, Sandakan, Sg Abai, Sg Kalabakan, Sg Kalumpang, Sg
Labuk, Sg Padas, Sg Papar, Sg Segama, Sg Sinsilog, Sg Sugut, Sg Tuaran, Sipitang, Southern
Sabah, Tawau, Trusan Kinabatangan) and Sarawak (Batang Balingian, Batang Baram, Batang
Kemena, Batang Kerian, Batang Lawas, Batang Lupar, Batang Mukah, Batang Oya, Batang
Rajang, Batang Sadong, Batang Samarahan, Batang Saribas, Batang Tatau, Batang Terusan,

161

Northern Sarawak, Sg Limbang, Sg Sarawak, Southern Sarawak) are presented in Figures
6.10 and 6.11, respectively. Future conditions are presented in terms of individual projections
(for RCP2.6, 4.5, 6.0, 8.5) and the ensemble average of the projections. The ensemble average
of the annual average air temperature gradually increases during the 21st century over each of
the 39 subregions although the annual air temperature in each of the 16 projections has large
fluctuations.

Figure 6.12 demonstrates the long-term mean of the daily minimum, average, and maximum
air temperature (oC) during the historical period (1970-2000), the early 21st century (2011-
2040), the middle 21st century (2041-2070), and the late 21st century (2071-2100), as well as
the change in the long-term mean of the daily minimum, average, and maximum air
temperature from the historical period, to the early, middle, and late 21st century for each of
the 39 subregions in Sabah and Sarawak.

Tables 6.7-6.8 show the long-term mean of the daily average air temperature (oC) during the
historical period (1970-2000), the early 21st century (2011-2040), the middle 21st century
(2041-2070), and the late 21st century (2071-2100), as well as the change in the long-term
mean of the daily average air temperature from the historical period, to the early, middle, and
late 21st century for each of the 39 subregions in Sabah and Sarawak.

The long-term mean of daily minimum air temperature gradually increases toward the late
21st century over each of the subregions. In comparison to the historical period, the change in
the long-term mean daily minimum air temperature over the subregions of Sabah varies from
0.71oC in Sandakan to 0.80oC in Kota Kinabalu in the early 21st century, from 1.36oC in
Sandakan to 1.51oC in Sg Papar in the middle 21st century, and 2.00oC in Sandakan to 2.18oC
in Sg Papar in the late 21st century. In comparison to the historical period, the change in the
long-term mean daily minimum air temperature over the subregions of Sarawak varies from
0.72oC in Batang Samarahan to 0.76oC in Batang Lawas in the early 21st century, from
1.36oC in Batang Samarahan to 1.45oC in Batang Lawas in the middle 21st century, and
1.98oC in Batang Samarahan to 2.11oC in Batang Terusan in the late 21st century.

The long-term mean of daily average air temperature gradually increases toward the late 21st
century over each of the subregions. In comparison to the historical period, the change in the

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long-term mean annual average air temperature over the subregions of Sabah varies from
0.70oC in Sg Padas to 0.76oC in Sg Segama in the early 21st century, from 1.33oC in Tawau
to 1.43oC in Sg Abai in the middle 21st century, and 1.95oC in Tawau to 2.08oC in Sg Abai
in the late 21st century. In comparison to the historical period, the change in the long-term
mean annual average air temperature over the subregions of Sarawak varies from 0.72oC in
Sg Limbang to 0.76oC in Batang Balingian in the early 21st century, from 1.35oC in Batang
Samarahan to 1.43oC in Batang Terusan in the middle 21st century, and 1.94oC in Batang
Samarahan to 2.05oC in Batang Terusan in the late 21st century.
The long-term mean of daily maximum air temperature gradually increases toward the late
21st century over each of the subregions. In comparison to the historical period, the change in
the long-term mean daily maximum air temperature over the subregions of Sabah varies from
0.60oC in Sg Padas to 0.80oC in Sg Segama in the early 21st century, from 1.21oC in Southern
Sabah to 1.41oC in Sg Segama in the middle 21st century, and 1.82oC in Southern Sabah to
1.98oC in Sg Segama in the late 21st century. In comparison to the historical period, the
change in the long-term mean daily maximum air temperature over the subregions of Sarawak
varies from 0.66oC in Sg Limbang to 0.78oC in Batang Balingian in the early 21st century,
from 1.30oC in Sg Limbang to 1.41oC in Batang Balingian in the middle 21st century, and
1.86oC in Sg Limbang to 1.97oC in Batang Terusan in the late 21st century.

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Beaufort
Beluran
Kota Kinabalu
Kudat

164

Lahad Datu
Pitas
Sandakan
Sg Abai

165

Sg Kalabakan
Sg Kalumpang
Sg Labuk
Sg Padas

166

Sg Papar
Sg Segama
Sg Sinsilog
Sg Sugut

167

Sg Tuaran
Sipitang
Southern Sabah
Tawau

168

Trusan Kinabatangan

Figure 6.10 - Time series plots of the annual average air temperature during the historical
(1970-2000) and the projected future (2010-2100) conditions for subregions in Sabah. Future
conditions are in terms of individual projections and the ensemble average of the projections.
Batang Balingian

Batang Baram

Batang Kemena

169

Batang Kerian
Batang Lawas
Batang Lupar
Batang Mukah

170

Batang Oya
Batang Rajang
Batang Sadong
Batang Samarahan

171

Batang Saribas
Batang Tatau
Batang Terusan
Northern Sarawak

172

Sg Limbang

Sg Sarawak

Southern Sarawak

Figure 6.11- Time series plots of annual average air temperature during the historical (1970-
2000) and the projected future (2010-2100) conditions for subregions in Sarawak . Future
conditions are in terms of individual projections and the ensemble average of the projections.

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a) Long-term mean of daily minimum
Daily average
Daily maximum

174

b) Change in the 30-year mean of daily minimum

Daily average

Daily maximum

Figure 6.12 - a) Long-term mean of the daily minimum, average, and maximum air
temperature (oC) during the historical period (1970-2000), the early 21st century (2011-2040),
the middle 21st century (2041-2070), and the late 21st century (2071-2100), and b) the change
in the 30-year mean of the daily minimum, average, and maximum air temperature from the
historical period, to the early, middle, and late 21st century for each of the 39 subregions in
Sabah and Sarawak.

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Table 6.7- Long-term mean of the daily average air temperature (oC) during the historical
period (1970-2000), the early 21st century (2011-2040), the middle 21st century (2041-2070),
and the late 21st century (2071-2100), and b) the change in the long-term mean of the daily
average air temperature from the historical period, to the early, middle, and late 21st century
for subregions in Sabah.

Long-term mean Change from Historical
period

Subregions in Sabah Hist Early Mid Late Early Mid Late
(1970- (2011- (2041- (2071- (2011- (2041- (2071-
Beaufort 2000) 2040) 2070) 2100) 2040) 2070) 2100)
Beluran 23.70 25.72
Kota_Kinabalu 24.66 24.45 25.12 26.64 0.75 1.41 2.02
Kudat 24.05 26.07
Lahad_Datu 24.05 25.40 26.04 26.04 0.74 1.38 1.98
Pitas 23.93 25.93
Sandakan 24.32 24.79 25.46 26.30 0.74 1.41 2.02
Sg_Abai 24.72 26.70
Sg_Kalabakan 19.81 24.77 25.43 21.89 0.72 1.38 1.99
Sg_Kalumpang 22.76 24.73
Sg_Labuk 23.39 24.68 25.31 25.35 0.74 1.38 1.99
Sg_Padas 22.19 24.22
Sg_Papar 21.08 25.05 25.70 23.08 0.74 1.38 1.99
Sg_Segama 21.42 23.48
Sg_Sinsilog 23.55 25.47 26.10 25.55 0.74 1.37 1.98
Sg_Sugut 23.28 25.28
Sg_Tuaran 22.35 20.54 21.24 24.36 0.73 1.43 2.08
Sipitang 22.24 24.27
Southern_Sabah 23.20 23.48 24.11 25.17 0.72 1.35 1.97
Tawau 22.59 24.56
Trusan_Kinabatangan 23.26 24.10 24.73 25.21 0.71 1.34 1.96
22.97 24.96
22.95 23.60 0.75 1.41 2.02

21.78 22.45 0.70 1.37 2.00

22.16 22.85 0.74 1.43 2.06

24.30 24.94 0.76 1.40 2.01

24.01 24.67 0.74 1.39 2.00

23.09 23.75 0.74 1.40 2.01

22.96 23.65 0.72 1.41 2.04

23.91 24.57 0.71 1.37 1.98

23.30 23.93 0.70 1.34 1.96

23.96 24.59 0.70 1.33 1.95

23.71 24.35 0.74 1.38 1.99

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Table 6.8- Long-term mean of the daily average air temperature (oC) during the historical
period (1970-2000), the early 21st century (2011-2040), the middle 21st century (2041-2070),
and the late 21st century (2071-2100), and b) the change in the long-term mean of the daily
average air temperature from the historical period, to the early, middle, and late 21st century
for subregions in Sarawak.

Long-term mean Change from Historical
period
Subregions in Hist Early Mid Late
Sarawak (1970- (2011- (2041- (2071- Early Mid Late
2000) 2040) 2070) 2100) (2011- (2041- (2071-
Batang_Balingian 24.70 25.46 26.10 26.69 2040) 2070) 2100)
Batang_Baram 22.31 23.05 23.71 24.33 0.76 1.40 1.99
Batang_Kemena 23.80 24.54 25.19 25.79 0.74 1.40 2.02
Batang_Kerian 24.53 25.26 25.89 26.47 0.74 1.39 1.99
Batang_Lawas 22.60 23.35 24.01 24.63 0.73 1.36 1.94
Batang_Lupar 24.04 24.79 25.41 25.99 0.74 1.41 2.02
Batang_Mukah 24.30 25.06 25.70 26.29 0.75 1.37 1.95
Batang_Oya 24.46 25.21 25.85 26.44 0.76 1.40 1.99
Batang_Rajang 23.58 24.31 24.96 25.56 0.76 1.40 1.98
Batang_Sadong 24.16 24.89 25.52 26.10 0.73 1.38 1.98
Batang_Samarahan 24.63 25.35 25.98 26.57 0.73 1.36 1.94
Batang_Saribas 24.30 25.05 25.68 26.26 0.72 1.35 1.94
Batang_Tatau 23.73 24.47 25.12 25.71 0.75 1.37 1.96
Batang_Terusan 21.15 21.90 22.58 23.20 0.74 1.39 1.99
Northern_Sarawak 24.60 25.35 25.99 26.58 0.75 1.43 2.05
Sg_Limbang 23.72 24.44 25.10 25.70 0.74 1.39 1.98
Sg_Sarawak 24.27 24.99 25.63 26.22 0.72 1.38 1.98
Southern_Sarawak 24.65 25.39 26.02 26.60 0.72 1.36 1.95
0.73 1.37 1.95

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6.3. Evapotranspiration

6.1.3. Peninsular Malaysia
Time series plots of annual evapotranspiration during the historical (1970-2000) and the
projected future (2010-2100) conditions for 13 watersheds (Batu Pahat, Johor, Muda, Kelang,
Kelantan, Linggi, Muar, Pahang, Perak, Selangor, Dungun, Kemaman, and Kuantan) and 12
coastal regions in Peninsular Malaysia are presented in Figures 6.13 and 6.14, respectively.
Future conditions are presented in terms of individual projections for five GCMs and four
emission scenarios RCP2.6, 4.5, 6.0, 8.5, and for the ensemble average of the projections.

Figure 6.15 and Tables 6.9-6.10 show the long-term mean of the annual evapotranspiration
(mm) during the historical period (1970-2000), the early 21st century (2011-2040), the middle
21st century (2041-2070), and the late 21st century (2071-2100), as well as the change in the
long-term mean of the annual evapotranspiration from the historical period, to the early,
middle, and late 21st century for each of the 13 watersheds and 12 coastal regions in Peninsular
Malaysia.

In comparison to the historical period, the change in the long-term mean annual
evapotranspiration over the 13 watersheds in Peninsular Malaysia varies from 0.7 percent in
Dungun to 2.6 percent in Perak in the early 21st century, from 0.7 percent in Dungun to 3.4
percent in Perak in the middle 21st century, and 0.8 percent in Dungun to 3.8 percent Perak in
the late 21st century.

In comparison to the historical period, the change in the long-term mean annual
evapotranspiration over the 12 coastal regions in Peninsular Malaysia varies from 0.6 percent
in Coastal Region 8 to 2.7 percent in Coastal Region 12 in the early 21st century, from 1.5
percent in Coastal Region 3 to 4.0 percent in Coastal Region 12 in the middle 21st century,
and 1.9 percent in Coastal Region 3 to 5.2 percent in Coastal Region 12 in the late 21st century.

178