17.1.4.3. Climate Change Projections for Small Island States
17.1.4.3.1. Surface air temperature
Tables 17-1, 17-2, and 17-3
provide an ensemble of climate change scenario results inferred from the five
AOGCMs referred to above for four regions. These tables summarize projected
seasonal mean changes in surface air temperature and precipitation during the
2050s and 2080s. The projected area-averaged annual mean warming as a consequence
of increases in atmospheric concentrations of GHGs over the Atlantic Ocean and
Caribbean Sea, the Pacific Ocean , the Indian Ocean, and the Mediterranean Sea
is approximately 2.0, 2.0, 2.1, and 2.8°C, respectively, for the 2050s,
and approximately 3.1, 3.0, 3.2, and 4.3°C, respectively, for the 2080s
(see Table 17-1). Projected warming over the Mediterranean
Sea area is marginally higher during Northern Hemisphere (NH) summer than during
NH winter for both time periods. The increase in surface air temperature is
more or less uniform in both seasons in the other three regions (Tables
17-2 and 17-3). The scatter of projected annual mean
surface temperature increase over each of the regions, as simulated by each
of the five GCMs, is depicted in Figures 17-4 to
17-7. The area-averaged annual increase in mean surface temperature resulting
from increases in GHGs is projected to be smallest over the Pacific Ocean region
and highest over the Mediterranean Sea. It is evident that even though aerosol
forcing marginally reduces surface warming, the magnitude of projected warming
is still considerable and could substantially impact the small island states.
With respect to diurnal changes, GCM simulations with increasing concentrations
of GHGs in the atmosphere suggest relatively more pronounced increases in minimum
temperature than in maximum temperature over the regions where the small island
states are located, on an annual mean basis as well as during winter, for both
the 2050s and the 2080s. Hence, a marginal decrease in diurnal temperature range
(between 0.3 and 0.7°C) is projected.
| Table 17-1: Ensemble of annual mean
climate change scenarios for small islands for the 2050s and 2080s as
inferred from AOGCMs (numbers in brackets show standard deviation between
model projections). |
 |
| |
Annual Mean Temperature Change (°C)
|
|
Annual Mean Precipitation Change (%)
|
|
|
2050s
|
2080s
|
|
2050s
|
2080s
|
| Regions |
GHG
|
GHG+A
|
GHG
|
GHG+A
|
|
GHG
|
GHG+A
|
GHG
|
GHG+A
|
|
Atlantic Ocean and Caribbean
|
2.03
(±0.43)
|
1.71
(±0.25)
|
3.06
(±0.84)
|
2.64
(±0.61)
|
|
-5.2
(±11.9)
|
-1.3
(±7.8)
|
-6.8
(±15.8)
|
-0.7
(±12.3)
|
| Pacific Ocean |
1.98
(±0.41)
|
1.63
(±0.23)
|
2.99
(±0.87)
|
2.54
(±0.63)
|
|
5.5
(±2.5)
|
4.9
(±0.8)
|
7.6
(±3.3)
|
7.0
(±1.9)
|
| Indian Ocean
|
2.10
(±0.43)
|
1.64
(±0.23)
|
3.16
(±0.89)
|
2.61
(±0.65)
|
|
3.1
(±4.5)
|
1.6
(±3.9)
|
5.1
(±4.3)
|
4.3
(±4.9)
|
| Mediterranean |
2.83
(±0.62)
|
2.31
(±0.29)
|
4.27
(±1.26)
|
3.57
(±0.83)
|
|
1.0
(±11.0)
|
-2.4
(±8.6)
|
4.3
(±14.9)
|
-0.1
(±12.9)
|
|
| Table 17-2: Ensemble of annual mean
climate change scenarios for small islands for the 2050s as inferred from
AOGCMs (numbers in brackets show standard deviation between model projections). |
|
| |
TemperatureChange(°C)
|
|
Precipitation Change (%)
|
|
December-February
|
June-August
|
|
December-February
|
June-August
|
| Regions |
GHG
|
GHG+A
|
GHG
|
GHG+A
|
|
GHG
|
GHG+A
|
GHG
|
GHG+A
|
|
Atlantic Ocean and Caribbean
|
2.00
(±0.46)
|
1.68
(±0.32)
|
2.01
(±0.44)
|
1.71
(±0.21)
|
|
3.4
(±14.3)
|
5.9
(±7.4)
|
-14.4
(±12.2)
|
-6.9
(±11.5)
|
| Pacific Ocean |
1.98
(±0.39)
|
1.65
(±0.20)
|
1.98
(±0.43)
|
1.61
(±0.27)
|
|
4.3
(±1.9)
|
3.7
(±1.2)
|
7.2
(±4.8)
|
6.8
(±3.3)
|
| Indian Ocean
|
2.11
(±0.43)
|
1.67
(±0.15)
|
2.09
(±0.44)
|
1.63
(±0.30)
|
|
3.5
(±6.0)
|
2.0
(±7.5)
|
-1.8
(±10.0)
|
4.7
(±4.5)
|
| Mediterranean |
2.64
(±0.72)
|
2.27
(±0.44)
|
2.93
(±0.53)
|
2.27
(±0.17)
|
|
8.1
(±14.7)
|
2.6
(±15.7)
|
-4.8
(±10.3)
|
-8.9
(±6.0)
|
|
| Table 17-3: Ensemble of annual mean
climate change scenarios for small islands for the 2080s as inferred from
AOGCMs (numbers in brackets show standard deviation between model projections). |
|
| |
Annual Mean Temperature Change (°C)
|
|
Annual Mean Precipitation Change (%)
|
|
December-February
|
June-Augus
|
|
December-February
|
June-Augus
|
| Regions |
GHG
|
GHG+A
|
GHG
|
GHG+A
|
|
GHG
|
GHG+A
|
GHG
|
GHG+A
|
|
Atlantic Ocean and Caribbean
|
3.01
(±0.87)
|
2.61
(±0.66)
|
3.07
(±0.86)
|
2.64
(±0.61)
|
|
4.8
(±14.6)
|
8.5
(±12.9)
|
-19.2
(±18.8)
|
-8.2
(±17.1)
|
| Pacific Ocean |
2.97
(±0.82)
|
2.56
(±0.57)
|
2.98
(±0.91)
|
2.52
(±0.67)
|
|
6.0
(±1.5)
|
5.6
(±1.6)
|
10.2
(±5.9)
|
8.9
(±4.9)
|
| Indian Ocean
|
3.18
(±0.88)
|
2.61
(±0.60)
|
3.16
(±0.91)
|
2.62
(±0.69)
|
|
5.9
(±10.3)
|
6.2
(±10.5)
|
-2.6
(±12.6)
|
-5.9
(±7.4)
|
| Mediterranean |
3.94
(±1.34)
|
3.31
(±1.01)
|
4.52
(±1.16)
|
3.70
(±0.72)
|
|
1.61
(±21.1)
|
9.9
(±21.6)
|
-7.4
(±16.2)
|
-11.6
(±10.7)
|
|
