Regional overview of climate change impacts

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Regional overview of climate change impacts
Summary
Based on the latest scenarios of the IPCC, the representative concentration pathways, the
data from the AR 4 in 2007 underestimated the expected changes. Provided that the RCP 8.5
seems at present to be the more likely scenario, changes of 2.7 to 3.0 deg C have to be
expected in Nepal and Pakistan by 2050, representatively. Precipitation is expected to
increase to a larger extent than expected in Nepal with about 120 mm increased precipitation
by 2050. In Pakistan the increase is marginal and less than was expected in 2007.
The working districts expect similar rates of change in the case of Pakistan, while in Nepal
higher temperature increases are expected for high altitude districts and precipitation is
expected to increase more in the working districts, especially at lower altitude.
Acknowledgement: The statistics of the downscaled data for the RCPs was received from Dr.
Robert Zomer, Kunming Institute of Botany, who processed the data as part of an International
Research Development Center funded and Kunming Institute of Botany-HELVETAS Swiss
Intercooperation implemented project on the Asian Highlands (www.asianhighlands.org)
Overview
On the basis of the IPCC scenarios in 2007 Karmacharya (2007) identified a change in
temperature of 1.7 to 2.4 deg C for South Asia and 1.9 to 2.6 deg C by 2050 in the Central
Himalaya, respectively (Table 1).
Table 1: Changes of temperature and precipitation based on IPCC AR 4 scenarios (Karmacharya et al., 2007)
Temperature Change [deg C]
2050s
Precipitation Change [mm]
2050s
Scenario
South Asia
B1
1.7
A1B
2.4
A2
2.2
45.8
73.0
53.0
Central Himalaya
B1
1.9
A1B
2.6
A2
2.4
49.3
84.9
58.4
These assessments showed a general increase in temperature of about 1.5 to 2.5 deg C and a
precipitation increase of between 50 and 75 mm in South Asia depending on the different
scenarios. The Central Himalaya is expected to experience a slightly higher increase in
temperature as well as a higher increase in precipitation.
Based on the latest scenarios of the IPCC, the representative concentration pathways, the data
from the AR 4 in 2007 underestimated the changes (Table 2). Provided that the RCP 8.5 seems
at present to be the more likely scenario, changes of 2.7 to 3.0 deg C have to be expected in
Nepal and Pakistan, representatively. Precipitation is expected to increase to a larger extent
than expected in Nepal with about 120 mm increased precipitation by 2050. In Pakistan the
increase is marginal and less than was expected in 2007.
Table 2: Changes of temperature and precipitation based on IPCC AR 5 scenarios (Robert Zomer, personal
communication)
Area
Nepal
Pakistan
Temperature [deg C]
Year 2050: Year 2050:
RCP 4.5
RCP 8.5
2.2
2.7
2.5
3.0
Precipitation [mm]
Year 2050: Year 2050:
RCP 4.5
RCP 8.5
116
121
9
26
Nepal
Overall temperatures and precipitation in Nepal are expected to increase overall throughout the
country, however the rates of change differ even within the proposed working districts. The
highest temperature increase is expected for high altitude districts where up to 3 deg C change
are expected depending on the scenario. Precipitation changes on the other hand are expected
to be higher in the lower situated districts, e.g. Surkhet and Achham. In these districts up to 170
to 220 mm are predicted.
Table 3: Precipitation and temperature Nepal (data: Zomer, personal communication)
Area
Achham
Dailek
Jajarkot
Jumla
Kalikot
Surkhet
Nepal
Precipitation [mm]
Year 2000 Year 2050: Year 2050:
RCP 4.5
RCP 8.5
1381
1512
1540
1322
1451
1474
1157
1253
1266
828
883
889
933
1003
1014
1643
1839
1873
1373
1489
1494
Temperature [deg C]
Year 2000 Year 2050: Year 2050:
RCP 4.5
RCP 8.5
18.5
20.7
21.3
17.3
19.5
20.1
13.6
15.9
16.4
6.8
9.3
9.9
11.6
13.9
14.5
20.7
22.8
23.3
14.1
16.3
16.8
Figure 1: Mean temperature (data: Zomer, personal communication)
Figure 2: Precipitation Nepal (data: Zomer, personal communication)
Pakistan
Precipitation throughout Pakistan is not expected to change significantly, however a slight
increase of 20 mm can be expected. However, in the working districts slightly higher
precipitation is expected at the rate of about 60 to 80 mm. Temperatures are expected to
increase by about 3 deg C depending on the scenario. In the working districts temperature
increases are expected at the same rate.
Table 4: Pakistan (data: Zomer, personal communication)
Area
Attock
Chakwal
Haripur
Swabi
Pakistan
Precipitation [mm]
Year 2000 Year 2050: Year 2050:
RCP 4.5
RCP 8.5
540
566
600
493
523
564
917
943
990
697
720
750
313
322
339
Temperature [deg C]
Year 2000 Year 2050: Year 2050:
RCP 4.5
RCP 8.5
22.4
24.9
25.4
22.4
24.9
25.5
20.6
23.2
23.7
21.6
24.2
24.8
19.1
21.6
22.1
Figure 3: Pakistan temperature (data: Zomer, personal communication)
Figure 4: Pakistan precipitation (data: Zomer, personal communication)
Outlook
At present the analyses of the data is only based on annual statistics as only statistics have
become available at this time. As soon as the raw data becomes available, more detailed
analyses on the basis of seasonal and monthly temporal disaggregation can be conducted.
These analyses are expected to present more distinct pictures of the expected changes.
Annex 1: Nepal
Achham
Annex 2: Pakistan
Attock
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