Uncertainty in Climate Change Projections: Results from Different GCMs/RCMs in the Context of Nepal

894 views

Published on

Nepal does not have own climate projection model. Therefore, climate change studies in Nepal completely depend on the results of available model throughout the world. Many field based studies have proven that Nepal is the most vulnerable country in the context of climate change due to limited capacity to adapt to it. On the other hand, it is a big challenge to natural scientists to demonstrate climate change physically because of limited resources. Due to the complex geography of Nepal, most of the global climate projections are not able to capture the temporal and spatial climatic variability. In consideration to this problem, the Department of Hydrology and Meteorology (DHM) of Nepal has initiated a project to downscale climatic parameters regionally with technical support from the Asian Disaster Preparedness Centre (ADPC) under the financial support of Asian Development Bank (ADB). They used three different Regional Climate Models (RCM); PRECIS, RegCM4, and WRF under AR4 scenarios. However, there is still a lot of discrepancy among these projections which have created confusion among the stakeholders. Therefore, the objective of my presentation will be to focus on the discussion over these issues among the climate experts at UNBC.

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
894
On SlideShare
0
From Embeds
0
Number of Embeds
6
Actions
Shares
0
Downloads
12
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • Major problem for the spatial distribution of the precipitation is orographic effect in this region. Slope and aspect of the lands is a vital factor that affects distribution of the climatic variables. Therefore, more rainfall occurs in the windward face of the mountains and less rain in the leeward face of the mountains.
  • Uncertainty in Climate Change Projections: Results from Different GCMs/RCMs in the Context of Nepal

    1. 1. Pabitra Gurung PhD Student Natural Resources and Environmental Studies (NRES) University of Northern British Columbia
    2. 2. Curious to Know?  What are the potential sources of uncertainty?  Is it due to Model resolution?  Is physics missing for such discrepancies?  Is it a problem to capture monsoon well?  Is this a common problem of the world? What is a scenario in Canada?  What can be done to improve the climate model to fit into the Himalayan regions?  Is there any improvement in IPCC AR5 that can address the orographic effects of the mountain?
    3. 3. Hindu-Kush Himalayan Region “Slope and Aspect” Source: Google Earth
    4. 4. How can we say climate is changing in the region?  Snow and Glacier Retreat  Shifting of Agro-ecological Zones  Drying up Spring Water Sources and Migration Source: From my own experiences and various studies
    5. 5. Climate Data Portal: http://dhm.gov.np/dpc Department of Hydrology and Meteorology (DHM)
    6. 6. Projected Climate Data of Nepal RCM Climate Variable Data Period GCM SRES Family Resolution Source PRECIS Rainfall (mm), Temperature (⁰C) (Min and Max), Relative Humidity, Wind Speed, Solar Radiation, & Other 1970-2000 (Baseline), 2030-2060 (Projected) HadCM3Q0, ECHAM5 A1B 20 km DHM RegCM4 1960-1990 (Baseline), 2030-2060 (Projected) ECHAM4 A2 20 km ECHAM5 A1B WRF 1970-2000 (Baseline) 2030-2060 (Projected) Era40, CCSM3, ECHAM5, GFDL-V2, HadCM3 A1B 12 km Source: ADB/DHM/ADPC
    7. 7. Projected Mean Annual Climatic Variables  3 RCMs (WRF, RegCM4 and PRECIS) for all scenarios from A1B….  grey lines: HadCM3Q0, ECHAM05, CCSM3, GFDL-V2, and HadCM3…  mean as black line representing scenario A1B … ... red line represents scenario A2: ECHAM04….. Precipitation Maximum Temperature Minimum Temperature Source: ADB/DHM/ADPC
    8. 8. Change of Annual Mean Precipitation (mm) (2030-2060) Source: ADB/DHM/ADPC
    9. 9. Change of Annual Mean Maximum Daily Temperature ( C) (2030-2060) Source: ADB/DHM/ADPC
    10. 10. Change of Annual Mean Minimum Daily Temperature ( C) (2030-2060) Source: ADB/DHM/ADPC
    11. 11. Change in Monsoon (JJAS) Rainfall WRF-ECHAM5 WRF-GFDL-V2 WRF-HADCM3 PRECIS-HadCM3Q0 RegCM4-ECHAM5 WRF-CCSM3 SRES Family – A1B Source: IWMI
    12. 12. Change in Monsoon (JJAS) Max. Temperature WRF-ECHAM5 WRF-GFDL-V2 WRF-HADCM3 PRECIS-HadCM3Q0 RegCM4-ECHAM5 WRF-CCSM3 SRES Family – A1B Source: IWMI
    13. 13. Example of Hydrological Modeling: West Seti River Sub- basin of Nepal - Located at Far Western Region of Nepal - Catchment Area: 7,438 km2 - Elevation : 314 m to 7043 m (2505 m) - Annual Rainfall: 1921 mm - > 75 % Rainfall occurs only in monsoon Source: IWMI
    14. 14. Agro-Hydrological Model: Soil Water Assessment Tool (SWAT) Source: SWAT Document
    15. 15. Precipitation (2031-2060) Percentage Change in Water Balance (-13% to +40%) (+6% to +45%) (-36% to 0%) (-19% to +25%) Actual ET (2031-2060) (-39% to +122%) (-29% to +108%) (-30% to +75%) (-42% to +50%) Source:IWMI
    16. 16. Percentage Change in Water Balance Total Flow Volume (2031-2060) (-74% to +736%) (-94% to +714%) (-96% to +475%) (-67% to +939%) Net Water Yield (2031-2060) (-68% to +64%) (-68% to +66%) (-80% to +15%) (-76% to +22%) Source:IWMI
    17. 17. Thank you !!! Acknowledgement Dr. Luna Bharati Senior Researcher International Water Management Institute (IMWI) Dr. Stephen Dery Associate Professor University of Northern British Columbia (UNBC) Climate Science Informal Seminar (CSIS) University of Northern British Columbia (UNBC)
    18. 18. Potential Issues to Discuss?  What are the potential sources of uncertainty?  Is it due to Model resolution?  Is physics missing for such discrepancies?  Is it a problem to capture monsoon well?  Is this a common problem of the world? What is a scenario in Canada?  What can be done to improve the climate model to fit into the Himalayan regions?  Is there any improvement in IPCC AR5 that can address the orographic effects of the mountain?

    ×