Climate change impacts on water resources in the southeastern U.S. – Can we adapt?
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Climate change impacts on water resources in the southeastern U.S. – Can we adapt? Peter Caldwell USDA Forest Service, Eastern Forest Environmental Threat Assessment Center Raleigh, NC SWPBA Annual Meeting, November 2011
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Climate change impacts on water resources in the southeastern U.S. – Can we adapt?. Peter Caldwell USDA Forest Service, Eastern Forest Environmental Threat Assessment Center Raleigh, NC SWPBA Annual Meeting, November 2011. Climate change- The scientific basis. IPCC AR4, 2007. - PowerPoint PPT Presentation
Transcript of Climate change impacts on water resources in the southeastern U.S. – Can we adapt?
Climate change impacts on water resources in the southeastern
U.S. – Can we adapt?
Peter CaldwellUSDA Forest Service, Eastern Forest Environmental Threat
Assessment Center
Raleigh, NC
SWPBA Annual Meeting, November 2011
Climate change- The scientific basis
IPCC AR4, 2007
Unprecedented rate of change
IPCC AR4, 2007
The evidence of change
IPCC AR4, 2007
Temperature
Sea level
Snow cover
IPCC AR4, 2007
“Global warming is unequivocal and primarily human-induced” USGCRP, 2009
Change
Variability
Variability v. Change
Bottom of Hill (current climate)
USGCRP Global Climate Change Impacts in the United States, 2009
Precipitation
USGCRP Global Climate Change Impacts in the United States, 2009
Temperature
Extremes: Drought
USGCRP, 2009
Extremes: Heavy precipitation
USGCRP, 2009
Global Circulation ModelsCoupled land &
atmosphere modelsGlobal coverageCoarse resolution
(e.g. 2° - ~100x100 km)
Have BiasesSpatial resolutionModel
parameterizationScale not appropriate
for impact studies
Bias correction and downscaling
Maurer, 2009
2° resolution(100x100 km)
1/8° resolution(12x12 km)
Dynamic or
statistical downscalin
g
Emission scenarios
IPCC AR4, 2007
Predicted global temperature
IPCC AR4, 2007
Temperature changes
IPCC AR4, 2007
A1B Scenario, change in temp from 1900-1950 mean, multi-model mean and range
A1B Scenario, change in temperature from 1980-1999 by 2080-2099, multi-model mean
Precipitation changes
Annual precipitation changeNumber of models
predicting increased precipitation
IPCC AR4, 2007
A1B Scenario, change in precipitation from 1980-1999 by 2090-2099, multi-model mean
Key Issues for the SoutheastHeat-related stresses for people, plants,
and animalsDecreased water availabilitySea-level rise, likely increase in hurricane
intensity and storm surgeEcological thresholds likely to be crossed
throughout the region
USGCRP, 2009
US Forest Service: A Legacy Water Resources ManagementOrganic Act of 1897
“…securing favorable conditions of water flows…”Weeks Law of 1911
“…..regulation of the flow of navigable streams or for the production of timber.”
Sustained Yield Forest Management Act of 1944“….. maintenance of water supply, regulation of stream
flow, prevention of soil erosion, amelioration of climate, and preservation of wildlife.”
National Forest Management Act of 1976“…multiple use and sustained yield of the products and
services obtained…the coordination of outdoor recreation, range, timber, watershed, wildlife and fish, and wilderness.”
The future of USFS water resources management
Supply Demand
Climate Landuse change Population
ReservoirGW Infrastructure
Economics
J. Am. Water Resour. Assoc. 44:1441 – 1457, 2008
Water Supply Stress Index (WaSSI) Model
Water BalanceET = f(PET, LAI, PPT, SM)Q = PPT – ET +/- DS
Carbon BalanceGEP = f(ET)Re = f(GEP)NEE = Re - GEP
BiodiversityBIO = f(ET)-Birds -Amphibians-Reptiles -Trees-Mammals -Vertebrates
PPT
ET
Q
GEP
Re
Watershed and Land Cover Based
Climate and Population Scenarios
Baseline (2001-2010) vs. Future (2051-2060)
Climate Scenario
Precipitation
PET
CSIROMK2-B2 14%CSIROMK3.5-
A1B5% 11%
HADCM3-B2 7% 15%MIROC32-A1B 8% 19%
Simulated 2001-2010 water yield
Predicted trend in water yield
100
150
200
250
300
350
400
450
2010 2020 2030 2040 2050 2060
Wat
er Y
ield
(mm
)
(b)
Predicted trend in water yield2011-2060
Simulated 2001-2010 streamflow
Predicted change in flow by 2051-2060
Change in water demand by 2051-2060
Water Supply Stress Index (WaSSI)
Water Stress: Average annual WaSSI ≥ 0.4
• United Nations (Raskin et al., 1997)• World Water Council (Alcamo, 2000; Cosgrove &
Rijsberman, 2000)• Vörösmarty et al., 2000
WaSSI =Demand
Surface + Groundwater Supply
Mean WaSSI in 2051-2060
Predicted trend in mean annual stream temperature 2010-2060, mean among four scenarios
Stream temperature changes
Sediment delivery changes
Predicted change in rainfall erosivity (R) by 2050
What can we do? Mitigate
Reduce carbon emissionsEnhance carbon sequestration
AdaptEnhance ecosystem resilienceEnhance infrastructure resilienceEmbrace uncertainty
“If mitigation is about carbon, then adaptation will be about water”
