Overview of Methodology for Overview of Methodology for Incorporating Climate Change Incorporating Climate Change in BDCP Impact Assessmentsin BDCP Impact Assessments

BDCP Steering Committee

October 22, 2009

NOT FOR DISTRIBUTION

BDCP Impacts and Effects AnalysesBDCP Impacts and Effects Analyses

Coordinated effort between state (DWR, DFG) Coordinated effort between state (DWR, DFG) and federal (Reclamation, FWS, and NMFS) and federal (Reclamation, FWS, and NMFS) agenciesagenciesAnalytical processes and tools to support 4 Analytical processes and tools to support 4 environmental documents:environmental documents:

HCP/NCCPHCP/NCCPEIR/SEIR/SBiological AssessmentBiological AssessmentBiological OpinionsBiological Opinions

BDCP Assessment Points in TimeBDCP Assessment Points in TimeProcess seeks Process seeks permit for a 50permit for a 50--yr periodyr periodQuantitative Quantitative analysis to be analysis to be prepared for prepared for disclosure of disclosure of impacts/ impacts/ effects at three effects at three points in timepoints in timeApproximately Approximately 2015, 2025, and 2015, 2025, and 20602060

Key Projected Climate ChangesKey Projected Climate Changes

Global and regional warmingGlobal and regional warmingChanges in precipitation: form, timing, and Changes in precipitation: form, timing, and quantity quantity Changes in runoff quantity and timingChanges in runoff quantity and timingSea level riseSea level rise

Potential Climate Change Impacts to BDCP ElementsPotential Climate Change Impacts to BDCP Elements

Delta Marsh Habitat • Broader area of inundation, upland migration

• Deeper water with increased predation pressures

• Salinity changes effects on vegetation and macro-invertebrate communities

• Changes to thermal refugia

• Changes to invasive species dynamics

Reservoir and Conveyance Facility Management

• Coldwater pool management

• Challenges to flood control operations

• Salinity changes and management

• Timing of water availability for export

• Changes to water supply reliability

Water Quality • Increased Delta salinity intrusion due to sea level rise, levee system failure/island flooding

• Changes to hydrodynamics and mixing

• Increased water temperatures

• Changes to dissolved oxygen

• Effects on water treatment and human health

Anadromous Fish Habitat (upstream)

• Changes to hydrograph and temperature

• Changes to spawning habitat/holding pools

• Timing of spawning and outmigration (life cycle impacts)

• Increased floodplain inundation

Previous State and Federal Efforts to Previous State and Federal Efforts to Incorporate Climate Change in CaliforniaIncorporate Climate Change in California

California Climate Action Team Reports, 2006California Climate Action Team Reports, 2006DWR Progress on Incorporating Climate ChangeDWR Progress on Incorporating Climate Change

Salton Sea Ecosystem Restoration Program, PEIR, 2007Salton Sea Ecosystem Restoration Program, PEIR, 2007State Water Project Reliability Report, 2007State Water Project Reliability Report, 2007Monterey Plus Amendment, EIR, 2007Monterey Plus Amendment, EIR, 2007Operations Criteria and Plan, 2008Operations Criteria and Plan, 2008

USFWS Delta Smelt Biological Opinion, 2008USFWS Delta Smelt Biological Opinion, 2008NMFS Salmon Biological Opinion, 2009NMFS Salmon Biological Opinion, 2009

California Climate Action Team Reports, 2009California Climate Action Team Reports, 2009Delta Risk Management Strategy, 2009Delta Risk Management Strategy, 2009Delta Vision, 2009Delta Vision, 2009BCDC Living with a Rising Bay: Vulnerability and Adaptation RepoBCDC Living with a Rising Bay: Vulnerability and Adaptation Report, 2009 rt, 2009 California Water Plan, OnCalifornia Water Plan, On--goinggoingSan Joaquin River Restoration Program, EIS, OnSan Joaquin River Restoration Program, EIS, On--goinggoingUSACE SF Bay to Stockton NIP, EIS, OnUSACE SF Bay to Stockton NIP, EIS, On--goinggoing

What do the Climate Models Show?What do the Climate Models Show?

Precipitation projections are Precipitation projections are not directionally consistentnot directionally consistentMultiMulti--decadal variability decadal variability complicates period analysiscomplicates period analysis

Temperature signal is strong and Temperature signal is strong and temporallytemporally--consistentconsistent

Projected Annual Temperature Change (Sacramento only)Cumulative Distribution Frequency (112 Emission-Climate Model Projections)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Temperature Change (deg C) Compared to 1971-2000

GC

M P

roje

ctio

n Fr

eque

ncy

(%)

2001-2030

2011-2040

2021-2050

2031-2060

2041-2070

2051-2080

2061-2090

Projected Annual Precipitation Change (Sacramento only)Cumulative Distribution Frequency (112 Emission-Climate Model Projections)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

-30% -20% -10% 0% 10% 20% 30%

Precip Change (%) Compared to 1971-2000

GC

M P

roje

ctio

n Fr

eque

ncy

(%)

2001-2030

2011-2040

2021-2050

2031-2060

2041-2070

2051-2080

2061-2090

Warming

Less Precip More Precip

Comparison of OCAP and CAT Comparison of OCAP and CAT ScenariosScenarios

At least 112 GCMAt least 112 GCM--emission scenario emission scenario projections have been projections have been downscaled and are downscaled and are availableavailableOCAP selected range OCAP selected range based on 10based on 10thth and 90and 90thth

percentile of annual percentile of annual ∆∆T T and and ∆∆P P CAT scenarios selected CAT scenarios selected based on output based on output availability and availability and historical performancehistorical performance

Regional Climate Change Regional Climate Change Scenario Selection CriteriaScenario Selection Criteria

1.1. Select a range of scenarios to reflect the uncertainty Select a range of scenarios to reflect the uncertainty with GCM projections and emission scenarios;with GCM projections and emission scenarios;

2.2. Select scenarios that reduce the Select scenarios that reduce the ““noisenoise”” inherent with inherent with any particular GCM projection;any particular GCM projection;

3.3. Select an approach that incorporates both the mean Select an approach that incorporates both the mean climate change trend and changes in variability; andclimate change trend and changes in variability; and

4.4. Select time periods that are consistent with the major Select time periods that are consistent with the major phases used in BDCP planning.phases used in BDCP planning.

Scenario Selection ApproachScenario Selection Approach

Develop quadrants Develop quadrants or statistical regions or statistical regions of change (Q1 thru of change (Q1 thru Q5)Q5)Identify projections Identify projections contained within contained within representative representative regionsregionsUtilize all Utilize all projections within projections within regions to develop regions to develop scenariosscenariosApply process for Apply process for every grid cell every grid cell (automated process)(automated process)

2055 Projection

2055 Projection

Relationship between Changes in Period-Mean Annual Precipitation and Temperature: Folsom

(112 projections, evaluated at 2060 [2046-75] relative to 1971-2000)

1

2

3

4

5

6

7

89

10

11

12

13

14

1516

17

18

19

20

21

22

23

24

25

26

27

28

29

30 3132 33

34

3536

37

40

4142

4344

45

46

47

48

49

50

51

52

53

5455

56

57

58 59 60

61

62

63

64

65

66

67

6869 70

71

72

73

7475

76 77

78

79

808182

83

84

85

868788

8990

9192

9394 95

969798

99

100

101

102 103

104105

106 107

108

109

110

111

112

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

-30% -20% -10% 0% 10% 20% 30%

Mean Annual Prcp Change (%)

Tavg

Cha

nge

(ºC)

AllCAT2008OCAP2008T75T25P75P25T50P50

Q2

Q1

Q3

Q4

Q5

Climate Scenario Development: ExampleClimate Scenario Development: ExampleGCM Projections Observed Precip

Monthly Precipitation Statistics: Observed vs Projected

0.0

2.0

4.0

6.0

8.0

10.0

12.0

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Non-Exceedance Probability (%)

Mon

thly

Pre

cipi

tatio

n (in

/mo)

Feb - Observed

Feb - Q3 @ 2060

Quantile Mapping: Projection & observed

Adjusted Precip Time SeriesObserved and Projected Precipitation Time Series

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Jan-7

8Mar-

78May-7

8Ju

l-78

Sep-78

Nov-78

Jan-7

9Mar-

79May-7

9Ju

l-79

Sep-79

Nov-79

Jan-8

0Mar-8

0May-8

0Ju

l-80

Sep-80

Nov-80

Jan-8

1Mar-8

1May

-81Ju

l-81

Sep-81

Nov-81

Prec

ipita

tion

(in/m

o)

Observed

Q3 Climate Scenario

Sea Level Rise ConsiderationsSea Level Rise ConsiderationsIPCC AR4 estimates are considered IPCC AR4 estimates are considered ““lowlow””

Do not include dynamic instability in Greenland and Do not include dynamic instability in Greenland and AntarticaAntartica ice sheetsice sheetsUnderUnder--predict recent observed sea level rise ratespredict recent observed sea level rise rates

Delta Vision/CALFED ISB recommended using Delta Vision/CALFED ISB recommended using RahmstorfRahmstorf (2007) approach(2007) approachsemisemi--empirical relationship to global air temperatureempirical relationship to global air temperature7070--100 cm (28100 cm (28--40 inches) by 2100, full uncertainty range 5040 inches) by 2100, full uncertainty range 50--140 cm (20140 cm (20--55 inches)55 inches)1212--18 cm (518 cm (5--7 inches) by 2025, 307 inches) by 2025, 30--60 cm (1260 cm (12--24 inches) by 206024 inches) by 2060

CAT 2008 applied CAT 2008 applied RahmstorfRahmstorf’’ss approach using air temp from the 12 CAT approach using air temp from the 12 CAT scenariosscenarios

Similar to range from full 112 projections at 2025 and 2060; butSimilar to range from full 112 projections at 2025 and 2060; but lower at 2100lower at 2100COE issued guidance this yearCOE issued guidance this year

High, medium, and low estimatesHigh, medium, and low estimatesHigh estimates:High estimates:

1.4 m (~4.5 ft) by 2100, ~60 cm (2 ft) by 2060, ~20 cm (0.6 ft) 1.4 m (~4.5 ft) by 2100, ~60 cm (2 ft) by 2060, ~20 cm (0.6 ft) by 2025by 2025BCDC evaluated two scenariosBCDC evaluated two scenarios

40 cm (~16 inches) by 205040 cm (~16 inches) by 20501.4 m (~55 inches) by 21001.4 m (~55 inches) by 2100

Sea Level Rise Estimates from Sea Level Rise Estimates from RahmstorfRahmstorf (2007)(2007)

BCDC 2009USACE 2009Delta Vision/CALFED ISB 2009DWR/CAT 2009OCAP BA 2007/BOs 2008-09

IPCC 2007

15 cm (6 inches)

45 cm (18 inches)

DRMS 2009

Climate Change Uncertainty and Climate Change Uncertainty and Incorporation in Physical ModelingIncorporation in Physical Modeling

Uncertainty in Regional Climate Change: Scenarios (Quadrant Approach)

Q5 (central)Q4Q3Q2Q1

No Climate ChangeSLR (ft)

SSSSSNT, ELT,

LLT0.0

ELTELTELTELTELTS0.5

(central)

S ?1.0

LLTLLTLLTLLTLLTS1.5

(central)

S ?2.0

Un

cert

ain

ty in

Sea

Lev

el R

ise

CALSIM II & DSM2 (FNA + Alternatives)

CALSIM only (FNA + Alternatives bracketing analysis)

No modelingSensitivity Analysis (FNA only)

S

NT = Near-Term; ELT = Early Long-Term; LLT = Late Long-Term; S = Sensitivity analysis; FNA = Future No Action

Making Use of Climate Change ResultsMaking Use of Climate Change ResultsAnalysis teams will have results from scenariosAnalysis teams will have results from scenarios

Without climate change, midWithout climate change, mid--range scenarios, and bracketing scenariosrange scenarios, and bracketing scenariosExample X2 Results With and Without Climate Change

No Action

50

55

60

65

70

75

80

85

90

95

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Del

ta X

2 Po

sitio

n (k

m)

No CCCC (Q5)CC (min)CC (max)

Example X2 Results With and Without Climate ChangeAlternative X

50

55

60

65

70

75

80

85

90

95

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Del

ta X

2 Po

sitio

n (k

m)

No CCCC (Q5)CC (min)CC (max)

Example X2 Results With and Without Climate ChangeAlternative X change from No Action

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Cha

nge

in D

elta

X2

Posi

tion

from

No

Act

ion

(km

)

No CCCC (Q5)CC (min)CC (max)

No Action Alternative X

Alternative X Change from No Action

Next StepsNext Steps

Management review of climate change Management review of climate change methodology proposalmethodology proposalAgency legal review for NEPA, CEQA, and Agency legal review for NEPA, CEQA, and ESA complianceESA complianceReview schedule implicationsReview schedule implicationsCertain technical aspects beginning immediatelyCertain technical aspects beginning immediately