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IINTEGRATEDNTEGRATED ASSESSMENTASSESSMENT, , WATERWATERRESOURCESRESOURCES ANDAND SCIENCESCIENCE--POLICYPOLICYRESOURCESRESOURCES, , ANDAND SCIENCESCIENCE--POLICYPOLICY
COMMUNICATIONCOMMUNICATION
Evan G.R. DaviesMohammad Khaled Akhtar
Gordon McBeanSlobodan P SimonovicSlobodan P. Simonovic
The University of Western Ontarioy
OOUTLINEUTLINE
Research GoalsModel Development
StructureEquations
Simulation & ExperimentationSimulation & ExperimentationConclusions
BBACKGROUNDACKGROUND
The climate is changingg g
People are partially responsible
Impacts of higher GHG concentrations:
“Large-scale, high-impact, non-linear, and potentially abrupt and irreversible changes in physical and abrupt and irreversible changes in physical and biological systems”
Source: Intergovernmental Panel on Climate Change (IPCC, 2001)
RRRRESEARCHESEARCH GOALSGOALS
Society
1. Examine how climate change affects long-term sustainability
EconomyEnvironment
2. Provide a tool to policy-makers
3 Stress importance of feedbacks3. Stress importance of feedbacksClimate Change Social
Adaptation
Understanding better policy
CCLIMATELIMATE CHANGECHANGE MODELLINGMODELLING
The usual approach:The usual approach:‘Drive’ complex model with emissions scenarios
The problem:The problem:These systems are interdependent
OOURUR APPROACHAPPROACH
The reality:Interaction between socio economic and natural Interaction between socio-economic and natural systems causes climate change
l h l dClimate Change Social Adaptation
Interaction determines the entire system’s evolutionevolution
MMETHODOLOGYETHODOLOGY
System Dynamics (modelling)Explicit modelling of feedbacksExplicit modelling of feedbacksFor systems with dynamic complexityImproves understanding of system behaviourImproves understanding of system behaviourModels the most important processesF d t di t di tiFocuses on understanding, not on prediction
SSYSTEMYSTEM DYNAMICSDYNAMICS APPROACHAPPROACHSSYSTEMYSTEM DYNAMICSDYNAMICS APPROACHAPPROACH
A rigorous method of system description, which facilitates feedback analysis usually via a simulation model of the effects of alternative system structure and control policies on system system structure and control policies on system behavior.
SSYSTEMYSTEM DYNAMICSDYNAMICS APPROACHAPPROACHSSYSTEMYSTEM DYNAMICSDYNAMICS APPROACHAPPROACH
Feedback Processes: Two kinds only
Positive = reinforcing
money200,000
150,000
100,000
50,000
00 10 20 30 40 50 60 70 80 90 100
Time (Year)
Negative = balancing
State100
75
50
25
00 5 10 15 20 25 30 35 40 45 50
Time (Second)
But when they combine …
1
1
1
1 1 1
1
1
1
MMMMODELODEL STRUCTURESTRUCTURE
Carbon cycle Land Use CarbonCarbon
+
AtmosphericCarbon cycleClimateWater Demand
Land Use Emissions
+ Land UseLand Use
Atmospheric CO2
EconomyEconomy
Temperature
+Carbon AbsorptionAtmospheric [CO2]Temperature Change
+− Industrial
emission
Water QualitySurface Flow
Clearing and
Burning ClimateClimate
Consumption and Labour
GDP per
+Water Use
Wastewater treatment and reuse EnergyEnergy
+
Energy Demand Intensity
Water use ffi i
PopulationLand Use
+PopulationPopulation
-
capita
+ Water QualityWater QualityWater Demand/UseWater Demand/Use
Wastewater
WastewaterReuse
−Water scarcityRenewable flow in changing climatePopulation growth = f(water scarcity)Biome coverage
+
Water use Intensity
+
efficiency
EconomyEnergy
+
TemperatureWater Stress
Surface Water AvailabilityWater
Consumption
WastewaterTreatment
WastewaterTreatment and
Reuse
( y)Biome coverageHuman action
GDP changeCarbon taxIndustrial emission
−
10
+Surface FlowSurface Flow
Reuse− +Emissions
Water UseEnergy demand
MMODELODEL SECTORSSECTORS
1 Carbon Cycle1. Carbon Cycle2. Climate System3. Water Demand4. Water Quality5. Surface Flow
P l ti6. Population7. Land-use8 Economy8. Economy9. Energy
SSOMEOME EQUATIONSEQUATIONS
Climate System:Climate System:
Domestic Water Withdrawal:
( )[ ] dttLtStLEtLtLtFQtH outheatheatdownupaatm ⋅−++−++= ∫ )()()()()()()(Energy [1024 Joules]
Domestic Water Withdrawal:
Economic Sector:( )( )[ ]2)(/)(
maxmin 1)()( tPtGDPD eDSWIDSWItPtW γ−−+⋅=Volume [km3 yr-1]
Economic Sector:
Population growth:
( ) γγµ −⋅⋅⋅⋅−⋅Ω= 11 )()()()()(1)()( 2 tLtKtAttbttQ b
GDP [1012 $US yr-1]
Population growth:
C b i At h)()(
)()(
tgtrdtdr
twtabtg
⋅=
⋅=
Growth [people yr-1]
Carbon in Atmosphere:dtOEBBNPPDDDC flux
iLit
iB
iiLit
iHum
iCharatm ⋅⎥
⎦
⎤⎢⎣
⎡−+⎟
⎠
⎞⎜⎝
⎛++−⎟
⎠
⎞⎜⎝
⎛++= ∫ ∑∑∑∑∑∑
====== 6..16..16..16..16..16..1Mass [Gt C yr-1]
CCARBONARBON SECTORSECTOR CAUSALCAUSAL DIAGRAMDIAGRAM
Emissions
Legend Atmosphere Deep Ocean
Emissions
Decomposition
Emissions
Biomass
NPP
Litter Fall LitterLand Use
Oceanic AbsorptionHumus
Stable HumusStable Humus
CCARBONARBON SECTORSECTOR FLOWFLOW DIAGRAMDIAGRAMAtmospheric CO2
Concentration
CO2 in Atmosphere
<Pjk>
CO2 Emissions
<Current Biome
Industrial CarbonEmissions E(t)
Turn On HumanEmissions
Biomass
NPP
Litt f ll
Decayto
HumusDecayfrom
<Pjk>
<Sigma (NPPj)>
Unburnt
BurntBiomass
BurntLitter
<Biomass to Atm>
<Litter to Atm>
CumulativeEmissions
Fossil Fuel BurningBiome Area
<Current BiomeArea>
<Init Biome Area>
Litter
LitterfallfromLitter
Decayfrom
HumusHumification
Decayfrom
Charcoal
<Tao(Bjk)>
<Lambda j>
<Tao(Lj)>
Wood
BiomasstoLitt t
<Dead biomass toHumus>
<Litter Burnt intoCharcoal>
<Internal HumusFlows Calculation>
Turn On HumanLand Use
<Litter Q10>
Humus
Stable Humusand Charcoal
Carbonization
<Phi j>
<Tao(Hj)>
T (Kj)
toCharcoalLitter to
Charcoal
<Burnt Biomass toCharcoal>
Internal HumusFlows
Internal Charcoal
<Humus Q10>
<Charcoal Q10>
<Tao(Kj)> Internal CharcoalFlows
<Internal CharcoalFlows Calculation>
CCCCARBONARBON SECTORSECTOR EQUATIONSEQUATIONS
Atmosphere( ) dtFEBBNPPDDDDA OLBKHLB ⋅−+++−+++= ∫
Biomass
( )∫ ⋅−−−−−= dtUBBFKFHFLNPPB jkjkBjkBjkBjkBjkjk
Net Primary Productivity15)(
Root Decay
15101)( ×⋅⋅= jjjkjk SANPPpNPP σ
( )( )00 ln1)()( AANPPNPP jj βσσ +×=
y)( 4
44
j
jjB B
BFH τ=
15
KKEYEY VARIABLESVARIABLESKKEYEY VARIABLESVARIABLES
Atmospheric CO2Available surface waterAvailable surface waterBiome areasCO2 emissionsE i t t (GDP)Economic output (GDP)Land use changePopulationS f Surface temperatureWater withdrawals and consumptionWater stressWastewater treatment and reuseCarbon taxInvestment strategiesgSubsidization of the renewable energy Zero carbon emission technology
MMMMODELODEL COMPLEXITYCOMPLEXITY
Number of Model Elements:740 variables
‘Variables’: ~1600 (incl. arrays)C 470 (i l )
Sector # of VariablesCarbon: 130Energy & Economy: 205Climate: 80Constants: ~470 (incl. arrays)
230 Stocks (many in arrays)2300 total
Climate: 80Water Treatment: 50Water Demand: 45Hydro. Cycle: 45Land Use/Change: 15Population: 10
600 equations99 major equations
Thousands of feedbacksPopulation: 4468 loops Water stress: 2756 loopsEconomic output: 203 loopsIndustrial emissions: 47 loopsp
17
EEXAMPLEXAMPLE
Wastewater ReuseIndividual Simulation
H t ll ti ff t t il bilitHow water pollution affects water availabilityHow water stress affects population growth
A C Approach: Compare experiment against base case results
18
EEXAMPLEXAMPLEEEXAMPLEXAMPLE
Untreated Returnable WatersTreated Returnable Waters1,468
1,164
860 82
976.99
751.00
525 01 860.82
556.74
252.67
525.01
299.03
73.041960 1974 1988 2002 2016 2030 2044 2058 2072 2086 2100
Time (Year)
Untreated Returnable Waters : Base km*km*km/YearUntreated Returnable Waters : No Treatment or Reuse km*km*km/Year
1960 1974 1988 2002 2016 2030 2044 2058 2072 2086 2100Time (Year)
Treated Returnable Waters : Base km*km*km/YearTreated Returnable Waters : No Treatment or Reuse km*km*km/Year
Less wastewater treatment - more pollutionMore pollution - less clean water available
EEXAMPLEXAMPLEPopulation
11.73 B
9.554 B
Water Stress1.062
7.376 B
5.198 B
3.02 B
0.7227
0.38321960 1974 1988 2002 2016 2030 2044 2058 2072 2086 2100
Time (Year)
Population to Use : Base personPopulation to Use : No Treatment or Reuse person
1960 1974 1988 2002 2016 2030 2044 2058 2072 2086 2100Time (Year)
"Withdrawals to Availability ratio incl. Pollution Effects" : Base Dimensionless"Withdrawals to Availability ratio incl. Pollution Effects" : No Treatment or Reuse Dimensionless
Simulation interpretation:oTrue water scarcity level not perceived using general definition
oWater scarcity reaches critical level
oAction to reduce water stress too late, damage is done
CCONCLUSIONSONCLUSIONS ((FROMFROM EEXPERIMENTXPERIMENT))
Water sector modelling:Water Pollution increases Water StressWater Pollution increases Water StressHigh water stress dangerousReuse, treated wastewater to reduce water scarcity
CCONCLUSIONSONCLUSIONSCCONCLUSIONSONCLUSIONS
Cost of this approach:ppSacrifice resolution for completeness
Benefits of our approach:Represents socio-economic adaption as part of physical process of climate changephysical process of climate changeIncludes vital socio-economic feedbacksAllows policy analysis, fast simulation runs
A shift is underway from a global-aggregate to a regional representation of global change.regional representation of global change.
NNEXTEXT STEPSSTEPS ININ RESEARCHRESEARCH
R i li i f h l b l d lRegionalization of the global model
Improvements of the water sectorImprovements of the water sector
Questions?Questions?