Soil carbon in dynamic Soil carbon in dynamic land use optimization land use optimization
models models
Uwe A. SchneiderUwe A. Schneider
Research Unit Sustainability and Global Research Unit Sustainability and Global ChangeChange
Hamburg UniversityHamburg University
TopicsTopics
I Land use modelsI Land use models
II Linking biophysical and economic modelsII Linking biophysical and economic models
III Soil carbon in economic modelsIII Soil carbon in economic models
IV FASOMIV FASOM
I Land use modelsI Land use models
Research QuestionsResearch Questions
Economic Economic SustainabilitySustainability– FoodFood– EnergyEnergy– CommoditiesCommodities
Environmental Environmental SustainabilitySustainability– AirAir– WaterWater– SoilSoil– Climate Climate – EcosystemsEcosystems
Policy analysisPolicy analysis– Economic Economic
potentialpotential– ImpactsImpacts
Focus of land use modelsFocus of land use models
Technologies (Species, Tillage, Technologies (Species, Tillage, Planting, Fertilizing, Protection, Planting, Fertilizing, Protection, Harvesting)Harvesting)
Economics (Market Prices, Trade, Economics (Market Prices, Trade, Income)Income)
Environment (Resources, Emissions, Environment (Resources, Emissions, Sinks, Wildlife, Climate)Sinks, Wildlife, Climate)
Land use estimationLand use estimation
StorylinesStorylines
StatisticsStatistics
OptimizationOptimization
OptimizationOptimization
Constrained welfare/profit Constrained welfare/profit maximizationmaximization
Normative economics (positive Normative economics (positive economics via calibration)economics via calibration)
Application to structural change Application to structural change beyond historical observationsbeyond historical observations
Land use optimizationLand use optimization
Find welfare maximizing land Find welfare maximizing land managementmanagement
s.t.s.t. resourcesresources
technologiestechnologies
marketsmarkets
policiespolicies
Linear ProgramLinear Program
jallfor0X
iallforbXa..
Xc
j
ij
jij
jjj
ts
Max
II Linking biophysical II Linking biophysical and economic modelsand economic models
Why linkage?Why linkage?
Standalone biophysical models Standalone biophysical models simulate environmental impacts of land simulate environmental impacts of land management but don’t explain why a management but don’t explain why a certain land management is chosencertain land management is chosen
Standalone economic models explain Standalone economic models explain land management adoption but cannot land management adoption but cannot internalize environmental impactsinternalize environmental impacts
ChallengesChallenges
Spatial resolution (field vs. globe)Spatial resolution (field vs. globe)
Temporal resolution (days vs. Temporal resolution (days vs. decades)decades)
Technological resolutionTechnological resolution
Environmental resolutionEnvironmental resolution
Types of Linkage (Problems)Types of Linkage (Problems)
A.A. Economic model Economic model Biophysical Biophysical model (no adaptation, no feedback)model (no adaptation, no feedback)
B.B. Biophysical model Biophysical model Economic Economic model (curse of dimensionality)model (curse of dimensionality)
C.C. Iterative link (costly, ITR)Iterative link (costly, ITR)
D.D. Fully integrated model Fully integrated model (computational limits)(computational limits)
Economic model Economic model Biophysical Biophysical modelmodel
Determine land use trajectory with Determine land use trajectory with economic model for different economic model for different scenariosscenarios
Simulate environmental impacts for Simulate environmental impacts for each scenarioeach scenario
Adaptation of land management to Adaptation of land management to environmental policies ignoredenvironmental policies ignored
Feedback of changing environment Feedback of changing environment on adaptation ignored as wellon adaptation ignored as well
Biophysical model Biophysical model Economic Economic modelmodel
Simulate environmental impacts for Simulate environmental impacts for all possible land use choicesall possible land use choices
Enter environmental impacts in Enter environmental impacts in economic modeleconomic model
Set values for environmental impacts Set values for environmental impacts (environmental policies)(environmental policies)
Find welfare maximizing levelsFind welfare maximizing levels
Curse of Dimensionality?Curse of Dimensionality?
20 Crops20 Crops 5 Management options per crop5 Management options per crop 100 Regions 100 Regions 5 Soil Types per region5 Soil Types per region
50,000 Land use alternatives
Curse of Dimensionality?Curse of Dimensionality?
20 Crops20 Crops 5 Management options per crop5 Management options per crop 100 Regions 100 Regions 5 Soil Types per region5 Soil Types per region 20 Periods20 Periods
5*E42 Trajectories (independent sites)
1*E94 Trajectories (dependent sites)
III Soil carbon in III Soil carbon in economic modelseconomic models
Soil carbon and economicsSoil carbon and economics
Productivity impact of soil carbon Productivity impact of soil carbon (yields, suitability)(yields, suitability)
Economic potential of carbon sinks Economic potential of carbon sinks for climate change mitigationfor climate change mitigation
Carbon sinks vs. bioenergy vs. Carbon sinks vs. bioenergy vs. biodiversity vs. traditional marketsbiodiversity vs. traditional markets
Soil Carbon DeterminantsSoil Carbon Determinants
Crop ChoiceCrop Choice TillageTillage IrrigationIrrigation FertilizationFertilization Residue MgtResidue Mgt Soil CarbonSoil Carbon
Soil Soil
Carbon Carbon
ChangeChange
Soi
l Org
anic
Car
bon
(tC
/ha/
20cm
)
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50Time (years)
Wheat-Lucerne 3/3
Wheat-Lucerne 6/3
No-till wheat-fallow
Tilled wheat-fallow
Simple Multi-Period Land Use Simple Multi-Period Land Use ModelModel
Market Environmentt t ,r,i,u t ,r,i,u t ,r,i,u
t ,
t ,r,i,u t ,r,
r,i,u
iu
s.
Max v v X
t. X l
Indexes: t = time, r = region, i = soil type, u = managementData: = interest rate, v = net benefit, l=land endowment Variables: X = land use
Explicit Land Use Explicit Land Use TrajectoriesTrajectories
d d d
d
d d
d
Market Environment
r,i,u r,i,u r,i,
r,i,u r,i,
ur,i,
u
u
u
Max v v X
s.t. X L
Indexes: r = region, i = soil type, ud = management path
Implicit Land Use Implicit Land Use Trajectories Trajectories
Assume that management history is Assume that management history is manifest in current soil carbon levelsmanifest in current soil carbon levels
Divide soil carbon rangeDivide soil carbon range
Implement Markov ChainImplement Markov Chain
Markov ProcessMarkov Process
Market Environmentt t ,r,i,u,o t ,r,i,u,o t ,r,i,u
t ,r,i,u,
t ,r,i,u,o r,i,u,o,o t 1,r,i,u,ou u,
,ot ,r,i,u,o
o t,r,io
o
u,
s.
Max v v X
X
t X l
X
.
Indexes: t = time, r = region, i = soil type, u = management
o,ố = soil carbon state = transition probability from old state ố to new state o
Soil Carbon Transition Soil Carbon Transition ProbabilitiesProbabilities
SOC1 SOC2 SOC3 SOC4 SOC5 SOC6 SOC7 SOC8
SOC1 0.81 0.19
SOC2 1
SOC3 0.09 0.91
SOC4 0.31 0.69
SOC5 0.5 0.5
SOC6 0.74 0.26
SOC7 1
SOC8 0.04 0.96
No-till wheat-Fallow
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50Time (years)
Wheat-Lucerne 3/3
Wheat-Lucerne 6/3
No-till wheat-fallow
Tilled wheat-fallowSoi
l Org
anic
Car
bon
(tC
/ha/
20cm
)
Curse of Dimensionality?Curse of Dimensionality?
20 Crops20 Crops 5 Management options per crop5 Management options per crop 100 Regions 100 Regions 5 Soil Types per region5 Soil Types per region 20 Periods20 Periods
5E42 Trajectories (independent sites)
1E94 Trajectories (dependent sites)
Curse of Dimensionality?Curse of Dimensionality?
20 Crops20 Crops 5 Management options per crop5 Management options per crop 100 Regions 100 Regions 5 Soil Types per region5 Soil Types per region 20 Periods20 Periods
1E6 Variables (No Soil Carbon)
1E7 Variables (Markov process with 10 states)
5E42..1E94 Variables (Explicit Path)
Extensions?Extensions?
Markov chains are applicable to Markov chains are applicable to relatively independent environmental relatively independent environmental qualities (humus, salt, qualities (humus, salt, contamination)contamination)
Method not suitable for complex Method not suitable for complex environmental properties (climate)environmental properties (climate)
IV Forest and IV Forest and Agricultural Sector Agricultural Sector Optimization Model Optimization Model
FASOMFASOM
Overall ObjectiveOverall Objective
Portray agricultural and forest Portray agricultural and forest commodity markets and internalize all commodity markets and internalize all
land use externalitiesland use externalities
Analyze PoliciesIntegrate Synergies, Trade-offs
Markets
Soil
ClimateWildlife
Land use decisions Water
Farmers
Model StructureModel Structure
Resources Land Use
Technologies
Processing Technologies
Products Markets
Inputs
Limits
Supply Functions
Limits
Demand Functions,Trade
Limits
Environmental Impacts
Economic Surplus Economic Surplus MaximizationMaximization
Implicit Supply and Demand
Forest InventoryLand Supply
Water Supply
Labor Supply
Animal Supply
National Inputs Import Supply
Processing Demand
Feed Demand
Domestic Demand
Export Demand
CS
PS
Spatial ResolutionSpatial Resolution
Soil textureSoil texture Stone contentStone content Altitude levelsAltitude levels SlopesSlopes Soil stateSoil state
Political regionsPolitical regions Ownership Ownership
(forests)(forests) Farm typesFarm types Farm sizeFarm size
Many crop and tree Many crop and tree speciesspecies
Tillage, planting Tillage, planting irrigation, fertilization irrigation, fertilization harvest regimeharvest regime
Altitude:1. < 300 m2. 300-600 m3. 600-1100 m4. >1100 m
Texture:1. Coarse2. Medium3. Medium-fine4. Fine 5. Very fine
Soil Depth:1. shallow2. medium3. deep
Stoniness:1. Low content2. Medium content3. High content
Slope Class:1. 0-3%2. 3-6%3. 6-10%4. 10-15%5. …
Homogeneous Response Units
DE13
DE12
DE11
DE14
Climate Change MitigationClimate Change Mitigation
0
100
200
300
400
500
0 20 40 60 80 100 120 140 160 180 200
Car
bon
pri
ce (
$/tc
e)
Emission reduction (mmtce)
CH4N2O
Ag-Soil sequestration
Afforestation
Biofuel offsets
Soil Carbon PotentialsSoil Carbon Potentials
0
100
200
300
400
500
0 20 40 60 80 100 120 140 160
Car
bon
pri
ce (
$/tc
e)
Soil carbon sequestration (mmtce)
Technical Potential
Economic Potential
Competitive EconomicPotential
Biofuel PotentialsBiofuel Potentials
0
100
200
300
400
500
0 50 100 150 200 250 300 350
Car
bon
pri
ce (
$/tc
e)
Emission reduction (mmtce)
Technical Potential
Economic Potential
Competitive EconomicPotential
Afforestation PotentialsAfforestation Potentials
0
100
200
300
400
500
0 50 100 150 200 250 300
Car
bon
pri
ce (
Eu
ro/t
ce)
Emission reduction (mmtce)
Technical Potential
Economic PotentialCompetitive
Economic Potential