Modeling Future Land Use, Regional Climate, and Maize
Yields in East AfricaNathan Moore, B Pijanowski, B Lofgren, G Alagarswamy,
J Andresen, J Olson
B43H-03
University of Dar Es Salaam
What is the nature and magnitude of climate-land interactions?
GCM versus RCMIPCC, radiative forcings
Coupling human and natural systems
Fundamental Research Question:
Focused Questions/Motivation
Question 1: What are likely Climate Change and Land Cover Change Impacts on Future East African Agriculture?
Question 2: Is Land Cover/Land Use Change asimportant as Greenhouse Gas Concentrations at the Regional Scale?
Conceptual Framework of the Modeling System
Spatial scales / temporal scales / uncertainty
Human Systems
Land Use & Land Cover
Climate
Effects on Agriculture
Herding, Agriculture,
Urban, Irrigation, etc
Surface Characteristics
Many pathways
Upper Embu coffee & maize farms --- slopes of Mt. Kenya
Major Data Sources and Models
• Land Use: Historical LUC studies, Africover. Model: Land Transformation Model (LTM)
• Land Cover: GLC 2000, MODIS fc & LAI (seasonal)
• Climate: CCSM 3.0 boundary conditions, RAMS 4.4, Worldclim station data,
ECHAM5, HadCM3
• NPP Models: CERES/Maize, LPJ
What changes do we expect in agricultural land cover?
Land cover in 2000 Land cover in 2050 (projected)
Lowered roughness, higher moisture
4 experiments for exploring climate and landscape effects
Land Cover Global Climate Comparison:
1: Current Current Baseline
2: Current 2050 decade Future climate effects only
3: 2050 decade Current Future land cover effects only
4: 2050 decade 2050 decade Synergistic effects
Results from the 4 experiments
Focus on Differences:
A.Future Climate Effects (2-1)
B. Land Cover/Land Use Effects (3-1)
C. Synergistic Effects (4-1)
Differences in Precipitation
Climate Change Land Cover/Land Use Synergistic EffectsEffects Change (LCLUC) Effects
Differences in Temperature
Climate Change LCLUC Synergistic EffectsEffects Effects
Climate Change LCLUC Synergistic EffectsEffects Effects (7.8 W/m2) (-2.8 W/m2) (8.6 W/m2)
Differences in Latent Heat Flux
Win
d pa
ttern
cha
nges
du
e to
LC
LUC
Projected in Maize Yield Climate and Landscape Forcings
Q1: Impacts on African Agriculture
Human Systems
Land Use & Land Cover
Climate
Effects on Agriculture
Herding, Agriculture,
Urban, Irrigation, etc
Surface Characteristics
Relative Impact of Greenhouse Gases vs. Land Use Change
Land Use and Climate may have strong impacts on East African Agriculture, and thus on humans (feedbacks)
Land Cover/Land Use may have impacts on the same scale as elevated Greenhouse Gas Concentrations, but highly localized effects
Tharaka, Kenya
Summary
Coupling Human Systems to Land Use/Land Cover
Human Systems
Land Use & Land Cover
Climate
Effects on Crops, Disease,
Ecosystems, etc
Herding, Agriculture,
Urban, Irrigation, etc
Surface Characteristics
Conclusion
• Potential problems related toagricultural futures in Africa
• Relative roles of greenhouses gases versus Land Cover/Land Use Change on climate
• Interdisciplinary issues of societal import; continuing savannas research
Surface Characteristics influencing Climate
Important to include regional and local characteristics
Human Systems
Land Use & Land Cover
Climate
Effects on Crops, Disease,
Ecosystems, etc
Herding, Agriculture,
Urban, Irrigation, etc
Surface Characteristics
Projected in Maize Yield Climate Forcings Only
Glo
bal
Cli
mat
e in
pu
ts a
t th
e b
ou
nd
arie
s
Landscape Inputs
An Illustration of Climate and Land Cover Drivers
The Climate Model Domain
Relative Impact of Greenhouse Gases vs. Land Use Change: Tmax
Projected in Maize Yield: Landscape Forcings Only
Differences in Sensible Heat Flux
Conceptual framework: A walk around “The Loop”
Global Climate:From CCSM model
CLIMATE DYNAMICS
RAMS simulations
CERES-MAIZE(Crop model)
Land Transformation Model (LTM)
Land cover input to RAMS
Land
cov
er (a
lbed
o, F
C, LAI)Tm
in, Tmax, solar, precip