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