Results of a Random Forest suitability classification study

Climate change impacts on cocoa in Ghana

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Cooperation with CRIG-COCOBOD

Application of a machine learning tool to cocoa in Ghana

Random Forest classification

Random Forests for classification

• A forest is an ensemble of trees. The trees are all slightly different from one another.

• The output is the mean classification

• Very robust against overfitting

Is the soil good?

Is the dry season long?

Is the heatstrong?

truefals

e

No cocoa!

true

fals

etruefalse

Cocoa!

One decision tree

Source: Criminisi et al 2013

Input locations

Input locations

Soil data included

Results

Random Forest classification

Current distribution of suitability classes for cocoa

Current distribution of suitability classes for cocoa

AEZ Bioclim A Bioclim B Soils

Type 1 Low annual precipitation Strong dry season Below average soils

Type 2 Low temperatures Long dry season Average soils

Type 3 Elevated temperatures Reliable precipitation Average soils

Type 4 High temp Low seasonal variation Above average soils

Current distribution of suitability classes for cocoa

• MSNW Moist semi-decidious North

West• MSSE

Moist semi-decidious South-East

• ME Moist evergreen

Current distribution of suitability classes for cocoa

Current distribution of suitability classes for cocoa

Future distribution of suitability classes for cocoa

Future distribution of suitability classes for cocoa

Transition of suitability classes

Climate change impact gradient

What does this mean for yields?

What does this mean for yields?

What does this mean for yields?

What does this mean for yields?

Current2050s

Current2050s

Conclusion

• Cocoa production is shaped by climate and soils• Cocoa soil characteristics are different from other soils in the

country

• Results show four distinct production zones that align with ecological zones in Ghana: Moist semi-deciduous, subtypes NW, (central),SE Moist evergreen

• The moist evergreen climate (type 4) will be the dominant climate in the future

• The moist semi-deciduous (type 1) region in the North West will become marginal

Conclusion

• Yield and production will be affected by climate change

• Adaptation has to be a priority for the cocoa sector

Questions

Answers&