Thresholds Database > Climate change with deforestation, West Africa

Certainty of shift: Proposed
Location: West Africa (southern coast), Nigeria, Ghana, Ivory Coast
System Type: Social-Ecological
Regime Shift Category: 3a
Ecosystem Type
Spatial Scale
Type of Resource Use
Number of Possible Regimes
Ecosystem Service
Food and fibre (agriculture, forestry), fuel (wood)
Time Scale of Change
Resource Users
Reversibility of Shift


This study illustrates that relatively small areas of land cover can determine the equilibrium state of the atmosphere-biosphere system of an entire region. Increases in population have resulted in land clearing for agriculture and timber harvesting for domestic and commercial use. In the early 1900's, rainforest covered about 500,000km2. by the end of the 20th century, less than 10% of the primary rainforest remained.

Alternate Regimes

1. Monsoons

2. Reduced rainfall

Fast or Dependent Variable(s)
Slow or Independent Variable(s)
Net surface radiation, entropy flux
Disturbance or Threshold Trigger(s)
External / Internal Trigger


Deforestation along the southern coast of West Africa may result in a reduction in regional rainfall and a possible collapse of monsoon circulation. Deforestation reduces the net surface radiation and entropy flux, resulting in a decrease of boundary layer entropy and rainfall over the coastal land, limiting the northward extension of the Intertropical Convergence Zone.

Management Decisions in Each Regime

Jacqui Meyers


CSIRO Sustainable Ecosystems,
PO Box 284,
Canberra ACT 2601

descriptive, conceptual model, Ecosystem Management, Physical/Climate, deforestation


Zheng, X. Y., and E. A. B. Eltahir. 1997. The Response to Deforestation and Desertification in a Model of West African Monsoons. Geophysical Research Letters 24, no. 2: 155-58. (M)

Zheng, X. Y., and E. A. B. Eltahir. 1998. The Role of Vegetation in the Dynamics of West African Monsoons. Journal of Climate 11, no. 8: 2078-96. (M)

Higgins, P. A. T., M. D. Mastrandrea, and S. H. Schneider. 2002. Dynamics of Climate and Ecosystem Coupling: Abrupt Changes and Multiple Equilibria. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 357: 647-55. (D)