Thresholds Database > Climate change with deforestation, West Africa

Background

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

Mechanism

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