Deforestation and Climate Change

Forest Carbon Storage

Forests store carbon in biomass, dead wood, litter, and soil. Tropical forests hold 150-250 tonnes carbon per hectare above ground. Globally forests store about 860 billion tonnes, more than the atmosphere. When cleared, carbon releases through burning (immediate) or decomposition (years). Agricultural conversion depletes soil carbon by 25-40 percent as disturbance accelerates organic matter breakdown.

Deforestation Patterns

Tropical deforestation dominates emissions. Amazon (cattle ranching), Congo basin (smallholder farming), and Southeast Asia (palm oil, pulpwood) are major fronts. Roads for logging enable subsequent agricultural conversion. Brazil reduced Amazon deforestation from peak 27,000 km2/year in 2004 but rates remain concerning.

Water Cycle Effects

Forests recycle water through evapotranspiration. Large tropical trees transpire 1,000 liters daily. Moisture falls as precipitation downwind, creating continental moisture transport. Amazon models suggest 20-25 percent forest loss could trigger dieback tipping point where reduced rainfall degrades remaining forest. Cleared areas are 2-5 degrees hotter from lost cooling.

Forests as Sinks

Intact forests absorb approximately 7.6 billion tonnes CO2 annually, exceeding deforestation emissions. This sink requires continued forest health. Climate change threatens forests through drought, heat, fire, and pests. New plantings take 20-50 years for rapid uptake and centuries to match old-growth density. Protection far more valuable than planting for near-term climate benefit.