Tropical Forests and Climate Change

updated January 2017

Deforestation releases carbon dioxide through disturbance of the residue of carbon in the soil, the decay of leaves and wood, and combustion. Figures published in 2013 by the Intergovernmental Panel on Climate Change showed that deforestation contributes about 10% of global greenhouse gas emissions, most of which relates to tropical forests.

Forest ecosystems will themselves react to the changing climate, creating a feedback loop. In very general terms, greater concentration of atmospheric carbon dioxide increases biomass formation whilst higher temperatures reduce it. The net effect is likely to be positive in temperate forest regions (mostly richer countries) and negative in the tropical forests (mostly poorer countries).

Tropical forests face the added uncertainty of regional climate instability brought about by deforestation, independent of the effect of global warming. In trying to make sense of this complex cocktail of environmental change, scientists are particularly concerned that warmer and drier conditions could transform parts of the Amazon rainforest into savannah, with implications for disrupting rainfall patterns in the United States.

The implications of a positive feedback loop between deforestation and climate change are far-reaching. The prospect of the rainforest ecosystem flipping from a sink to a source of carbon dioxide emissions casts doubt on the wisdom of regarding a two degree average temperature rise as tolerable in UN climate negotiations. There can be limited certainty that this threshold lies within the boundaries of the precautionary principle for sustainable rainforest ecosystems.

As the scientific understanding of the impact of global warming on tropical forests is far from confident, adaptation strategies remain difficult. One scenario under urgent consideration is the risk of fire – for which rainforests have no natural protection.

The urgency surrounding climate change has created opportunities to embed measures to protect forests within proposed international agreements on emissions. However, the interminable delays in climate negotiations contrast with the rampant global forces that ultimately drive deforestation.

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more Forests briefings
Importance of Tropical Forests
Deforestation and Forest Degradation
Causes of Deforestation
Sustainable Development Goal for Deforestation
Consumer Solutions to Deforestation
Rights-based Solutions to Deforestation
Market-based Solutions to Deforestation
Source material and useful links

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