LOCAL AND NATIONAL CONSEQUENCES
LOSS OF LOCAL CLIMATE REGULATION
The local level is where deforestation has the most immediate effect. With forest loss, the local community loses the system that performed valuable but often underappreciated services like ensuring the regular flow of clean water and protecting the community from flood and drought. The forest acts as a sort of sponge, soaking up rainfall brought by tropical storms while anchoring soils and releasing water at regular intervals. This regulating feature of tropical rainforests can help moderate destructive flood and drought cycles that can occur when forests are cleared.
When forest cover is lost, runoff rapidly flows into streams, elevating river levels and subjecting downstream villages, cities, and agricultural fields to flooding, especially during the rainy season. During the dry season, such areas downstream of deforestation can be prone to months-long droughts which interrupt river navigation, wreak havoc on crops, and disrupt industrial operations.
Situated on steep slopes, montane and watershed forests are especially
important in ensuring water flow and inhibiting erosion, yet during the 1980s, montane formations suffered the
highest deforestation rate of tropical forests.
There is serious concern that widespread deforestation could lead to a significant decline in rainfall and trigger a positive-feedback process of increasing dessication for neighboring forest cover; reducing its moisture stocks and its vegetation would then further the dessication effect for the region. Eventually the effect could extend outside the region, affecting important agricultural zones and other watersheds. At the 1998 global climate treaty conference in Buenos Aires, Britain, citing a disturbing study at the Institute of Ecology in Edinburgh, suggested the Amazon rainforest could be lost in 50 years due to shifts in rainfall patterns induced by global warming and land conversion.
The newly dessicated forest becomes prone to devastating fires. Such fires materialized in 1997 and 1998 in conjunction with the dry conditions created by el Niño. Millions of acres burned as fires swept through Indonesia, Brazil, Colombia, Central America, Florida, and other places. The Woods Hole Research Center warned that more than 400,000 square kilometers of Brazilian Amazonia were highly vulnerable to fire in 1998.
Such losses of freshwater resources are considered one of the most immediate threats to national security in many countries. Freshwater—required for human consumption, agriculture, and industrial operations—or the lack thereof can have a tremendous effect on the social, economic, and political climate of a country. Realizing the importance of water, politicians of the future may try to secure their existing freshwater supplies or wage war to acquire other sources of water. Demand for water increases as the standard of living improves, so politicians of the future will look to guarantee freshwater supplies. Developing countries, where political and social conditions are often tense, will likely experience the most pressure from shrinking water supplies. In the future, wars may be fought over water, not oil. Already Egypt has made it known to its upstream neighbors—Sudan and Ethiopia—that it is willing to go to war over the Nile's water
[full photo version]
Continued: Structure of the tropical rainforest - part II
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