Deforestation
What do you think?
What country lost forest at the fastest rate between 2000 and 2005? (Choose the best answer.)
The correct answer is d) Brazil.
Data from Food and Agriculture Organization of the United Nations,
State of the World’s Forests 2009 (Annex 4)
Between 2000 and 2005 Brazil led the world in the rate of forest loss. Interestingly, Spain (and several other countries not shown) actually increased the size of its forests. Globally, an area equal to more than twice the size of Venezuela is cleared of tropical forests every year. Cutting in the Amazon basin is responsible for over half of that. By 2001, a total of 837,000 square kilometers of forest had been lost.
In Brazil, almost 20% of tropical forest —an area equivalent to the size of France— has been cleared and converted to other uses in the last 30 years. The southern and eastern margins of the forest suffered the most, as cattle pasture and soybean fields expanded there.
Some forest is not cleared outright but instead degraded by poor timber-cutting practices. About one-third of the Amazon has been degraded in this way, and it accounts for about 25% of emissions from deforestation in the Brazilian Amazon. The combined effect of deforestation, degradation, and slash-and-burn agriculture increases the fire risk greatly for millions of hectares of still-untouched forest.
Degraded forests release their carbon slowly as the forest materials decay, while fires vaporize it at once. In either case, the surrounding forest can be weakened by the extra light, heat, and dryness.
Many other things happen after forest is cleared that put carbon in the atmosphere. About 25-30% of the carbon in newly-deforested, ploughed soil returns to the air when dead plant material and some soil microbes are exposed to air. Air exposure allows them to decay more quickly. And grazing and cultivation of newly cleared land lead to other greenhouse gas emissions. Nitrogen-rich fertilizers sprayed on crops cause soil to release nitrous oxide, another greenhouse gas. Livestock, manure, and rice paddies release methane.
