"The tendency of an increase in deforestation has been controlled", said Environmental Minister Jose Sarney Filho.
It is estimated that until 1970, deforestation had amounted to approximately 100,000 square kilometers, especially in the states of Pará and Maranhão. From 1978 to 1988, the average annual rate is estimated at 21,500 square kilometers. Starting in 1988, a downward trend is evident: in 1988-89, the rate was estimated at 18.842 square kilometers; in 1989-1990, it was 13,813 square kilometers - a 27% decrease. This is consistent with changes that have been observed in land use in the northern region and seems to be a response to the policies adopted by the Brazilian authorities that will be described later. The total deforested area, as estimated by Brazil's National Space Research Institute (INPE) in February 1991, was 415,215 square kilometers.
On 11 May 1994, the Subcommittee on Western Hemisphere Affairs of the United States Congress promoted a hearing on the issue of deforestation in the Brazilian Amazon. Two scientists, Compton Tucker and David Skole, presented the results of an independent study commissioned by NASA in order to dispel doubts regarding the many conflicting and scientifically debatable assessments about deforestation in the Amazon, which have in the past led to criticism of Brazilian environmental policies. These results were published in the March 25, 1993 issue of "Science" magazine and gave rise to considerable repercussions within the scientific community.
In their presentation, Tucker and Skole stressed that the difficulty of monitoring changes in such a vast region as the Amazon gave rise to tremendous discrepancies with regard to the extent of deforestation. They specifically mentioned the erroneous figures published by the World Bank in 1988, which stated that 600.000 square kilometers (12%) of the Amazon Region had been cleared by that year, while the Brazilian National Space Research Institute (INPE) has reached the much lower estimate of 280.000 square kilometers (5%) for the same period. This was precisely the discrepancy that motivated NASA to commission the independent study. The conclusions of the study are similar to those published by INPE and its estimates are even lower.
Tucker and Skole declared that "we therefore conclude that Brazilian estimates of deforestation in Brazil's Amazon are scientifically accurate". The scientists also indicated that the present rate of deforestation in the Amazon tropical forest has fallen, in 1992/1993, to 11,000 square kilometers per year, which translates as a yearly clearing of 0.3% of forest area. They compared these figures with the yearly deforestation rates in the United States, estimated at 1%. They also declared that "the government of Brazil has been extremely active since 1990 trying to reduce the rate of illegal deforestation in Brazil. This and the removal of tax incentives for deforestation has dramatically lowered the deforestation rate in the Amazon of Brazil to present levels. We hope that this trend continues and the example of the Brazilians in this regard is very encouraging".
The scientists ended their presentation by indicating that "we thus conclude that while the rate of tropical deforestation in the Amazon of Brazil is substantially lower than previous estimates, it is important to continue to minimize deforestation and thus minimize habitat fragmentation and additional losses to biological diversity. This applies to tropical forests as well as the forests of North America". It must be said that the public appears to have, in general, an exaggerated view of deforestation in the Brazilian Amazon. This happens probably because some important facts have received less exposure than the deforestation figures.
Firstly, care must be taken with regard to the definition of "forest". The figures estimated by INPE refer to an area of approximately 390 million hectares which includes the rain forest itself plus the transitional forest and parts of the scrub forest or savanna known as "cerrado". The critical areas of deforestation in legal Amazonia are located in a peripheral zone to the east, south, and southwest, where the vegetation consists basically of "cerrado" interspersed with tracts of semi-humid transitional forests. This is the area where human occupation is most recent. The great nucleus of the Amazon basin, the real Hylaea Amazonica, is still practically intact.
Secondly, the fires detected in the dry season, especially during the months of August, September and October, were interpreted as forest destruction, whereas these, in many cases, represent the clearing of land in agricultural fields for the preparation of the upcoming harvest or the clearing of pastures.
Thirdly, the sense of urgency concerning deforestation in the Amazon resulted largely from the publication of projections based on premises that proved incorrect. One such trend analysis, made in the early 1980's, indicated that the states of Pará, Mato Grosso, Maranhão, Goiás and Rondônia would be completely deforested by 1990. Data obtained from satellite imagery show that in Rondônia, the most deforested of Amazonian states, not more than 12.6% had been cleared in 1990. The basic flaw of these predictions seems to have been the assumption that certain behaviors that are responsible for deforestation would continue to grow, when in fact this has not happened.
Finally, if we consider the time frame of deforestation in the Amazon by dividing the forest area into the annual rate of deforestation to obtain the number of years over which the forest would be cleared, it could be concluded that, as of last year, deforestation was proceeding with a time frame of about 300 years, well above the recovery period of 20 years for the restoration of biomass density, or 80 to 100 years for full recovery. This does not take into account the significant percentage of forest clearings that have been abandoned with the resulting re-growth of the forest.
These facts demonstrate that the image of the Amazon forest being cut down or burnt to the last tree has much more to do with the imagination than with reality. This is not to deny the seriousness of deforestation but to indicate that it is necessary to view the problem in its true proportions.
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