"Newspaper reports in recent days show that forest burnings have increased in recent months in Brazil, especially in the Amazonian region. According to the 'Folha de Sao Paulo' of October 01, 38.6 thousand such burnings were registered in all of Brazil during the months of July, August and September of this year. This compares with a total of 32.9 thousand such burnings during the same period last year - an increase of 17%.
In Mato Grosso alone during the month of September, 6 thousand burnings were registered by satellites. In the State of Para, 6600 burnings were registered between July and September of 1996 as compared to 8800 during the same period this year - an increase of 33%.
The burnings have left much smoke in the air in these regions and has been responsible for problems in many of the airports. The airport of Maraba, State of Para, needed to use instruments to help planes land during 120 hours in September - the visibility was seriously impaired. The airport in Imperatriz, State of Maranhao, experienced such difficulties during 32 hours in September while the airport in Carajas, State of Para, was forced to close on two occasions. On September 29 smoke was responsible for a 40% increase in the number of people who sought medical aid in hospitals because of problems with breathing in the city of Manaus, Amazonas. Pilots claim that visibility approaching the city is usually over 5 thousand meters; during recent days at best it has been between 2 thousand and 5 thousand meters.
During the last week we received the following study on this question prepared by the Environmental Defense Fund which we would like to share with you.
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Fires in the Amazon - An Analysis of NOAA-12 satellite data 1996 - 1997
Stephan Schwartzman<steves@edf.org>
Analysis of NOAA satellite data indicates that burning in the Brazilian Amazon increased 28% between 1996 and 1997. A sample of 41 consecutive days for which data are available starting from 08/01/96 (08/01/96 - 09/16/96) and 41 consecutive days for which data are available starting 08/01/97 (08/01/97 - 09/21/97) shows the increased burning. The sample was selected taking the first 41 days starting August 1st 1997 for which NOAA 12 data could be obtained from the National Institute for Space Research (INPE) (http://condor.dsa.inpe.br.mapas_ que) and the first 41 days starting August 1st 1996, in order to create comparable data sets from the burning season in the two years. Occurrence and distribution of fires is observed from thermal anomalies in data from NOAA satellite Advanced Very-High Resolution Radiometers (AVHRR). Images are processed and fires counted by INPE from June to November.
A total of 19,115 fires are reported from the NOAA-12 satellite images in the sample in 1996, while 24,549 fires appear in the 1997 data over the period, an increase of 28%. The average number of fires per day increased from 466 to 599. The actual increase for the year may be even greater, since 1997 is drier than 1996 and burning continues. INPE has not yet released analysis of deforestation, based on Landsat Thematic Mapper images, for 1995 or 1996. Increased burning, however, strongly suggests that deforestation rates continue to rise. The most recent deforestation analysis, released last year, showed that forest clearing had risen about 34% between 1991 and 1994, reaching 14,896 square kilometers a year.1/
Burning was concentrated principally in the Amazon states of Mato Grosso, and Para, followed by Tocantins, Rondonia and Maranhao. Half of the fires registered in 1997 were in Mato Grosso alone. The state of Mato Grosso has since 1992 been the beneficiary of a $205 million World Bank loan intended to halt deforestation -- the Mato Grosso Natural Resource Management Program.
These data underestimate the actual number of fires probably by an order of magnitude, since the NOAA-12 satellite passes over the Amazon region at night, recording only the largest and longest- burning conflagrations. Fires to burn cleared forest and pasture are started in the daytime. Previous analyses of burning relied on the NOAA-14 satellite, which orbits the region during the day, and thus records much higher totals.2/ Use of the NOAA-14 satellite data to calculate the number of fires during the burning season was discontinued by the Brazilian government, under the allegation that sun glint, the reflection of the sun from bodies of water or the earth during the Amazon dry season, could erroneously register as burning on the satellite's sensors, inflating the number of fires.
While analysis of the NOAA-12 data under-counts the actual number of fires, comparison of the data from two years does yield a reliable estimate of change in burning activity.
The number of fires is not a direct measure of new deforestation, because old cattle pasture and secondary forest is typically burned every year, in addition to forest newly felled for cattle ranching. Burning in areas not previously cleared is a good indication of new deforestation, and increased burning in past years has in fact presaged increased deforestation.
Of the 12% to 13% of the forested area of the Amazon cleared and burned to date, an area about the size of California, only about 12% is farmed. The rest is cattle pasture, and most new forest clearing is for the creation of cattle pasture. New areas are typically first made accessible to ranching and agriculture by building of logging roads, particularly for mahogany extraction.
Were the 28% increase in burning to represent an equal increase in the annual deforestation rate, and were such an increase to have occurred twice in the three years since 1994, when the last deforestation data were released, the current rate would be higher than 21,130 square kilometers per year recorded by INPE between 1978 - 1988.
The variations in annual deforestation rates since the end of the 1980s are in part explained by economic cycles. As Brazil's economic stabilization plan takes hold and growth picks up, most observers expect increased deforestation.
Equally important is that since 1989, Brazil's environmental agency (IBAMA) has had no statutory authority to enforce environmental legislation. A recent Brazilian national security agency (SAE) report on forestry policy concluded that 80% of the timber produced in the Amazon is extracted illegally.3/ The environmental agency collects about 6.5% of the fines it levies. The 1965 Forestry Code specified penalties to be applied by the courts, but failed to authorize executive agencies to enforce the law. This was temporarily rectified by executive order during the military dictatorship (Decreto-Lei 289/67), but under the 1988 Constitution this order should have been made law by the Congress within 180 days, but was not. Consequently, IBAMA is powerless to levy fines, apprehend timber stolen from public lands or otherwise carry out its mandate. There is thus practically no environmental law enforcement in the Amazon. The government introduced draft legislation that would enable IBAMA to function in 1991; only in 1997 did the legislation pass the Senate and it is now blocked in the House of Representatives.
Researchers at the Institute of People and the Environment in the Amazon (IMAZON) have shown that current fire use practices act synergistically with selective logging in the region to promote fire, even in normally fire-resistant living forests.4/ Individual fires of this type may encompass hundreds or even thousands of square kilometers of forest. Amazonian forest fires (as opposed to burning of felled forest) take place under the tree canopy and may not be detected by current satellite methods. IMAZON estimates that for every hectare of forest that is cut down and burns, at least one more hectare burns beneath the canopy. Mortality of trees subjected to even light fires can be 40%-50%. Once burned, a forest is much more likely to burn again in subsequent years. These recurrent forest fires have been shown to reduce living biomass in the forest by as much as 80%. This implies carbon emissions that are not accounted for in current estimates, which are based solely on deforestation.
Increased burning may provoke unexpected larger consequences. The Woods Hole Research Institute and Institute of Environmental Research in the Amazon (IPAM) estimate that as much as half of the forest, in the eastern and southern Amazon where deforestation and burning have been heaviest, is near the limit of its capacity to remain evergreen during the Amazonian dry season. With the drier climate predicted by climate models could become flammable. Under these circumstances, much larger conflagrations consuming larger areas of the forest and increasing carbon emissions drastically become a serious risk.
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