Brasília - The III Scientific Conference of the LBA (Large-Scale Biosphere-Atmosphere Experiment in Amazônia) got underway Tuesday (27) in Brasília. Around 800 scientists from Brazil and abroad are gathered to discuss the process of transformation in Amazon ecosystems and the consequences for global climatic patterns. The conference ends today.
The researchers engaged in the LBA experiment meet every two years to present their findings and debate how their research results can best be incorporated into the formulation of government policies aimed at the region's sustainable development.
According to the scientists, deforestation and burnings in Amazônia are altering the climate and amplifying the greenhouse effect around the planet. Therefore, an understanding of the role of the Amazon in the Earth's environmental balance is of strategic importance. The topics under debate range from the chemistry of the atmosphere to hydrology and cover such matters as carbon storage and exchange, changes in land use, and the phyics of climate.
In Brazil, the accelerated deforestation of the Amazon threatens to shorten the rainfall cycle in the Southern and Southeastern regions, convert large forest areas into savannahs, and modify humidity levels in the region.
In his talk on interactions between climate and vegetation in the Amazon, the coordinator of the LBA, Carlos Nobre, a scientist attached to the National Institute of Space Research (Inpe), was emphatic in contending that climate change in Amazônia "is a fact." He informed that what they are trying to determine "is the scale on which this is taking place." Nobre pointed out that the climate in deforested regions has suffered variations of up to three degrees in maximum temperatures.
According to the scientist, a transformation trend already exists in 15% of the Brazilian Amazon, but it is still too soon to state categorically the extent of its real impact, since the modifications are spread across the six million square kilometers of Continental Amazônia. "If the modifications were concentrated in a single location, we would already be observing more changes," he explained.
"If our physical knowledge is correct in asserting that large-scale deforestation can lead to diminished rainfall and global heating, the projections indicate that Amazônia will be transformed into savannah in a period of 50-100 years," Nobre warns. According to him, in the worst scenario, the savannah takes over 60% of the forest and, in the average scenario, it replaces 20-30%. "In the best scenario, it doesn't take over anything, and that is what we want."
To study the interaction between the Amazon Forest and atmospheric and climatic conditions, the participants in the LBA utilize a variety of equipment, such as data-gathering towers scattered throughout the forest and remote sensoring instruments installed in satellites. The research conducted by the LBA has already produced findings on the role of aerosols in the absorption of solar radiation, the plant nutrient cycle, and the importance of water vapor emitted by the Amazon in the formation of clouds and rain, among other results.
The III Scientific Conference of the LBA was opened by the Minister of Environment, Marina Silva.
Agência Brasil
Reporter: Maurício Cardoso
Translator: David Silberstein
07/29/2004
