ABSTRACT
The Amazonas rainforest is being destroyed at high rates. Since the beginning of the 70s, the deforested area has increased by about 300 thousand km2 which, if added to previous deforestation, amounts to approximately 415 thousand km2, or 11.3% of the Brazilian Amazon Forest. The main causes for deforestation appear to be the government’s geopolitical decision to occupy the region with the consequent opening of roads. The increasing population, as well as mechanisation of agriculture, in Southern Brazil are among the causes of high migratory fluxes into the Region. Large-scale deforestation may affect the global climate. The first hypothesis is that the Amazonas Forest plays an important role in the chemistry of the atmosphere, regulating the Greenhouse Effect; deforestation and burning may increase carbon-dioxide concentrations and thus enhance the Greenhouse Effect. The second hypothesis is that the forest is a source of heat forthe atmosphere and regions outside of the tropics depend on the heat exported by Amazonia. Deforestation may reduce the power of the heat source, less heat would be available to be transported poleward, therefore affecting present climate stability. It is argued that these two hypotheses are not antagonistic but both contribute to global climate changes.
