Drought

With an area spanning almost 6 million square kilometers, the Amazonian rainforest is a vast region spread out over nine countries, the largest of which is Brazil. This region contains approximately one fifth of the total species on earth, with over 10,000 species of trees. Each year, the Amazon rainforest processes 18 billion tonnes of carbon dioxide, or approximately three times the amount of fossil fuel emissions produced in the world. On the other hand, the processes of tree respiration and the decomposition of organic materials in the soils result in the release of an almost equivalent amount of carbon dioxide into the atmosphere.

The drought that is currently ravaging Amazonia has led to a series of devastating consequences for the communities in this region. Numerous tributaries of the Amazon River have completely dried up, causing the destruction of biodiversity in the area and the loss of a mode of commercial transportation of goods. In several regions, the customary delivery of food and medical supplies on these waterways has been disrupted, which could lead to an increased risk of epidemics and famine.

In Brazil, the dry season typically occurs during the months of September and October. This year, the dry season began in the month of August and has extended into November. Scientists have postulated various theories to explain the possible causes of this worrisome drought, but none can pinpoint the cause with certainty since the factors that contribute to the region’s climatic stability are varied and complex. Some cite the source of the problem as the heating up of the oceans’ surfaces and the massive deforestation that has occurred in the Amazonian rainforests. Others claim that selective and clear cut logging have reduced rainforest density, decreasing its ability to retain moisture. This circumstance may have also led to the damaging fires that occurred in the Peruvian and Bolivian Amazon.

The increase in tree mortality due to drought has tended to reduce the rate of carbon dioxide absorption, and to increase the release of carbon dioxide. This is transforming the role of the Amazonian rainforest from that of a carbon “sink” to that of a carbon “source” for the atmosphere.