BRAZIL, 2005

A houseboat lying on the dry bed of the former Rio Paraná de Manaquiri, a tributary of the Amazon

 

Rogers

© Reuters / Rickey Rogers


In 2005, the Amazon was hit by one of the most severe droughts of the last century, causing damage lasting for years. The most widely accepted hypothesis is that this unusual event was a consequence of the rising surface temperature of the tropical Atlantic, believed by some to be a natural climate cycle and by others to be the result of anthropogenic climate change.
Whatever the cause, hundreds of thousands of hectares of forest have been destroyed in fires and many of the surviving trees, particularly the tallest, have died due to their inability to convey the water deriving from the meagre rainfall to the top leaves. The resulting defoliation, an important indicator of stress in a rainforest, also damaged the surviving plants, limiting their ability to absorb carbon dioxide. Space reconnaissance has observed variations and thinning in the leaf pattern covering these regions and this is thought to have exacerbated the effects of the drought, with loss of the important “precipitation” component deriving from the condensation of moisture rising from the ground.
Dropped to historic lows, the rivers have also been affected by this exceptional event, causing problems for river transport, electricity production and agriculture.
The Amazon rainforest is thus losing its classic function as a “natural sink” of carbon dioxide and is instead becoming a source of emissions as fires release carbon previously stored as biomass into the atmosphere.

Nicolò Berdin