Drought in the Amazon

Drought in the Amazon rainforest Twice in the past decade there has been severe drought in the Amazon rainforest. Experts are warning of a significant global risk due to increased CO2 caused by these droughts.

When you think of the Amazon rainforest you imagine a dense damp atmosphere. This environment is what makes the Amazon so diverse and such a powerful carbon sink for the planet. Yet drought in 2005, and again in 2010, is threatening this fragile ecosystem.

One of the features of the Amazon Rainforest is that it can create its own rain. Moisture from the trees and plants evaporate into the air and create droplets, which then form clouds. It is estimated that nearly half the rainfall is produced within the Amazon itself.

When drought occurs, it dramatically alters the ecosystem. Trees and plants die. As they die, they release carbon into the atmosphere. As more trees are lost, the amount of rain produced in future years reduces, starting a spiral of decline.

In a normal year, the Amazon will absorb about 1.5 billion tonnes of CO2 from the atmosphere. In the first drought in 2005, an estimated 5 billion tonnes will be released into the atmosphere in future years. This release is caused by the dying and rotting trees releasing the carbon they have accumulated over 300 years or more. The estimated figure for the drought in 2010 is even higher: 8 billion tonnes.

The drought in 2005 was the worst in 100 years and a state of emergency was declared. There has been research completed to try and find the cause for the drought. One of the reasons may be due to the warmer water temperatures in the Atlantic Ocean. There can also be other reasons including deforestation and also the decline of the glaciers in the Andes, which may be a source for as much as 50% of the water in the upper Amazon.

The 2010 drought covers 57% area of the Amazon compared to 37% in 2005 but is less intense. Temperatures in 2010 were on average between 2-3 degrees warmer than normal years. Scientists are still studying the data and satellite images from 2010, before an assessment to the causes can be made.

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Did you know?

In the 2005 drought, an estimated 5 billion tonnes of CO2 will be released from dead and rotting trees.

 
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