Fires cool the Amazon

2002/02/18 Elhuyar Zientzia

• Ekologia
• Klima

The fires that occur in the Amazon rainforest are not usually extremely large (at least locally), but, according to researchers at Sao Paulo University, their influence is greater than expected: although it seems untrue, they cool wide regions.

Researchers at the University of Sao Paulo have calculated that the effects of fires in Amazonas have burned around 15% to obtain agricultural and livestock land, in the middle of the virgin forest. In fact, millions of particles emitted into the atmosphere by fires reflect sunlight. These particles can reach a height of 10-15 kilometers and cover wide areas. As a result, the arrival of heat to the earth's surface is reduced and, during fires, the average temperature of some regions drops by about 3 °C. In some regions a loss of 40% of the incident radiation on the Earth's surface has been measured.

Although it was known that the particles emitted by the fires had the ability to reflect sunlight, for the first time its influence in Amazonas has been measured. But it is not the only damage it produces. It seems that they also influence the formation of clouds, avoiding the growth of water drops. Due to fires, in some regions rainfall has decreased by 30%.

All these investigations have been presented at the annual meeting of the American Association for the Advancement of Science (AAAS).