Rainforest burning in the southwestern Amazon region (Brazil, Peru and Bolivia) may exacerbate the melting of tropical glaciers in the Andes in South America, a study has found. Scientists from the State University of Rio de Janeiro, Brazil, used data collected between 2000 and 2016 to model the possible effects of biomass combustion in the Amazon basin on Bolivia’s Zongo glacier. They found that aerosols produced by biomass combustion, such as black carbon, can be transported by wind to the tropical Andean glaciers.
Aerosols such as black carbon are deposited in the snow and have the potential to increase melting of glaciers, as snow that is blackened by black carbon or dust particles reflects less sunlight (reduced albedo). Scientists focused on 2007 and 2010, when fires were frequent in the Amazon basin. Their modelsuggests that black carbon or dust alone could increase annual glacial melting by 3-4%, and that when both occur, they increase the annual melting of glaciers by 6%.
Pressures related to global food demand could lead to further deforestation in Brazil, leading to increased black carbon and carbon dioxide emissions, which could affect the Andean glaciers. In September 2019, seven South American countries agreed to protect the Amazon basin amid fears of the world’s largest tropical forest fire. Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru and Suriname signed an agreement establishing disaster response networks and satellite monitoring systems.