Carbon released by fires raging in the Amazon rainforest could be directly contributing to the melting of tropical glaciers in the Andes, scientists claim.
The burning of biomass in southwestern Amazonia releases aerosols such as black carbon, which blow from the Amazon Basin (the Brazilian, Peruvian and Bolivian Amazon) to the Bolivian Zongo Glacier.
These dark carbon pieces then settle in the snow, and may speed up the melting of the Andean glaciers, according to researchers from Rio de Janeiro State University.
This is because snow that is darkened by black carbon or dust particles reflects less light and is therefore absorbs more heat – melting faster.
Newton de Magalhães Neto and colleagues modelled the possible effect by using data collected between 2000 and 2016 on fire events, the movement of smoke plumes, precipitation and glacier melting.
Focusing their analyses on the years 2007 and 2010 when fire seasons were the most critical for the Amazon Basin, the authors investigated the snow’s lack of light reflection due to being covered in black carbon alone or black carbon in the presence of previously reported quantities of dust.
Their model showed that black carbon or dust alone had the potential to increase annual glacier melting by three to four per cent or by six per cent when both were present.
If dust concentrations were high, dust alone had the potential to increase annual melting by 11 to 13 per cent and by 12 to 14 per cent in the presence of black carbon.
The findings suggest that the impact of Amazon biomass burning depends on how much of the dust from the fires ends up in the snow.
Pressure related to global food demand may result in further expansion of Brazilian agriculture – which often means the burning of forest for quick deforestation.
This could result in enhanced black carbon and CO2 emissions that may impact Andean glaciers as explained.
The study was published by Rio de Janeiro State University, Brazil in Scientific Reports.