CO₂, CO, hydrocarbon gases and PM_2.5 emissions on dry season by deforestation fires in the Brazilian Amazonia

The rate of deforestation in Brazil increased by 29% between 2015 and 2016, resulting in an increase of greenhouse gas emissions (GHG) of 9%. Deforestation fires in the Amazonia are the main source of GHG in Brazil. In this work, amounts of CO₂, CO, main hydrocarbon gases and PM_2.5 emitted during deforestation fires, under real conditions directly in Brazilian Amazonia, were determined. A brief discussion of the relationship between the annual emission of CO₂ equivalent (CO_2,eq) and Paris Agreement was conducted. Experimental fires were carried out in Western Amazonia (Candeias do Jamari, Rio Branco and Cruzeiro do Sul) and results were compared with a previous fire carried out in Eastern Amazonia (Alta Floresta). The average total fresh biomass on the ground before burning and the total biomass consumption were estimated to be 591 ton ha^-1 and 33%, respectively. CO₂, CO, CH₄, and non-methane hydrocarbon (NMHC) average emission factors, for the four sites, were 1568, 140, 8, and 3 g kg^-1 of burned dry biomass, respectively. PM_2.5 showed large variation among the sites (0.9-16 g kg^-1). Emissions per hectare of forest were estimated as 216,696 kg of CO₂, 18,979 kg of CO, 1,058 kg of CH₄, and 496 kg of NMHC. The average annual emission of equivalent CO₂ was estimated as 301 ± 53 Mt year^-1 for the Brazilian Amazonia forest. From 2013, the estimated CO_2,eq showed a trend to increase in Amazon region. The present study is an alert and provides important information that can be used in the development of the public policies to control emissions and deforestation in the Brazilian Amazonia.