21st Century drought-related fires counteract the decline of Amazon deforestation carbon emissions

• Published in: Nature communications Vol. 9; no. 1; pp. 536 - 12
• Main Authors: Aragão, Luiz E. O. C., Anderson, Liana O., Fonseca, Marisa G., Rosan, Thais M., Vedovato, Laura B., Wagner, Fabien H., Silva, Camila V. J., Silva Junior, Celso H. L., Arai, Egidio, Aguiar, Ana P., Barlow, Jos, Berenguer, Erika, Deeter, Merritt N., Domingues, Lucas G., Gatti, Luciana, Gloor, Manuel, Malhi, Yadvinder, Marengo, Jose A., Miller, John B., Phillips, Oliver L., Saatchi, Sassan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.02.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 704/106/694/682; 704/172/4081; 704/47/4113; Carbon; Carbon dioxide; Deforestation; Drought; Emission inventories; Emissions; Forest & brush fires; Forest fires; Forests; Humanities and Social Sciences; Incidence; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-02771-y

Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, emissions from drought-induced forest fires are, usually, not included in national-level carbon emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated forest fire carbon emissions over the period 2003–2015. We show that despite a 76% decline in deforestation rates over the past 13 years, fire incidence increased by 36% during the 2015 drought compared to the preceding 12 years. The 2015 drought had the largest ever ratio of active fire counts to deforestation, with active fires occurring over an area of 799,293 km 2 . Gross emissions from forest fires (989 ± 504 Tg CO 2 year −1 ) alone are more than half as great as those from old-growth forest deforestation during drought years. We conclude that carbon emission inventories intended for accounting and developing policies need to take account of substantial forest fire emissions not associated to the deforestation process. Deforestation carbon emissions from the Brazilian Amazon have declined steeply, but how much drought-induced forest fire emissions add to this process is still unclear. Here the authors show that gross emissions from forest fires are more than half as great as those from deforestation during drought years.