The Amazon rainforest is an important ecosystem and acts as a large carbon sink that can influence global warming. However, the region is threatened by deforestation and also suffers from some of the effects of climate change. Removing parts of the forest causes an increase in temperature because the cooling effect of water evaporation is reduced. This, in turn, increases the risk of forest fires and threatens even larger areas.
Luciana V. Gatti, National Institute for Space Research (INPE), São José dos Campos, Brazil, and Nuclear and Energy Research Institute (IPEN), São Paulo, Brazil, and colleagues have studied the “carbon budget” of the Amazon. The team used airplanes to measure concentrations of carbon dioxide and carbon monoxide above four different sites in the Amazon from 2010 to 2018. They used CO2 levels to estimate the overall carbon flux and the ratios of CO2 to CO to gauge the effects of forest fires on the overall carbon levels.
The team found that the eastern Amazon, in particular, has shifted from a carbon sink to a net carbon emitter. The western parts are less influenced by human disturbances such as deforestation and still act as a net carbon sink. Much of the difference between the regions can be explained by emissions caused by fires, which not only release CO2 in the short term, but also over the following years due to dying and decomposing trees. This is affected by climate change: more intense dry seasons lead to degradation of the forests, increase the likelihood of fires, and further promote higher carbon emissions.
- Amazonia as a carbon source linked to deforestation and climate change,
Luciana V. Gatti, Luana S. Basso, John B. Miller, Manuel Gloor, Lucas Gatti Domingues, Henrique L. G. Cassol, Graciela Tejada, Luiz E. O. C. Aragão, Carlos Nobre, Wouter Peters, Luciano Marani, Egidio Arai, Alber H. Sanches, Sergio M. Corrêa, Liana Anderson, Celso Von Randow, Caio S. C. Correia, Stephane P. Crispim, Raiane A. L. Neves,
Nature 2021.
https://doi.org/10.1038/s41586-021-03629-6