Amazon Rainforest fires: what were the effects on the climate?

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Amazon Rainforest fires: what were the effects on the climate?

Have the wildfires that hit Amazon Rainforest since 2019 generated any changes to the planet's climate? Deforestation is the transformation of forest areas into deforested areas, and is very active in the Amazon basin.

More than a fifth of the forest has already been destroyed and the entire ecosystem remains in danger. This work of destruction began in the 1940s, when the governments of the region decided to exploit forest and mineral resources.

In fact, deforestation allows the sale and export of timber, which can be very valuable, the increase of land for agriculture, which is strongly needed due to the growth of the population, and the exploitation of mineral deposits.

Over the years, numerous highways have also been built to connect large cities, which have not only been primary sources of deforestation but have also encouraged the construction of new villages along them, making the problem worse. Deforestation is also at the root of the massive fires that have hit the lungs of the planet since 2019.

The study: Climate influence on the 2019 fires in Amazonia, published on the The Science of the total environment, said us: "Amazonia experienced unusually devastating fires in August 2019, leading to huge regional and global environmental and economic losses.

The increase in fires has been largely attributed to anthropogenic deforestation, but anomalous climate conditions could also have contributed. This study investigates the climate influence on Amazonia fires in August 2019 and underlying mechanisms, based on statistical correlation and multiple linear regression analyzes of 2001-2019 satellite-based fire products and multiple observational or reanalyzed climate datasets.

Positive fire anomalies in August 2019 were mainly located in southern Amazonia. These anomalies were mainly driven by low precipitation and relative humidity, which increased fuel dryness and contributed to 38.9 ± 9.5% of the 2019 anomaly in pyrogenic carbon emissions over the southern Amazonia ons were associated with southerly wind anomalies over southern Amazonia that suppressed the climatological southward transport of water vapor originating from the Atlantic.

The southerly wind anomalies were caused by the combination of a Gill-type cyclonic response to the warmer North Atlantic sea surface temperature (SST), and enhancement of the Walker and Hadley circulations over South America due to the colder SST in the eastern Pacific, and a mid-latitude wave train triggered by the warmer condition in the western Indian Ocean.

Our study highlights, for the first time, the important role of Indian Ocean SST for fires in Amazonia. It also reveals how cold SST anomalies in the tropical eastern Pacific link the warm phase of the El Niño-Southern Oscillation (ENSO) in the preceding December-January to the dry-season fires in Amazonia.

Our findings can develop theoretical basis of global tropical SST-based fire prediction, and have potential to improve prediction skill of extreme fires in Amazonia and thus to take steps to mitigate their impacts which is urgency given that dry conditions led to the extreme fires are becoming common in Amazonia. "