‘Amazon Rainforest shows signs of exhaustion’, warns Carlos Nobre, specialist from USP

Bruno Pacheco – from Cenarium

MANAUS (AM) – Amidst the increase of 1.07°C in global temperature compared to pre-industrial levels, evidenced in the report of the Intergovernmental Panel on Climate Change (IPCC), the Amazon Rainforest shows signs of exhaustion and is no longer able to remove carbon dioxide from the atmosphere, according to an expert on climate change and the Amazon, researcher Carlos Nobre, from the National Institute for Space Research (INPE) and the Institute for Advanced Studies (IEA) at the University of São Paulo (USP).

In a study developed by Inpe and recently published in the scientific journal Nature, called “Amazon as a source of carbon linked to deforestation and climate change”, scientists warn that the Amazon is heading towards becoming a savanna, due to the increase in deforestation in recent years. The research, conducted between the years 2010 to 2018, also shows that the fires were caused by man and not by natural causes.

“The research published by Nature magazine shows for the first time that areas of the southern Amazon, the forest, are losing carbon. Much of the Amazon removes carbon dioxide from the atmosphere, a carbon sink, but the south of the Amazon, the north of Mato Grosso, the south of Pará, the study shows for the first time that even the forest without deforestation, without burning, it is no longer absorbing carbon. This is worrying, showing that the forest is losing the typical characteristic of forests all over the planet of removing carbon dioxide from the atmosphere”, commented Nobre, speaking to the radio station.

Warnings

In 1990, Nobre had already made the first warning about the case, pointing to an Amazon with less biodiversity. For him, the results of these studies make even clearer the enormous risk of “savannization” of the Amazon Forest.

“This is an idea that I myself did in 1990, launching the hypothesis, at that time, that deforestation could lead to savannization, of a large part of the Amazon becoming a very degraded tropical savanna, different from the Cerrado. A tropical savanna with less biomass and biodiversity. And this study clearly shows that we are very close to this point of no return of savannization”, he highlighted.

Carbon Sink

Carbon sinks are a denomination given to a process in which there is a greater absorption of carbon dioxide than emission. According to the INPE study, the Amazon is considered one of the most important carbon sinks in the world because it harbors the largest tropical forests on the planet. However, according to the research, this sink seems to be in decline as a result of factors such as deforestation and climate change.

To arrive at the study’s results, the scientists conducted 590 aircraft vertical profile measurements of lower tropospheric concentrations of carbon dioxide and carbon monoxide at four sites in the Amazon over the nine years of research.

“We find that total carbon emissions are higher in the eastern Amazonia than in the western part, mainly as a result of spatial differences in fire emissions derived from carbon monoxide. The southeastern Amazon, in particular, acts as a net source of carbon (total carbon flux minus fire emissions) to the atmosphere,” says an excerpt from the research.

According to the study, over the past 40 years, the eastern Amazon has been subject to more deforestation, warming, and moisture stress than the western part, especially during the dry season, with the southeast experiencing the strongest trends.

Tendencies

In exploring the effect of climate change and deforestation tendencies on carbon emissions at the study sites, the researchers found that intensification of the dry season and an increase in deforestation appear to promote ecosystem stress, increased fire occurrence, and higher carbon emissions in eastern Amazonas.

“The region that presents the greatest transformations is the Southern Amazon, which goes from the South of Bolivia, Acre, Rondônia, Northern Mato Grosso, Southern and Southeastern Pará. It is there that we are seeing the greatest transformations of savannization risk and, in part of these regions, the forest is losing carbon and it is there that the greatest number of deforestation and fires occur”, points out Carlos Nobre.

For the specialist, the only way to prevent the Amazon from reaching its limit and being destroyed is to zero deforestation in the coming years. “There is no other way than to zero deforestation in the next few years. We can’t wait any longer. We have to change the occupation model of the Amazon, because a regrowing Amazon forest removes carbon dioxide from the atmosphere. This is our great challenge”, concluded researcher Carlos Nobre.