Will the Amazon rainforest disappear before the end of the century? A recent study sought an answer to this bleak question, by analyzing potential thresholds that could push the Amazon rainforest to the point of no return.
The study, in which Spain's Supreme Council for Scientific Research (CSIC) participated, suggests that by 2050, between 10% and 47% of the Amazon forest may be irreversibly changed and disappear. “The primary goal of the study was to evaluate how close or far we are from crossing the safe planetary boundaries with respect to the largest continuous tropical forest on the planet,” explains Encarni Montoya, CSIC researcher in Geosciences Barcelona (GEO3BCN) and co-author. the study. .
The study, conducted by Bernardo Flores, of the Federal University of Santa Catalina (Brazil), suggests that potential changes depend on rising temperature, decreased rainfall, increased dry season, and the intensity of seasonal rainfall. and deforestation. Crossing the tipping point of these five factors, caused directly or indirectly by global climate change, could cause local and systemic changes in the Amazon region.
According to the study, the levels of deforestation and degradation of the Amazon forest have already been exceeded by now, and the tipping point was cumulative deforestation of 20%. In this case, the research team set the safe limit at 10%, although 13% has already been exceeded.
Taking into account models of global warming, the work suggests that the critical threshold for an increase in global average temperature, in this case, lies at 2°C, making 1.5°C a safe limit for the Amazon. . Regarding rainfall decline, the tipping point is at 1000 mm of annual rainfall, indicating 1800 mm as a safe limit. The study also found that the rain deficit does not exceed 450 mm annually during periods of drought. In this case, the study authors set 350 mm as a safe limit. Similarly, they propose a maximum duration of the dry season, setting the critical threshold at eight months and the safe limit at five months.
The study's research team, consisting of more than 20 specialists from research centers and universities in Europe and America, also focuses on the need to work on improving the integration of field or experimental data into simulations. They consider it necessary for technological advances in incorporating powerful models to simulate different variables that interact with each other and can cause cascading reactions and effects.
“The approaches presented in this study are very conservative due to the lack of knowledge about how different change agents associated with water stress and intrinsic properties of Amazonian ecosystems interact with each other and accelerate or slow rates of change,” Montoya laments. .
The Amazon region is home to 47 million people. (Photo: Bernardo Flores)
Climatic and social consequences
The disappearance of the Amazon forests would affect the regulation of the planet's climate, as well as the loss of biological and cultural diversity at the global level. “As the largest continuous tropical forest on the planet, what happens in the Amazon has ramifications on a global scale, among other factors, due to its role as a climate regulator,” Montoya asserts. This also involves a loss of cultural diversity: the Amazon region is home to 47 million people, including 2.2 million indigenous people and local communities belonging to about 400 different ethnicities and cultures.
To limit possible negative consequences and prevent the disappearance of the Amazon, they appeal to local and international responsibility. “In addition to developing restoration and conservation policies at the local level to slow down degradation, actions must now be taken at the supra-governmental level, in the global political sphere, with the aim of reducing the emission of greenhouse gases, as well as avoiding or reducing the ‘overexploitation of natural resources’,” explains researcher GEO3BCN-CSIC. .
The study's authors also emphasize strengthening the participation of indigenous governance territories in decision-making, as well as the adoption of traditional practices. According to Montoya, “protected areas, especially areas governed by indigenous people, are often better protected spaces.”
The study is titled “Critical Transformations in the Amazon Forest System.” It was published in the academic journal Nature. (Source: Lara Gallery / GEO3BCN / CSIC)
